Patent Grant
10100450
The present invention relates to a sewing machine and, more particularly, to an embroidery sewing machine.
Hitherto-known methods for creating hollow embroidery (hollow three-dimensional embroidery) are to make embroidery while placing plate-shaped members on a cloth to be embroidered and, subsequently, to dissolve the plate-shaped member.
For instance, according to a method stated in Patent Document 1 for manufacturing embroidery having hollow three-dimensional patterns, a foundation cloth is embroidered by use of water-insoluble embroidery thread and an embroidery back thread. After the foundation cloth is further embroidered with an overlapping unwoven cloth and/or a woven cloth formed from water-soluble fiber, the water-soluble fiber is dissolved and removed in water whose dissolution temperature is higher than that of the water-soluble fiber by at least 10° C. or more, thereby obtaining hollow embroidery.
According to an embroidery patch and a processing method in Patent Document 2, an embroidery patch internally including an organdy core material in an integrated manner is obtained through: an embroidery step of embroidering organdy with an overlapping synthetic resin plate which dissolves in an organic solvent; a separation step of cutting off unwanted portions of the synthetic resin plate other than the embroidered portion formed in the embroidery step; a plate dissolution step of dissolving and eliminating the synthetic resin plate still left in the embroidery by bringing the embroidered portion cut off in the separation step into contact with the organic solvent along with the organdy and the synthetic resin plate provided inside; and a heat-cutting step of cutting the organdy with heat along an outer brim of the embroidery.
In relation to an auxiliary embroidery member, and an embroidery method, and an embroidery product utilizing the auxiliary embroidery member mentioned in Patent Document 3, an embroidery method utilizing a spacer is to obtain hollow three-dimensional embroidery through the steps of: placing a spacer on a foundation cloth; sewing the foundation cloth with the embroidery thread by way of the spacer; and dissolving the spacer in tetrachloroethylene.
The applicants have already filed the patent applications of Patent Document 4 and Patent Document 5 in connection with a sewing machine including: an upstream grip section having an upstream grip section section main body for gripping a needle thread by pinching; a downstream grip section that is placed at a downstream position on a needle thread path with reference to the upstream grip section and that has a downstream grip section main body which grips the needle thread by pinching; and a circular movement section for circularly moving the needle thread between the upstream grip section main body and the downstream grip section main body.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 11-21758
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2003-250611
Patent Document 3: WO 98/59101
Patent Document 4: WO 2012/014610
Patent Document 5: WO 2013/047477
However, under the method for manufacturing hollow embroidery mentioned in Patent Documents 1 through 3, a cloth to be embroidered is embroidered while a plate-shaped member is put on the cloth, and the plate-shaped member is dissolved. Hence, in addition to the cloth to be embroidered, the plate-shaped member is necessary, which incurs the cost of the other member. Since additional operation for dissolving the plate-shaped member becomes necessary, it entails consumption of labor and expenses. Moreover, since embroidery is carried out while plate-shaped members are superposed, difficulty is encountered in adjusting the length of the needle thread (the height of hollow embroidery) on a per-stitch basis and obtaining elaborate hollow embroidery.
Accordingly, the objective of the present invention is to provide a sewing machine which does not need the plate-shaped member to be superposed on the cloth to be embroidered; which does not need to dissolve the plate-shaped member; which enables adjustment of the length of the needle thread on a per-stitch basis; and which enables production of elaborate hollow embroidery.
The present invention has been created to solve the above-mentioned drawbacks. First, there is provided a sewing machine comprising:
a thread take-up lever (12a) formed in a swayable manner;
a sewing needle (12ba) that is supported on a vertically-movable needle bar and into which the needle thread is to be inserted;
a shuttle (12d) that makes stitches (which can also be mentioned as “making stitches by entwining, in a hooking manner, the needle thread inserted into the sewing needle with a hook bobbin thread”) by hooking the needle thread inserted into the sewing needle;
an upstream grip section (40) that has an upstream grip section main body (41) for gripping the needle thread in a pinching manner and an upstream drive section (50) for switching the upstream grip section main body between a closed state where the needle thread is gripped and an open state where the gripped needle thread is released;
a downstream grip section (60)
a circular movement section (80)
a needle thread fixing section (230, 216f) that fixes a second needle thread portion (Jb) of the needle thread situated between a cloth and the thread take-up lever at a position apart from a cloth surface and at a position deviating toward the cloth surface from a position where the sewing needle is to be inserted;
a needle thread fixing drive section (240) that performs switching between a fixed state where the needle thread is fixed by the needle thread fixing section and a released state where the needle thread fixed by the needle thread fixing section is released; and
a control section (90)
In relation to the sewing machine having the first configuration, the circular movement arm performs circular movement through an angle corresponding to the stitch reference length, which is a stitch length achieved when the n+1th stitch is fixed by the needle thread fixing section in the first segment. Hence, the needle thread having the length required for the n+1th stitch is prepared between the cloth and the circular movement arm. When the shuttle descends from its top dead center to hook the needle thread, the second needle thread portion is fixed by the needle thread fixing section. Therefore, there is no risk of the shuttle withdrawing the needle thread from the stitch fixed by the needle thread fixing section (i.e., the nth stitch). In addition, the upstream grip section stays closed, and the downstream grip section stays open. Accordingly, there is no fear of the needle thread being withdrawn from an upstream position with respect to the upstream grip section.
Subsequently, the thread take-up lever ascends in the second segment. However, in the course of ascending action of the thread take-up lever, the circular movement arm performs circular movement in the first direction, thus withdrawing the needle thread from the nth stitch. For this reason, the remaining length of the needle thread of the nth stitch correspondingly becomes shorter. By specifying the remaining length of the needle thread for each stitch in advance, the height of hollow embroidery can thereby be controlled on a per-stitch basis.
Thereafter, although the sewing needle is subsequently inserted into the cloth, the needle thread is held fixed by the needle thread fixing section. Therefore, the needle thread becomes folded back at the position of the needle thread fixing section.
Then, circular movement is performed in the first direction in the third segment. However, on this occasion, the upstream grip section stays open, and the downstream grip section stays closed. Therefore, the needle thread is withdrawn from an upstream position with respect to the upstream grip section. Thereby, the needle thread will not become deficient in subsequent stitches.
As above, the sewing machine of the present invention creates hollow embroidery by fixing the needle thread with the thread hooking rod. Therefore, the plate-shaped member to be used for superposing the needle thread on the cloth to be embroidered is unnecessary by the needle thread fixing section, nor is required dissolution of the plate-shaped member. Moreover, the length of the needle thread can be controlled on a per-stitch basis by means of the angle of circular movement of the circular movement arm in the second segment. Therefore, there can be provided a sewing machine capable of creating elaborate hollow embroidery. The length of the needle thread (i.e., the remaining length of the needle thread) is made longer, thereby preventing excessive pulling of the cloth, which would otherwise be caused by making stitches, and the embroidered cloth does not become wavy (or uneven). Further, stitches can be made soft.
In the first configuration, the control section can also be embodied as follows. Specifically, “the control section (90) that controls the operation of the upstream drive section, the operation of the downstream drive section, the operation of the needle thread motor, and the operation of the needle thread fixing drive section (or can also be referred to as a “needle thread fixing section”); that, in the first segment which is at least the portion of a time segment from the top dead center of the shuttle to the bottom dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the second direction through an angle corresponding to a stitch reference length which is the stitch needle thread length achieved while an n+1th stitch next to a proximal nth stitch (“n” is an integer), among stitches already made in the cloth, is fixed to the needle thread fixing section; that, in the second segment which is at least a portion of a time segment from the bottom dead center of the shuttle to the top dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the first direction through the angle corresponding to the length which is the length of the needle thread obtained by subtracting a remaining length of the needle thread, or the length of the needle thread projecting out of the cloth surface in the nth stitch, from the stitch reference length in the nth stitch; that, in the third segment which is at least the portion of the time segment from the end position of the second segment to the position where the shuttle hooks the needle thread, circularly moves the circular movement, by control of the needle thread motor, up to the first end position in the first direction; that controls the upstream drive section, thereby bringing the upstream grip section into the closed state at any position in a time segment from the end position of the third segment section to the position where the shuttle hooks the needle thread, and brings the upstream grip section into an open state at any position (which can also be taken as “any time position in a time segment, and the same also applies to any counterparts throughout the specification) in a time segment from the end position of the second segment to the start position of the third segment; that controls the downstream drive section, thereby bringing the downstream grip section into the closed state at any position in a time segment from the end position of the second segment section to the position where the upstream grip section is switched from the closed state to the open state, and brings the downstream grip section into the open state at any position in a time segment from the position where the upstream grip section is switched from the open state to the closed state to the position where the shuttle hooks the needle thread; and that controls the needle thread fixing drive section, thereby bringing the second needle thread portion into the fixed state by means of the needle thread fixing section at least when the sewing needle is inserted into the cloth and when the shuttle hooks the needle thread.”
In the first configuration, the control section can also be embodied as follows. Specifically, “a control section (90) that controls operation of the upstream drive section, operation of the downstream drive section, operation of the needle thread motor, and operation of the needle thread fixing drive section (or can also be called a “needle thread fixing section”); that, in the first segment which is at least a portion of a segment from the top dead center of the shuttle to the bottom dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the second direction through an angle corresponding to a stitch reference length which is a stitch needle thread length achieved while the n+1th stitch next to the proximal nth stitch (“n” is an integer), among the stitches already made in the cloth, is fixed to the needle thread fixing section; that, in the second segment which is at least a portion of the segment from the bottom dead center of the shuttle to the top dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the first direction through an angle corresponding to the length which is the length of the needle thread obtained by subtracting a remaining length of the needle thread, or the length of the needle thread projecting out of the cloth surface in the nth stitch, from the stitch reference length in the nth stitch; that, in the third segment which is at least a portion of the time segment from termination of the second segment to a position where the shuttle hooks the needle thread, circularly moves the circular movement, by control of the needle thread motor in the first direction, up to the first end position; that controls the upstream drive section, thereby bringing the upstream grip section into a closed state at any time in the segment from termination of the third segment section to a position where the shuttle hooks the needle thread, and brings the upstream grip section into an open state at any time in the segment from termination of the second segment to initiation of the third segment; that controls the downstream drive section, thereby bringing the downstream grip section into a closed state at any time in the segment from termination of the second segment section to a time when the upstream grip section is switched from the closed state to the open state, and brings the downstream grip section into an open state at any time in the segment from a time when the upstream grip section is switched from the open state to the closed state to a time when the shuttle hooks the needle thread; and that controls the needle thread fixing drive section, thereby bringing the second needle thread portion into a fixed state by means of the needle thread fixing section at least when the sewing needle is inserted into the cloth and when the shuttle hooks the needle thread.”
Second, the first configuration is characterized by comprising a presser foot (12c) which moves between a cloth surface contact position where the presser foot contacts the cloth surface and a cloth surface apart position where the presser foot is apart from the cloth surface, and the presser foot is provided with the needle thread fixing section.
Third, the second configuration is characterized in that the presser foot has a presser foot main body (210) having a cloth surface contact section (216) (which can also be referred to as a “leading-end structure section,” and the same also applies to any counterparts throughout the specification) which contacts the cloth surface when the presser foot is at the cloth surface contact position;
the needle thread fixing section has
the thread hooking rod support moves with respect to the presser foot main body such that the thread hooking rod swivels as a result of driving of the needle thread fixing drive section; and
at a time of swiveling of the thread hooking rod, driving of the needle thread fixing drive section is stopped at least in a segment from when the sewing thread is inserted into the cloth to when the shuttle hooks the needle thread, thereby achieving a fixed state where the thread hooking rod fixes the needle thread by pinching together with the needle thread receiving section. Therefore, the needle thread can be fixedly pinched between the thread hooking rod and the needle thread receiving section.
