Patent Application
20130160685
This application claims the benefit of Korean Patent Application No. 10-2010-0082243, filed on Aug. 25, 2010, Korean Patent Application No. 10-2011-0010076, filed on Feb. 1, 2011 and Korean Patent Application No. 10-2011-0023358, filed on Mar. 16, 2011 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
The present invention relates to a lower thread supply device of a sewing machine and is new technology that can innovatively enhance a load amount of one time of a lower thread, compared with an existing lower thread supply device while almost equally using an existing sewing machine structure.
In general, as shown in
The BC includes a BC base 30 housed in the hook body 20 and called an inner rotary hook and a BC body 50 for receiving a bobbin at the outside of the bobbin 40.
At the bottom of the BC base 30, a stud 31 is provided, and at the stud 31, the bobbin 40 is rotatably installed.
The BC formed with the BC base 30 and the BC body is integrally formed, and a protrusion 75 of a hook retainer 70 separately installed in a sewing machine body is inserted into a groove 33 to formed in the BC base 30 to prevent the BC from moving. Further, a needle through-hole 34 that is adjacent to the groove 33 and that penetrates a needle when the needle moves downward is formed.
In the bobbin 40, a winding shaft 41 in which the lower thread is wound, and flanges 43 and 45 formed at both ends of the winding shaft 41 are formed.
When the hook body 20 is driven by such a structure, the hook retainer 70 prevents the BC base 30 from rotating along the hook body due to a rotation of the hook body 20 and thus the BC base 30 maintains a fixed state, and an upper thread 3 that is hooked to a hook 21 of the hook body 20 and that revolves over the BC base 30 and the bobbin 40 and that moves upward by hooking a lower thread 4 is guided through the groove 33 (precisely, between a side wall of the groove and the protrusion 75 of the hook retainer within the groove) of the BC base (see
Therefore, the groove 33 functions as a key groove that inserts the protrusion 75 of the hook retainer, and a width 33a thereof is added to a width 75a of the protrusion not to have a trouble when the upper thread 3 escapes and thus the groove 33 is formed in a size for securing an upper thread passage gap.
In such a conventional rotary hook 100, when the lower thread wound in the bobbin 40 is consumed, operation of the sewing machine is stopped and the BC body 50 is opened, and the bobbin 40 should be replaced, and in order to replace one bobbin 40, about 1 minute is generally consumed.
When it is assumed that a length of the lower thread wound in the bobbin 40 is 40 meter, a length of a stitch is 1 millimeter, and the reciprocating rotation motion number of a needle bar is 4000 RPM, if 10 minutes have elapsed, entire lower thread is consumed and thus the sewing machine should be stopped every 10 minutes and the bobbin 40 should be replaced, and in a large-sized sewing machine in which a plurality of (e.g., 50 to 100) needle bars and rotary hooks 100 are disposed in a line in a transverse direction, if a wound lower thread of any one of the bobbins 40 is consumed, operation of the sewing machine should be stopped and the entire bobbins 40 should be replaced.
Therefore, work delay (stop) according to replacement of the bobbin 40 and remaining lower threads in the remaining bobbins 40 are entirely disposed and thus a resource is largely wasted.
If more lower threads can be wound in the bobbin 40, such a problem can be considerably solved, but an amount of wound lower threads is limited by a size of an external form of the bobbin 40. That is, in order to increase a load amount of the lower thread, a diameter or a width of the bobbin 40 should be enlarged.
However, when enlarging a diameter or a width of the bobbin 40, the following problems occur.
When a diameter or a width of the bobbin 40 is enlarged, a size of the BC for housing the bobbin 40 should be also enlarged, and when a size of the BC is enlarged, a supply length of the upper thread 3 that moves upward the lower thread 4 by hooking while revolving the BC should be extended.
However, a supply length of the upper thread 3 depends on a stroke distance of a thread take-up crank, and thus a size or a structure of the thread take-up crank should be also changed.
That is, there is a problem that a sewing machine should be newly designed and produced, and when a supply length of an upper thread increases, before the upper thread forms a stitch together with a lower thread, a length that performs a reciprocating motion by vertically penetrating a cloth increases and thus there is a problem that the upper thread itself is damaged and a stitch is not appropriately formed due to a frictional heat.
In order to solve such a frictional heat, it is necessary to reduce the reciprocating motion number of a needle bar, and when the reciprocating motion number is reduced, work efficiency is deteriorated and thus there is a problem that an increase effect of a load amount of the lower thread is decreased.
