The present invention relates to sewing machines capable of sewing a string-shaped material, such as a tape or a cord, to a sewing workpiece (base fabric), such as a cloth.
Heretofore, there have been known sewing machines capable of sewing a string-shaped material, such as a tape or a cord, to a sewing workpiece by feeding the string-shaped material to a needle entry position while zigzag-swinging the string-shaped material. Patent Literatures 1 and 2 set forth below each disclose an embroidery sewing machine provided with an embroidery head capable of performing so-called zigzag stitching. In the embroidery sewing machine disclosed in Patent Literature 1, a machine head includes: a needle bar that has a sewing needle provided on a lower end portion thereof and that is driven in an up-down direction; a fabric pressing member or presser foot that is driven in the up-down direction at predetermined timing in response to the up-and-down movement of the needle bar; a rotation member mounted concentrically with the needle bar and rotatable about the axis of the rotation member; and a guide member swingably mounted to the rotation member via a lever pin, and a string-shaped material supplied from a bobbin is passed through the guide member, which swings in a left-right direction (namely, in a lateral direction), to be fed to the needle entry position of the sewing needle. Further, in the embroidery sewing machine disclosed in Patent Literature 2, a machine head is constructed in such a manner that a guide member is slid horizontally in a left-right direction along a guide rail via a swing member that is swingably mounted via a lever pin, and a string-shaped material supplied from a bobbin is passed through a guide member, which is moved horizontally, to be fed to a needle entry position of a sewing needle.
In the embroidery sewing machines provided with such machine heads, sewing-progressing directions relative to the sewing workpiece are calculated on the basis of predetermined sewing data and the string-shaped material is fed to the needle entry position of the sewing needle while being zigzag-swung in a predetermined pattern, by the guide member being swung in the left-right direction or horizontally moved while direction control is being performed on the rotation member in such a manner that the lever pin is always located ahead in the sewing-progressing directions. In this manner, the string-shaped material is sewn to the sewing workpiece through lock stitching with the needle bar and the presser foot driven in the up-down direction.
Further, in recent years, such sewing machines have been used for preform molding of a fiber-reinforced composite material, as well as for sewing a decorative string-shaped material to a sewing workpiece. Patent Literature 3 set forth below discloses an example of such preform molding. More particularly, Patent Literature 3 discloses a method for sewing a string-shaped material, formed of reinforcing fibers such as carbon fibers and glass fibers, to a sewing workpiece (base fabric) by use of an embroidery sewing machine constructed similarly to the aforementioned sewing machines provided with machine heads capable of performing zigzag stitching. The carbon fibers and glass fibers mainly used as the reinforcing fibers are forms of products called “tows”, “rovings”, and the like each formed generally as a bundle of one thousand to several tens of thousands thin single fibers that each have a diameter of a few microns and that are gathered together in a uniform direction. In the sewing machine disclosed in Patent Literature 3, the tow (or roving) is wound on a small-sized bobbin pivoting around the needle bar or on a bobbin provided above the machine head, and such a tow (or roving) is passed through the guide member and then fed to the needle entry position of the sewing needle.
The conventionally known presser foot of the sewing machine functions to assist in achieving stabilized sewing by pressing an area of the sewing workpiece around a needle drop position during the sewing. Because a bottom portion of the conventionally known presser foot only has to have a size sufficient for performing the sewing-workpiece pressing function, the size of the bottom portion is not so large. However, when the string-shaped material is swung in the left-right direction by the guide member for zigzag stitching, the width over which the string-shaped material is swung leftward and rightward may exceed the size of the bottom portion of the presser foot. In such a case, the string-shaped material, swung in the left-right direction, positionally deviates from a string-shaped material covering area of the bottom portion of the presser foot in the left-right direction as viewed in plan view, and thus, the swung string-shaped material may interfere with (or catch on) the presser foot moving in the up-down direction. Normally, in a case where a stroke of the up-and-down movement of the presser foot is of an ordinary length (namely, relatively long), the guide member is swung leftward and rightward (in the lateral direction) at timing when the presser foot has been moved upward over a relatively long distance, and thus, the string-shaped material, such as a tow (long fiber bundle), leading from the guide member to the sewing workpiece (base fabric) will not interfere with (catch on) the presser foot. If the up-and-down movement stroke of the presser foot is made shorter, however, there can arise a problem of the string-shaped material interfering with (catching on) the presser foot. Namely, as the up-and-down movement stroke length of the presser foot is made shorter, the string-shaped material leading from the guide member to the base fabric may more easily positionally deviate from the bottom portion of the presser foot to go up off the bottom portion of the presser foot, and thus more easily catches on a side surface of the presser foot or an edge or the like of the bottom portion of the presser foot, when the string-shaped material is swung in the left-right direction.