Incidentally, the third configuration can also be embodied as follows. Specifically, “the presser foot has the presser foot main body (210) having the cloth surface contact section (216) (which can also be referred to as a “leading-end structure section,” and the same also applies to any counterparts throughout the specification) that contacts the cloth surface when the presser foot is at the cloth surface contact position. The needle thread fixing section has the thread hooking rod support (231) that reciprocally moves in a second sideway direction orthogonal to the first sideway direction, while swaying in the first sideway direction with respect to the presser foot main body, by means of the crank mechanism to be driven by the needle thread fixing drive section; the rod-shaped thread hooking rod (236) fixed to the thread hooking rod support; and the needle thread receiving section (216f) provided at the position on the cloth surface contact section deviating toward the cloth surface with respect to the insertion position where the sewing needle is to be inserted and which fixes the needle thread by pinching the needle thread, hooked by the thread hooking rod, along with the thread hooking rod. As a result of the needle thread fixing drive section being driven, the thread hooking rod support moves to and fro in the second sideway direction while swaying in the first sideway direction, whereby the thread hooking rod swivels. At the time of swiveling of the thread hooking rod, the needle thread fixing drive section stops driving at least in a segment from when the sewing thread is inserted into the cloth to when the shuttle hooks the needle thread, thereby achieving a fixed state where the thread hooking rod fixes the needle thread by pinching together with the needle thread receiving section.”
In addition, the third configuration can also be embodied as follows. Specifically, “in relation to the second configuration, the presser foot has the presser foot main body (210) having the cloth surface contact section (216) that contacts the cloth surface when the sewing needle is inserted into the cloth and a main body structure section (214) formed closer to a rear side than the cloth surface contact section when one of the sideway direction is taken as a rear side of the presser foot. The needle thread fixing section has the thread hooking rod support (231) that reciprocally moves in a front-back direction while swaying in a right-left direction with respect to the main body structure section by means of the crank mechanism to be driven by the needle thread fixing drive section; the rod-shaped thread hooking rod (236) fixed to the thread hooking rod support; and the needle thread receiving section (216f) provided at the position on the cloth surface contact section deviating toward the cloth surface with respect to the insertion position where the sewing needle is to be inserted and which fixes the needle thread by pinching the needle thread hooked by the thread hooking rod, along with the thread hooking rod. As a result of the needle thread fixing drive section being driven, the thread hooking rod support moves to and fro in the second sideway direction while swaying in the first sideway direction, whereby the thread hooking rod swivels. At the time of swiveling of the thread hooking rod, the needle thread fixing drive section stops driving at least in a segment from when the sewing thread is inserted into the cloth to when the shuttle hooks the needle thread, thereby achieving a fixed state where the thread hooking rod fixes the needle thread by pinching together with the needle thread receiving section.”
Fourth, the third configuration is characterized in that the thread hooking rod support reciprocally moves in a second sideway direction orthogonal to a first sideway direction, while swaying in the first sideway direction with respect to the presser foot main body, by means of a crank mechanism to be driven by the needle thread fixing drive section; and the thread hooking rod swivels as a result of the thread hooking rod support reciprocally moving in the second sideway direction while swaying in the first sideway direction.
Fifth, the third or fourth configuration is characterized in that the needle thread receiving section has an elastic section (216f-1) provided at a position on the cloth surface contact section deviating toward the cloth surface with respect to the insertion position where the sewing needle is to be inserted, and a needle thread receiving section main body (216f-2) that is attached to the elastic section and that fixedly pinches the needle thread together with the thread hooking rod.
Therefore, since the elastic section is attached to the needle thread receiving section, the needle thread can be reliably fixed and pinched between the thread hooking rod and the needle thread receiving main body.
The following configuration can also be adopted. Specifically, “the third, fourth, or fifth configuration can also be embodied as a sewing machine characterized in that the cloth surface contact section has a pair of sideway plates provided in parallel to each other along the sideway direction; that each of the pair of sideway plates has an inserted portion for insertion of the sewing needle; and that the thread hooking rod swivels at a position between the pair of sideway plates in the up-down direction.”
Alternatively, the following configuration can also be adopted. Specifically, “the third, fourth, or fifth configuration can also be embodied as a sewing machine, wherein connection section which connects the pair of sideway plates is provided at a position deviating toward the cloth surface (that can also be referred to as an “upper surface of the cloth”) with respect to the sewing needle insertion position, and the connection section is provided with the needle thread receiving section.”
Sixth, any of the third to fifth configurations is characterized in that the presser foot main body has a main body structure section (214) that is continued from the cloth surface contact section and faces the thread hooking rod support; a shaft (215) is inserted into one of the main body structure section and the thread hooking rod support; that an elongated opening (232k) with the shaft inserted is opened in a remaining one of the two; and that the thread hooking rod swivels by rotationally moving an end area of the thread hooking rod support opposite the thread hooking rod.
Seventh, any of the third to sixth configurations is characterized in that the needle thread fixing drive section is a motor fixed to the presser foot main body; and that the thread hooking rod support is reciprocally moved in the second sideway direction, while swaying in the first sideway direction with respect to the presser foot main body, by means of torque of the motor.
Alternatively, the following configuration can also be adopted. Specifically, “the sixth configuration can also be embodied as a sewing machine characterized in that a support which supports the needle thread fixing drive section is provided on a side of the main body structure section of the presser foot main body section opposite to the cloth surface contact section (which can also be a “rear-side of the main body structure section”); that the needle thread fixing drive section is a motor fixed to the support; that a rotary disc is attached to a rotary shaft of the motor; that an end area on the rear-side of the thread hooking rod support is connected at a position deviating from a rotation center of the rotary disc; and that the thread hooking rod support reciprocally moves in the second sideway direction (which can also be taken as a “front-back direction”) while swaying in the first sideway direction (which can also be taken as a “right-left direction”) with respect to the main body structure section by means of torque of the motor.”
Eighth, any of the third to sixth configurations is characterized in that the needle thread fixing drive section is a motor fixed to a case making up a housing of the sewing machine; and the thread hooking rod support is reciprocally moved in the second sideway direction by means of torque of the motor while swaying in the first sideway direction with respect to the presser foot main body.
The following configuration can also be adopted. Specifically, “the sixth configuration can also be embodied as a sewing machine characterized in that the needle thread fixing drive section is a motor fixed to a case making up a housing of the sewing machine; that a rotary disc concentric with the rotation center of the motor is attached to the motor so as to be reciprocally movable; that there is provided a transmission section for transmitting the torque of the motor to the rotary disc; an end area opposite a portion of the thread hooking rod support opposite the thread hooking rod is connected to the rotary disc at the position deviating from the rotation center of the rotary disc; and that the thread hooking rod support is reciprocally moved in the second sideway direction while swaying in the first sideway direction with respect to the main body structure section by means of the torque of the motor.”
Ninth, in relation to the first configuration, the needle thread fixing section has
a rod-shaped thread hooking rod (236),
a thread hooking rod support (231) that supports the thread hooking rod,
a needle thread receiving section (216f, 214c) that fixedly pinches the needle thread hooked by the thread hooking rod by pinching together with the thread hooking rod, and
the sewing machine has a needle thread fixing main body (212-1) that supports the needle thread receiving section, wherein
the thread hooking rod support moves with respect to the needle thread fixing main body such that the thread hooking rod swivels by means of driving of the needle thread fixing drive section. Therefore, the needle thread can be pinched and fixed by the thread hooking rod and the needle thread receiving section.
Alternatively, the following configuration can also be adopted. Specifically, “in relation to the ninth configuration, the thread hooking rod support moves to and fro in the second sideway direction orthogonal to the first sideway direction while swaying in the first sideway direction with respect to the needle thread fixing section main body by means of the crank mechanism to be driven by the needle thread fixing drive section, and the thread hooking rod swivels as a result of the thread hooking rod support moving to and fro in the second sideway direction while swaying in the first sideway direction.”
Tenth, in relation to the ninth configuration, the needle thread receiving section has an elastic section (216f-1, 214c-1) provided on the needle thread fixing main body and the needle thread receiving section main body (216f-2, 214c-2) that is attached to the elastic section and fixedly pinches the needle thread together with the thread hooking rod.
Accordingly, since the elastic section is attached to the needle thread receiving main body, the needle thread can be reliably pinched and fixed by the thread hooking rod and the needle thread receiving main body.
Further, the following configuration can also be adopted. Specifically, “the ninth or tenth configuration can also be embodied as a sewing machine characterized in that the needle thread fixing main body has the main body structure section (214) opposite the thread hooking rod support; that the shaft (215) is inserted into one of the main body structure section and the thread hooking rod support; that the elongated opening (232k) with the shaft inserted is opened in a remaining one of the two; and that the thread hooking rod swivels by rotationally moving an end area of the thread hooking rod support opposite the thread hooking rod.”
Alternatively, the following configuration can also be adopted. Specifically, “the ninth or tenth configuration can also be embodied as a sewing machine characterized in that the needle thread fixing drive section is the motor fixed to the needle thread fixing main body; and that the thread hooking rod support is reciprocally moved in the second sideway direction while swaying in the first sideway direction with respect to the needle thread fixing main body by means of the torque of the motor.”
Alternatively, the following configuration can also be adopted. Specifically, “the ninth or tenth configuration can also be embodied as a sewing machine characterized in that the needle thread fixing drive section is a motor fixed to the case making up the housing of the sewing machine; and the thread hooking rod support is reciprocally moved in the second sideway direction while swaying in the first sideway direction with respect to the main body structure section by means of torque of the motor.”
Eleventh, any of the first through tenth configurations is characterized in that the sewing machine further comprises a storage section (92) that stores embroidery data including data pertaining to a stitch length and a remaining length of the needle thread for each stitch, wherein the control section generates from the embroidery data, on a per-stitch basis, angle correspondence data which specify an angle of the needle thread motor representing a rotational position of the needle thread motor, for each angle of a main shaft motor representing a rotational position of the main shaft motor which rotates the main shaft for transmitting torque to the thread take-up lever; and the control section also controls, on the basis of the angle correspondence data, a position of the needle thread motor to an angle of the needle thread motor corresponding to the angle of the main shaft motor, as the angle of the main shaft motor changes as a result of rotation of the main shaft motor.”
Twelfth, any one of the first through tenth configurations is characterized in that the sewing machine further comprises a storage section (92) that stores embroidery data including data pertaining to a stitch length and a remaining length of the needle thread for each stitch, wherein the control section generates data for circular movement arm for storing, on a per-stitch basis, data pertaining to an angle corresponding to a stitch reference length used in the first segment and also storing, on a per-stitch basis, data pertaining to angle data corresponding to a length determined by subtracting a remaining length of the needle thread from the stitch reference length used in the second segment; and the control section generates from the embroidery data and the data for circular movement arm, on a per-stitch basis, angle correspondence data which specify an angle of the needle thread motor representing a rotational position of the needle thread motor, for each angle of a main shaft motor representing a rotational position of the main shaft motor which rotates the main shaft for transmitting torque to the thread take-up lever; and the control section also controls, on the basis of the angle correspondence data, a position of the needle thread motor to an angle of the needle thread motor corresponding to the angle of the main shaft motor, as the angle of the main shaft motor changes as a result of rotation of the main shaft motor.”
Thirteenth, any one of the first through twelfth configurations is characterized in that the sewing machine further comprise a needle thread support member (88) that supports in a sideway direction a range on both sides of the first needle thread portion of the needle thread including the first needle thread, wherein a direction of a circulatory movement axis of the circular movement arm is a sideway direction; a first direction in the direction of circular movement of the circular movement arm is an upward direction of circular movement; and a second direction is a downward direction of circular movement.
