Combined-drive upper differential lockstitch sewing machine

Abstract

The utility model relates to the technical field of lockstitch sewing machines, in particular to a combined drive upper differential lockstitch sewing machine. Comprising a rack, and an upper cloth feeding mechanism is arranged on the rack; the upper cloth feeding mechanism comprises a swing seat, a lower cloth feeding mechanism and an upper cloth feeding mechanism, the swinging assembly is used for driving the swinging seat to swing; the lifting assembly comprises a presser foot rod, and the presser foot rod is used for driving the swing seat to move in the vertical direction; wherein the swinging assembly comprises a driving motor, and a first cam is connected to a motor shaft of the driving motor; one end of the first cam connecting rod is arranged outside the first cam in a sleeving manner; the upper end of the swing rod is connected with the first cam connecting rod, and the lower end of the swing rod is hinged to the swing seat; when the first cam connecting rod drives the swing rod to rotate, the lower end of the swing rod can pull the swing seat to swing. The swing assembly and the lifting assembly are matched so that the swing base can execute the cloth feeding action.

Description

Technical Field

[0001] The utility model relates to the technical field of lockstitch sewing machines, in particular to a combined-drive upper differential lockstitch sewing machine. Background Art

[0002] A common sewing machine is used for sewing single or multi-layered materials, effectively stitching together multiple layers. An improved version of the lockstitch sewing machine, the upper differential lockstitch sewing machine uses an upper feed dog to synchronize the feed action with the lower feed dog. This ensures that both the upper and lower layers of material move synchronously when sewing multiple layers, improving sewing accuracy.

[0003] As described in the sewing machine and the integrated upper and lower differential feeding mechanism disclosed in Chinese patent CN202122387456.6, an adjusting motor is provided on the frame, which drives the upper feed dog assembly to perform the feeding action by adjusting the crank assembly.

[0004] As described in a differential feeding mechanism on a flat-bed sewing machine disclosed in Chinese patent CN202420477757.9, the driving motor drives the upper feed dog to perform the feeding action through the first crank and the second crank.

[0005] The prior art has the following deficiencies:

[0006] Existing technical solutions usually adopt a crank transmission method. When performing the feeding action, it is possible that the crank swing angle does not reach the designed angle, resulting in insufficient lifting height of the upper feed dog, which affects the smooth advancement of the sewing material, resulting in a loss of step, affecting the quality and appearance of the product. Utility Model Content

[0007] The utility model aims to provide a jointly driven upper differential lockstitch sewing machine to solve the problem that when the lockstitch sewing machine sews multiple layers of sewing materials, the upper and lower layers of sewing materials sometimes cannot move synchronously, which affects the sewing effect and product quality.

[0008] The purpose of this utility model is achieved in this way:

[0009] A combined-drive upper differential lockstitch sewing machine comprises: a frame, on which an upper cloth feeding mechanism is provided;

[0010] The upper cloth feeding mechanism comprises:

[0011] A swing seat, on which an upper feed dog is provided;

[0012] A swing assembly, used for driving the swing seat to swing;

[0013] A lifting assembly comprising a presser foot rod, wherein the presser foot rod is used to drive the swing seat to move in a vertical direction;

[0014] Wherein, the swing assembly includes:

[0015] A driving motor, wherein a cam 1 is connected to the motor shaft;

[0016] a cam connecting rod 1, one end of which is sleeved on the outside of the cam 1;

[0017] a swing lever, the upper end of which is connected to the cam link, and the lower end of which is hinged to the swing seat;

[0018] When the cam link drives the swing lever to rotate, the lower end of the swing lever can pull the swing seat to swing;

[0019] The cooperation between the swing assembly and the lifting assembly enables the swing seat to perform a cloth feeding action.

[0020] Preferably, a connecting piece is sleeved on the presser foot rod, a hinge groove is formed at one end of the connecting piece, and the swing rod is movably hinged to the hinge groove.

