Sewing machine trimming, stitch length, tooth height, presser foot lifting and differential ratio adjusting mechanism

Abstract

The utility model belongs to the technical field of sewing machines, and particularly relates to a trimming, stitch length, tooth height, presser foot lifting and differential ratio adjusting mechanism of a sewing machine. Comprising a motor, a thread trimming driving assembly, a stitch length adjusting driving assembly, a presser foot lifting driving assembly, a tooth adjusting driving assembly and a differential ratio adjusting driving assembly. One motor serves as a power source, five performance parameters including thread trimming, needle pitch adjustment, tooth height adjustment, presser foot lifting and differential ratio adjustment can be adjusted, presser foot lifting and tooth height adjustment can be linked, teeth move downwards to the position below a needle plate face while a presser foot is lifted, namely, a downward supply mode is achieved, and the device has the advantages of being compact in structure, capable of reducing cost and high in practicability. The enterprise production efficiency and the product quality are improved.

Description

Technical field:

[0001] The utility model belongs to the technical field of sewing machines, in particular to a mechanism for adjusting thread trimming, stitch length, tooth height, presser foot lifting and differential ratio of a sewing machine. Background technology:

[0002] In order to adapt to the requirements of different fabrics, the overlock sewing machine needs to frequently lift the presser foot, trim the thread, adjust the stitch length and differential ratio, etc. If manual operation is chosen, not only the efficiency is low, but also the quality cannot be guaranteed. With the improvement of science and technology, sewing machines have gradually realized automation. However, in order to achieve thread trimming, stitch length adjustment, tooth height adjustment, presser foot lifting and differential ratio adjustment, most overlock sewing machines need to be equipped with multiple power sources such as motors and electromagnets, resulting in high production costs and large size. Summary of the invention:

[0003] The utility model aims to provide a sewing machine thread trimming, stitch length, tooth height, presser foot lifting and differential ratio regulating mechanism which can reduce production cost and has a compact structure.

[0004] The utility model is achieved in this way:

[0005] The thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism of a sewing machine comprises: a motor, a thread trimming drive assembly, a stitch length adjustment drive assembly, a presser foot lifting drive assembly, a tooth adjustment drive assembly and a differential ratio adjustment drive assembly; the presser foot lifting drive assembly comprises a presser foot lifting cam arranged on the rotating shaft of the motor, one end of the presser foot lifting shaft of the presser foot lifting assembly is connected to one end of the presser foot lifting lever, the other end of the presser foot lifting lever is provided with a presser foot lifting cam follower, and the presser foot lifting cam follower is in contact with the cam surface of the presser foot lifting cam; the thread trimming drive assembly comprises a thread trimming cam arranged on the rotating shaft of the motor, and the scissors shaft of the thread trimming assembly is connected to the cam surface of the presser foot lifting cam through a third thread trimming lever, a thread trimming connecting rod and a thread trimming connecting rod connected in sequence. The second thread trimming lever is connected to the first thread trimming lever, and the second thread trimming lever is rotatably connected to the mounting block through the first pin shaft. One end of the second thread trimming lever connected to the first thread trimming lever is a ball head, and the first thread trimming lever is rotatably connected to the casing through the second pin shaft. One end of the first thread trimming lever is located above the ball head, and the other end is in contact with the cam surface of the thread trimming cam; the tooth adjustment drive assembly includes a tooth adjustment cam arranged on the rotating shaft of the motor, the tooth adjustment eccentric shaft of the tooth adjustment assembly is connected to one end of the tooth adjustment shaft lever, and the other end of the tooth adjustment shaft lever is provided with a tooth adjustment cam follower, and the tooth adjustment cam follower is in contact with the cam surface of the tooth adjustment cam; the stitch length adjustment drive assembly includes a needle length differential adjustment assembly The stitch cam driving member and the stitch cam on the joint driving shaft, the stitch cam is connected to the stitch differential adjustment driving shaft through the first one-way bearing, the stitch cam driving member is connected to the first one-way bearing, the cloth feeding shaft of the stitch adjustment assembly is connected to the cloth feeding assembly through the cloth feeding crank, the second stitch adjustment connecting rod, and the cloth feeding assembly connecting rod connected in sequence, the cloth feeding assembly connecting rod is also connected to the stitch adjustment shaft through the first stitch adjustment connecting rod and the second stitch adjustment lever connected in sequence, the stitch adjustment shaft is provided with a first stitch adjustment lever, the first stitch adjustment lever is provided with a stitch cam follower, and the stitch cam follower is in contact with the cam surface of the stitch cam; the differential ratio adjustment driving assembly includes a A differential cam driving member on a needle distance differential adjustment driving shaft and a differential adjustment shaft located on one side of the differential cam driving member, a first differential adjustment lever and a differential cam are arranged on the differential adjustment shaft, a differential drive cam follower is arranged on the first differential adjustment lever, the differential drive cam follower is in contact and connected with the cam surface of the differential cam driving member, the differential cam is connected to the differential adjustment shaft through a second one-way bearing, the second differential adjustment lever is connected to the differential shaft of the differential ratio adjustment assembly, a differential cam follower is arranged on the second differential adjustment lever, the differential cam follower is in contact and connected with the cam surface of the differential cam; the rotating shaft of the motor is connected to the needle distance differential adjustment driving shaft and drives it to rotate.