Fourteenth, a sewing machine comprises:
a thread take-up lever (12a) that is formed in a swayable manner and that includes a swaying axis provided in a right-left direction and a needle thread hooking section for hooking a needle thread provided closer to a front side than the swaying axis;
a sewing needle (12ba) that is supported by a vertically-movable needle bar and into which the needle thread is to be inserted;
a shuttle (12d) that makes stitches (which can also be referred to as “making stitches by entwining, in a hooking manner, the needle thread inserted into the sewing needle with a hook bobbin thread”) by hooking the needle thread inserted into the sewing needle;
an upstream grip section (40) that has an upstream grip section main body (41) which grips the needle thread in a pinching manner and an upstream drive section (50) which switches the upstream grip section main body between a closed state where the needle thread is gripped and an open state where the gripped needle thread is released;
a downstream grip section (60)
a circular movement section (80)
a needle thread support member (88) that supports, in a right-left direction, a range on both sides of the first needle thread portion of the needle thread including the first needle thread;
wherein the presser foot main body has a cloth surface contact section (216) that contacts the cloth surface when the presser foot is at the cloth surface contact position and a main body structure section (214) formed closer to a rear side than the cloth surface contact section, and
that moves between a cloth surface contact position where the presser foot contacts the cloth surface and a cloth surface apart position where the presser foot is apart from the cloth surface;
a needle thread fixing drive section (240) that actuates the crank section and performs switching between a fixed state where the needle thread fixing section fixes the needle thread and a released state where the needle thread fixed by the needle thread fixing section is released;
a storage section (92) that stores embroidery data including data pertaining to a stitch length and a remaining length of the needle thread for each stitch; and
a control section (90)
In relation to the sewing machine having the fourteenth configuration, the circular movement arm performs circular movement through an angle corresponding to the stitch reference length, which is a stitch length achieved when the n+1th stitch is fixed by the needle thread fixing section in the first segment. Hence, the needle thread having the length required for the n+1th stitch is prepared between the cloth and the circular movement arm. When the shuttle descends from its top dead center to hook the needle thread, the second needle thread portion is fixed by the needle thread fixing section. Therefore, there is no risk of the shuttle withdrawing the needle thread from the stitch fixed by the needle thread fixing section (i.e., the nth stitch). In addition, the upstream grip section stays closed, and the downstream grip section stays open. Accordingly, there is no fear of the needle thread being withdrawn from an upstream position with respect to the upstream grip section.
Subsequently, the thread take-up lever ascends in the second segment. However, in the course of ascending action of the thread take-up lever, the circular movement arm performs circular movement in the first direction, thus withdrawing the needle thread from the nth stitch. For this reason, the remaining length of the needle thread of the nth stitch correspondingly becomes shorter. By specifying the remaining length of the needle thread for each stitch in advance, the height of hollow embroidery can thereby be controlled on a per-stitch basis.
Thereafter, although the sewing needle is subsequently inserted into the cloth, the needle thread is held fixed by the needle thread fixing section. Therefore, the needle thread becomes folded back at the position of the needle thread fixing section.
Then, circular movement is performed in the first direction in the third segment. However, on this occasion, the upstream grip section stays open, and the downstream grip section stays closed. Therefore, the needle thread is withdrawn from an upstream position with respect to the upstream grip section. Thereby, the needle thread will not become deficient in subsequent stitches.
As above, the sewing machine of the present invention creates hollow embroidery by fixing needle thread with the thread hooking rod. Therefore, the plate-shaped member to be used for superposing the needle thread on the cloth to be embroidered is unnecessary with the needle thread fixing section, nor is required dissolution of the plate-shaped member. Moreover, the length of the needle thread can be controlled on a per-stitch basis by means of the angle of circular movement of the circular movement arm in the second segment. Therefore, there can be provided a sewing machine capable of creating elaborate hollow embroidery. The length of the needle thread (i.e., the remaining length of the needle thread) is made longer, thereby preventing excessive pulling of the cloth, which would otherwise be caused by making stitches, and the embroidered cloth does not become wavy (or uneven). Further, stitches can be made soft.
In the fourteenth configuration, the control section can also be embodied as follows. Specifically, “the control section (90) that controls the operation of the upstream drive section, the operation of the downstream drive section, the operation of the needle thread motor, and the operation of the needle thread fixing drive section (or can also be referred to as a “needle thread fixing section”); that, in the first segment which is at least the portion of a time segment from the top dead center of the shuttle to the bottom dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the second direction through an angle corresponding to a stitch reference length which is a needle thread length of a stitch achieved while an n+1th stitch next to a proximal nth stitch (“n” is an integer), among stitches already made in the cloth, is fixed to the needle thread fixing section; that, in the second segment which is at least a portion of a time segment from the bottom dead center of the shuttle to the top dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the first direction through the angle corresponding to the length which is obtained by subtracting a needle thread remaining length, or the length of the needle thread obtained by subtracting the length of the needle thread projecting out of the cloth surface in the nth stitch, from the stitch reference length in the nth stitch; that, in the third segment which is at least the portion of the time segment from the end position of the second segment to the position where the shuttle hooks the needle thread, circularly moves the circular movement arm, by control of the needle thread motor, up to the first end position in the first direction; that, on occasion of control of the needle thread motor, generates from the embroidery data, on a per-stitch basis, angle correspondence data that specify an angle of the needle thread motor representing a rotational position of the needle thread motor, for each angle of a main shaft motor representing a rotational position of the main shaft motor that rotates the main shaft for transmitting torque to the thread take-up lever, and also controls, on the basis of the angle correspondence data, a position of the needle thread motor to an angle of the needle thread motor corresponding to the angle of the main shaft motor, as the angle of the main shaft motor changes as a result of rotation of the main shaft motor; that controls the upstream drive section, thereby bringing the upstream grip section into the closed state at any position in a time segment from the end position of the third segment section to the position where the shuttle hooks the needle thread, and brings the upstream grip section into an open state at any position (which can also be taken as “any time position in a time segment, and the same also applies to any counterparts throughout the descriptions) in a time segment from the end position of the second segment to the start position of the third segment; that controls the downstream drive section, thereby bringing the downstream grip section into the closed state at any position in a time segment from the end position of the second segment section to the position where the upstream grip section is switched from the closed state to the open state, and brings the downstream grip section into the open state at any position in a time segment from the position where the upstream grip section is switched from the open state to the closed state to the position where the shuttle hooks the needle thread; and that controls the needle thread fixing drive section, whereby the needle thread fixing drive section stops driving, and the thread hooking rod fixedly pinches the needle thread together with the needle thread receiving section, in at least a time segment from when the sewing needle is inserted into the cloth to when the shuttle hooks the needle thread.”
In the fourteenth configuration, the control section can also be embodied as follows. Specifically, “a control section (90) that controls operation of the upstream drive section, operation of the downstream drive section, operation of the needle thread motor, and operation of the needle thread fixing drive section (or can also be called a “needle thread fixing section”); that, in the first segment which is at least a portion of a segment from the top dead center of the shuttle to the bottom dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the second direction through an angle corresponding to a stitch reference length which is a needle thread length of a stitch achieved while the n+1th stitch next to the proximal nth stitch (“n” is an integer), among the stitches already made in the cloth, is fixed to the needle thread fixing section; that, in the second segment which is at least a portion of the segment from the bottom dead center of the shuttle to the top dead center of the shuttle, circularly moves the circular movement arm, by control of the needle thread motor, in the first direction through an angle corresponding to the length which is obtained by subtracting a needle thread remaining length, or the length of the needle thread obtained by subtracting the length of the needle thread projecting out of the cloth surface in the nth stitch, from the stitch reference length in the nth stitch; that, in the third segment which is at least a portion of the time segment from termination of the second segment to a position where the shuttle hooks the needle thread, circularly moves the circular movement arm, by control of the needle thread motor, up to the first end position in the first direction; that, on occasion of control of the needle thread motor, generates from the embroidery data, on a per-stitch basis, angle correspondence data which specify an angle of the needle thread motor representing a rotational position of the needle thread motor, for each angle of a main shaft motor representing a rotational position of the main shaft motor that rotates the main shaft for transmitting torque to the thread take-up lever, and also controls, on the basis of the angle correspondence data, a position of the needle thread motor to an angle of the needle thread motor corresponding to the angle of the main shaft motor, as the angle of the main shaft motor changes as a result of rotation of the main shaft motor; that controls the upstream drive section, thereby bringing the upstream grip section into a closed state at any time in the segment from termination of the third segment section to a position where the shuttle hooks the needle thread, and brings the upstream grip section into an open state at any time in the segment from termination of the second segment to initiation of the third segment; that controls the downstream drive section, thereby bringing the downstream grip section into a closed state at any time in the segment from termination of the second segment section to a time when the upstream grip section is switched from the closed state to the open state, and brings the downstream grip section into an open state at any time in the segment from a time when the upstream grip section is switched from the open state to the closed state to a time when the shuttle hooks the needle thread; and that controls the needle thread fixing drive section, whereby the needle thread fixing drive section stops driving, and the thread hooking rod fixedly pinches the needle thread together with the needle thread receiving section, in at least a segment from when the sewing needle is inserted into the cloth to when the shuttle hooks the needle thread.”
Fifteenth, in relation to the fourteenth configuration, the control section generates data for circular movement arm for storing, on a per-stitch basis, data pertaining to an angle corresponding to a stitch reference length used in the first segment and also storing, on a per-stitch basis, data pertaining to angle data corresponding to a length determined by subtracting a remaining length of the needle thread from the stitch reference length used in the second segment; and generates angle correspondence data from the embroidery data and the data for circular movement arm.
Sixteenth, in relation to any of the first to fifteenth configurations, in the second segment, the control section circularly moves the circular movement arm in the first direction through an angle that is obtained by subtracting the angle corresponding to the remaining length of the needle thread which is a length of the needle thread projecting out of the cloth surface in the nth stitch, from an angle corresponding to the stitch reference length in the nth stitch, instead of circularly moving the circular movement arm in the first direction through an angle corresponding to a length which is obtained by subtracting the remaining length of the needle thread, which is the length of the needle thread projecting out of the cloth surface in the nth stitch, from the stitch reference length in the nth stitch.
A sewing machine based on the present invention creates hollow embroidery by fixing a needle thread with the needle thread fixing section. Therefore, the plate-shaped member to be used for superposing the needle thread on the cloth to be embroidered is unnecessary, nor is required dissolution of the plate-shaped member. Moreover, the length of the needle thread (in other words, a remaining length of the needle thread) can be controlled on a per-stitch basis by means of the angle of circular movement of the circular movement arm in the second segment. Therefore, there can be provided a sewing machine capable of creating elaborate hollow embroidery. Further, the length of the needle thread (i.e., the remaining length of the needle thread) is made longer, thereby preventing excessive pulling of the cloth, which would otherwise be caused by making stitches, and the embroidered cloth does not become wavy (or uneven). Further, stitches can be made soft.
In the present invention, an object of providing a sewing machine, which needs neither a plate-shaped member to be superposed on a cloth to be embroidered nor dissolution of the plate-shaped member and which is also capable of adjusting the length of a needle thread on a per-stitch basis and obtaining elaborate hollow embroidery, is accomplished as will be stated below.
A sewing machine 5 of an embodiment is an embroidery sewing machine and configured as illustrated in
The head 7 is positioned above an approximately-flat-plate-shaped sewing machine table 3. A frame 120 (see
The head 7 is configured as illustrated in
The machine element group 10 includes respective machine elements to be actuated in the head 7, and the machine elements include a thread take-up lever 12a, a needle bar 12b, and a presser foot 12c. As in the case of an existing sewing machine, the thread take-up lever 12a and the needle bar 12b are actuated by transmitting torque of the main shaft 22 by way of power transmission means, such as a cam mechanism and a belt mechanism.