Therefore, a new concept of lower thread supply device that can increase only a load amount of the lower thread without greatly changing an existing sewing machine structure while maintaining the reciprocating motion number of the needle bar and a supply length of the upper thread 3 is requested.
Further, in a conventional lower thread supply device, as shown in
The present invention is made to overcome the above mentioned problems, and it is an object of the present invention is as follows.
A first object of the present invention is to provide a means that can innovatively enhance a lower thread to be loaded at one time.
A second object of the present invention is to provide a means that can increase a load amount of a lower thread while maintaining a supply length of an upper thread by a thread take-up as an important process for making a knot before forming a stitch.
A third object of the present invention is to provide a lower thread supply device of a new structure that can almost equally use an existing sewing machine structure.
A fourth object of the present invention is to provide a new concept of lower thread supply device that can minimize a vibration of a hook body by stably supporting a hook body even at a high speed rotation.
A fifth object of the present invention is to provide a means that can sense the remaining amount of a lower thread and notify a worker of this.
A technical configuration of the present invention for achieving the above objects is as follows.
To achieve the above objects, there is provided a lower thread supply device for supplying a lower thread of a sewing machine, the lower thread supply device including: a housing 100 that is fixed to a main body of the sewing machine and that has a cylindrical pipe shape in which a front surface and a rear surface are opened along a central axis and in which an outer circumferential surface of one side is cut out to form a housing cutout portion 110; a rotation plate 200 that is connected to a power shaft of the sewing machine and that has a circular plate shape and that has a power transmission protrusion 210 at a front surface of the circular plate and that is installed at an inner side surface of the rear end of the housing 100 for rotating; a hook body 300 that is rotatably installed at the inside of the housing 100 and that has a front surface of an opened cylindrical shape and that has a protrusion receiving portion 320 that is engaged with the power transmission protrusion 210 to receive torque of the rotation plate 200 at the outside of a rear surface and that has a bobbin mounting post 330 at an inner side of the rear surface and that has a hook 310 for pulling an upper thread by passing through a loop formed by the upper thread moved downward along a needle of the sewing machine at an outer circumferential surface of one side; a bobbin 400 that is inserted into the bobbin mounting post 330 of the hook body 300 to be rotatably installed and that has a spool shape in which the lower thread is wound; and a cap 500 that passes through the center of the bobbin 400 and that is detachably coupled to the bobbin mounting post 330 to prevent the bobbin from separating from the hook body 300.
Effects according to a configuration of the present invention are as follows.
First, the present invention can innovatively enhance an amount of a lower thread to be loaded at one time.
In other words, in the present invention, at the inside of a hook body 300 that forms a stitch with a lower thread while pulling and rotating an upper thread, a bobbin 400 is mounted, and entire internal space of the hook body 300 can be used as lower thread load space, however in a conventional lower thread supply device, at the inside of the hook body 20 rotating while pulling an upper thread, the BC base 30 is mounted, and the bobbin 40 is mounted at the inside of the BC base 30, and when sizes of hook bodies (outer diameter and width) are the same, a size (diameter and width) of the bobbin is reduced. That is, in the present invention, a separate BC base 30 is not required at the inside of the hook body 300, unlike a conventional case and thus internal space of the hook body 300 can be used to the maximum and a size of the bobbin 400 is thus enlarged, and a load amount of one time of the lower thread can be remarkably enhanced.
Second, in a process (thread take-up process) for making a knot before forming a stitch, a structure that can reduce a consumption amount of an upper thread pulled by a hook is suggested and thus an outer diameter and a height of a hook body are enlarged and a load amount of the lower thread can be thus enhanced.
That is, in a conventional lower thread supply device shown in
Third, a most existing sewing machine structure can be used, and when only a lower thread supply device is replaced without newly producing an entire sewing machine, an existing sewing machine can exhibit the same technical effect as that of the present invention.
In other words, a power shaft of an existing sewing machine is used, and it is necessary that a rotation plate 200 and a power shaft of a replaced new lower thread supply device are simple fastened and connected, and thus while a separate additional cost is minimized, a performance of an existing equipment can be innovatively improved.
Fourth, even at a high speed rotation, a hook body is stably supported and a vibration of the hook body can be minimized.
In other words, a structure in which the hook body 300 rotates with housed at the inside of the housing 100 is achieved and thus the housing 100 safely supports the hook body 300 and stably guides a rotation of the hook body 300. Therefore, unlike a conventional case, even at a high speed rotation, a vibration of the hook body 300 can be efficiently prevented.