Particularly, in order to prevent poor or defective thread tightening caused by flapping of the base fabric (namely, uplifting of the base fabric caused by an upper thread at the time of thread tightening) and improve thread tightening quality without increasing tension of the upper thread, it is desirable to reduce the up-and-down movement stroke of the presser foot as short as possible. However, if the up-and-down movement stroke of the presser foot is reduced, there can arise the problem of the string-shaped material interfering with (catching on) the presser foot, as noted above. Particularly, with a sewing machine employing the construction disclosed in Patent Literature 1, when tows (long fiber bundles) are sewn to a base fabric in a plurality of layers, it is necessary to adjust in advance the guide member to a relatively high position in anticipation of a layered height of the tows with a view to avoiding the guide member from interfering with the layered tows. However, in such a case, a tilt angle of the tows (long fiber bundles) leading from the guide member to the base fabric becomes large (namely, the tows take a more upright posture), and thus, the problem of the tows catching on the presser foot becomes more serious.
In view of the foregoing prior art problems, it is one of the objects of the present invention to provide a sewing machine that prevents a string-shaped material, swung in a lateral direction via a guide member, from catching on a nearby component part (particularly, a presser foot) of the sewing machine.
In order to accomplish the aforementioned object, the present invention provides a sewing machine capable of sewing a string-shaped material to a sewing workpiece, which includes: a guide member for guiding the string-shaped material toward a sewing position; a reciprocation mechanism for reciprocatingly moving the guide member in a lateral direction; and a restriction member disposed close to the guide member and having a laterally elongated section, the laterally elongated section having a length corresponding to a range of reciprocating movement of the guide member.
According to the present invention, the laterally elongated section of the restriction member has a length corresponding to the range of reciprocating movement of the guide member. Therefore, when the guide member is reciprocatingly moved, a portion of the string-shaped material extending from the distal end of the guide member downward to the sewing position located below the distal end of the guide member can be reliably positioned (restricted) beneath the laterally elongated section (in such a manner that unwanted upward movement of the string-shaped material can be restricted or suppressed by the laterally elongated section). Thus, when the string-shaped material is swung in the lateral (left-right) direction, the string-shaped material can be prevented from catching on a nearby component part or portion (particularly, a presser foot, or a side surface or the like of the restriction member in a case where the restriction member itself functions also as the presser foot). Namely, even where an up-and-down movement stroke of the presser foot (or an up-and-down movement stroke of the restriction member in the case where the restriction member itself functions also as the presser foot) is small, the string-shaped material can be reliably restricted to be located beneath the laterally elongated section of the restriction member without positionally deviating from a string-shaped material covering area of the laterally elongated section, and hence, the string-shaped material can be reliably prevented from catching on the presser foot (or the restriction member).
A support 9 is fixed to the lower end of the support cylinder 4. The support 9 has a lower end section formed in a bifurcated shape, and a key groove 10 extending in the upright direction is formed in an outer side surface of one of leg portions of the bifurcated lower end section of the support 9. A rotation cylinder 11 is mounted on the outer circumference of the fixed sleeve 5. The rotation cylinder 11 is mounted around and concentrically with the needle bar 2 and only rotatable about the axis of the needle bar 2. A timing pulley section 12 is formed on the outer circumference of an upper end portion of the rotation cylinder 11, and a timing belt 16 is wound on and extends between the timing pulley section 12 and a drive pulley 15 fixed to a rotation shaft 14 of a motor 13. Thus, as the motor 13 is driven to rotate the drive pulley 15, the rotation cylinder 11 is rotated via the timing belt 16 and the timing pulley section 12. A key member 17 engaging with the key groove 10 of the support 9 is fixed to the lower end of the rotation cylinder 11. With such arrangements, the support 9 not only moves up and down as the support cylinder 4 moves up and down but also rotates about the axis of the needle bar 2 as the rotation cylinder 11 rotates.