[0006] In the above-mentioned sewing machine thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism, the presser foot lifting shaft is rotatably connected to the casing through the presser foot lifting shaft sleeve, one end of the presser foot lifting lever is mounted on the presser foot lifting shaft, and a limit retaining ring is also mounted on the presser foot lifting shaft. The presser foot lifting lever is axially limited between the limit retaining ring and the presser foot lifting shaft sleeve, and the limit retaining ring is fixedly connected to the presser foot lifting shaft.

[0007] In the above-mentioned sewing machine thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism, a top block is provided at one end of the presser foot lifting lever, and a protrusion is provided on the limiting position retaining ring, and the protrusion abuts against the top block. When the presser foot lifting lever rotates counterclockwise, the top block acts on the protrusion to drive the limiting retaining ring and the presser foot lifting shaft to rotate counterclockwise.

[0008] In the above-mentioned sewing machine thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism, a notch is provided at the lower end of the stitch length cam driving component, and a limit block is provided on the casing below the stitch length cam driving component, and the upper end of the limit block extends into the notch.

[0009] In the above-mentioned sewing machine thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism, the presser foot lifting cam, thread trimming cam, tooth adjustment cam, stitch length cam, differential drive cam and differential cam all include a drive segment and a base circle segment.

[0010] In the above-mentioned sewing machine thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism, the rear side surface of the casing is provided with a recess opposite to the front side surface, the motor, thread trimming drive assembly, stitch length adjustment drive assembly and presser foot lifting drive assembly are arranged in the recess, the stitch length differential adjustment drive shaft is rotatably arranged on the casing and extends out of the left side surface of the casing, the stitch length cam, differential cam driving member and differential cam are located outside the left side surface of the casing and are covered by the sewing table.

[0011] The outstanding advantages of the utility model compared with the prior art are:

[0012] 1. The utility model uses a motor as a power source to adjust the five performance parameters of thread trimming, needle spacing adjustment, tooth height adjustment, presser foot lifting and differential ratio adjustment, and can link the presser foot lifting and tooth height adjustment to achieve the teeth descending below the needle plate surface while the presser foot is lifted, that is, the bottom supply mode. It has the advantages of compact structure, reduced costs, improved enterprise production efficiency and product quality, and helps the textile industry develop in the direction of digitalization, informatization, and technology.

[0013] 2. The motor of the utility model is embedded in the rear side of the casing, so that each drive component is built into the casing, which effectively improves the problem that the previous structure is external, resulting in the whole machine being too large, affecting the packaging and transportation problems. Description of the drawings:

[0014] Figure 1 It is one of the three-dimensional schematic diagrams of the utility model installed on the casing;

[0015] Figure 2 This is the second three-dimensional schematic diagram of the utility model installed on the casing;

[0016] Figure 3 It is a three-dimensional schematic diagram of the utility model;

[0017] Figure 4 It is a schematic diagram of the connection between the presser foot lifting drive assembly, the motor, and the presser foot lifting assembly of the utility model;