Fifth, the remaining amount of a lower thread is detected and notified to a worker at an appropriate time point, and thus the worker can estimate a replacement time of the lower thread, and a failure such as erroneous sewing due to shortage (consumption) of the lower thread can be previously prevented.
Hereinafter, a specific embodiment of the present invention will be described in detail with reference to the accompanying drawings.
A housing 100 is fixed to an appropriate position according to a lower portion of a main body of the sewing machine or a characteristic of the sewing machine and has a cylindrical pipe shape in which a front surface and a rear surface are opened along a central axis.
The housing 100 is fixed to a main body of the sewing machine using generally known various brackets, fixing volts, or pins, and a separate description thereof will be omitted. The housing 100 is fixed to the main body of the sewing machine, and even if a power shaft of the sewing machine rotates, the housing 100 does not rotate and maintains a fixed state.
An outer circumferential surface (portion in which a needle of the sewing machine moves downward) of one side of such a housing is cut out to form a housing cutout portion 110, and the housing cutout portion 110 provides space in which an upper thread of an instantaneously formed loop form while moving upward after being moved downward by being hooked to a needle hole is engaged with a hook 310.
That is, the hook 310 attached to a hook body 300 rotating in the housing cutout portion 110 is engaged with the upper thread while passing through the upper thread that instantaneously forms a loop form according to a motion of the needle and rotates while pulling the upper thread.
An upper thread guide 120 is installed in a direction opposite to the hook 310 at one side of the housing cutout portion 110 of the housing 100, and when the hook 310 rotates while pulling the upper thread, an upper thread guide grooves 121 in which both sides of the upper thread that forms a loop are housed are provided at both sides of the upper thread guide 120.
When the hook 310 of the hook body 300 starts to rotate while pulling the upper thread, the upper thread guide 120 enables both sides of the upper thread forming a loop to always stay at a constant position.
The upper thread guide 120 may have a structure that assembles a separate part in the housing 100 and may be integrally formed with the housing 100.
At the inside of the housing 100, power is transferred between a rotation plate 200 and the hook body 300, and for a stable rotation of the rotation plate 200 and the hook body 300, at an inner side surface of the housing 100, elements that guide a rotation thereof are provided.
As shown in
The rotation plate separation prevention ring 140 has a circular ring shape and is coupled to an end portion of the rear side of the housing 100 to prevent the rotation plate 200 from separating from the rotation plate guide groove 130 and ensures a stable rotation movement of the rotation plate 200, space between the rotation plate guide groove 130 and the rotation plate separation prevention ring 140 is space larger than a thickness of a rotation plate guide rail 220 to allow a clearance of a front-rear direction of the rotation plate 200 itself, and an allowance range of such a clearance should be limited to a range that does not release engagement between a power transmission protrusion 210 of the rotation plate 200 and a protrusion receiving portion 320 of the hook body 300.
As shown in
A hook body separation prevention ring 160 has a shape in which a partial area corresponding to the housing cutout portion 110 is cut out in a circular ring, is coupled to a front end portion of the housing 100 to prevent the hook body 300 from separating from a hook body guide groove A 150, and ensures a stable rotation movement of the hook body 300.
The rotation plate 200 is connected to a power shaft of the sewing machine and has a circular plate shape, and the power transmission protrusion 210 is formed at a front surface (surface opposite to the hook body 300) of the circular plate.
The rotation plate guide rail 220 is housed at space between the rotation plate separation prevention ring 140 and the rotation plate guide groove 130 of an inner side surface of the rear end of the housing 100 and thus the rotation plate 200 stably rotates, and the rotation plate guide rail 220 is protruded along an outer diameter of the rotation plate 200 to be housed at space between the rotation plate guide groove 130 and the rotation plate separation prevention ring 140, and as shown in
As shown in
A coupling binding portion 230 is protruded from a rear surface of a circular plate to maintain a constant gap, and in
At the center of a coupling 250, a power shaft binding hole 240 for inserting and coupling the power shaft of the sewing machine is provided, and the coupling 250 is radially extended about the power shaft binding hole 240 to entirely form a cross (+) form and is housed in space between the coupling binding portions 230.
At the center of a coupling separation prevention plate 260, a hollow that passes through the power shaft of the sewing machine is formed to be coupled to an end surface of the rear side of the coupling binding portion 230, thereby preventing the coupling 250 from separating.