The thread take-up lever 12a is disposed in the case 110 and formed so as to be swayable around an axis (a rotation center) extending in a horizontal direction (an X1-X2 direction), thus circularly moving between the bottom dead center (one dead center) and the top dead center (the other dead center). Specifically, the thread take-up lever 12a is pivotally supported by the case 110 so as to be swayable around a rotation center (which can also be taken as a pivot) 12ab. A needle thread inserted into a sewing needle 12ba is inserted into the thread take-up lever 12a. A leading end of the thread take-up lever 12a projects to the front (Y1 side) out of an opening 116d formed in a front section 110-1 of the case 110, thus being exposed. A tension spring 102 [that can also be referred to as a “thread take-up spring” (generally called a “high tension spring”)] that guides a needle thread J sent from an upstream position (i.e., from the downstream grip section 60) while eliminating flexure or a slack in the needle thread J is fixedly mounted at a position on the front section 110-1 of the case 110 in a neighborhood of a lower portion of the opening 116d. The tension spring 102 inverts the needle thread J guided from the upper position and subsequently guides the needle thread to the thread take-up lever, and tension is exerted on the needle thread J by the tension spring 102. As in the case of the guide member 100, a rod-shaped guide member can also be used in place of the tension spring 102.
The needle bar 12b is provided so as to be movable in the vertical direction with reference to the case 110. The sewing needle 12ba (the needle thread is inserted into a pin hole 12bb of the sewing needle 12ba) is fixedly provided at a lower end of the needle bar 12b. A needle bar connecting stud 14a is fixedly provided at an approximately intermediate position on the needle bar 12b in the vertical direction.
Further, a base needle bar 14c is disposed in the vertical direction in the case 110. The base needle bar 14c is equipped with a needle bar up-down member 14b (or can also be referred to as a “needle bar up-down actuation component” or a “needle bar elevation element”) which is to engage with a needle bar connecting stud 14a, so as to be vertically movable along the base needle bar 14c. The needle bar up-down member 14b is vertically moved by use of a mechanism for vertically moving the needle bar up-down member 14b, whereby the needle bar connecting stud 14a is vertically actuated, and the needle bar 12b is also vertically moved.
An up-down actuation mechanism 14 serving as a mechanism for actuating the needle bar 12b up and down has the needle bar connecting stud 14a, the needle bar up-down member 14b, and a crank rod 14d for actuating the needle bar up-down member 14b up and down. A transmission mechanism (not shown) for transmitting torque of the main shaft 22 is joined to the crank rod 14d. As a result of the main shaft 22 being rotated, the crank rod 14d also rotates, and the needle bar up-down member 14b thereby moves up and down along the base needle bar 14c. Thus, the needle bar 12b reciprocally moves in the vertical direction.
The presser foot 12c is provided at a bottom side of the case 110 so as to be movable up and down with respect to the case 110, and also has a thread hooking rod 236 (which can also be a “rod-shaped member”) for hooking the needle thread in a sideway direction.
Specifically, as shown in
The main body (a presser foot main body) 210 has a base 212 and a shaft 220 fixed to the base 212.
The base 212 has a main body structure section (which can also be taken as a “central configuration section”) 214 assuming the shape of a quadrate (specifically, a “rectangular shape”) plate; a leading-end structure section (which can also be taken as a “leading end section”) (a “cloth surface contact section”) 216 continued from a front-side end (one of a pair of short sides) of the main body structure section 214, a needle thread receiving section 216f attached to an interior surface of a vertical plate 216e of the leading-end structure section 216, and a base end 218 continued from a rear-side end (a remaining one of the pair of the short sides). The entirety of the base 212 except for a shaft 215 (which will be described later) and the needle thread receiving section 216f is integrally formed. The leading-end structure section 216 is equivalent to “the cloth surface contact section which contacts a cloth surface when the presser foot is situated at a cloth surface contact position.”
As shown in
Moreover, the leading-end structure section 216 has a sidewise-elongated quadrate vertical plate 216a continued downwardly from a front-side end of the main body structure section 214, a sideway plate 216b continued from a front-side end to a front side of the vertical plate 216a, a vertical plate 216c continued downward from a front-side end of the sideway plate 216b, a sidewise-elongated rectangular sideway plate 216d continued from a lower end of the vertical plate 216c to the rear side, and a vertical plate 216e (see
The sideway plate 216b and the sideway plate 216d assume the shape of a quadrate (specifically a “rectangular shape”) plate and are formed parallel to each other. A circular opening 216bk is formed in the sideway plate 216b, and a circular opening 216dk is formed in the sideway plate 216d. The opening 216bk and the opening 216dk are holes for insertion of the needle thread and the sewing needle 12ba. The opening 216bk and the opening 216dk are formed so as to have the same diameter (which can also be said to be substantially the same), and the opening 216bk and the opening 216dk are placed at the same position in the horizontal direction (in other words, a direction other than the vertical direction). In other words, the openings 216bk and 216dk are inserted portions for insertion of the sewing needle. As above, the sideway plate 216b and the sideway plate 216d are formed to have the same size and the same shape. When the sewing needle 12ba is inserted into a cloth, the presser foot 12c stays descended, and the leading-end structure section 216 remains in contact with the cloth surface. While the leading-end structure section 216 remains in contact with the cloth surface, the lower surface of the sideway plate 216d comes into contact with the cloth surface.
A spacing h1 (see
A length of the sideway plate 216b and a length of the sideway plate 216d achieved in a right-left direction (the X1-X2 direction) are made longer than a length of the main body structure section 214 achieved in the right-left direction. Positions of sides on right-side surfaces of the sideway plates 216b and 216d achieved in the right-left direction coincide with position of side on the right-side surface of the main body structure section 214 achieved in the right-left direction (side of the right-side surface of the sideway plate 216b and side of the right-side surface of the main body structure section 214 are in line when viewed from the above). Hence, the sideway plates 216b and 216d are formed so as to project to the left-side direction with respect to the left-side surface of the main body structure section 214.
The needle thread receiving section 216f has an elastic section 216f-1 provided on an interior surface of the vertical plate 216e and a plate-shaped section (a needle thread receiving main body) 216f-2 fixed to an end of the elastic section 216f-1 opposite to the vertical plate 216e. The elastic section 216f-1 is a coil spring that is fixed at one end thereof to the vertical plate 216e and at the other end to the plate-shaped section 216f-2. The plate-shaped section 216f-2 is formed from; for instance, metal or a synthetic resin. The needle thread receiving section 216f is for fixedly pinching the needle thread together with the thread hooking rod 236. When the needle thread pushed toward the needle thread receiving section 216f by the thread hooking rod 236 comes into contact with the plate-shaped section 216f-2, the needle thread is pinched by the thread hooking rod 236 and the plate-shaped section 216f-2. In short, an axis line (a center line) of the coil spring making up the elastic section 216f-1 is formed in the right-left direction (the X1-X2 direction). An extension of the axis of the coil spring is formed so as to pass through a center (or its neighborhood) of the opening 216bk and the opening 216dk. Specifically, the elastic section 216f-1 is for forcing the thread hooking rod 236 having swiveled, substantially toward the left-side surface (in X1 direction), and at least the elastic section 216f-1 forces the thread hooking rod 236 having swiveled, in the sideway direction. Incidentally, since the elastic section 216f-1 is provided, the orientation of the plate-shaped section 216f-2 becomes variable. Even when the orientation of the thread hooking rod 236 has changed as a result of the thread hooking rod 236 being swiveled, the needle thread (i.e., a second needle thread portion Jb (see
The needle thread receiving section 216f is placed at a position deviating toward the cloth surface with respect to the position of insertion of the sewing thread 12ba (i.e., a position deviating toward X2). The thread hooking rod 236 fixes the needle thread at a position apart from the cloth surface (i.e., the upper surface of the cloth). Hence, the swayingly reciprocating mechanism section 230 (particularly, the thread hooking rod 236) and the needle thread receiving section 216f in the main body 210 fix a second needle thread portion, which is a portion of the needle thread located between the cloth and the thread take-up lever, at a position deviating from the position of insertion of the sewing needle toward the upper surface of the cloth as well as at a position higher than the upper surface of the cloth. More specifically, the swayingly reciprocating mechanism section 230 (particularly, the thread hooking rod support 231 and the thread hooking rod 236) and the needle thread receiving section 216f of the main body 210 make up “a needle thread fixing section that fixes a second needle thread portion of the needle thread situated between a cloth and the thread take-up lever at a position apart from a cloth surface and at a position deviating toward the cloth surface from a position where the sewing needle is to be inserted.”
Since the needle thread receiving section 216f is placed at the position deviating from the position of insertion of the sewing needle 12ba toward the cloth surface, the needle thread comes to straddle the thread hooking rod 236 (i.e., the needle thread is folded back at the position of the thread hooking rod 236) when the sewing needle 12ba is inserted into the cloth while the needle thread is pressed by the thread hooking rod 236 and the needle thread receiving section 216f.
The opening 216bk and the opening 216dk are not limited to the circular shape, and cutouts can also be used in lieu of the opening 216bk and the opening 216dk. In short, when the cutouts are used, the opening 216bk is formed to the leading end of the sideway plate 216b, and the opening 216dk is formed to the leading end of the sideway plate 216d. Moreover, an opening is formed in the vertical plate 216c so as to interconnect the opening 216bk and the opening 216dk. As a consequence, a cutout extending from the sideway plate 216bk up to the sideway plate 216dk via the vertical plate 216c is thus formed.
The base end 218 has a sidewise-elongated rectangular vertical plate 218a continued upwardly from a rear-side end of the main body structure section 214 and a sideway plate 218b continued from an upper end of the vertical plate 218a to the rear side. The vertical plate 218a forms a right angle with respect to the main body structure section 214, and the sideway plate 218b forms a right angle with respect to the vertical plate 218a. A right-left length of the vertical plate 218a and a right-left length of the sideway plate 218b are made substantially the same, and the right-left length of the vertical plate 218a and the right-left length of the sideway plate 218b are made substantially identical with a right-left length of the main body structure section 214.
A shaft 220 is fixed at an end position on a front-side upper surface of the sideway plate 218b of the base end 218, and stands upright with respect to the upper surface of the sideway plate 218b.
The structure of the base 212 exclusive of the needle thread receiving section 216f makes up a needle thread fixing section main body 212-1 that supports the needle thread receiving section 216f.
The swayingly reciprocating mechanism section 230 has the sideway plate 232 supported by the shaft 215, a vertical plate 234 continued downward from a front-side end of the sideway plate 232, the thread hooking rod 236 fixed to the vertical plate 234, and a rotary disc 238 rotatably attached to the sideway plate 232.
The sideway plate 232 assumes a strip shape, or the shape of a strip whose upper surface assumes the shape of a combination of one short side of a rectangular shape with a semicircular shape. A width of the sideway plate 232 in the direction of its shortness is substantially identical with a shorter width of the main body structure section 214. In addition, an opening 232k elongated in the front-back direction is formed in the sideway plate 232. The shaft man body 215b of the shaft 215 is inserted into the opening 232k. The shaft main body 215b becomes slidable relatively with respect to the sideway plate 232 in a lengthwise direction of the opening 232K.
The vertical plate 234 is a rectangular plate and forms a right angle with respect to the sideway plate 232. A right-side end of the vertical plate 234 and a right-side end of the sideway plate 232 coincide with each other in the right-left direction. However, the vertical plate 234 projects in excess of the sideway plate 232 in the left-side direction, so that an left-side end of the vertical plate 234 is situated further leftward in excess of a left-side end of the sideway plate 232. A hole for insertion of the thread hooking rod 236 is formed in the vertical plate 234. The sideway plate 232 and the vertical plate 234 make up the thread hooking rod support (which can also be taken as the “swayingly reciprocating mechanism section”) 231.
The thread hooking rod 236 has a columnar thread hooking rod main body 236a and a head 236b which is provided at an end of the thread hooking rod main body 236a and larger in diameter than the thread hooking rod main body 236a. The thread hooking rod 236 is fixed to the vertical plate 234 by inserting the thread hooking rod main body 236a into the hole of the vertical plate 234. The thread hooking rod 236 is made of; for instance, metal. A conceivable method for fixing the thread hooking rod 236 to the vertical plate 234; for instance, is to cut a screw thread in a portion of the thread hooking rod main body 236a facing a head 236b, to cut a screw thread in the hole of the vertical plate 234, and to screw-engage the thread hooking rod main body 236a in the vertical plate 234.