[0018] Figure 5 It is a schematic diagram of the connection between the thread trimming drive assembly, the motor and the thread trimming assembly of the utility model;

[0019] Figure 6 It is a schematic diagram of the connection between the tooth adjustment drive component, the motor and the tooth adjustment component of the utility model;

[0020] Figure 7 It is a schematic diagram of the connection between the needle distance adjustment drive component, the motor and the needle distance adjustment component of the utility model;

[0021] Figure 8 It is an exploded view of the connection between the needle distance cam and the needle distance differential adjustment drive shaft of the utility model;

[0022] Fig. 9 It is a schematic diagram of the connection between the differential ratio adjustment drive component, the motor and the differential ratio adjustment component of the utility model;

[0023] Fig.10 It is an exploded schematic diagram of the utility model in which the first differential adjustment lever and the differential cam are arranged on the differential adjustment shaft.

[0024] In the figure: 1, motor; 2, presser foot lifting cam; 3, presser foot lifting shaft; 4, presser foot lifting lever; 5, presser foot lifting cam follower; 6, presser foot lifting shaft sleeve; 7, housing; 8, limit ring; 9, top block; 10, bump; 11, presser foot arm; 12, presser foot assembly; 13, needle plate surface; 14, thread trimming cam; 15, scissors shaft; 16, third thread trimming lever; 17, thread trimming connecting rod; 18, second thread trimming lever; 19, first thread trimming lever; 20, mounting block; 21. Ball head; 22. Moving knife; 23. Thread trimmer reset torsion spring; 24. Adjusting cam; 25. Adjusting eccentric shaft; 26. Adjusting shaft lever; 27. Adjusting cam follower; 28. Adjusting reset torsion spring; 29. ​​Lifting slider; 30. Tooth rack assembly; 31. Tooth assembly; 32. Stitch differential adjustment drive shaft; 33. Stitch cam drive; 34. Stitch cam; 35. First one-way bearing; 36. Feed shaft; 37. Feed crank; 38. Second needle 39. Feed assembly connecting rod; 40. Feed assembly; 41. First stitch length adjustment connecting rod; 42. Second stitch length adjustment connecting rod; 43. Stitch length adjustment shaft; 44. First stitch length adjustment lever; 45. Stitch length cam follower; 46. Stitch length reset torsion spring; 47. Coupling; 48. Notch; 49. Stopper; 50. Drive member reset torsion spring; 51. Torsion spring abutment column; 52. Differential cam drive member; 53. Differential adjustment shaft; 54. First differential dynamic adjustment lever; 55, differential cam; 56, differential drive cam follower; 57, second differential adjustment lever; 58, differential shaft; 59, differential cam follower; 60, differential reset torsion spring; 61, second one-way bearing; 62, third differential adjustment lever; 63, differential adjustment connecting rod; 64, differential adjustment slider; 65, differential tooth rack; 66, differential tooth; 67, feed dog; 68, differential adjustment drive reset torsion spring; 69, sewing table; 70, electronic control. Specific implementation method:

[0025] The present invention is further described below with reference to specific embodiments. Figure 1 —10:

[0026] The utility model provides a sewing machine thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism, the adjustment mechanism comprises: a motor 1, a thread trimming drive assembly, a stitch length adjustment drive assembly, a presser foot lifting drive assembly, a tooth adjustment drive assembly, and a differential ratio adjustment drive assembly, wherein in this embodiment, the motor 1 is preferably a stepping motor. The motor 1 is mounted on the housing 7 through a motor mounting seat. Figure 1 , Figure 2 , Figure 3 and Figure 4The presser foot lifting driving assembly includes a presser foot lifting cam 2 arranged on the rotating shaft of the motor 1, one end of the presser foot lifting shaft 3 of the presser foot lifting assembly is connected to one end of the presser foot lifting lever 4, and the other end of the presser foot lifting lever 4 is provided with a presser foot lifting cam follower 5, and the presser foot lifting cam follower 5 is in contact with the cam surface of the presser foot lifting cam 2, and the cam surface of the presser foot lifting cam 2 includes a presser foot lifting driving section and a base circle section. The presser foot lifting cam follower 5 is usually a roller or a bearing. When the presser foot is lifted, the presser foot lifting cam follower 5 rolls on the presser foot lifting driving section, and when an action other than lifting the presser foot is performed, the presser foot lifting cam follower 5 rolls on the base circle section, and the presser foot lifting assembly does not perform any action.