The coupling 250 coupled in this way has a clearance to allow a sliding movement in the front-rear direction in a state coupled to the coupling binding portion 230, and a clearance range should be limited to a range that does not release engagement between the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300. This is because a clearance is so wide, and as the rotation plate 200 and the coupling separation prevention plate 260 recede together to the rear side along the power shaft of the sewing machine and thus when engagement between the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 is released, torque of the power shaft is not transferred to the hook body 300.
As shown in
At the outside of a rear surface of the hook body 300, the protrusion receiving portion 320 that receives torque of the rotation plate 200 by engaging with the power transmission protrusion 210 of the rotation plate 200 is formed, and at the inside of a rear surface thereof, a bobbin mounting post 330 is formed.
As shown in
In a state in which the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 are engaged, when the rotation plate 200 rotates, the hook body 300 rotates with the rotation plate 200 in the same rotation speed by interlocking with a rotation of the rotation plate 200, a clearance for discharging the upper thread should be secured between the power transmission protrusion 210 and the protrusion receiving portion 320.
As shown in
At an outer circumferential surface of the front end of the hook body 300, a hook body guide rail A 360 that is housed at space between the hook body guide groove A 150 and the hook body separation prevention ring 160 and that perform a rotation movement is protruded to guide a stable rotation of the hook body 300.
As shown in
As shown in
The cap 500 is detachably coupled to the bobbin mounting post 330 through a cap detachment lever 550 and a clip 540, and when pulling the cap detachment lever 550 to the front side, coupling between the clip 540 and the bobbin mounting post 330 is released, and the cap 500 may be separated, and in a state in which the bobbin 400 is mounted, when the cap is pushed, binding between the clip 540 and the bobbin mounting post 330 is performed to prevent the cap 500 from separating.
Although not separately shown in the accompanying drawing, at an inner side surface of the cap 500, an elastic body such as a flat spring that elastically supports one side surface of the bobbin 400 is further provided to control a rotation speed of the bobbin 400, thereby preventing the bobbin 400 from idling, and an existing lower thread supply device has a similar function due to such a structure and therefore a specific illustration or description thereof will be omitted.
As shown in
That is, as shown in
In the cap 500, a cap hole 520 that penetrates a central portion is formed, and at a side surface of the front side in which the tension adjustment piece 510 is mounted, a lower thread penetration hole A 530 communicating with the cap hole 520 is formed.
As shown in
When a power shaft of the sewing machine rotates, the rotation plate 200 connected thereto rotates, and because the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 are engaged, the hook body 300 rotates together with the rotation plate 200.
Further, because the cap 500 is in a state engaged with the hook body 300 by the tension adjustment piece 510, the cap 500 rotates together with the hook body 300.
When the hook 310 of the hook body 300 rotates while pulling the upper thread, the upper thread of a loop form is wound to a front-rear surface of the hook body 300. In this case, the upper thread wound to a rear surface of the hook body 300 passes through space between the hook body 300 and the rotation plate 200, and a clearance for passing through the upper thread is formed between the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300. Further, the upper thread guide 120 performs a function of guiding the upper thread to well wind the front and rear surfaces of the hook body 300.
The housing 100 is fixed to a main body of the sewing machine and has a cylindrical pipe shape in which a front surface and a rear surface are opened along a central axis.
The housing 100 is fixed to a main body of the sewing machine using generally known various brackets, fixing volts, or pins, and a separate description thereof will be omitted. The housing 100 is fixed to the main body of the sewing machine, and even if the power shaft of the sewing machine rotates, the housing 100 does not rotate and maintains a fixed state.
An outer circumferential surface (portion in which a needle of the sewing machine moves downward) of one side of such a housing is cut out to form the housing cutout portion 110, and the housing cutout portion 110 provides space in which the upper thread moving downward in a loop form by being hooked by a needle is engaged to the hook 310.
That is, after the hook 310 attached to the hook body 300 rotating in the housing cutout portion 110 is engaged with the upper thread while passing through the upper thread of a loop form moved downward along the needle, the hook 310 rotates while pulling the upper thread.
The upper thread guides 120 are installed in a direction opposite to the hook 310 at one side of the housing cutout portion 110 of the housing 100 and are provided at both sides of the upper thread guide groove 121 in which both sides of the upper thread forming a loop are housed when the hook 310 rotates while pulling the upper thread.
