TWI582285B - Cloth feeding tooth differential mechanism for a sewing machine - Google Patents

Description

Feeding tooth differential mechanism of sewing machine

The invention provides a feed tooth differential mechanism of a sewing machine, which is related to a sewing feeding mechanism.

With the maturity of textile technology and the diversification of fabric design, the functions and sewing patterns of sewing machines are also facing development. In the case of feed teeth, the early sewing machines were only equipped with a single feed tooth for feeding. With the sewing requirements, the sewing machine with double feed teeth can be produced accordingly. The speed difference between the two feed teeth can be used to sew wrinkles or flatter fabrics. How to provide users with simple and fast Adjusting the difference between the two feed teeth is the subject of the present invention. In view of this, the inventors have devoted themselves to research and intensively conceived, and after many trials and developments, finally invented a feed tooth differential mechanism of a sewing machine.

The present invention provides a feed tooth differential mechanism for a sewing machine, the main object of which is to provide a mechanism for easily and quickly adjusting a feed tooth.

In order to achieve the above objective, the present invention provides a feed tooth differential mechanism of a sewing machine, which is provided with a driving shaft driven by a power source in a machine seat of a sewing machine, and the power of the driving shaft Transmitting to a feeding device having a first feeding tooth and a second feeding tooth through a differential device disposed on the base, the first feeding tooth and the second feeding tooth system are mutually The first feeding piece and the second feeding piece are driven by the first feeding piece and the second feeding piece. The differential device has a first linking piece, a second linking piece and a third linking piece, wherein the first linking piece is the The first shaft of the first feed dog table and the second link member are respectively pivoted to the first feed dog table and the second link member is driven to move forward or backward, and the second link member swings, the second link member The other end of the third linking member is pivotally connected to one end of the third linking member, and the other end of the third linking member is pivotally disposed on the second feeding carrier to drive forward or backward, and between the two ends of the third linking member An adjustment slot is disposed, and an adjustment support member is slidably received in the adjustment slot and is adjustable for the user to adjust the position of the adjustment support member on the third linkage member. When the third linking member is linked by the second linking member, different swings are generated to reach the first feeding rack and the second Table cloth and the differential gear change by the first feed teeth and a second feed tooth feed amplitude.

The present invention drives the first feed dog and the second feed dog through the differential device, and changes the position of the adjustment support while changing the yaw pivot of the third linkage that drives the first feed dog, thereby achieving rapid It is easy to adjust the purpose of the two feed teeth differential.

"this invention"

10‧‧‧ machine base

11‧‧‧Active shaft

12‧‧ ‧ socket

20‧‧‧ Feeding rocker

30‧‧‧Feed drive adjustment unit

31‧‧‧ first link

32‧‧‧Second link

33‧‧‧Chain

34‧‧‧ Third Link

341‧‧‧ Slider

35‧‧‧fourth link

351‧‧ ‧ chute

36‧‧‧ fifth link

37‧‧‧ Sixth link

38‧‧‧cloth axis

381‧‧‧cloth adjustment limit gear

382‧‧‧cloth knob

383‧‧‧ Width limiting shrapnel

40‧‧‧Differential device

41‧‧‧First linkage

42‧‧‧Second linkage

43‧‧‧ Third linkage

431‧‧‧Adjustment slot

50‧‧‧Feeding device

51‧‧‧First delivery table

511‧‧‧Band

512‧‧‧ slot

513‧‧‧ wearing parts

514‧‧‧Device space

515‧‧‧through

516‧‧ ‧ slots

52‧‧‧second feed table

521‧‧‧ seat

522‧‧‧Second spring

59‧‧‧ Third spring

53‧‧‧First delivery teeth

54‧‧‧second delivery teeth

55‧‧‧First pivot

56‧‧‧ wearing rod

57‧‧‧First spring

58‧‧‧ pivot

581‧‧‧ wearing a sleeve

582‧‧‧ pivot

60‧‧‧Differential adjustment device

61‧‧‧Differential adjustment shaft

62‧‧‧Differential adjustment seat

621‧‧‧Adjustment support

63‧‧‧First moving parts

64‧‧‧Second moving parts

65‧‧‧third moving parts

66‧‧‧Differential axis

661‧‧‧Differential adjustment limit gear

662‧‧‧Differential knob

663‧‧‧Differentially restricted shrapnel

D1‧‧‧ first direction

D2‧‧‧ second direction

D3‧‧‧ third direction

Fig. 1 is a schematic view showing the overall appearance of a feed tooth differential mechanism of a sewing machine of the present invention.