[0027] The presser foot lifting shaft 3 of the utility model is rotatably connected with the housing 7 through the presser foot lifting shaft sleeve 6, one end of the presser foot lifting lever 4 is sleeved on the presser foot lifting shaft 3, and a limit retaining ring 8 is also sleeved on the presser foot lifting shaft 3, the presser foot lifting lever 4 is axially limited between the limit retaining ring 8 and the presser foot lifting shaft sleeve 6, and the limit retaining ring 8 is fixedly connected with the presser foot lifting shaft 3. A top block 9 is arranged at one end of the presser foot lifting lever 4, and a convex block 10 is arranged on the limit retaining ring 8, and the convex block 10 abuts against the top block 9. When the presser foot lifting lever 4 rotates counterclockwise, the top block 9 acts on the convex block 10 to drive the limit retaining ring 8 and the presser foot lifting shaft 3 to rotate counterclockwise, thereby performing the presser foot lifting action.

[0028] In order to realize the automatic reset of the presser foot lifting lever 4, the utility model is provided with a presser foot lifting reset torsion spring on the presser foot lifting shaft sleeve 6, one end of the presser foot lifting reset torsion spring is connected to the presser foot lifting lever 4, and the other end is connected to the housing. When the presser foot lifting cam follower 5 rolls on the base circle segment, the presser foot lifting reset torsion spring drives the presser foot lifting lever 4 to reset.

[0029] Comparison Figure 4 The working principle of the presser foot lifter drive assembly is as follows:

[0030] The stepper motor reverses and drives the presser foot lifting cam 2 to reverse, and the presser foot lifting cam 2 pushes the presser foot lifting cam follower 5 installed on the presser foot lifting lever 4, so that the presser foot lifting lever 4 rotates counterclockwise, and the presser foot lifting lever 4 drives the limit ring 8 fixed on the presser foot lifting shaft 3 to rotate counterclockwise, so that the presser foot lifting shaft 3 rotates counterclockwise, and the presser foot lifting shaft 3 drives the presser foot arm 11 to swing upward, and the presser foot arm 11 drives the presser foot assembly 12 to lift upward, so as to realize the presser foot lifting action. The stepper motor resets, and the presser foot lifting lever 4 resets under the action of the presser foot lifting reset torsion spring, and the presser foot assembly 12 falls back onto the needle plate surface 13, completing the reset of the presser foot assembly 12.

[0031] Comparison Figure 1 , Figure 2 , Figure 3 and Figure 5The thread trimming drive assembly includes a thread trimming cam 14 arranged on the rotating shaft of the motor 1, and the scissor shaft 15 of the thread trimming assembly is connected to the first thread trimming lever 19 through the third thread trimming lever 16, the thread trimming connecting rod 17, and the second thread trimming lever 18 connected in sequence. The second thread trimming lever 18 is rotatably connected to the mounting block 20 through the first pin shaft, and the mounting block 20 is fixed on the housing 7 through screws. One end of the second thread trimming lever 18 connected to the first thread trimming lever 19 is a ball head 21, and the first thread trimming lever 19 is rotatably connected to the housing 7 through the second pin shaft. One end of the first thread trimming lever 19 is located above the ball head 21, and the other end is in contact with the cam surface of the thread trimming cam 14, and the cam surface of the thread trimming cam 14 includes a thread trimming drive segment and a base circle segment.

[0032] It should be noted that the first thread trimming lever 19 is S-shaped, the inner arc surface of the upper end of the first thread trimming lever 19 is in contact with the ball head 21, and the outer arc surface of the other end is in contact with the cam surface of the thread trimming cam 14. A thread trimming reset torsion spring 23 is mounted on the first pin shaft, one end of the thread trimming reset torsion spring 23 is connected to the second thread trimming lever 18, and the other end is connected to the mounting block 20, driving the second thread trimming lever 18 to reset. When trimming, the outer arc surface of the other end of the first thread trimming lever 19 moves in the thread trimming drive section, and when performing actions other than trimming, the outer arc surface base circle section of the other end of the first thread trimming lever 19 moves.