When the hook 310 of the hook body 300 starts to rotate while pulling the upper thread, the upper thread guide 120 enables both sides of the upper thread forming a loop to always position at a constant position.
The upper thread guide 120 may have a structure that assembles a separate part in the housing 100 and may formed integrally with the housing 100.
At the inside of the housing 100, power is transferred between the rotation plate 200 and the hook body 300, and for a stable rotation of the rotation plate 200 and the hook body 300, at an inner side surface of the housing 100, element that guide a rotation thereof are provided.
As shown in
The rotation plate separation prevention ring 140 has a circular ring shape and is coupled to an end portion of the rear side of the housing 100 to prevent the rotation plate 200 from separating from the rotation plate guide groove 130 and to ensure a stable rotation movement of the rotation plate 200, and space between the rotation plate guide groove 130 and the rotation plate separation prevention ring 140 is space larger than the rotation plate guide rail 220 and allows a clearance in a front-rear direction of the rotation plate 200 itself, and an allowance range of the clearance should be limited to a range that does not release engagement between the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300.
As shown in
The hook body separation prevention ring 160 has a shape in which a partial area corresponding to the housing cutout portion 110 is cut out in a circular ring and is coupled to an end portion of the front side of the housing 100 to prevent the hook body 300 from separating from the hook body guide groove A 150 and ensures a stable rotation movement of the hook body 300.
As shown in
The rotation plate 200 is connected to a power shaft of the sewing machine and has a circular plate shape, and the power transmission protrusion 210 is formed at a front surface (surface opposite to the hook body 300) of the circular plate.
The rotation plate guide rail 220 is housed at space between the rotation plate separation prevention ring 140 and the rotation plate guide groove 130 of an inner side surface of the rear end of the housing 100 and thus the rotation plate 200 performs a stable rotation, and the rotation plate guide rail 220 is protruded along an outer diameter of the rotation plate 200 to be housed at space between the rotation plate guide groove 130 and the rotation plate separation prevention ring 140, and as shown in
As shown in
The coupling binding portion 230 is protruded from a rear surface of a circular plate to maintain a constant gap, and in
At the center of the coupling 250, the power shaft binding hole 240 for inserting and coupling the power shaft of the sewing machine is provided, and the coupling 250 is radially extended about the power shaft binding hole 240 to entirely form a cross (+) form and is housed in space between the coupling binding portions 230.
At the center of the coupling separation prevention plate 260, a hollow that passes through the power shaft of the sewing machine is formed to be coupled to an end surface of the rear side of the coupling binding portion 230, thereby preventing the coupling 250 from separating.
The coupling 250 coupled in this way has a clearance between the coupling 250 and the coupling binding portion 230 in a state coupled to the coupling binding portion 230, and a clearance range should be limited to a range that does not release engagement between the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300. This is because a clearance is so wide, and as the rotation plate 200 and the coupling separation prevention plate 260 recede together to the rear side along the power shaft of the sewing machine, when engagement between the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 is released, torque of the power shaft is not transferred to the hook body 300. Further, due to such a clearance, because the coupling 250 and the coupling binding portion 230 performs a function similar to an universal joint, even if the power shaft of the sewing machine and the hook body 300 or a rotation shaft of the rotation plate 200 are not arranged in a straight line but deviated a little, power transfer can be smoothly performed. Therefore, when producing a product, a processing tolerance or an assembly tolerance can be further allowed and thus a production cost can be lowered and an assembly and processing time can be shortened.
As shown in
At the outside of a rear surface of the hook body 300, the protrusion receiving portion 320 that receives torque of the rotation plate 200 by engaging with the power transmission protrusion 210 of the rotation plate 200 is formed, and at the inside of a rear surface of the hook body 300, the bobbin mounting post 330 is formed.
As shown in
In a state in which the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 are engaged, when the rotation plate 200 rotates, the hook body 300 rotates with the same rotation speed as that of the rotation plate 200 by interlocking with the rotation plate 200, and a clearance for discharging the upper thread should be defined between the power transmission protrusion 210 and the protrusion receiving portion 320.
As shown in
As shown in
At an outer circumferential surface of the front end of the hook body 300, the hook body guide rail A 360 that is housed at space between the hook body guide groove A 150 and the hook body separation prevention ring 160 and that performs a rotation movement is protruded to guide a stable rotation of the hook body 300.
As shown in
In the light transmission device 370, the bar code sensor 620 installed at the sensor mounting device 170 while performing a passage function of light of the light source unit 630 radiated to recognize the optical sensor 660 or the bar code 610 mounted in the bobbin 400 performs a function of an opened window for sensing the bar code 610 attached to the bobbin 400.