2 is a partial structural schematic view of a hidden machine base of a feed tooth differential mechanism of the sewing machine of the present invention.

3 is a schematic structural view of a hidden machine base of a feed tooth differential mechanism of the sewing machine of the present invention.

4 is a schematic view showing another perspective of the hidden frame of the feed tooth differential mechanism of the sewing machine of the present invention.

Figure 5 is a side view of the hidden machine base and some components of the feed tooth differential mechanism of the sewing machine of the present invention.

Figure 6 is a perspective structural view showing the hidden frame of the feed tooth differential mechanism of the sewing machine of the present invention.

Figure 7 is a cross-sectional view showing the structure of a hidden machine base of a feed tooth differential mechanism of the sewing machine of the present invention.

Figure 8 is a cross-sectional view of the hidden machine base of the feed tooth differential mechanism of the sewing machine of the present invention, and is a state in which the adjustment support is located at the middle of the adjustment groove.

Figure 9 is an action diagram of the state of Figure 7.

Figure 10 is a cross-sectional view of the hidden machine base of the feed tooth differential mechanism of the sewing machine of the present invention, and is a state in which the adjustment support is located in the adjustment groove near the position of the second linkage.

Figure 11 is an action diagram of the state of Figure 9.

Figure 12 is a cross-sectional view showing the hidden carriage of the feed tooth differential mechanism of the sewing machine of the present invention, and in a state in which the adjustment support is located in the adjustment groove near the position of the first feed carrier.