A support member 25 having a generally U shape (or a generally U angle-like shape) as viewed in plan is fixed to the support 9. The support 9 is coupled with one arm of the support member 25, and a guide rail 26 is fixed to the other arm (located opposite from the one arm) of the support member 25. Further, a restriction member 38 is mounted to a mounting portion of the support member 25 between the two arms, as described in detail later. A slider 27 is provided on the guide rail 26 in such a manner that the slider 27 is slidingly movable in the lateral direction. A guide member 29 is fixed to the slider 27 via a bracket 28 formed in a U shape. The guide member 29 is, for example, in the form of a plate spring and flexible in the up-down direction with a fixed portion of the guide member 29, which is fixed to the bracket 28, functioning as a flexibly bending base. The bracket 28 has a fitting groove 30 formed in its surface opposed to the swing lever 21, and the roller 24 of the swing lever 21 is fitted in the fitting groove 30. A guide tube 29a for passing therethrough the string-shaped material T to feed the string-shaped material T to a needle entry position (namely, a sewing position) of the sewing needle 3 is provided at the lower end of the guide member 29. Further, a bobbin bracket 32 is fixed to an outer circumferential portion of the rotation cylinder 11 via the bracket 20 and an arm member 31, and a bobbin 33 having the string-shaped material T wound thereon is rotatably supported on the bobbin bracket 32. The string-shaped material T pulled out from the bobbin 33 is passed through the guide tube 29a to extend downward from the distal end of the guide tube 29a and is then placed on the base fabric (namely, the sewing workpiece) (not illustrated in the drawings) laid on a needle plate 37.
As conventionally known, in embroidering sewing machines, an embroidery frame (not illustrated in the drawings) holding thereon a base fabric (sewing workpiece) is driven two-dimensionally per stitch in accordance with a desired sewing pattern. Thus, the base fabric (sewing workpiece) is moved relative to the machine head H. In order to sew the string-shaped material T to the base fabric (sewing workpiece) in accordance with the sewing pattern, the driving of the motor 13 is controlled in accordance with a sewing-progressing direction, the rotation cylinder 11 is rotated in response to the driving of the motor 13, and the lever pin 22 is controlled to rotate around the needle bar 2 in such a manner as to be oriented in the sewing-progressing direction. Thus, the guide member 29 is controlled to rotate around the needle bar 2 in such a manner that the distal end of the guide member 29, namely, the distal end of the guide tube 29a, is always oriented toward the center of the needle bar 2. In this manner, the string-shaped material T extending out from the distal end of the guide member 29, namely, from the distal end of the guide tube 29a, is directed or guided toward the sewing position (needle entry position). In this manner, the guide member 29 performs a function of guiding the string-shaped material T toward the sewing position, and the aforementioned elements 13, 11, 22, etc. related to the string-shaped material guiding function as a device and/or a mechanism that controls a basic string-shaped material guiding direction of the guide member 29.
A type, shape, etc. of the string-shaped material T are determined appropriately in accordance with a purpose of a sewn product that is to be finished by use of the inventive sewing machine. For example, in a case where a decorative string-shaped material T is to be sewn to a sewing workpiece (not illustrated in the drawings), a tape, a string, or a cord having a color, a size, and an outer shape (flat or somewhat round outer shape) suited for a desired decoration purpose is used as the string-shaped material T. Further, in a case where a tow (long fiber bundle) that functions as reinforcing fibers for preform molding of a fiber-reinforced composite material is to be sewn to a sewing workpiece (not illustrated), the tow that functions as reinforcing fibers is used as the string-shaped material T. In such a case, the string-shaped material T is formed of carbon fibers, glass fibers, aramid fibers, boron fibers, xyron fibers, and/or the like, as the reinforcing fibers for making the preform (interim product made by pre-processing the reinforcing fibers into a shape close to a shape of a molded product), and the string-shaped material T in this case is a long belt-shaped fiber bundle called “tow”, “roving” or “filament”. Alternatively, the string-shaped material T may be a composite material formed by half-impregnating a reinforcing fiber bundle with a resin, a composite material formed by combining carbon fibers and resin fibers (commingled yarn), or a fiber bundle formed by roving chemical fibers and/or the like into a belt shape. Note that the guide tube 29a in the illustrated example has an elongated rectangular cross-sectional shape and is suited for a wide, flat string-shaped material T (such as a flat tow material).