As shown in
As shown in
In the bar code 610, an one-dimensional bar code formed with a line or a two-dimensional bar code formed with a surface may be used, and a line or a surface constituting the bar code may use fluorescence dyes. A color bar code printed with various colors and widths may be used.
Therefore, by sensing the bar code 610 exposed by unwinding of the lower thread, a present remaining amount of the lower thread can be easily detected.
The bar code sensor 620 is installed in the sensor mounting device 170 of the housing 100 to sense the bar code 610, thereby performing a function of detecting the remaining amount of the lower thread, and such a bar code sensor 620 is formed with a bar code detection sensor, which is a kind of an optical sensor, and as a color bar code, an existing color sensor or a CMOS sensor may be used. Further, in the bar code sensor 620, it is preferable that the light source units 630 formed with a lighting device such as an LED that radiates light toward the bobbin 400 are installed in parallel to enable the bar code sensor 620 to smoothly sense.
As shown in
A bar code value sensed in the bar code sensor 620 is converted to a digital value in the decoder 710, and the processor 720 compares the converted digital value and a reference value that is preset in the setting unit 730. As a comparison result, in order to represent a signal according to the remaining amount of the lower thread to the outside, a speaker or a light emitting means (signal lamp) may be used. For example, a green lamp, a yellow lamp, and a red lamp are connected to the controller 700, and when the remaining amount of the lower thread is enough, the green lamp may be set to be turned on, and as the remaining amount of the lower thread is gradually reduced, when the remaining amount of the lower thread arrives at a preset first warning time point, the yellow lamp may be set to be turned on, and as the remaining amount of the lower thread is extremely reduced, when the remaining amount of the lower thread arrives at a preset time point in which replacement is necessary, the red lamp may be set to be turned on. Further, even when a constant time has elapsed after the red lamp is turned on, if the lower thread is not replaced, a driving motor of the sewing machine may be set to be stopped. Even when a speaker is used, similarly, by generating a previously stored voice or sound signal according to a level, the remaining amount of the lower thread may be notified to a user.
As shown in
In this way, when the bar code 610 is attached along an outer circumferential surface of the rotation shaft 410 of the bobbin 400, the lower thread should be sequentially wound according to a region of the rotation shaft 410. For example, as shown in
In
The RFID tag 670 is connected to the optical sensor 660 to perform a function of transmitting a signal transferred from each optical sensor 660.
As shown in
As shown in
In
In this case, similar to
In
In some case, the remaining amount of the lower thread wound in the bobbin 400 may be directly measured without installing a separate bar code or optical sensor in the bobbin 400.
That is, although separately not shown, by installing a laser distance measuring device in an attached portion of the bar code sensor 620 and the light source unit 630 and by measuring a distance to the lower thread wound in the bobbin 400, the remaining amount of the lower thread may be detected. As the lower thread is consumed, a distance between the laser distance measuring device and the lower thread increases, by measuring such a distance, a consumed amount of the lower thread and the present remaining amount of the lower thread can be calculated. Even when such a laser distance measuring device is used, operation performed in the controller 700, a speaker, and a signal lamp is the same as that shown in
As shown in
The cap 500 is detachably coupled to the bobbin mounting post 330 through the cap detachment lever 550 and the clip 540, when pulling the cap detachment lever 550 to the front side, coupling between the clip 540 and the bobbin mounting post 330 is released, and thus the cap 500 may be separated, and in a state in which the bobbin 400 is mounted, when the cap 500 is pushed, binding between the clip 540 and the bobbin mounting post 330 is performed and thus the cap 500 is prevented from separating.
Although not separately shown in the accompanying drawings, at an inner side surface of the cap 500, an elastic body such as a flat spring that elastically supports one side surface of the bobbin 400 is further provided to control a rotation speed of the bobbin 400, thereby preventing the bobbin 400 from idling, and an existing lower thread supply device has a similar function due to such a structure and therefore a specific illustration or description thereof will be omitted.
As shown in
That is, the lower thread unwound from the bobbin 400 passes though the inside of the tension adjustment piece 510, and in this process, the tension adjustment piece 510 gently grasps the lower thread by an elastic force.
In the cap 500, the cap hole 520 that penetrates a central portion is formed, and at a side surface of the front side in which the tension adjustment piece 510 is mounted, the lower thread penetration hole A 530 communicating with the cap hole 520 is formed.