[0033] Comparison Figure 5 The working principle of the thread trimming drive component driving the thread trimming component to perform the thread trimming action is as follows:

[0034] The stepper motor rotates forward, driving the thread trimming cam 14 to rotate forward. The thread trimming cam 14 pushes up the rear end of the first thread trimming lever 19, causing the front end of the first thread trimming lever 19 to move downward, pressing down the left end ball head 21 of the second thread trimming lever 18, causing the right section of the second thread trimming lever 18 to swing upward, driving the third thread trimming lever 16 to swing clockwise through the thread trimming connecting rod 17, and the third thread trimming lever 16 drives the scissor shaft 15 and the movable knife 22 connected to the scissor shaft 15 to rotate clockwise to complete the thread trimming action. The stepper motor resets, and under the action of the thread trimming reset torsion spring 23, the thread trimming assembly completes the reset.

[0035] Comparison Figure 1 , Figure 2 , Figure 3 and Figure 6The tooth adjustment drive assembly includes a tooth adjustment cam 24 arranged on the rotating shaft of the motor 1, and the tooth adjustment eccentric shaft 25 of the tooth adjustment assembly is connected to one end of the tooth adjustment shaft lever 26. The other end of the tooth adjustment shaft lever 26 is provided with a tooth adjustment cam follower 27, and the tooth adjustment cam follower 27 is in contact with the cam surface of the tooth adjustment cam 24. The cam surface of the tooth adjustment cam 24 includes a tooth adjustment drive segment and a base circle segment. The tooth adjustment cam follower 27 is usually a roller or a bearing. When adjusting the teeth, the tooth adjustment cam follower 27 rolls on the tooth adjustment drive segment, and when performing actions other than tooth adjustment, the tooth adjustment cam follower 27 rolls on the base circle segment, and the tooth adjustment assembly does not perform any action.

[0036] The utility model has a thread adjustment reset torsion spring 28 mounted on the thread adjustment eccentric shaft 25 , one end of the thread adjustment reset torsion spring 28 is connected to the thread adjustment shaft lever 26 , and the other end is connected to the housing 7 .

[0037] Comparison Figure 6 The working principle of the tooth adjustment drive assembly to drive the tooth height adjustment is as follows:

[0038] The stepper motor reverses and drives the tooth adjustment cam 24 to rotate counterclockwise. The tooth adjustment cam 24 pushes up the tooth adjustment cam follower 27 installed on the tooth adjustment shaft lever 26, so that the tooth adjustment shaft lever 26 swings upward. The tooth adjustment shaft lever 26 drives the tooth adjustment eccentric shaft 25 to rotate clockwise. The tooth adjustment eccentric shaft 25 drives the tooth lifting slider 29 to lift upward. The tooth lifting slider 29 drives the left end of the tooth frame assembly 30 to move upward and the right end to move downward, so that the height of the tooth assembly 31 installed at the right end of the tooth frame assembly 30 is reduced. The corresponding tooth height can be obtained by controlling the stepper motor to rotate a certain angle.

[0039] Comparison Figure 1 , Figure 2 , Figure 3 , Figure 7 and Figure 8The needle distance adjustment driving assembly includes a needle distance cam driving member 33 and a needle distance cam 34 arranged on the needle distance differential adjustment driving shaft 32. The needle distance cam 34 is connected to the needle distance differential adjustment driving shaft 32 through a first one-way bearing 35. The needle distance cam driving member 33 is connected to the first one-way bearing 35. The connection method is as follows: a groove is arranged on the inner ring of the first one-way bearing 35, and a connecting column inserted into the groove is arranged on the needle distance cam driving member 33. It should be noted that the first one-way bearing 35 adopts a one-way ratchet bearing. The cloth feed shaft 36 of the stitch length adjustment assembly is connected to the cloth feed assembly 40 through the cloth feed crank 37, the second stitch length adjustment link 38, and the cloth feed assembly link 39 which are connected in sequence. The cloth feed assembly link 39 is also connected to the stitch length adjustment shaft 43 through the first stitch length adjustment link 41 and the second stitch length adjustment lever 42 which are connected in sequence. The stitch length adjustment shaft 43 is provided with a first stitch length adjustment lever 44, and the first stitch length adjustment lever 44 is provided with a stitch length cam follower 45. The stitch length cam follower 45 is in contact with the cam surface of the stitch length cam 34.