In order to enable the reviewing committee to have a better understanding and understanding of the purpose, features and effects of the present invention, please refer to the following [detailed description of the drawings] as follows: the preferred embodiment of the feed tooth differential mechanism of the sewing machine of the present invention The embodiment is shown in FIG. 1 to FIG. 12, and includes a base 10 pivotally disposed with a driving shaft 11 extending from one end of the driving shaft 11 to the power source, and the driving shaft 11 is disposed on the driving shaft 11 a bearing 12, the extending direction of the driving shaft 11 is defined as a first direction D1, and perpendicular to the first direction D1, a second direction D2 and a third direction D3 perpendicular to each other can be further defined; a feeding rocker 20 The first direction D1 is pivotally disposed on the base 10 and one end extends out of the base 10; a feed drive adjustment unit 30 includes a first link 31 and a second link 32. A string of shafts 33, a third link 34, a fourth link 35, a fifth link 36 and a sixth link 37. One end of the first link 31 is fixedly coupled to the feed rocker 20, the other end of the first link 31 is pivotally coupled to one end of the second link 32, and the other end of the second link 32 is pivotally coupled to the third link 34 through the string 33 The other end of the third link 34 is eccentrically sleeved on the driving shaft 11 and can be driven by the driving shaft 11 . One end of the string shaft 33 passes through the second connecting rod 32 and the third connecting rod 34 . A slider 341 is slidably received in a sliding slot 351 of the fourth connecting rod 35. The fourth connecting rod 35 is disposed at one end of the fourth connecting rod 35 and can be pivoted. The other end of the fourth link 35 is pivotally coupled to one end of the fifth link 36, and the other end of the fifth link 36 is fixedly coupled to a sixth link 37. The other end of the sixth link 37 is fixedly coupled to a fabric shaft 38 pivotally coupled to the base 10 and is drivable by the cloth shaft 38. The end of the cloth shaft 38 Pivotablely bonded to the a seat 10, the other end of the fabric shaft 38 is fixedly sleeved by a fabric adjustment limiting gear 381 and a fabric knob 382. The outer circumference of the fabric adjustment limiting gear 381 has a plurality of teeth, and the housing 10 is Further, adjacent to the fabric adjustment restricting gear 381, a web restraining elastic piece 383 is disposed. The one end of the web restricting elastic piece 383 is fixed to the base 10, and the other end is elastically engaged with the teeth of the fabric adjusting restricting gear 381. a differential device 40 includes a first linking member 41, a second linking member 42, and a third linking member 43. The middle portion between the two ends of the first linking member 41 is fixedly coupled to the feeding roller. The rod 20 extends from one end of the base 10, so that the first linking member 41 can be driven by the driving shaft 11. One end of the first linking member 41 can pivotally couple one end of the second linking member 42. The other end of the second linking member 42 is pivotally coupled to one end of the third linking member 43 . The second linking member 42 pivotally couples the first linking member 41 and the third linking member 43 and becomes a second connecting member 42 can also swing when the first linking member 41 is yawed; Third vicinal between both ends of the movable member 43 An adjustment slot 431 is disposed through; a feeding device 50 includes the first feed tray 51, the second feed rack 52, the first feed dog 53, and the second feed tooth 54, One end of the first feed dog table 51 is formed with a pivot portion 511, and the other end is formed with a clamping groove 512, and a position between the pivot portion 511 of the first feed dog table 51 and the clamping groove 512 is formed into a wearing portion. 513, a device space 514 is formed between the pivot portion 511 and the wearing portion 513, and the through portion 515 is disposed through the through hole 515. The position of the pivot portion 511 relative to the through hole 515 is a certain slot 516. The first feed dog table 51 is pivotally connected to the other end of the first link member 41 and the pivot portion 511 of the first feed dog table 51 through a first pivot 55 extending in the first direction D1. The first feed dog table 51 is pivotally coupled to the first link member 41. The first feed dog 53 is fixedly disposed on the first feed dog table 51, and the first feed dog tooth The table 51 is slidably supported by the socket 12 on the drive shaft 11; and the second feed dog 54 is fixedly coupled to the second feed rack 52. The second feed tray 52 can be Sliding along the second direction D2 The first feed dog 53 and the second feed tooth 54 are respectively slidably sleeved by the first feed dog table 51 and the second feed in the clip slot 512 of the first feed dog table 51. The cloth feed table 52 is driven, and the second feed rack 52 is fixedly coupled to one end of the wear rod 56 through a fixed seat 521. The wear rod 56 extends in the second direction D2 and the other end extends through the through passage 515. Positioned in the fixed slot 516, the wear rod 56 of the embodiment is a round rod, and the wear rod 56 is sleeved in the wearing space 514 between the wearing portion 513 and the pivot portion 511. 57 and a pivoting seat 58, and the position of the wearing rod 56 between the wearing portion 513 and the fixing seat 521 is a second spring 522, and a pair of third springs 59 are respectively hooked on the fixed rod The base 521 and the base 10; and the pivot base 58 is coupled to the wear rod 56 by a sleeve end 581 at one end, and the other end of the pivot base 58 is a pivot 582 extending in the first direction D1. The other end of the third linking member 43 is pivotally coupled to the pivot shaft 582; a differential adjustment device 60, comprising a differential adjustment shaft 61, a differential adjustment seat 62, a first moving member 63, a second moving member 64, and a third moving member 65, the differential adjusting shaft 61 is pivotally disposed on the base 10, and one end of the differential adjustment shaft 61 extends from the base 10 and is fixedly coupled to one end of the differential adjustment seat 62. The other end of the differential adjustment seat 62 is disposed. An adjusting support 621 is slidably received in the adjusting groove 431 of the third linking member 43 . The differential adjusting shaft 61 is pivotally sleeved on the first moving member 63 . The other end of the first movable member 63 is pivotally coupled to one end of the second movable member 64, and the other end of the second movable member 64 is pivotally coupled to one end of the third movable member 65. The other end of the third movable member 65 is fixedly coupled to a differential shaft 66 pivotally coupled to the base 10 and is drivable by the differential shaft 66. The differential shaft 66 is pivotally coupled at one end. In the base 10, the other end of the differential shaft 66 is fixedly sleeved by a differential adjustment limiting gear 661 and a differential knob 662. The outer circumference of the differential adjustment limiting gear 661 has a plurality of teeth. And a differential limiting elastic piece 663 is disposed on the base 10 and adjacent to the differential adjustment limiting gear 661. The differential limiting elastic piece 663 is fixed at one end to the base 10, and the other end is elastically locked to the The differential adjustment limits the teeth of the gear 661.