As illustrated in
As well known, the zigzag swinging motor 36 is driven to sew the string-shaped material T to the basic fabric (sewing workpiece) through zigzag swing stitching (zigzag stitching). Namely, although the sewing-progressing direction, in which the string-shaped material T is to be sewn to the basic fabric, is controlled via the aforementioned motor 13, the sewing of the string-shaped material T through the zigzag swing stitching (zigzag stitching) is controlled via the zigzag swinging motor 36. The aforementioned elements 36, 34, 35, 35a, 19, 18, 23, 21, 28, 27, 26, etc. together function to zigzag-swing the string-shaped material T; in other words, these elements together function as a reciprocation mechanism for reciprocatingly moving the guide member 29 in the lateral direction.
As illustrated in
A height of the restriction section 38c relative to the support member 25 (namely, relative to the guide member 29) can be adjusted by adjusting, via the screw, a fixed position of the fixing section 38a relative to the support member 25 along the elongated hole 39. In this way, it is possible to adjust a height relationship between the restriction section (laterally elongated section) 38c and the distal end of the guide member 29 (namely, the distal end of the guide tube 29a). In this embodiment, the restriction section (laterally elongated section) 38c provided at the lower end of the restriction member 38 functions also as a fabric pressing member or a presser foot during a sewing operation. Namely, the driving of the aforementioned motor 7 (
The restriction section (laterally elongated section) 38c has a length corresponding to a range of the reciprocating movement of the guide member 29. A specific example of such a corresponding relationship is illustrated in (a) and (b) of
Thus, when the guide member 29 is reciprocatingly moved as noted above, the portion of the string-shaped material T extending downward from the distal end of the guide member 29 to the sewing position can be reliably located beneath the restriction section (laterally elongated section) 38c of the restriction member 38 to contact (or to be at least covered with) the covering area of the lower surface of the restriction section (laterally elongated section) 38c (and thus, unwanted upward movement of the string-shaped material T can be restricted or suppressed). In this way, when the string-shaped material T is swung laterally (in the left-right direction), it is possible to reliably prevent the string-shaped material T from catching on a nearby component part or portion (particularly, the presser foot, or an edge portion or the like of the restriction member 38 in the case where the restriction member 38 is caused to function as the presser foot). Namely, even where the up-and-down movement stroke of the presser foot (or the up-and-down movement stroke of the restriction member 38 if the restriction member 38 is constructed to function also as the presser foot as in the present embodiment) is small, the string-shaped material T can be reliably positioned to be located beneath the restriction member 3 without largely positionally deviating from the string-shaped material covering area of the restriction section (laterally elongated section) 38c, and hence, the string-shaped material T can be reliably prevented from catching on the presser foot (restriction member 38).