The rotary disc 238 assumes the shape of a circular plate, and an output shaft 242a is fixed to a center position of the rotary disc 238. The rotary disc 238 and the sideway plate 232 are connected to each other at a position apart from the output shaft 242a of a thread hooking rod drive motor 240 (i.e., a position eccentric from the rotation center of the rotary disc 238). Specifically, a through hole for insertion of a shaft 239 is made at a position eccentric from the rotation center of the rotary disc 238. A through hole for insertion of the shaft 239 is formed at a center of an end region in the right-left direction on the rear-side of the sideway plate 232. The rotary disc 238 and the sideway plate 232 are connected by inserting the shaft 239 into the respective through holes. Specifically, the shaft 239 has a head 239a which is larger in diameter than the through hole of the rotary disc 238, a shaft main body 239b which continually extends from the head 239a and is inserted into each of the through holes, and a retaining section 239c fixed to an end of the shaft main body 239b opposite to the head 239a.
The thread hooking rod drive motor 240 is fixed to the base 212 (specifically a sideway plate 218b of the base end 18). An output shaft 240a of the thread hooking rod drive motor 240 is perpendicular to an upper surface of the sideway plate 232, and the output shaft 240a is perpendicular to a pair of upper and lower planes of the rotary disc 238, so that the rotary disc 238 and the sideway plate 232 are formed in parallel with each other.
Since the presser foot 12c is configured as mentioned above, the rotary disc 238 rotates when the thread hooking rod drive motor 240 is driven. The rear side of the sideway plate 232 rotates as a result of rotation of the rotary disc 238. When the rear side of the sideway plate 232 rotates, the sideway plate 232 moves to and fro in a front-back direction (a second horizontal direction) while swaying in the right-left direction (a first horizontal direction) because the shaft main body 215b is inserted into the opening 232k. As a result of the sideway plate 232 moving to and fro while swaying in the right-left direction, the thread hooking rod 236 also moves to and fro in the same manner while swaying in the right-left direction, whereupon the thread hooking rod 236 swivels along a sideway surface (plane) (which can also be taken as a horizontal (or substantially horizontal) surface (plane)) (in other words, the thread hooking rod 236 swivels along a plane parallel (substantially parallel) to the cloth surface). Incidentally, the thread hooking rod 236 can also be said to swivel along a surface (plane) that is at a right angle (which can also be substantially right angels) to the direction of the second needle thread portion (which can also be a direction of ranges on both sides of the second needle thread) (the vertical direction). Thereby, a leading end 236Q of the thread hooking rod 236 swivels along a sideway direction (which can also be a “horizontal direction”), thereby forming a substantially elliptical locus when viewed from above as shown in
The swayingly reciprocating mechanism section 230 reciprocally moves in the front-back direction by the crank mechanism while swaying in the right-left direction with respect to the main body structure section 214 of the base 212. The crank mechanism can be said to be made up of the rotary disc 238, the sideway plate 232 connected to the rotary disc 238 at a position eccentric from its rotation center, and the shaft 215.
As shown in
The presser foot 12c is actuated up and down by an up-down actuation mechanism 250. Specifically, the up-down actuation mechanism 250 has a fixed component 252 fixed to the shaft 220, a shaft 254 fixed to the case 110, a presser foot up-down component 256 formed so as to be movable up and down along the shaft 254, and a crank rod 258. The fixed component 252 is formed similarly to the needle bar connecting stud 14a, and the shaft 254 is placed at a right angle to a bottom section 110-3 of the case 110 and formed in a perpendicular direction. The presser foot up-down component 256 is in engagement with the fixed component 252. A transmission mechanism (not shown) for transmitting torque of the main shaft 22 is joined to the crank rod 258. When the main shaft 22 rotates, the crank rod 258 also rotates, whereby the presser foot component 256 moves up and down along the shaft 254. Thus, the presser foot 12c reciprocally moves in the vertical direction.
The presser foot 12c moves (or can also move to and fro) between the bottom dead center (a cloth surface contact position) where a contact with the cloth surface is achieved and the top dead center (a position apart from the cloth surface) apart from the cloth surface. The presser foot 12c is situated at the bottom dead center in a segment of a predetermined range. A start position of a bottom dead center segment is located at an arbitrary position between a position where the frame actuator 24 has stopped and a position where the sewing needle 12ba is inserted into the cloth (a position of about 100 degrees in
The shuttle 12d is placed at a position that is beneath the head 7 and lower than an upper surface of the sewing machine table. Specifically, the shuttle 12d is supported, below the pinhole 5a of the throat plate 5, by a shuttle base (not shown) disposed below the sewing machine table. A bobbin is accommodated in the shuttle 12d, and a bobbin thread is wound around the bobbin. The shuttle 12d rotates when receiving the torque of the main shaft 22 being transmitted, and a point 12d-1 (see
The sewing frame 12e is a member for holding a cloth (specifically, a cloth to be embroidered) under tension and placed at an elevated position above (or an upper surface of) the sewing machine table.
The main shaft 22 is rotated by the main shaft motor 20, and torque of the main shaft 22 is transmitted by a predetermined power transmission mechanism, whereby respective machine elements, such as the thread take-up lever 12a, the needle bar 12b, and the presser foot 12c, and the shuttle 12d are actuated. The main shaft motor 20 is configured so as to rotate in one direction.
The frame actuator 24 is for moving the sewing frame 12e in an X-axis direction (the direction X1-X2) and a Y-axis direction (the direction Y1-Y2) in response to a command from the control circuit 90. The sewing frame 12e is moved in synchronization with up-down movements of the needle bar 12b. The frame actuator 24 is specifically made up of a servo motor for moving the sewing frame 12e in the X-axis direction, a servo motor for moving the sewing frame 12e in the Y-axis motor, and others.
The upstream grip section 40 is placed at an upstream position in the head 7; in other words, above the circular movement section 80, and has a grip section main body (upstream grip section main body) 41 and a magnet section (an upstream drive section, or an upstream magnet section) 50 provided on a rear side of the grip section main body 41.
The grip section main body 41 has a first plate-shaped section unit 42 and a second plate-shaped section (an upstream second plate-shaped section) 44 provided at the rear side of the first plate-shaped section 42a of the first plate-shaped section 42 and on the front side of the front section 110-1 of the case 110.
As shown in
The second plate-shaped section 44 is one plate-shaped member provided on the rear side of the first plate-shaped section 42a in the first plate-shaped section unit 42, and assumes the shape of an elongated rectangular shape. Specifically, the second plate-shaped section 44 is formed so as to become longer than the length of the first plate-shaped section 42a in the right-left direction and become approximately identical in length with (in a rigorous sense, slightly shorter than) the first plate-shaped section 42a in the up-down direction. A left end of the second plate-shaped section 44 when viewed from front is situated further leftward than a side of the left side surface of the first plate-shaped section 42a, and fixed to the front section 110-1 by a presser plate 46. Moreover, a right end of the second plate-shaped section 44 when viewed from front is situated further rightward than a side of the right side surface of the first plate-shaped section 42a, and fixed to the front section 110-1 by the presser plate 46. Namely, the second plate-shaped section 44 is present in parallel to the first plate-shaped section 42a at the rear of the first plate-shaped section unit 42a. The second plate-shaped section 44 is formed from a magnet-unattractive material (a material to which a magnet does not adhere); in other words, a non-magnetic substance; for instance, a synthetic resin film. The second plate-shaped section 44 can also be formed from aluminum or stainless steel.
An sidewise-elongated rectangular opening (a second opening) 116a is formed in an upper portion of the front section 110-1 of the case 110, and the second plate-shaped section 44 is provided so as to cover the opening 116a from the front. Specifically, the opening 116a is formed smaller than the second plate-shaped section 44, and the vertical height of the second plate-shaped section 44 is made larger than a leading end of the magnet section 50 in such a way that the leading end of the magnet section 50 can pass through the opening 116a.
The hooking hole 110a for hooking the hooking section 42b of the first plate-shaped section unit 42 is formed at a position above the opening 116a on the front section 110-1. The hooking hole 110a is formed so as to penetrate through the front section 110-1.
The magnet section 50 is made of an electromagnet, and the leading end of the magnet section 50 is situated in the opening 116a and formed so as to contact a rear-side surface of the second plate-shaped section 44. A leading-end surface of the magnet section 50 (a surface facing the second plate-shaped section 44) serves as an attracting surface. The magnet section 50 assumes the shape of a substantially square pole (the same also applies to a magnet section 70). Incidentally, the magnets 50, 70 have the same structure as that of an ordinary electromagnet. The magnet has a core made of a magnetic material and a coil wound around the core, and magnetic forces develop as a result of energization of the coil. One magnet section 50 is provided in the upstream grip section 40. The control circuit 90 activates the magnet section 50, whereby the first plate-shaped section 42a is attracted by the magnetic force. Thus, clearance between the first plate-shaped section 42a and the second plate-shaped section 44 becomes closed. The magnet section 50 is supported by a support 112a of the case 110.
Moreover, rod-shaped guide members (first guide members) 52 and 54 are provided above and below the first plate-shaped unit section 42 when viewed from front. Specifically, the guide members 52 and 54 are fixed to the front-side 110-1 of the case 110. The guide members 52 and 54 are placed such that the needle thread J diagonally passes by the rear-side of the first plate-shaped section. The guide member 52 is provided at the left side above the first plate-shaped section 42a when viewed from front, and the guide member 54 is provided at the right side below a lower portion of the first plate-shaped section 42a when viewed from front. A path for the needle thread J laid on the rear-side of the first plate-shaped section 42a can thereby be made longer, so that the needle thread J can be more reliably gripped between the first plate-shaped section 42a and the second plate-shaped section 44.
The downstream grip section 60 is placed at an approximately intermediate position on the head 7 in the up-down direction; namely, below the circular movement section 80, and has a grip section main body (a downstream grip section main body) 61 and a magnet section (a downstream drive section or a downstream magnet section) 70 provided on a rear-side of the grip section main body 61.
The grip section main body 61 has the same structure as that of the grip section main body 41; namely, has a first plate-shaped section unit 62 and a second plate-shaped section (a downstream second plate-shaped section) 64 provided at the rear side of the first plate-shaped section 62a of the first plate-shaped section 62 and on the front side of the front section 110-1 of the case 110.
As shown in
The second plate-shaped section 64 has the same structure as that of the second plate-shaped section 44, and is one plate-shaped member provided on the rear side of the first plate-shaped section 62a in the first plate-shaped section unit 62 and assumes the shape of an elongated rectangular shape. Specifically, the second plate-shaped section 64 is formed so as to become longer than the length of the first plate-shaped section 62a in the right-left direction and become approximately identical in length with (in a rigorous sense, slightly shorter than) the first plate-shaped section 62a in the up-down direction. A left end of the second plate-shaped section 64 when viewed from front is situated further leftward than a side of the left side surface of the first plate-shaped section 62a, and fixed to the front section 110-1 by a presser plate 66. Moreover, a right end of the second plate-shaped section 44 when viewed from front is situated further rightward than a side of the right side surface of the first plate-shaped section 62a, and fixed to the front section 110-1 by the presser plate 66. Namely, the second plate-shaped section 64 is present in parallel to the first plate-shaped section 62a at the rear of the first plate-shaped section 62a of the first plate-shaped section unit 62. The second plate-shaped section 64 is formed from a magnet-unattractive material (a material to which a magnet does not adhere); namely, a non-magnetic substance; for instance, a synthetic resin film. The second plate-shaped section 64 can also be formed from aluminum or stainless steel.