[0021] Preferably, a limiting sleeve is provided on the swing rod, and a strip-shaped hole 1 is formed on the limiting sleeve;

[0022] A connecting shaft is provided in the hinge groove, and the connecting shaft can be placed in the strip-shaped hole 1, so that the swing arm can be movably hinged to one end of the connecting member.

[0023] Preferably, a mounting slot is provided on the frame, a through hole 1 is provided on a side of the mounting slot, and the through hole 1 passes through the frame;

[0024] The swing lever comprises a connecting head and a connecting rod portion, wherein the connecting head is arranged in the mounting groove;

[0025] The lower end of the swing rod is formed into a connecting rod portion, and the lower end of the connecting rod portion is hinged to the hinge groove (6);

[0026] The connecting head is sleeved on the outside of the limiting sleeve, and the connecting rod portion is movably inserted into the limiting sleeve.

[0027] Preferably, a rotation shaft is provided at the bottom end of the swing lever, and the swing lever is hinged to one end of the swing seat via the rotation shaft;

[0028] A limiting connecting rod is also provided on the rotating shaft, and the upper end of the limiting connecting rod is connected to the connecting shaft.

[0029] Preferably, the presser foot rod is connected to the upper shaft of the sewing machine, and the lower end of the presser foot rod is connected to a roller;

[0030] A rolling groove is formed on the swing seat, and the roller can move in the rolling groove;

[0031] An avoidance groove 1 is provided on the swing seat, and the avoidance groove 1 leads to the rolling groove, and the presser foot rod can pass through the avoidance groove 1; and the roller cannot pass through the avoidance groove 1, so that the lifting component can drive the swing seat to lift.

[0032] Preferably, the lifting assembly further comprises:

[0033] Cam 2, which is sleeved on the upper shaft;

[0034] a second cam connecting rod connected to the second cam;

[0035] a second transmission member connected to the second cam connecting rod, wherein the second transmission member is provided with a pushing portion;

[0036] A toggle member having a first toggle arm and a second toggle arm formed thereon;

[0037] The presser foot rod is provided with a toggle portion;

[0038] When the second cam link drives the second transmission member to rotate, the pushing portion can push the first toggle arm and drive the toggle member to rotate; and make the second toggle arm contact the toggle portion, thereby driving the presser foot rod to move by pushing the toggle portion.

[0039] Preferably, a fixing sleeve is sleeved on the outer side of the presser foot rod, a second through hole is opened on the frame, and the fixing sleeve is inserted into the second through hole;

[0040] A return spring 1 is provided in the fixed sleeve, the upper end of the return spring 1 abuts against the inner side of the fixed sleeve, and the lower end of the return spring 1 abuts against the upper end surface of the presser foot rod;

[0041] The fixing sleeve is further provided with a second strip-shaped hole, and the second strip-shaped hole is used for the dialing part to pass through.

[0042] Preferably, the fixing sleeve comprises a sleeve and a connecting seat, and the lower end of the connecting seat is screwed to the upper end of the sleeve;

[0043] The upper end of the connecting seat is connected to an adjustment component, and the adjustment component includes:

[0044] an adjusting rod, the lower end of which presses against the upper end of the connecting seat;

[0045] A fixing seat, which is screwed to the frame, is provided with a third through hole, and the adjusting rod is passed through the third through hole;

[0046] The upper end of the adjusting rod is connected to a limit block, and the limit block cannot pass through the third through hole;

[0047] By rotating the fixing seat, the length of the upper end of the fixing seat extending out of the frame can be adjusted, and by limiting the position of the limit block, the position of the lower end of the adjusting rod can be changed.

[0048] Preferably, the connecting seat is protrudingly formed with a convex ring portion;

[0049] A second return spring is sleeved on the exterior of the adjusting rod, and the lower end of the second return spring abuts against the convex ring portion.