[0040] It should be noted that the needle distance differential adjustment driving shaft 32 is connected to the rotating shaft of the motor 1 through the coupling 47, and the motor 1 drives the needle distance differential adjustment driving shaft 32 to rotate.

[0041] The cam surface of the stitch cam 34 includes a stitch adjustment drive section and a base circle section. The stitch cam follower 45 is usually a roller or a bearing. When the stitch is adjusted, the stitch cam follower 45 rolls on the stitch adjustment drive section. When an action other than stitch adjustment is performed, the stitch cam follower 45 rolls on the base circle section, and the stitch adjustment component does not perform an action.

[0042] The utility model is provided with a needle distance reset torsion spring 46 on the outer surface of the needle distance adjustment shaft 43, and the needle distance reset torsion spring 46 is limited between the end screw and the first needle distance adjustment lever 44 through the end screw. One end of the needle distance reset torsion spring 46 is connected to the first needle distance adjustment lever 44, and the other end is connected to the corresponding position on the housing 7.

[0043] In addition, a notch 48 is provided at the lower end of the needle distance cam driving member 33, and a limit block 49 is provided on the housing 7 below the needle distance cam driving member 33, and the upper end of the limit block 49 extends into the notch 48. A driving member reset torsion spring 50 is also provided on the needle distance differential adjustment driving shaft 32, and a torsion spring abutting column 51 is provided on the outer surface of the needle distance cam driving member 33, one end of the driving member reset torsion spring 50 abuts on the torsion spring abutting column 51, and the other end is connected to the housing 7.

[0044] Comparison Figure 7 , Figure 8 The working principle of the needle distance adjustment drive component to drive the needle distance adjustment is as follows:

[0045] The stepper motor drives the stitch differential adjustment drive shaft 32 to rotate clockwise through the coupling 47, and the stitch differential adjustment drive shaft 32 drives the stitch cam driving member 33 to rotate clockwise, and the stitch cam driving member 33 drives the first one-way bearing 35 to rotate clockwise, and the first one-way bearing 35 drives the stitch cam 34 to rotate clockwise, and the stitch cam 34 pushes the stitch cam follower 45 installed on the first stitch adjustment lever 44 downward, so that the first stitch adjustment lever 44 swings counterclockwise, and the first stitch adjustment lever 44 drives the stitch adjustment shaft 43 to rotate counterclockwise, and the stitch adjustment shaft 43 drives the second stitch adjustment lever 42 to swing upward, and the second stitch adjustment lever 42 drives the cloth feeding assembly connecting rod 39 and the second stitch adjustment connecting rod 44 to swing upward through the first stitch adjustment connecting rod 41. The cloth feed assembly 48 drives the cloth feed crank 37 to rotate through the cloth feed assembly connecting rod 39 and the second stitch length adjustment connecting rod 38, and the cloth feed crank 37 drives the cloth feed shaft 36 to rotate. The rotation amplitude of the cloth feed shaft 36 determines the speed of the sewing material transportation, that is, the stitch length. During the process that the second stitch length adjustment lever 42 drives the cloth feed assembly connecting rod 39 and the second stitch length adjustment connecting rod 42 to swing upward through the first stitch length adjustment connecting rod 41, the relative position angle formed by the cloth feed assembly connecting rod 39 and the second stitch length adjustment connecting rod 42 becomes smaller, so that the effective force arm formed by the cloth feed assembly connecting rod 39 and the second stitch length adjustment connecting rod 42 becomes shorter, so that the swing amplitude transmitted by the cloth feed assembly 40 to the cloth feed crank 37 becomes smaller, and then the rotation amplitude of the cloth feed shaft 36 is reduced, that is, the stitch length is reduced. The stepper motor is reset, and the stitch length cam driving member 33 returns to the original position under the action of the driving member reset torsion spring 50 and the limit block 49. The physical characteristics of the first one-way bearing 35 determine that the first one-way bearing 35 can only rotate in one direction and cannot be reversed, so the stepper motor is reset, and the needle distance cam 34 is still in the adjustment position. Under the action of the needle distance reset torsion spring 44, the needle distance adjustment mechanism is locked, thereby locking the needle distance size. The stepper motor is controlled to rotate the set angle and then reset, and this cycle is repeated to drive the needle distance cam 34 to rotate one circle, thereby completing the adjustment of the needle distance from the maximum needle distance to the minimum needle distance and then back to the maximum needle distance.