The above is the structural configuration and characteristics of the feed tooth differential mechanism of the sewing machine of the present invention. In operation, the power source output power drives the drive shaft 11 to rotate, and the drive shaft 11 rotates to drive the eccentricity The three links 34 are yawed, and when the third link 34 is yawed, the second link 32 can be yawed at the same time, and the yaw action of the second link 32 can drive the feed rocker When the feed rocker 20 rotates, a reverse yaw is generated at both ends of the first link member 41 pivotally connected to the feed rocker 20, and the end of the second link member 42 is pivotally driven. The second linking member 42 is displaced, and the one end of the first feeding table 51 is pivotally driven to displace the first feeding table 51. The first feed dog table 51 can drive the first feed dog 53 to be displaced; and when the second link member 42 is displaced, the first link member 43 pivotally connected thereto is pivoted at the same time. The other end of the three-linking member 43 drives the rod 56 to translate through the pivoting seat 58, and the threading rod 56 can synchronously drive the second feeding rack 52 to translate. The second feeding rack 52 drives the first The two feed teeth 54 are displaced, thereby generating smooth operation of the double feed teeth; accordingly, the drive shaft 11 transmits power to the first feed dog 53 and the second feed tooth 54 through the differential device 40. The operation flow of the cloth device 50; and as shown in FIGS. 7 and 8, when the adjustment support 621 of the differential adjustment seat 62 is located at the middle of the adjustment groove 431 of the third linkage member 43, The yaw at the two ends of the third linking member 43 is yawed with the adjusting support member 621 as a fulcrum. At this time, the adjusting support member 621 is equivalent to the distance between the two ends of the third linking member 43. Therefore, the two ends of the third linking member 43 are The yaw amplitude is also equivalent. Under the link mechanism, the yaw amplitude of the first linking member 41 pivotally connected to the second linking member 42 The first feed dog table 51 and the second feed gear table 52 that are driven by the third link member 43 and the first link member 41 can also generate the yaw amplitude of the third link member 43. The displacement of the same distance, the first feed dog 53 and the second feed dog 54 are in a state of almost no speed difference in this state; and when the first feed dog 53 and the second feed are to be adjusted When the speed difference between the teeth 54 is different, the differential knob 662 is rotated, the differential knob 662 drives the differential shaft 66 to rotate, and when the differential shaft 66 rotates, the differential adjustment limit on the differential shaft 66 The gear 661 rotates synchronously and springs against the differential limiting elastic piece 663. The elastic locking of the differential limiting elastic piece 663 and the differential adjustment limiting gear 661 produces a significant adjustment tactile sensation and sound, and the differential limiting elastic piece can be 663 pairs should be differentially adjusted to limit the tooth of each gear 661, to avoid excessive over-adjustment, and accordingly improve the accuracy of adjustment; When the differential shaft 66 rotates, the differential shaft 66 drives the second movable member 64 through the third movable member 65, and the second movable member 64 drives the first movable member 63. The first movable member 63 can drive the differential adjustment shaft 61 to rotate, and when the differential adjustment shaft 61 rotates, the differential adjustment seat 62 fixed to the differential adjustment shaft 61 is yawed, and the differential adjustment seat The other end of the adjustment member 621 can be slid in the adjustment slot 431 of the third linkage member 43. When the adjustment support member 621 changes the position in the adjustment slot 431, it represents the rotation of the third linkage member 43. The fulcrum is changed accordingly; when the adjustment support 621 is displaced to the point where the adjustment groove 431 is closest to the second linkage member 42, as shown in FIGS. 9 and 10, the fulcrum of the third linkage member 43 is moved downward, The yoke swing of the third link member 43 pivotally connected to one end of the second link member 42 is smaller than the end of the third link member 43 pivotally connected to the pivot seat 58, and the wear rod 56 is driven by the pivot seat 58. The second feed dog 52 drives the second feed dog 54 to have a larger displacement distance than the first feed member that is pivotally connected to the first link member 42 of the second link member 42. The displacement distance of the first feed dog 53 of the table 51, according to which the differential adjustment of the first feed dog 53 and the second feed dog 54 is formed; otherwise, the adjustment support 621 is adjusted as shown in FIGS. When the fulcrum of the third linking member 43 rises, the yaw of the third linking member 43 pivotally connected to one end of the second linking member 42 is greater than the yaw of the second linking member 42 The third linking member 43 is pivotally connected to one end of the pivoting seat 58. The displacement distance of the second feeding dog 54 driven by the wearing rod 56 and the second feeding gear table 52 driven by the pivoting seat 58 is less than a displacement distance of the first feed dog 53 of the first feed dog table 51 driven by the first link member 41 pivotally connected to the second link member 42, thereby forming the first feed dog 53 and the second feed cloth The differential adjustment of the teeth 54; in addition, since the feeding width of the first feed dog 53 and the second feed dog 54 is controlled by the differential device 40, when the user wants to adjust the first feed When the feeding width of the tooth 53 and the second feeding tooth 54 is rotated, the cloth width knob 382 can be rotated, and the cloth width knob 382 drives the cloth The web axis 38 rotates, and when the web shaft 38 rotates, the web adjustment restricting gear 381 on the web shaft 38 rotates synchronously and springs against the web restraining elastic piece 383, through which the elastic piece 383 is restrained The elastic adjustment of the web adjustment limit gear 381 produces a significant adjustment of the tactile sensation and sound, and enables the web restriction ejector 383 to be engaged with each tooth of the web adjustment limit gear 381 to avoid infinity. Over-adjusting, and thereby improving the accuracy of the adjustment; and when the fabric shaft 38 rotates, the fabric shaft 38 drives the sixth link 37 to yaw, and the sixth link 37 drives the fifth link 36 yaw, the fifth link 36 drives the fourth link 35 to pivot, and when the fourth link 35 pivots, the slider 341 received in the sliding slot 351 of the fourth link 35 is As the position of the slider 341 changes, the position of the second link 32 changes, and is pivotally connected to the second link 32 and is used to drive the feed rocker 20 The first link 31 will change the swing accordingly, according to which the swing of the feed rocker 20 can be changed, and the first feed dog 53 can be changed accordingly. The second feed teeth 54 displaced from the cloth, the feed varied amplitude.