The lower thread, having passed through the tension adjustment piece 510 is discharged to the front side of the cap 500 by passing through the lower thread penetration hole A 530 and the cap hole 520, and the discharged lower thread moves upward and meets with the lower thread guide A 340, forms a stitch with the upper thread at a cloth, and a constant tension operates in the lower thread between the cloth and the cap hole 520 by a function of the tension adjustment piece 510, and the lower thread is thus in a somewhat pulled state, thereby smoothly forming a stitch with the upper thread.
When the power shaft of the sewing machine rotates, the rotation plate 200 connected thereto rotates, and because the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 are engaged, the hook body 300 rotates together with the rotation plate 200.
Further, because the cap 500 is in a state engaged with the hook body 300 by the tension adjustment piece 510, the cap 500 rotates together with the hook body 300.
When the hook 310 of the hook body 300 rotates while pulling the upper thread, the upper thread of a loop form winds a front-rear surface of the hook body 300. In this case, the upper thread winding a rear surface of the hook body 300 passes through space between the hook body 300 and the rotation plate 200, and a clearance for passing through the upper thread is formed between the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300. Further, the upper thread guide 120 performs a function of guiding the upper thread to well wind the front and rear surfaces of the hook body 300.
The housing 100 is fixed to a main body of the sewing machine and has a cylindrical pipe shape in which a front surface and a rear surface are opened along a central axis.
The housing 100 is fixed to a main body of the sewing machine using generally known various brackets, fixing volts, or pins, and a separate description thereof will be omitted. The housing 100 is fixed to the main body of the sewing machine, and even if the power shaft of the sewing machine rotates, the housing 100 does not rotate and maintains a fixed state.
An outer circumferential surface (portion in which a needle of the sewing machine moves downward) of one side of such a housing is cut out to form the housing cutout portion 110, and the housing cutout portion 110 provides space in which the upper thread moving downward in a loop form by being hooked by a needle is engaged to the hook 310.
That is, after the hook 310 attached to the hook body 300 rotating in the housing cutout portion 110 is engaged with the upper thread while passing through the upper thread of a loop form moved downward along a needle, the hook 310 rotates while pulling the upper thread.
The upper thread guide 120 is provided to be protruded in a direction opposite to the hook 310 at one side of the housing cutout portion 110 of the housing 100 and performs a function of guiding the upper thread to the rear side of the hook body 300 by hooking the upper thread forming a loop when the hook 310 rotates while pulling the upper thread.
The upper thread guide 120 may have a structure that assembles a separate part in the housing 100 and may be formed integrally with the housing 100.
At an inner side surface of the housing 100, a hook body guide rail B 180 that guides a rotation of the hook body 300 is protruded, and the hook body guide rail B 180 is housed in a hook body guide groove B 390 cut out along an outer circumferential surface of the hook body 300.
The rotation plate 200 is connected to the power shaft of the sewing machine, has a circular plate shape, and the power transmission protrusion 210 is formed at a front surface of a circular plate. The rotation plate 200 is installed at the rear end of the housing 100 to transfer torque to the hook body 300.
That is, in a state in which the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 are engaged, when the rotation plate 200 is connected to the power shaft of the sewing machine for rotating, the hook body 300 rotates together by interlocking with the rotation plate 200.
In a state in which that the power transmission protrusion 210 of the rotation plate 200 and the protrusion receiving portion 320 of the hook body 300 are engaged, a clearance (gap) for discharging the upper thread exists between the power transmission protrusion 210 and the protrusion receiving portion 320. That is, the power transmission protrusion 210 and the protrusion receiving portion 320 rotate while engaging in a state in which some allowance space exists.
The hook body 300 is rotatably installed at the inside of the housing 100, and has a cylindrical shape having an opened front surface, and at the outside of a rear surface thereof, the protrusion receiving portion 320 that receives torque of the rotation plate 200 by being engaged with the power transmission protrusion 210 is formed.
At the inside of a rear surface of the hook body 300, the bobbin mounting post 330 is formed to perform a function of a rotation shaft of the bobbin 400.
The hook 310 is attached to an outer circumferential surface of one side of the hook body 300 and performs a function of pulling the upper thread while passing through a loop formed by the upper thread moved downward along a needle of the sewing machine.