A sidewise-elongated rectangular opening (a third opening) 116c is formed at an approximately-center portion of the front section 110-1 of the case 110 in its vertical direction, and the second plate-shaped section 64 is provided so as to cover the opening 116c from the front. Specifically, the opening 116c is formed smaller than the second plate-shaped section 64, and the vertical width of the second plate-shaped section 64 is made larger than a leading end of the magnet section 70 in such a way that the leading end of the magnet section 70 can pass through the opening 116c.
The hooking hole 110b for hooking the hooking section 62b of the first plate-shaped section unit 62 is formed at a position above the opening 116c on the front section 110-1. The hooking hole 110b is formed so as to penetrate through the front section 110-1.
Like the magnet section 50, the magnet section 70 is made of an electromagnet such that the leading end of the magnet section 70 is situated in the opening 116c and contacts a rear-side surface of the second plate-shaped section 64. A leading-end surface of the magnet section 70 (a surface facing the second plate-shaped section 64) serves as an attracting surface. The magnet section 70 assumes the shape of a substantially square pole and is formed into (or approximately) the same size and shape as those of the magnet section 50. One magnet section 70 is placed in the downstream grip section 60. The control circuit 90 activates the magnet section 70, whereby the first plate-shaped section 62a is attracted by the magnetic force. Thus, clearance between the first plate-shaped section 62a and the second plate-shaped section 64 becomes closed. The magnet section 70 is supported by the support 112b of the case 110.
Moreover, rod-shaped guide members (first guide members) 72 and 74 are provided above and below the first plate-shaped unit 62 when viewed from front. Specifically, the guide members 72 and 74 are fixed to the front-side section 110-1 of the case 110. The guide members 72 and 74 are placed such that the needle thread J diagonally passes by the rear-side of the first plate-shaped section. The guide member 72 is provided at the left side above an upper portion of the first plate-shaped section 62a when viewed from front, and the guide member 74 is provided at the right side below a lower portion of the first plate-shaped section 62a when viewed from front. A path for the needle thread J laid on the rear-side of the first plate-shaped section 62a can thereby be made longer, so that the needle thread J can be more reliably gripped between the first plate-shaped section 62a and the second plate-shaped section 64.
The circular movement section 80 is placed at an approximately intermediate position in the up-down direction between the upstream grip section 40 and the downstream grip section 60. Namely, the circular movement section 80 is placed at a downstream position with respect to the upstream grip section 40 and an upstream position with respect to the downstream grip section 60 in the direction feeding the needle thread. The circular movement section 80 is for circularly moving the needle thread between the grip section main body 41 and the grip section main body 61 (which can also be called a portion (position) of the needle thread situated between the grip section main body 41 and the grip section main body 61). The circular movement section 80 has a circular movement arm 81 and a needle thread motor 86 that rotates the circular movement arm 81.
As shown in
The needle thread motor 86 is secured to a support 112c of the case 110. The axis of the output shaft of the needle thread motor 86 is oriented in the right-left direction.
A lower limit position (a position designated by 81 (B) in
In the direction (the first direction) in which the circular movement arm 81 ascends, a degree of flexure of the needle thread becomes greater. In a direction (a second direction) in which the circular movement arm 81 descends, the degree of flexure of the needle thread becomes smaller. In
Alternatively, at the lower limit position in the range of circular movement of the circular movement arm 81, the position where the groove 84a of the hook 84 receives the needle thread can also be situated above the position where the connection members 88c of the pair of needle thread support members 88 receive the needle thread. At the lower limit position of the circular movement arm 81, the needle thread is in contact with the pair of needle thread support members 88 and the circular movement arm 81. A portion of the needle thread situated between the pair of needle thread support members 88 can also be made bent around a portion of the needle thread supported by the circular movement arm 81 when viewed from front.
The control circuit 90 controls circular movement of the needle thread motor 86, and the needle thread motor 86 is positionally controlled in accordance with angle-correspondence data (
The needle thread support members 88 are disposed on respective sides of an opening 116b on the front section 110-1 of the case 110. The needle thread support member 88 is for supporting the needle thread J in the right-left direction. Specifically, the pair of needle thread support members 88 are provided on both sides of the opening 116a, and the respective needle thread support members 88 have the same structure and formed by folding back a wire into a circular-arc. Specifically, each of the needle thread support members 88 has a shape formed by integration of: a circular-arc member 88a formed (or approximately) concentrically with the rotation center of the needle thread motor 86; a circular-arc member 88b formed at an opposite side of axis (the axis passing through the rotation center) of the output shaft of the needle thread motor 86 with respect to the circular-arc member 88a opposite to the axis (the axis passing through the rotation center) in approximately parallel with the circular-arc member 88a in a manner (or approximately) concentric with the rotation center of the needle thread motor 86; and the connection member 88c made by joining the circular-arc member 88a to the circular-arc member 88b at their lower end positions in a circular-arc shape. Specifically, the circular-arc member 88a and the circular-arc member 88b are formed concentrically with the rotation center of the needle thread motor 86 as viewed in side elevation. In one needle thread support member 88, the circular-arc member 88a and the circular-arc member 88b are formed along planes orthogonal to the axis (the axis passing through the rotation center) of the output shaft of the needle thread motor 86, and formed at spacing therebetween in a direction orthogonal to the axis of the output axis. The circular-arc member 88a and the circular-arc member 88b are formed at the same position in the right-left direction. Further, the pair of needle thread support members 88 are provided at spacing in the right-left direction. In addition, a portion of the circular-arc member 88a and a portion of the circular-arc member 88c are provided in the opening 116b, and the circular-arc member 88b projects in excess of a front surface of the front section 110-1 in front direction. The needle thread is thereby inserted into a position between the circular-arc member 88a and the circular-arc member 88b from above the pair of needle thread support members 88 and laid on the pair of connection members 88c. Thereby, the needle thread J can be interposed between the connection members 88c of the pair of needle thread support members 88 in the right-left direction. Even when pulled up by the circular movement arm 81, the needle thread J still stays between the circular-arc member 88a and the circular-arc member 88b. Specifically, the needle thread support member 88 supports the needle thread at the position of the opening 116b [in other words, the position of the opening 116b in the up-down direction and the right-left direction (specifically, a lower position in the opening 116b)] in the right-left direction. More specifically, the needle thread support member 88 supports the needle thread on the front side of the opening 116b (which can also be “at a position on the front side of the opening 116b”) in the right-left direction when viewed from front. As above, the needle thread support member 88 supports, in the right-left direction, a range on both sides of the first needle thread portion, including the first needle thread portion of the needle thread. The needle thread support member 88 can also support the needle thread in the opening 116b (in other words, a position between the front-side surface and the rear-side surface of the front section 110-1 in the front-back direction) in the right-left direction.
A rod-shaped guide member (a first needle thread path inversion member) 100 for guiding the needle thread J delivered from above (in other words, the needle thread delivered from the upstream grip section 40) to the needle thread support members 88 is fixedly provided on the front section 110-1 of the case 110 at a position near a lower portion of the opening 116b. The guide member 100 guides in an inverting manner the needle thread delivered from above to the needle thread support members 88.
In accordance with data stored in the storage device 92, the control circuit 90 is a circuit for controlling operation of the respective sections as well as operation of the main shaft motor 20, the needle thread motor 86, the thread hooking rod drive motor 240, the magnet section 50, the magnet section 70, and the frame actuator 24. Specifically, the control circuit 90 generates main shaft data (see
From the embroidery data, the control circuit 90 calculates an amount of descent of the circular movement arm in a descending segment (a first segment) of the circular movement arm and an amount of ascent of the circular movement arm in an ascending segment of the circular movement arm (a second segment), thereby generating data for circular movement arm (see
In the descending segment of the circular movement arm, the amount of descent of the circular movement arm corresponds to an amount of descent for circularly moving the circular movement arm 81 downward. Specifically, the amount of descent is specified by a rotation angle of the needle thread motor 86. As to the amount of descent of the rotational arm, an amount of descent corresponding to a length expressed by Equation 1 provided below is specified.
Specifically, as shown in
The amount of ascent of the circular movement arm is an amount of ascent for circularly moving the circular movement arm 81 upwardly in the ascending segment (the second segment) of the circular movement arm and, specifically, specified by the rotation angle of the needle thread motor 86. As to the amount of ascent of the circular movement arm, there is specified an amount corresponding to a value determined by subtracting a remaining length L2 of the needle thread (the remaining length of the needle thread is stored in the embroidery data) from the length of the needle thread [a length calculated by Equation 1 (the stitch reference length)] corresponding to the amount of descent of the circular movement arm. In short, a table of correspondence between values determined by subtraction and the rotation angles of the needle thread motor 86 is prepared in advance, and the amount of ascent of the circular movement arm is determined from the value determined by subtraction and the correspondence table. More specifically, the control circuit 90 calculates the amount of ascent of the circular movement arm on a per-stitch basis, preparing the data for circular movement arm.
In operation of a stitch (a second stitch) subsequent to a certain stitch (a first stitch), the circular movement arm 81 is ascent in accordance with the amount of ascent of the circular movement arm, thereby adjusting a remaining length of the needle thread for the first stitch. Accordingly, the amount of ascent of the circular movement arm in the second stitch is set to a value calculated from the remaining length of the needle thread for the first stitch. In
The amount of ascent of the circular movement arm is defined as “a rotation angle corresponding to a value determined by subtracting the remaining length of the needle thread for the stitch “n” from the length of the needle thread corresponding to the amount of descent of the circular movement arm for the stitch “n.”” However, the amount of ascent of the circular movement arm can also be defined as a “rotation angle calculated by subtracting an angle corresponding to the remaining length of the needle thread for the stitch “n” from the angle corresponding to the amount of descent of the circular movement arm for the stitch “n.”
The control circuit 90 generates angle correspondence data (see
As the position data, there are stored a start position and an end position of the descending segment of the circular movement arm, a start position and an end position of the ascending segment of the circular movement arm, and the start position and the end position of the needle thread withdrawal segment (the third segment) of the circular movement arm. Further, as data for circular movement arm, there are stored the amount of descent of the circular movement arm and the amount of ascent of the circular movement arm on per-stitch basis. Angle correspondence data specifying correspondence between an angle of the main shaft and an angle of the needle thread motor (an angle of the needle thread motor) (a rotational position of the needle thread motor 86) are generated on a per-stitch basis.
On the occasion of generation of the angle correspondence data, the circular movement arm 81 is set to the upper limit position at an end position of a needle thread withdrawal segment. The upper limit position of the circular movement arm 81 serves as an end position in a direction of circular movement achieved when the circular movement arm 81 withdraws the needle thread from a more upstream position with respect to the circular movement arm 81.
In the descending segment of the circular movement arm 81, the angle of the needle thread motor is determined for each main shaft angle according to the start position and the end position of the descending segment and the amount of descent of the circular movement arm in such a way that the needle thread motor 86 rotates downward from the start position to the end position of the descending segment only by the amount of descent of the circular movement arm. The circular movement arm 81 thereby performs circular movement by an angle corresponding to the stitch reference length for the stitch n+1.
In the ascending segment of the circular movement arm 81, the angle of the needle thread motor is determined for each main shaft angle according to the start position and the end position of the ascending segment and the amount of ascent of the circular movement arm in such a way that the needle thread motor 86 rotates upward from the start position to the end position of the ascending segment by the amount of ascent of the circular movement arm. The circular movement arm 81 thereby ascends by an angle corresponding to a length determined by subtracting a remaining length of the needle thread, which is a length of the needle thread projecting out of the cloth surface at the stitch “n,” from the stitch reference length for the stitch “n.”
In the needle thread withdrawal segment of the circular movement arm 81, the angle of the needle thread motor is determined for each main shaft angle according to the start position and the end position of the needle thread withdrawal segment such that the circular movement arm 81 performs circular movement from the end position of the ascending segment of the circular movement arm 81 to the upper limit position (the position of the first end) of the circular movement arm 81.