[0050] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects:

[0051] The driving motor and the swing rod in this technical solution are connected through a cam, so that the transmission effect is more precise, and the swing seat can be driven to move stably, preventing the upper feed dog from being too low to hinder the advancement of the sewing material, thereby avoiding the occurrence of loss of step, thereby improving the quality of sewn products and reducing the defective rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a structural diagram of the utility model;

[0053] Figure 2 This is a schematic diagram of the structure of the utility model after the frame is removed;

[0054] Figure 3 It is a cross-sectional view of the utility model;

[0055] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0056] Figure 5 This is a schematic diagram of the cooperation between the swing assembly and the connecting piece of the utility model;

[0057] Figure 6 for Figure 5 Enlarged view of point B in the middle;

[0058] Figure 7 It is a structural diagram of the lifting assembly of the utility model;

[0059] Figure 8 for Figure 3 Enlarged view of point C in the middle.

[0060] Reference numerals:

[0061] 1. Frame; 11. Mounting slot; 12. Through hole 1; 13. Through hole 2;

[0062] 2. Lifting assembly; 21. Presser foot bar; 211. Toggle unit; 212. Roller; 22. Fixing sleeve; 221. Return spring 1; 222. Strip hole 2; 23. Cam 2; 24. Cam connecting rod 2; 25. Transmission member 2; 251. Pushing unit; 26. Toggle member; 261. First toggle arm; 262. Second toggle arm; 27. Sleeve; 28. Connecting seat; 281. Raised ring; 282. Connecting core; 29. ​​Positioning seat;

[0063] 3. Swing assembly; 31. Drive motor; 32. Cam 1; 33. Cam connecting rod 1; 34. Transmission part 1;

[0064] 4. Swing seat; 41. Rolling groove; 411. Opening; 412. Avoidance groove 1; 42. Upper feed dog mounting portion;

[0065] 5. Swinging rod; 51. Connecting head; 52. Connecting rod; 53. Rotating shaft;

[0066] 6. Connecting piece; 61. Hinge slot; 62. Connecting shaft;

[0067] 7. Limit sleeve; 71. Strip hole 1;

[0068] 8. Limit connecting rod;

[0069] 9. Adjustment assembly; 91. Adjustment rod; 92. Fixed seat; 93. Through hole three; 94. Limit block; 95. Return spring two; 96. Adjustment nut; 97. Connecting groove. DETAILED DESCRIPTION

[0070] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments.

[0071] like Figure 1 -and Figure 2 The illustrated embodiment of a combined drive upper differential lockstitch sewing machine comprises: a frame 1 on which an upper cloth feeding mechanism is provided;

[0072] Upper cloth feeding mechanism includes:

[0073] The swing seat 4 is provided with an upper feed dog for performing the cloth feeding action;

[0074] The swing assembly 3 is used to drive the swing seat 4 to swing;

[0075] The lifting assembly 2 includes a presser foot rod 21, which is used to drive the swing seat 4 to move in the vertical direction. The lifting assembly 2 drives the presser foot to lift through the presser foot rod 21, thereby facilitating the movement of the sewing material.

[0076] Wherein, the swing component 3 includes:

[0077] A driving motor 31, the motor shaft of which is connected to a cam 32;

[0078] A cam connecting rod 33, one end of which is sleeved on the outside of the cam 32;

[0079] The upper end of the swing rod 5 is connected to the cam connecting rod 33, and the lower end of the swing rod 5 is hinged on the swing seat 4.

[0080] When the cam link 33 drives the swing rod 5 to rotate, the lower end of the swing rod 5 can pull the swing seat 4 to swing. Compared with the current common scheme using a connecting rod for transmission, the present technical scheme uses a cam to drive the swing rod 5 to swing, which can drive the swing rod 5 to swing more stably. As a result, when performing the cloth feeding action, the lifting and lowering timing of the swing seat 4 can be made more accurate, which is more convenient for coordination with the lower feed dog, and prevents the situation of losing step that affects product quality and appearance.

[0081] The cooperation between the swing assembly 3 and the lifting assembly 2 enables the swing seat 4 to perform the cloth feeding action, so as to ensure that the chopped sewing materials can move synchronously and avoid the situation of losing step during the sewing process.