[0046] Comparison Figure 1 , Figure 2 , Figure 3 , Fig. 9 and Fig.10The differential ratio adjustment drive assembly includes a differential cam drive member 52 disposed on the needle distance differential adjustment drive shaft 32 and a differential adjustment shaft 53 located on one side of the differential cam drive member 52, wherein the differential cam drive member 52 is located at the outer end of the drive member reset torsion spring 50. The differential adjustment shaft 53 is provided with a first differential adjustment lever 54 and a differential cam 55, and the first differential adjustment lever 54 is provided with a differential drive cam follower 56, which is in contact with the cam surface of the differential cam drive member 52, and the differential cam 55 is connected to the differential adjustment shaft 53 through a second one-way bearing 61, and the second one-way bearing 61 is a one-way ratchet bearing. The second differential adjustment lever 57 is connected to the differential shaft 58 of the differential ratio adjustment assembly, and the second differential adjustment lever 57 is provided with a differential cam follower 59, and the differential cam follower 59 is in contact with the cam surface of the differential cam 55.

[0047] It should be noted that the cam surfaces of the differential cam driver 52 and the differential cam 55 both include a driving segment and a base circle segment. The differential drive cam followers 56 and the differential cam followers 59 are usually rollers or bearings. When the differential ratio is adjusted, the differential drive cam followers 56 and the differential cam followers 59 roll on the driving segments of the differential cam driver 52 and the differential cam 55, respectively. When performing actions other than adjusting the differential ratio, the differential drive cam followers 56 and the differential cam followers 59 roll on the base circle segments of the differential cam driver 52 and the differential cam 55, respectively, and the differential ratio adjustment component does not perform any action.

[0048] In addition, the utility model is provided with a differential adjustment drive reset torsion spring 68 on the differential adjustment shaft 53, one end of which is connected to the first differential adjustment lever 54 and the other end is connected to the housing 7. A differential reset torsion spring 60 is provided on the differential shaft 58, one end of which is connected to the second differential adjustment lever 57 and the other end is connected to the housing 7.

[0049] Comparison Fig. 9 , Fig.10 The working principle of the differential ratio adjustment drive component driving the differential ratio adjustment is as follows:

[0050] The stepper motor drives the needle pitch differential adjustment drive shaft 32 to rotate counterclockwise through the coupling 47, and the needle pitch differential adjustment drive shaft 32 drives the differential cam drive member 52 to rotate counterclockwise. The differential cam drive member 52 pushes the differential drive cam follower 56 installed on the first differential adjustment lever 54 to the right, so that the first differential adjustment lever 54 swings clockwise, and the first differential adjustment lever 54 drives the differential adjustment shaft 53 to rotate clockwise, and the differential adjustment shaft 53 drives the second one-way bearing 61 to rotate clockwise, and the second one-way bearing 61 drives the differential cam 55 to rotate clockwise, and the differential cam 55 pushes the differential cam installed on the second differential adjustment lever 57 downward. The follower 59 causes the second differential adjustment lever 57 to swing counterclockwise, the second differential adjustment lever 57 drives the differential shaft 58 to rotate counterclockwise, the differential shaft 58 drives the third differential adjustment lever 62 to swing counterclockwise, the third differential adjustment lever 62 drives the differential adjustment link 63 to move downward, the differential adjustment link 63 drives the differential adjustment slider 64 to move downward, so that the force arm driving the differential tooth frame 65 to move left and right is reduced, so that the left and right movement amplitude of the differential tooth frame 65 is reduced, the left and right movement amplitude of the differential tooth 66 installed on the differential tooth frame 65 is reduced, and the left and right movement amplitude of the feed tooth 67 is relatively fixed, so that the ratio of the two is reduced, that is, the differential ratio is reduced. The stepper motor is reset, and the first differential adjustment lever 54 returns to the original position under the action of the differential adjustment drive reset torsion spring 68. The physical characteristics of the second one-way bearing 61 determine that the second one-way bearing 61 can only rotate in one direction and cannot be reversed, so the stepper motor is reset, and the differential cam 55 is still in the adjustment position. Under the action of the differential reset torsion spring 60, the differential adjustment component is locked, thereby locking the differential ratio. The stepper motor is controlled to rotate the set angle and then reset, and the cycle is repeated to drive the differential cam 55 to rotate one circle, thereby completing the adjustment of the differential ratio from the limit surplus to the limit deficit and then back to the limit surplus.