On the occasion of generation of the angle correspondence data, a range from a main shaft angle ax corresponding to a start position of each target segment (e.g., the descending segment, the ascending segment, and the needle thread withdrawal segment) to a main shaft angle ay corresponding to the position of the end point of the target segment is equally divided by a predetermined interval (unit angle) [in other words, equally divided by 1/N (N is an integer) (equally divided by 1/integer)]. As illustrated in
On the occasion of generation of the angle correspondence data, when an interval exists between an end position of a certain segment and a start position of a subsequent segment in connection with adjacent segments among the descending segment, the ascending segment, and the needle thread withdrawal segment (in other words, when the end position of the certain segment does not coincide with the start position of the next segment), the angle of the needle thread motor achieved at the end position of the certain segment is maintained up to the start position of the next segment. For instance, in an example shown in
In accordance with the position data shown in
In accordance with the position data shown in
Moreover, in accordance with the position data shown in
In accordance with the position data shown in
Specifically, as shown in
More specifically, in addition to generating the angle correspondence data used for controlling the needle thread motor 86 in accordance with the embroidery data read from the memory device 92, the control circuit 90 performs control, such as that represented by the timing chart shown in
An encoder 21 for detecting an angle of the main shaft motor 20 (the rotational position of the main shaft motor 20) is interposed between the main shaft motor 20 and the control circuit 90. An encoder 87 (see
As shown in
As shown in
The stitch length used herein refers to a length “b”, on an upper surface of the cloth, from one position m1 where the needle thread is inserted into the cloth (a position where the needle thread and the upper surface of the cloth cross) to another position m2 where the needle thread is to be inserted into the cloth (see
The stitching direction is data pertaining to an angle value corresponding to a predetermined direction (e.g., one direction in the horizontal direction). For instance, in an example shown in
The remaining length of the needle thread is a length L2 that extends along the needle thread from the one insertion position m1 to the other insertion position m2 (see
The position data 92b include, as information about angles of the main shaft (namely, information about the rotational position of the main shaft motor 20), drive start positions and drive end positions of the thread hooking rod drive motor 240, the magnet section 50, the magnet section 70, and the frame actuator 24. Further, as to the circular movement arm 81, the position data 92b include, as information about angles of the main shaft (i.e., information about the rotational positions of the main shaft motor 20), the start position and the end position of the circular movement arm descending segment (the first segment), the start position and the end position of the circular movement arm ascending segment (the second segment), and the start position and the end position of the needle thread withdrawal segment (a third segment).
The drive start position and the drive end position of the thread hooking rod drive motor 240 are set within an area from a point of the bottom dead center of the shuttle (can also be called the “point of the bottom dead center of the thread take-up lever) (about 290 degrees in
The drive start position of the magnet section 50 is set to an arbitrary position [a position (about 190 degrees) immediately subsequent to the end position of the thread withdrawal segment in
Further, the drive start position of the magnet section 70 is set to an arbitrary position (a position of about 90 degrees in
A drive start position and a drive end position of the frame actuator 24 are set in a segment where the sewing needle stays uninserted into the cloth. Specifically, the drive segment of the frame actuator 24 is set in a segment where the sewing needle is not inserted into the cloth. In
The start position and the end position of the circular movement arm achieved in the descending segment are set to arbitrary positions in an area from the top dead center of the shuttle (or the bottom dead center of the needle bar) to the bottom dead center of the thread take-up lever (or a position immediately after the bottom dead center of the thread take-up lever) [in other words, the descending segment is at least a portion of the segment from the top dead center of the shuttle (or the bottom dead center of the needle bar) to the bottom dead center of the thread take-up lever (or a position immediately after the bottom dead center of the thread take-up lever)]. Specifically, the circular movement arm is lowered in accordance with withdrawal of the needle thread performed by the shuttle 12d (more specifically, the point 12d-1 of the shuttle 12d), so that the area between the top dead center of the shuttle and the bottom dead center of the shuttle is taken as the descending segment. In
The start position and the end position of the circular movement arm achieved in the ascending segment are set to arbitrary positions in an area from the bottom dead center of the thread take-up lever to the top dead center of the thread take-up lever (or a position immediately after the top dead center of the thread take-up lever) (in other words, the ascending segment is at least a portion of the area from the bottom dead center of the thread take-up lever to the top dead center of the thread take-up lever). Specifically, a remaining length of the needle thread is determined by elevating the circular movement arm in synchronism with pulling-up of the needle thread performed by the thread take-up lever. Accordingly, the ascending segment is an arbitrary area from the bottom dead center of the thread take-up lever to the top dead center of the thread take-up lever (or a position immediately after the top dead center of the thread take-up lever). In
The start position and the end position in the needle thread take-up segment of the circular movement arm are set to any positions in an overlap between a segment from the end position of the ascending segment of the circular movement arm to the position where the shuttle hooks (or captures) the needle thread and another segment from the drive end position of the magnet section 50 to the drive start position of the magnet section 50 (in other words, the needle thread withdrawal segment is at least an area from the end position of the ascending segment to the position where the shuttle hooks the needle thread). Specifically, in order to withdraw the needle thread from an upstream position with respect to the magnet section 50, the end position must be set to, at least, a position in front of the position where the shuttle hooks the needle thread. Further, since the upstream grip section 40 must be in an open state, the start position is set to a position subsequent to the position where the magnet section 50 is released from an activated state, and the end position is set to a position in front of the drive start position of the magnet section 50. In
A start point of one stitch in the embroidery data 92a shown in
The case 110 makes up a housing of the sewing machine 5 (specifically, the head 7) and is secured to the frame 120.
The case 110 has the front section 110-1, an upper section 110-2, the bottom section 110-3, side sections 110-4, 110-5, a rear section 110-6, the supports 112a and 112b continued from the front section 110-1 and the side sections 110-4 and 110-5, and the support 112c continued from the side sections 110-4 and 110-5.
The needle thread guide 104 is attached to an upper end region (a region above the guide member 52) on the front surface of the front section 110-1, and guides the needle thread in an insertable manner. The needle thread guide 106 is attached to the lower end region on the front surface of the front section 110-1, and guides the needle thread in an insertable manner.
The main shaft motor 20, the encoder 21, and the main shaft 22 can also be provided outside the case 110 making up the head 7.
When the path of the needle thread is explained, the needle thread J led from a wound yarn (not shown) contacts the guide member 52 from the needle thread guide 104, passing through a spacing between the first plate-shaped section 42 and the second plate-shaped section 44 of the upstream grip section 40. Subsequently, the needle thread J contacts the guide member 54, subsequently undergoes inversion in the guide member 100, and reaches the needle thread support members 88. The needle thread J passed through the pair of needle thread support members 88 contacts the guide member 72, passes through a spacing between the first plate-shaped section unit 62 and the second plate-shaped section unit 64 of the downstream grip section 60. Then, the needle thread contacts the guide member 74, and reaches the thread take-up lever 12a via the tension spring 102, and further reaches the sewing needle 12ba of the needle bar 12b from the thread take-up lever 12a via the needle thread guide 106. Further, the needle thread reaches an interior of the opening 216bk and an interior of the opening 216dk of the leading-end structure section 216 of the presser foot 12c. The needle thread travels from the upstream to the downstream in sequence mentioned above.
Operation of the sewing machine 5 is now described. First, the control circuit 90 generates main shaft data (see
When the control circuit 90 generates the main shaft data, an entirety of embroidery data made up of a plurality of stitches can also be generated in advance. Alternatively, actual embroidering can also be performed while the main shaft data are being generated, by means of generating main shaft data pertaining to a stitch located several stitches ahead of a stitch which will be actually embroidered by the respective machine elements (the needle bar, the thread take-up lever, the shuttle, and the like).
In accordance with the embroidery, the control circuit 90 calculates, from the embroidery data, the amount of descendent of the circular movement arm in the descending segment of the circular movement arm and the amount of ascent of the circular movement arm in the ascending segment of the circular movement arm, thereby generating the data for circular movement arm (see
In accordance with the position data read from the storage device 92 and the generated data for circular movement arm, the control circuit 90 generates angle correspondence data (see
Actual embroidery operation is now described. As shown in
In accordance with the detected main shaft angle (S1), it is determined whether or not the thread hooking rod drive motor 240, the magnet section 50, the magnet section 70, the frame actuator 24, and the needle thread motor 86 are in the drive segment (S2). When they are in the drive segment, driving is performed (S3). When they are not in the drive segment, driving is stopped (S4). As to the thread hooking rod drive motor 240, the drive segment corresponds to a segment from the drive start position to a point immediately before the drive end position (the drive end position belongs to the stop segment rather than the drive segment). As to the magnet section 50, the drive segment corresponds to a segment from the drive start position to a point immediately before the drive end position (the drive end position belongs to the stop segment rather than the drive segment). As to the magnet section 70, the drive segment corresponds to a segment from the drive start position to a point immediately before the drive end position (the drive end position belongs to the stop segment rather than the drive segment). As to the circular movement arm 81, the drive segment corresponds to a segment from the start position of the descending segment to a point immediately before the end position of the descending segment (the end position belongs to the stop segment rather than the drive segment); a segment from the start position of the ascending segment to a point immediately before the end position of the ascending segment (the end position belongs to the stop segment rather than the drive segment); and a segment from the start position of the needle thread withdrawal segment to a point immediately before the end position of the needle thread withdrawal segment (the end position belongs to the stop segment rather than the drive segment).
The thread hooking rod drive motor 240 starts driving at the drive start position (about 290 degrees in
Operation for one stitch is explained by reference to
In the segment where the shuttle 12d withdraws the needle thread [from the top dead center of the shuttle (about 190 degrees) to the bottom dead center of the shuttle (about 290 degrees)], the thread hooking rod 236 stays standstill at the position in
In the descending segment of the circular movement arm 81, the magnet section 50 is activated, and the upstream grip section 40 stays closed. Hence, even if the shuttle 12d withdraws the needle thread, the needle thread will not be withdrawn from an upstream position with respect to the upstream grip section 40.
Subsequently, the thread hooking rod 236 starts rotating at a position of about 290 degrees, whereby the thread hooking rod 236 departs from the fixed stitch (the stitch “n” in
Thereupon, the thread take-up lever 12a also ascends in the ascending segment of the circular movement arm 81. When the thread take-up lever 12a ascends, the remaining length of the needle thread for one preceding stitch (the stitch “n” in
Subsequently, the thread hooking rod 236 contacts the needle thread at a position of about 70 degrees, and the thread hooking rod 236 presses the needle thread (i.e., the second needle thread portion Jb) against the plate-shaped section 216f at the position of about 90 degrees, thereby fixing the needle thread while the needle thread is pinched between the thread hooking rod 236 and the plate-shaped section 216f-2.
Thereafter, the presser foot 12c reaches the bottom dead center at a position of about 100 degrees, contacting the cloth U. The sewing needle of the needle bar 12b is then inserted into the cloth U at a position of about 110 degrees. The stitch (the stitch n+1 in
Subsequently, the circular movement arm 81 ascends from the start position of the needle thread withdrawal segment to the end position of the same, thereby withdrawing the needle thread from an upstream position with respect to the upstream grip section 40. Specifically, the needle thread is withdrawn from the wound yarn (not shown) provided at an upstream position with respect to the needle thread guide 104. On this occasion, the upstream grip section 40 is open, and the downstream grip section 60 is closed. As a result of ascending of the circular movement arm 81, the needle thread is withdrawn from an upstream position with respect to the upstream grip section 40.
Even when the amount of ascent of the circular movement arm 81 (an angle of ascending circular movement) in the ascending segment is small; and even when the length of the upstream needle thread (in other words, the length between the position m3 and the first plate-shaped section unit 42) at an upstream position with respect to a proximal insertion position where the needle thread is inserted into the cloth (a proximal position where the needle thread contacts the cloth) (the position m3 in FIG. 20(c)) is short, on account of the needle thread being withdrawn from the upstream position with respect to the upstream grip section 40 in the needle thread withdrawal segment, the amount of ascent of the circular movement arm 81 in the needle thread withdrawal segment becomes greater correspondingly. Hence, the needle thread can be fully withdrawn from the upstream position with respect to the upstream grip section 40, and therefore the needle thread for subsequent stitches will not become deficient.