In summary, the present invention mainly provides a mechanism for the mechanism of the double feed teeth, and the user can rotate the cloth width knob 382 or the differential knob 662 through the configuration of the connecting rod to adjust the feeding width and adjust the first sending. The difference between the cloth teeth 53 and the second feed teeth 54 provides a simple adjustment and use mode, improves the convenience of use, and accordingly satisfies the user's needs, improves the consumer's desire to purchase and further enhances economic benefits.

11‧‧‧Active shaft

12‧‧ ‧ socket

20‧‧‧ Feeding rocker

40‧‧‧Differential device

41‧‧‧First linkage

42‧‧‧Second linkage

43‧‧‧ Third linkage

431‧‧‧Adjustment slot

50‧‧‧Feeding device

51‧‧‧First delivery table

511‧‧‧Band

512‧‧‧ slot

513‧‧‧ wearing parts

514‧‧‧Device space

515‧‧‧through

516‧‧ ‧ slots

52‧‧‧second feed table

521‧‧‧ seat

522‧‧‧Second spring

59‧‧‧ Third spring

53‧‧‧First delivery teeth

54‧‧‧second delivery teeth

55‧‧‧First pivot

56‧‧‧ wearing rod

57‧‧‧First spring

58‧‧‧ pivot

581‧‧‧ wearing a sleeve

582‧‧‧ pivot

61‧‧‧Differential adjustment shaft

62‧‧‧Differential adjustment seat

621‧‧‧Adjustment support

D1‧‧‧ first direction

D2‧‧‧ second direction

Claims (8)