[0082] Furthermore, a connecting piece 6 is sleeved on the presser foot rod 21 , and a hinge groove 61 is formed at one end of the connecting piece 6 , and the swing rod 5 is movably hinged to the hinge groove 61 .

[0083] Since the presser foot rod 21 is fixed on the frame 1, the position of the swing rod 5 can be further fixed through the connecting member 6, thereby constraining the moving trajectory of the swing rod 5, and then constraining the moving trajectory of the swing seat 4, thereby improving the accuracy of the sewing action.

[0084] like Figures 1-6 As shown, a limiting sleeve 7 is sleeved on the swing rod 5, and a strip-shaped hole 71 is formed on the limiting sleeve 7.

[0085] A connecting shaft 62 is provided in the hinge groove 61 , and the connecting shaft 62 can be placed in the strip hole 71 , so that the swing rod 5 can be movably hinged to one end of the connecting member 6 .

[0086] like Figure 2-Figure 4 As shown, a mounting slot 11 is formed on the frame 1, and a through hole 12 is formed on the side of the mounting slot 11. The through hole 12 passes through the frame 1;

[0087] The swing lever 5 includes a connecting head 51 and a connecting rod 52, and the connecting head 51 is disposed in the mounting groove 11;

[0088] The lower end of the swing lever 5 is formed into a connecting rod portion 52 , and the lower end of the connecting rod portion 52 is hinged to the hinge groove 61 ;

[0089] The connecting head 51 is sleeved on the outside of the limiting sleeve 7, and the connecting rod portion 52 is movably inserted into the limiting sleeve 7. The connecting head 51 is connected to the transmission member 1 34.

[0090] When the drive motor 31 is working, the cam link 1 33 can drive the transmission member 1 34 to swing, and drive the connecting head 51 to rotate. Because the connecting head 51 is sleeved on the outside of the limiting sleeve 7, the connecting head 51 can drive the connecting rod 52 to swing through the limiting sleeve 7.

[0091] like Figure 2-Figure 6 As shown, a rotation shaft 53 is provided at the bottom end of the connecting rod portion 52 of the swing lever 5 , and the connecting rod portion 52 is hinged to the swing seat 4 through the rotation shaft 53 .

[0092] A limit link 8 is provided on the rotating shaft 53 , and the upper end of the limit link 8 is connected to the connecting shaft 62 .

[0093] Since the limiting sleeve 7 is hinged in the hinge groove 61 of the connecting member 6, the swing path of the limiting sleeve 7 can be constrained, thereby facilitating the determination of the motion trajectory of the swing seat 4 when performing the cloth feeding action.

[0094] By setting a limit link 8, the limit link 8 is connected to the connecting shaft 62 and the rotating shaft 53 respectively, which can further constrain the movement trajectory of one end of the swing seat 4, so that a fixed distance is maintained between one end of the swing seat 4 and the connecting shaft 62, so as to limit the movement trajectory of the swing seat 4 and improve the accuracy when performing the cloth feeding action.

[0095] like Figures 1-6 As shown, the presser foot rod 21 is connected to the upper shaft of the sewing machine, and the lower end of the presser foot rod 21 is connected to a roller 212;

[0096] A rolling groove 41 is formed on the swing seat 4 , and an opening 411 is formed at one end of the rolling groove 41 . The roller 212 can be placed into the rolling groove 41 through the opening 411 and can move in the rolling groove 41 .

[0097] The swing seat 4 is provided with an escape groove 412 that leads to the rolling groove 41. The presser foot rod 21 can pass through the escape groove 412, while the roller 212 cannot pass through the escape groove 412. This allows the lifting assembly 2 to lift the swing seat 4. The swing assembly 3, in conjunction with the swing rod 5, drives the swing seat 4 to swing, enabling the upper feed dog to perform the cloth feeding action.

[0098] An upper feed dog mounting portion 42 is formed at the lower end of the swing seat 4, and the upper feed dog mounting portion 42 is used to set the upper feed dog.