Now, a description will be given about an example of a sewing operation for sewing the string-shaped material T to the base fabric (sewing workpiece) through lock stitching by the machine head H constructed in the above-described manner. First, the bobbin 33 having the string-shaped material T wound thereon is set on the bobbin bracket 32, and the string-shaped material T is paid out from the bobbin 33 and passed through the guide tube 29a to be led to the needle drop position (needle entry position) of the sewing needle 3. In this state, lock stitching is performed in the conventionally known manner, through the functions of the sewing needle 3 and a not-illustrated rotary hook, by moving the embroidery frame (not illustrated), holding the base fabric (sewing workpiece), in X-Y directions on the basis of predetermined embroidery data but also moving up and down the needle bar 2. During that time, the guide member 29 is reciprocatingly swung, by driving of the zigzag swinging motor 36, leftward and rightward between the leftmost end position illustrated in (a) of
During the sewing operation, in response to the rotation cylinder 11 being rotated by the driving of the motor 13, the lever pin 22 is controlled to be always located ahead in a relative advancing direction of the machine head H based on the movement of the embroidery frame. Further, in response to the driving of the motor 7, the restriction member 38 is moved up and down at predetermined timing relative to the up-and-down movement of the needle bar 2. During this time, the guide member 29 is moved up and down together with the restriction member 38 through the aforementioned arrangements. Note that when the sewing of the string-shaped material T has been completed (or when the sewing of the string-shaped material T is not to be carried out), the guide member 29 can be moved upward to a retracted position together the restriction member 38 by the driving of the motor 7.
Height setting/control of a bottom dead point of the restriction member 38, which is moved up and down by the driving of the motor 7, can be performed by setting a height of the bottom dead point of the restriction member 38, for example, via an operation panel in accordance with a thickness of the sewing workpiece and a type of the string-shaped material T in a manner similar to that of setting a bottom dead point of the presser foot. Further, because the guide member 29 is moved up and down together with the restriction member 38 as noted above, a height position of the guide member 29 is automatically changed in accordance with a change of the height of the bottom dead point of the restriction member 38.
In a case where string-shaped materials T in the form of bundles of long reinforcing fibers, such as carbon fibers and glass fibers, are to be sewn to a sewing workpiece (base fabric) in a plurality of layers, a height of the reinforcing fibers sewn increases each time a layer of the string-shaped material T is superimposed on the sewing workpiece (base fabric). In order to deal with such a height change, a new height of the bottom dead point of the restriction member 38 may be set via the operation panel per layer sewing step. In this manner, per layer sewing step, the height position of the guide member 29 is changed automatically in response to the height setting of the restriction member 38.
In the above-described embodiment of
In
The arm portion 51b of the swing lever 51 is connected to a guide member 50 via a connection member 52. A guide tube 50a for guiding the string-shaped material to the sewing position is mounted to the distal end of the guide member 50. Note that the guide member 50 in the illustrated example of
As the interlocking member 18 and the connection piece 19 is moved up and down in response to the driving of the zigzag swinging motor 36 (
In
With such arrangements, as the guide member 50 is reciprocatingly moved (swung), the portion of the string-shaped material (not illustrated) extending from the distal end of the guide member 50 downward to the sewing position below the guide member 50 can be reliably positioned beneath the restriction section (laterally elongated section) 60c in such a manner as to contact (or at least to be covered by) the lower surface of the restriction section (laterally elongated section) 60c (namely, in such a manner that unwanted upward movement of the string-shaped material can be restricted or suppressed by the lower surface of the restriction section 60c). In this way, when the string-shaped material is swung laterally (in the left-right direction), it is possible to reliably prevent the string-shaped material from catching on a nearby component part or portion (particularly, the presser foot, or a side surface of the restriction member 60 in this embodiment). Namely, even where the up-and-down movement stroke of the presser foot (or up-and-down movement stroke of the restriction member 60 in the case where the restriction member 60 itself functions also as the presser foot as in this embodiment) is small, the string-shaped material can be reliably restricted to be located beneath the restriction section 60c without positionally deviating from the string-shaped material covering area of the restriction section (laterally elongated section) 60c, and thus, the string-shaped material can be reliably prevented from catching on the presser foot (or the restriction member 60).
In the embodiment illustrated in
Any of the above-described embodiments of the invention may be modified as follows. Namely, in the case where the restriction member 38 or 60 is not caused to function as the presser foot, an ordinary or conventional presser foot (not illustrated in the drawings) may be mounted to the lower end of the support 9, and the shape and position of the restriction section (laterally elongated section) 38c or 60c may be appropriately modified in such a manner as to not disturb the up-and-down movement of the needle bar 3 and the conventional presser foot. Note that in the case where the embodiment of
Number | Date | Country | Kind |
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2019-236471 | Dec 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/046654 | 12/15/2020 | WO |