For instance, in
When the amount of ascent of the circular movement arm 81 is large in the ascending segment of the circular movement arm 81, the amount of ascent of the circular movement arm 81 in the needle thread withdrawal segment is correspondingly small. However, in the ascending segment, the needle thread is withdrawn from the upstream position with respect to the proximal insertion position where the needle thread is to be inserted into the cloth. Hence, as a result of the circular movement arm 81 being circularly moved up to the upper limit position in the needle thread withdrawal segment, there can resultantly be assured a length which will be obtained when the circular movement arm 81 performs circular movement over the range of circular movement. Hence, the needle thread for subsequent stitches will not become deficient.
For instance, in
After the end position (about 180 degrees) of the needle thread withdrawal segment of the circular movement arm 81 is achieved, the start position (about 190 degrees) of the descending segment of the circular movement arm 81 is then achieved. Subsequently, the above operations are repeated on a per-stitch basis.
In
Control of the needle thread motor 86 is performed as follows. Specifically, data pertaining to angles of the needle thread motor are read from the angle correspondence data (S11 in
Next, an amount of change per unit time is detected on the basis of the thus-read angle of the needle thread motor, thereby calculating speed data (S12 in
Subsequently, the amount of change in speed data per unit time is detected, thereby calculating torque data (S13 in
Torque compensation data are calculated from the torque data calculated in step S13 (S14 shown in
Data (a count value of the encoder) output from the encoder 87 (the encoder corresponding to the needle thread motor 86) are subtracted from the angle data read in step S11 (S15 shown in
The value calculated in step S15 is now multiplied by a predetermined constant, thereby calculating a speed value (S16 in
A current motor speed value is calculated by differentiating the output from the encoder 87 (S17 in
Next, the current motor speed value calculated in step S17 is subtracted from the speed value calculated in step S17, and the speed data calculated in step S12 are added to a subtraction result (S18 in
The value calculated in step S18 is multiplied by a predetermined constant, thereby calculating a torque value (S19 shown in
The torque compensation data calculated in step S14 are added to the torque value calculated in step S19 (S20 in
The value calculated in step S21 is multiplied by a predetermined constant, thereby calculating a voltage value to be output to the PWM circuit 90b (a voltage command to the PWM circuit) (S22 in
The PWM circuit 90b outputs a pulse signal as a voltage signal in accordance with an input signal, thereby supplying an electric current to the needle thread motor 86 (S24 shown in
As above, processing provided in the flowchart shown in
A method for controlling the main shaft motor 20 is implemented in the same way as position control of the needle thread motor 86.
First, angle data (which can also be position data) are read from the main shaft data (S11 in
Speed data are calculated by detecting an amount of change in the detected main shaft angle per unit time (S12 in
The torque data are calculated by detecting the amount of change in speed data per unit time (S13 in
Control of the main shaft motor 20 is performed by performing processing represented by flowcharts in
As above, the sewing machine 5 of the present embodiment creates hollow embroidery by fixing the needle thread with the thread hooking rod 236 and the needle thread receiving section 216f. Neither a plate-shaped member used for superposing the needle thread on the cloth to be embroidered nor dissolution of the plate-shaped member is necessary. Further, the length of the needle thread (i.e., a remaining length of the needle thread) can be adjusted on a per-stitch basis by an angle of circular movement of the circular movement arm 86 in the second segment, so that elaborate hollow embroidery can be obtained. Further, excessive stretch of cloth, which would otherwise be caused by making stitches, can be prevented by making the length of the needle thread (i.e., the remaining length of the needle thread) longer. Hence, an embroidered cloth does not become wavy (or uneven). In addition, stitches can be made soft. Specifically, when the stitches are formed firm by shortening the length of the needle thread, the embroidered cloth may become wavy (or uneven). In particular, when the cloth has a small thickness, there is a high probability of occurrence of being wavy. In the case of the present embodiment, the embroidered cloth can be prevented from becoming wavy.
The above description states that, in the presser foot 12c, the main body structure section 214 of the base 212 has a through hole 214a for insertion of the shaft 215; and that the elongated opening 232k is provided in the sideway plate 232 of the swayingly reciprocating mechanism section 230. As shown in
In the presser foot 12c, the leading-end structure section 216 is arranged so as to face the front side of the presser foot 12c. However, the leading-end structure section 216 can also be arranged so as to face another orientation other than the front side of the presser foot 12c. For instance, the leading-end structure section 216 can also be arranged on the left side surface (a side X1) such that the base end 218 faces the right side surface (a side X2). Alternatively, the leading-end structure section 216 can also be arranged on the right side surface (the side X2) such that the base end 218 faces the left side surface (the side X1).
In the above explanations, the thread hooking rod drive motor 240 for driving the thread hooking rod 236 is provided on the presser foot 12c but can also be provided on the case 110. Specifically, as shown in
As above, the thread hooking rod drive motor 240 is configured separately from the presser foot 12c, whereby the weight of the presser foot 12c can be reduced. Thus, up-down movements of the presser foot 12c can be facilitated.
In the descriptions, the needle thread fixing section made up of the swayingly reciprocating mechanism section 230 (particularly, the thread hooking rod 236) and the needle thread receiving section 216f is provided on the presser foot 12c. However, the structure for fixing the needle thread can also be provided as a structure differing from the presser foot.
Specifically, the needle thread fixing unit 12f shown in
Namely, as shown in
The main body 210 has the base 212 and the shaft 220 fixed to the base 212.
The base 212 has the main body structure section 214 and the base end 218 continued from the rear-side end of the main body structure section 214. The main body structure section 214 has a sideway plate 214a assuming the shape of a substantially-L-shaped plate, and the quadrate vertical plate 214b downwardly continued from the end on the right side of the leading end of the sideway plate 214a, and a needle thread receiving section 214c attached to an interior surface of the vertical plate 214b. The structure of the base 212 other than the needle thread receiving section 214c; namely, the sideway plate 214a, the vertical plate 214b, and the base end 218, makes up the needle thread fixing section main body 212-1 that supports the needle thread receiving section 214c.
The needle thread receiving section 214c has the same structure as that of the needle thread receiving section 216f. The needle thread receiving section 214c has an elastic section 214c-1 provided on an interior surface of the vertical plate 214b and a plate-shaped section (a needle thread receiving section main body) 214c-2 fixed to an end of the elastic section 214c-1 opposite to the vertical plate 214b. The elastic section 214c-1 is a coil spring, and one end of the elastic section 214c-1 is fixed to the vertical plate 214b. The other end of the elastic section 214c-1 is fixed to a plate-shaped section 214c-2. The needle thread receiving section 214c pinches the needle thread along with the thread hooking rod 236. When the needle thread pushed by the thread hooking rod 236 toward the needle thread receiving section 214c contacts the plate-shaped section 214c-2, the needle thread becomes pinched between the thread hooking rod 236 and the plate-shaped section 214c-2.
The base end 218 is analogous in configuration to the base end 218 of the presser foot 12c, and hence its explanations are omitted.
The swayingly reciprocating mechanism section 230 in the needle thread fixing unit 12f is analogous in configuration to the swayingly reciprocating mechanism section 230 in the presser foot 12c. Further, the thread hooking rod motor 240 in the needle thread fixing unit 12f is analogous in configuration to the thread hooking rod 240 in the presser foot 12c, and hence their explanations are omitted. In this regard, in the swayingly reciprocating mechanism section 230, the thread hooking rod support 231 is made up of the sideway plate 232 and the vertical plate 234. The swayingly reciprocating mechanism section 230 (particularly, the thread hooking rod support 231 and the thread hooking rod 236) and the needle thread receiving section 214c make up “a needle thread fixing section that fixes a second needle thread portion of the needle thread situated between a cloth and the thread take-up lever at a position apart from a cloth surface and at a position deviating toward the cloth surface from a position where the sewing needle is to be inserted.” Since the needle thread fixing unit 12f does not need to move up and down in contrast with the presser foot 12c and hence is fixedly provided. Specifically, the shaft 220 of the needle thread fixing unit 12f is fixed to the case 110.
In relation to a configuration in
In the above description, the elastic sections 216f-1 and 214c-1 are mentioned as the coil springs. However, they can also be other elastic bodies, like leaf springs. In addition, in order to enhance the force for pinching the needle thread between the plate-shaped section 216f-2 (214c-2) and the thread hooking rod 236, a magnet (specifically, permanent magnet) can also be attached to the plate-shaped section 216f-2 (214c-2), or the plate-shaped section 216f-2 (214c-2) can also be made up of a magnet (specifically, a permanent magnet). Namely, the thread hooking rod 236 is made up of a magnetic substance [in other words, a material (e.g., metal) attracted by a magnet, such as iron], whereby the needle thread can be intensely gripped and fixed between the plate-shaped section 216f-2 (214c-2) and the thread hooking rod.
The above description states that the needle thread is fixed by the thread hooking rod 236 and the needle thread receiving section 216f by swiveling the thread hooking rod 236 through use of the crank mechanism. However, the needle thread can also be fixed by reciprocally moving the thread hooking rod in both the right-left direction and the front-back direction, through use of a device for causing reciprocal actuation in the front-back direction (a front-back-direction drive device) and another device for causing reciprocal actuation in the right-left direction (a right-left-direction drive device). For instance, the front-back-direction drive device is equipped with the right-left-direction drive device, and the thread hooking rod 236 is attached to the right-left-direction drive device. While the thread hooking rod is situated at the left side and the front side with respect to the needle thread (this state is taken as an “initial state”), the thread hooking rod is moved toward the right side by the right-left-direction drive device, thereby fixing the needle thread with the thread hooking rod 236 and the needle thread receiving section 216f. Subsequently, the front-back-direction drive device moves the right-left-direction device toward the rear side, thereby releasing the needle thread from its fixed state. Subsequently, the right-left-direction drive device moves the thread hooking rod toward the left side. Then, the front-back-direction drive device moves the right-left-direction drive device to the front side, whereby the right-left-direction drive device returns to its initial state. In this regard, an actuator, such as a solenoid, is mentioned as a device for performing reciprocal actuation.
Although the presser foot 12c is mentioned as being moved up and down by the torque of the main shaft 22. However, a presser foot motor that is a motor for moving the presser foot 12c up and down can also be separately provided. Further, presser foot data specifying angles of the main shaft and the rotational position of the presser foot motor are provided, thereby operating the presser foot motor in accordance with the presser foot data and thus moving the presser foot 12c up and down.
In the description, the direction of the circular movement axis of the circular movement arm 81 is mentioned as the right-left direction, and the range on both sides of the first needle thread portion Ja including the first needle thread portion Ja of the needle thread is supported in the right-left direction by the needle thread support member 88. However, the direction of the circular movement axis of the circular movement arm 81 is not limited to that mentioned above. The direction of the circular movement axis of the circular movement arm 81 can also be oriented to the up-down direction. A portion of the needle thread, which lies in the vertical direction, between the upstream grip section main body 41 and the downstream grip section main body 61 can also be taken as a first needle thread portion and circularly moved. In this case, the portion of the needle thread hooked by the circular movement arm 81 in the up-down direction is circularly moved in the sideway direction.
In the drawing, a Y1-Y2 direction is a direction perpendicular to the X1-X2 direction, and a Z1-Z2 direction is a direction perpendicular to the X1-X2 direction and the Y1-Y2 direction.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-186052 | Sep 2013 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/073077 | 9/2/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2015/033934 | 3/12/2015 | WO | A |
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| 11-021758 | Jan 1999 | JP |
| 2003-250611 | Sep 2003 | JP |
| WO-9859101 | Dec 1998 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20160153129 A1 | Jun 2016 | US |