[0099] like Figure 1-Figure 7 As shown, the lifting assembly 2 also includes:

[0100] Cam 23, which is sleeved on the upper shaft;

[0101] Cam connecting rod 24 connected to cam 23;

[0102] The second transmission member 25 is connected to the second cam link 24 and is provided with a pushing portion 251;

[0103] A toggle member 26 having a first toggle arm 261 and a second toggle arm 262 formed thereon;

[0104] The presser foot rod 21 is provided with a toggling portion 211 .

[0105] Specific as Figure 3 and Figure 7 As shown, when the cam link 24 drives the transmission member 25 to rotate, the pushing part 251 can push the first toggle arm 261 and drive the toggle member 26 to rotate; and make the second toggle arm 262 contact with the toggle part 211, and then the second toggle arm 262 can push the toggle part 211 to rise, thereby driving the presser foot rod 21 to lift.

[0106] When the cam link 24 rotates a certain angle, the pushing portion 251 separates from the first toggle arm 261. At this time, the toggle portion 211 still abuts against the upper end of the second toggle arm 262. When the pushing portion 251 no longer applies force to the first toggle arm 261, the second toggle arm 262 cannot support the weight of the presser foot bar 21, so that the presser foot bar 21 can be lowered and the presser foot can be pressed against the sewing material.

[0107] Furthermore, a fixing sleeve 22 is sleeved on the outer side of the presser foot rod 21 , and the upper end of the fixing sleeve 22 is inserted into the positioning seat 29 , and the position of the upper end of the fixing sleeve 22 is determined by the positioning seat 29 .

[0108] The frame 1 is further provided with a second through hole 13 , and the middle portion of the fixing sleeve 22 is passed through the second through hole 13 to fix the position of the presser foot rod 21 and to enable the presser foot rod 21 to be lifted or lowered only in the vertical direction.

[0109] A return spring 221 is disposed within the fixed sleeve 22. The upper end of the return spring 221 abuts against the inner side of the fixed sleeve 22, while the lower end of the return spring 221 abuts against the upper end surface of the presser foot rod 21. When the push portion 251 separates from the first toggle arm 261, the second toggle arm 262 is unable to support the presser foot rod 21, and the return spring 221 can further apply force to the presser foot rod 21, allowing the presser foot rod 21 to quickly reset. Furthermore, since the return spring 221 is disposed within the fixed sleeve 22, and the fixed sleeve 22 is sleeved onto the outside of the presser foot rod 21, the fixed sleeve 22 can further secure the position of the return spring 221, ensuring that the return spring 221 can stably abut against the upper end of the presser foot rod 21.

[0110] The fixing sleeve 22 is further provided with a second strip-shaped hole 222 for the shifting portion 211 to pass through.

[0111] As a preferred embodiment, the toggle portion 211 is a fixing pin. When the presser foot rod 21 is inserted into the fixing sleeve 22 , the toggle portion 211 can pass through the second strip hole 222 and be inserted into the upper end of the presser foot rod 21 .

[0112] At the same time, the second strip-shaped hole 222 can also limit the travel of the toggle portion 211 , thereby limiting the distance that the presser foot rod 21 moves the presser foot to rise.

[0113] like Figures 1-8 As shown, the fixing sleeve 22 further includes a sleeve 27 and a connecting seat 28 , and the sleeve 27 is sleeved on the outer side of the presser foot rod 21 .

[0114] The lower end of the connecting seat 28 is threaded onto the upper end of the sleeve 27. A protruding ring portion 281 is formed on the connecting seat 28, and the protruding ring portion 281 abuts against the upper end of the sleeve 27. A connecting core 282 is also threaded into the connecting seat 28. The connecting core 282 partially penetrates into the sleeve 27, and the upper end of the return spring 221 is sleeved on the lower end of the connecting core 282.