A guide channel 301 depressed toward a rear surface of the hook body 300 along one side of an outer circumferential surface of the hook body 300 to which the hook 310 is attached to guide the upper thread to the rear side of the hook body 300 is provided, and a guide bank A 302 protruded parallel to the guide bank A 302 along one side of the guide channel 301 to guide the upper thread to the inside of the guide channel 301 is provided.
When the hook 310 rotates while pulling the upper thread by passing through a loop formed by the upper thread moved downward along the needle of the sewing machine, the upper thread guide 120 installed opposite to the hook 310 guides the upper thread to enter into the guide channel 301 while passing through a loop formed by the upper thread, and the guide bank A 302 performs a function of a blocking film that prevents the upper thread from being inserted into a gap between the hook body guide rail B 180 and the hook body guide groove B 390 by enabling the upper thread to pass through an upper portion of the guide channel 301 instead of entering into the guide channel 301.
At an outer circumferential surface of the hook body 300, a hook body guide groove B 390 that houses the hook body guide rail B 180 is cut out. The hook body guide rail B 180 and the hook body guide groove B 390 perform a function of guiding the hook body 300 to perform a stable rotation within the housing 100. Although not separately illustrated in the accompanying drawing, in some case, the hook body guide rail B 180 may be provided in an outer circumferential surface of the hook body 300, and the hook body guide groove B 390 may be provided at an inner side surface of the housing 100.
The bobbin 400 is inserted into the bobbin mounting post 330 of the hook body 300 to be rotatably installed, and such a bobbin 400 has a spool shape in which a lower thread is wound like a bobbin of a general lower thread supply device.
The cap 500 is detachably coupled to the bobbin mounting post 330 by passing through the center of the bobbin 400 and performs a function of preventing the bobbin 400 from separating from the hook body 300.
A lower thread guide B 580 is coupled to a front surface of a outer cover 570, which is a front end portion of the cap 500 and is protruded to the front side further than a tip of the hook 310 to perform a function of maintaining a gap so that the lower thread supplied from the bobbin 400 does not meet with the hook 310.
The cap 500 includes an inner cover 560, a separation prevention piece 562, a cap detachment lever 550, a spring 564, and an outer cover 570.
In the inner cover 560, a mounting post receiving hole 561 coupled to the bobbin mounting post 330 of the hook body 300 by passing through the bobbin 400 is long provided and becomes a portion directly contacting with the bobbin 400.
As shown in
The separation prevention piece 562 is slidably coupled to a front surface of the inner cover 560.
A separation prevention protrusion 563 formed in an end portion of one side of the separation prevention piece 562 is housed in a separation prevention piece receiving portion 303 provided at one side of a front end portion of the hook body 300, and in this way, when the separation prevention protrusion 563 is inserted into the separation prevention piece receiving portion 303 of the hook body 300, the separation prevention protrusion 563 prevents the cap 500 from separating and resultantly enables the bobbin 400 to stably stay within the hook body 300.
The spring 564 is installed in the inner cover 560 and elastically supports the separation prevention piece 562, and pushes the separation prevention piece 562 in a direction of the separation prevention piece receiving portion 303 in order to maintain a state in which the separation prevention protrusion 563 is housed in the separation prevention piece receiving portion 303 of the hook body 300.
The cap detachment lever 550 is rotatably coupled to a front surface of the separation prevention piece 562, and when the cap detachment lever 550 rotates to the front side, the cap detachment lever 550 pushes the separation prevention piece 562 so that the separation prevention protrusion 563 discharges from the separation prevention piece receiving portion 303. When the cap detachment lever 550 is released, the separation prevention piece 562 and the cap detachment lever 550 are returned to an original position by operation of the spring 564.
As shown in
The outer cover 570 is positioned at a front surface of the cap detachment lever 550 and is coupled to the inner cover 560.
The cap detachment lever 550 and the separation prevention piece 562 are installed between the outer cover 570 and the inner cover 560, and a central portion of the outer cover 570 is opened to be protruded to the front side by rotating the cap detachment lever 550.
Further, at one side extended toward the bobbin 400 from the outer cover 570, the lower thread penetration hole B 571 that discharges the lower thread unwound from the bobbin 400 is provided.
Here, as shown in
As shown in
Although exemplary embodiments of the present invention have been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications and alterations should therefore be seen as within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2010-0082243 | Aug 2010 | KR | national |
| 10-201-10010076 | Feb 2011 | KR | national |
| 10-2011-0023358 | Mar 2011 | KE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2011/006234 | 8/23/2011 | WO | 00 | 2/22/2013 |