A feed tooth differential mechanism of a sewing machine is provided with a driving shaft driven by a power source in a machine seat of a sewing machine, and the power of the driving shaft is transmitted to a differential device through a differential device disposed on the machine base a first feeding tooth and a second feeding tooth feeding device, wherein the first feeding tooth and the second feeding tooth are respectively one of a first feeding table and a second feeding Driven by the toothed table, the differential device has a first linking member, a second linking member and a third linking member. The first linking member is driven by the driving shaft and the two ends are respectively pivotally connected to the first feeding tooth And the other end of the second linking member is pivotally connected to one end of the third linking member, the first end of the second linking member is forwarded or retracted, and the other end of the second linking member is pivotally connected to one end of the third linking member The other end of the third linkage is pivotally disposed on the second feed carrier and drives it forward or backward, and an adjustment slot is disposed between the two ends of the third linkage, and an adjustment support is slidably received The adjustment slot is provided for the user to adjust the position thereof, by adjusting the adjustment support to the third connection The upper position of the piece causes the third linking member to generate a different swing when the second linking member is interlocked, and reaches the first feeding table, the second feeding table, and the first feeding tooth, The differential change of the second feed dog feed width. The feed tooth differential mechanism of the sewing machine according to claim 1, wherein the drive shaft extends in a first direction, and the first direction defines a second direction perpendicular to the first direction, the first feed rack One end is formed with a pivot portion, and the other end is formed with a clamping groove, and a position between the pivot portion of the first feed dog table and the clamping groove forms a wearing portion, and a gap is formed between the pivot portion and the wearing portion. a device space, the through portion is provided with a through passage, the pivot portion is provided with a slot corresponding to the position of the through passage, and the first feed rack is pivotally transmitted through a first pivot extending in the first direction Connecting the other end of the first linking member and the pivot portion of the first feeding carrier to pivotally couple the first feeding table and the first linking member, and the first feeding tooth is fixedly disposed On the first feed rack; The second feed dog is fixedly coupled to the second feed rack, and the second feed rack is slidably disposed in the second slot of the first feed rack, and the second feed dog The two-feeding tooth carrier is fixedly coupled to one end of the wearing rod, the extending rod extends in the second direction and the other end penetrates through the through-channel and is positioned in the fixed slot, and the wearing rod is at the wearing portion and the pivot portion a pivoting seat is disposed in the intervening space; and the pivoting seat is coupled to the wearing rod by a sleeve end of one end, and the other end of the pivoting seat is a pivot extending in the first direction, The other end of the third linkage is pivotally coupled to the pivot. The feeding tooth differential mechanism of the sewing machine of claim 2, wherein the driving shaft is provided with a socket, and the first feeding tooth table is slidably supported by the bearing; The second feed rack is fixedly coupled to the wear rod through a certain seat; and the wear rod is sleeved with a first spring and the pivot seat in the insertion space between the wearing portion and the pivot portion, and the wear rod is A position between the wearing portion and the fixing seat is sleeved by a second spring, and two ends of a third spring are respectively hooked on the fixing seat and the base. The feed tooth differential mechanism of the sewing machine of claim 1, wherein the machine base is pivotally provided with a feed rocker and extends one end, and the first link between the two ends The middle position is fixedly coupled to one end of the feed rocker extending from the base, and the second linkage is pivotally coupled to the first link and the third link and becomes a dove link; The first rocking rod is fixedly coupled to the first connecting rod, the other end of the first connecting rod is pivotally coupled to one end of the second connecting rod, and the other end of the second connecting rod is pivotally coupled through the shaft The other end of the third link is coupled to the other end of the third link and is eccentrically received by the drive shaft. The feed tooth differential mechanism of the sewing machine of claim 4, wherein one end of the string shaft passes through the second link and the third link and is fixedly disposed with a slider, the slider is slidable The grounding member is disposed in a sliding slot on a fourth connecting rod, and the sliding slot is disposed at one end of the fourth connecting rod The other end of the fourth link is pivotally coupled to one end of a fifth link, and the other end of the fifth link is fixedly coupled to one end of a sixth link. The other end of the sixth link is fixedly coupled to a fabric shaft pivotally coupled to the frame and is drivable by the fabric shaft, and one end of the fabric shaft is pivotally coupled to the machine The other end of the fabric shaft is fixedly sleeved by a fabric knob. The feed tooth differential mechanism of the sewing machine of claim 5, wherein the other end of the cloth width shaft is further provided with a cloth width regulating limiting gear, and the outer circumference of the cloth width regulating limiting gear has a plurality of teeth And the frame is further disposed adjacent to the cloth width regulating limiting gear to provide a web limiting elastic piece, the cloth limiting elastic piece is fixed at one end of the frame, and the other end is elastically clamped to the cloth width regulating limiting gear Tooth. The feed tooth differential mechanism of the sewing machine according to the first aspect of the invention, wherein the machine base further comprises a differential adjustment device, wherein the differential adjustment device comprises a differential adjustment shaft and a differential adjustment seat. a first moving member, a second moving member and a third moving member, the differential adjusting shaft is pivotally disposed on the base, and one end of the differential adjusting shaft extends from the base and is fixed The adjustment support member is slidably received in the adjustment groove of the third linkage member, and the differential adjustment shaft One end of the first moving member is pivotally passed, and the other end of the first moving member is pivotally coupled to one end of the second moving member, and the other end of the second movable member is pivotally coupled to the first One end of the third moving member is fixedly coupled to a differential shaft pivotally coupled to the base and is drivable by the differential shaft. The differential shaft is pivotable at one end. The grounding joint is coupled to the base, and the other end of the differential shaft is fixed to the sleeve and a differential knob. The feed tooth differential mechanism of the sewing machine according to claim 7, wherein The other end of the differential shaft is further fixed to the sleeve and a differential adjustment limiting gear. The differential adjustment restricting gear has a plurality of teeth on the outer circumference, and the differential is disposed adjacent to the differential adjustment limiting gear. The elastic piece is restrained, and the differential limiting elastic piece is fixed at one end to the base, and the other end is elastically engaged with the tooth of the differential adjustment limiting gear.