[0115] The upper end of the connecting seat 28 is connected to the adjusting assembly 9, which includes:

[0116] The lower end of the adjusting rod 91 presses against the upper end of the connecting seat 28;

[0117] The fixing base 92 is screwed onto the frame 1 , and a through hole 3 93 is formed on the fixing base 92 . The adjusting rod 91 is passed through the through hole 3 93 , and an adjusting nut 96 is sleeved on the outside of the fixing base 92 . The adjusting nut 96 can easily drive the fixing base 92 to rotate, thereby changing the position of the fixing base 92 on the frame 1 .

[0118] The upper end of the adjusting rod 91 is connected to a limiting block 94 , and the limiting block 94 cannot pass through the third through hole 93 .

[0119] By rotating the fixing seat 92 , the length of the upper end of the fixing seat 92 extending out of the frame 1 can be adjusted, and by limiting the position of the limit block 94 , the position of the lower end of the adjusting rod 91 can be changed.

[0120] A connecting groove 97 is formed on the adjusting rod 91, so that the upper end of the connecting core 282 can be placed in the connecting groove 97 and the connecting core 282 is connected to the adjusting rod 91. When the position of the adjusting rod 91 moves, the position of the fixing sleeve 22 can be driven to move through the connecting core 282.

[0121] Since the toggle portion 211 is inserted into the second strip-shaped hole 222 , when the position of the fixing sleeve 22 changes, the height of the presser foot rod 21 will also change, thereby achieving the purpose of adjusting the height of the presser foot.

[0122] Furthermore, the outer sleeve of the adjusting rod 91 is provided with a second return spring 95, and the lower end of the second return spring 95 abuts against the convex ring portion 281. This can further limit the position of the fixing sleeve 22 and avoid unnecessary shaking of the fixing sleeve.

[0123] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification for the understanding and reading of those familiar with this technology, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose of the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be considered as the scope of the implementation of the present invention without substantially changing the technical content.

[0124] It should also be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element through an intervening element.

[0125] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

Claims

1. A combined drive upper differential lockstitch sewing machine, characterized in that: include: A frame (1), wherein an upper cloth feeding mechanism is provided on the frame (1); The upper cloth feeding mechanism comprises: A swing seat (4) on which an upper feed dog is provided; A swing assembly (3) is used to drive the swing seat (4) to swing; A lifting assembly (2), comprising a presser foot rod (21), wherein the presser foot rod (21) is used to drive the swing seat (4) to move in a vertical direction; Wherein, the swing assembly (3) comprises: A driving motor (31) having a cam (32) connected to its motor shaft; A cam connecting rod (33), one end of which is sleeved on the outside of the cam (32); A swing rod (5), the upper end of which is connected to the cam connecting rod (33), and the lower end of which is hinged on the swing seat (4); When the cam link (33) drives the swing rod (5) to rotate, the lower end of the swing rod (5) can pull the swing seat (4) to swing; The cooperation between the swing assembly (3) and the lifting assembly (2) enables the swing seat (4) to perform a cloth feeding action.

2. A combined drive upper differential lockstitch sewing machine according to claim 1, characterized in that ； The presser foot rod (21) is sleeved with a connecting piece (6), one end of the connecting piece (6) is formed with a hinge groove (61), and the swing rod (5) is movably hinged to the hinge groove (61).

3. A combined drive upper differential lockstitch sewing machine according to claim 2, characterized in that; The swing rod (5) is provided with a limiting sleeve (7), and the limiting sleeve (7) is formed with a strip-shaped hole (71); A connecting shaft (62) is provided in the hinge groove (61), and the connecting shaft (62) can be placed in the strip hole (71), so that the swing rod (5) can be movably hinged to one end of the connecting member (6).

4. The combined drive upper differential lockstitch sewing machine according to claim 3, characterized in that: The frame (1) is provided with a mounting groove (11), a through hole (12) is provided on a side of the mounting groove (11), and the through hole (12) passes through the frame (1); The swing rod (5) comprises a connecting head (51) and a connecting rod portion (52), wherein the connecting head (51) is arranged in the mounting groove (11); The lower end of the swing rod (5) is formed into a connecting rod portion (52), and the lower end of the connecting rod portion (52) is hinged to the hinge groove (61); The connecting head (51) is sleeved on the outside of the limiting sleeve (7), and the connecting rod portion (52) is movably inserted into the limiting sleeve (7).

5. The combined drive upper differential lockstitch sewing machine according to claim 4, characterized in that; A rotating shaft (53) is provided at the bottom end of the swing lever (5), and the swing lever (5) is hinged to one end of the swing seat (4) via the rotating shaft (53); A limiting connecting rod (8) is also provided on the rotating shaft (53), and the upper end of the limiting connecting rod (8) is connected to the connecting shaft (62).

6. A combined drive upper differential lockstitch sewing machine according to any one of claims 1 to 5, characterized in that; The presser foot rod (21) is connected to the upper shaft of the sewing machine, and the lower end of the presser foot rod (21) is connected to a roller (212); A rolling groove (41) is formed on the swing seat (4), and the roller (212) is capable of moving in the rolling groove (41); The swing seat (4) is provided with an avoidance groove (412), the avoidance groove (412) leading to the rolling groove (41), the presser foot rod (21) can pass through the avoidance groove (412), and the roller (212) cannot pass through the avoidance groove (412), so that the lifting assembly (2) can drive the swing seat (4) to lift.

7. The combined drive upper differential lockstitch sewing machine according to claim 6, characterized in that: The lifting assembly (2) further comprises: Cam 2 (23), which is sleeved on the upper shaft; Cam connecting rod 2 (24), connected to cam 2 (23); A second transmission member (25) is connected to the second cam connecting rod (24), and a pushing portion (251) is provided on the second transmission member (25); A toggle member (26) having a first toggle arm (261) and a second toggle arm (262) formed thereon; The presser foot rod (21) is provided with a toggle portion (211); When the second cam connecting rod (24) drives the second transmission member (25) to rotate, the pushing portion (251) can push the first toggle arm (261) and drive the toggle member (26) to rotate; and make the second toggle arm (262) contact the toggle portion (211), and drive the presser foot rod (21) to move by pushing the toggle portion (211).

8. The combined drive upper differential lockstitch sewing machine according to claim 7, characterized in that: The outer side of the presser foot rod (21) is provided with a fixed sleeve (22), the frame (1) is provided with a second through hole (13), and the fixed sleeve (22) is inserted into the second through hole (13); A return spring (221) is provided in the fixing sleeve (22), the upper end of the return spring (221) abuts against the inner side of the fixing sleeve (22), and the lower end of the return spring (221) abuts against the upper end surface of the presser foot rod (21); The fixing sleeve (22) is also provided with a second strip-shaped hole (222), and the second strip-shaped hole (222) is used for allowing the shifting portion (211) to pass through.

9. The combined drive upper differential lockstitch sewing machine according to claim 8, characterized in that: The fixing sleeve (22) comprises a sleeve (27) and a connecting seat (28), wherein the lower end of the connecting seat (28) is screwed to the upper end of the sleeve (27); The upper end of the connecting seat (28) is connected to an adjusting assembly (9), and the adjusting assembly (9) includes: An adjusting rod (91), the lower end of which presses against the upper end of the connecting seat (28); A fixing seat (92) is screwed onto the frame (1), a third through hole (93) is formed on the fixing seat (92), and the adjusting rod (91) is passed through the third through hole (93); The upper end of the adjusting rod (91) is connected to a limiting block (94), and the limiting block (94) cannot pass through the third through hole (93); By rotating the fixing seat (92), the length of the upper end of the fixing seat (92) extending from the frame (1) can be adjusted, and by limiting the position of the limit block (94), the position of the lower end of the adjusting rod (91) can be changed.

10. The combined drive upper differential lockstitch sewing machine according to claim 9, characterized in that: The connecting seat (28) is protrudingly formed with a convex ring portion (281); The outer portion of the regulating rod (91) is provided with a second return spring (95), and the lower end of the second return spring (95) abuts against the convex ring portion (281).

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