[0051] In addition, the control Figure 1 , Figure 2 The rear side of the housing 7 is provided with a concave in the opposite direction to the front side, and the motor 1, the thread trimming drive assembly, the stitch length adjustment drive assembly, and the presser foot lifting drive assembly are arranged in the concave, the stitch length differential adjustment drive shaft 32 is rotatably arranged on the housing 7 and extends out of the left side of the housing 7, and the stitch length cam 34, the differential cam driving member 52, and the differential cam 55 are located outside the left side of the housing 7 and covered by the sewing platform 69. The rear side of the housing 7 is also provided with a rear cover, which is connected to the cover of the electric control 70.

[0052] By installing the stepper motor in an embedded manner at the rear of the housing 7, the corresponding driving components are built into the housing 7, which effectively improves the problem that the previous external structure makes the whole machine too large, affecting the packaging and transportation.

[0053] The working principle of the utility model is as follows:

[0054] Motor 1 rotates clockwise to complete the thread trimming, and continues to rotate clockwise after passing the thread trimming area to enter the stitch length adjustment area, and reciprocates at a small angle to complete the stitch length adjustment. Rotate counterclockwise to complete the tooth height adjustment, and set it as the stepper motor zero position, and use the stepper motor to lock the tooth adjustment mechanism. Continue to rotate counterclockwise, the teeth completely descend below the needle plate surface to enter the presser foot lifting area, and while the presser foot is lifted, the teeth are in the lower supply mode below the needle plate. Continue to rotate counterclockwise to enter the differential adjustment area, and reciprocate at a small angle to complete the differential ratio adjustment.

[0055] The above embodiment is only one of the preferred embodiments of the present utility model, and is not intended to limit the scope of implementation of the present utility model. Therefore, any equivalent changes made based on the shape, structure, and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A sewing machine thread trimming, stitch length, tooth height, presser foot lift and differential ratio adjustment mechanism, characterized in that: include: Motor (1), thread trimming drive assembly, stitch length adjustment drive assembly, presser foot lifting drive assembly, tooth adjustment drive assembly, differential ratio adjustment drive assembly; The presser foot lifting driving assembly comprises a presser foot lifting cam (2) arranged on the rotating shaft of the motor (1); one end of the presser foot lifting shaft (3) of the presser foot lifting assembly is connected to one end of the presser foot lifting lever (4); the other end of the presser foot lifting lever (4) is provided with a presser foot lifting cam follower (5); the presser foot lifting cam follower (5) is in contact with the cam surface of the presser foot lifting cam (2); The thread trimming drive assembly comprises a thread trimming cam (14) arranged on the rotating shaft of the motor (1); the scissor shaft (15) of the thread trimming assembly is connected to the first thread trimming lever (19) through a third thread trimming lever (16), a thread trimming connecting rod (17), and a second thread trimming lever (18) which are connected in sequence; the second thread trimming lever (18) is rotatably connected to the mounting block (20) through a first pin shaft; one end of the second thread trimming lever (18) connected to the first thread trimming lever (19) is a ball head (21); the first thread trimming lever (19) is rotatably connected to the housing (7) through a second pin shaft; one end of the first thread trimming lever (19) is located above the ball head (21) and the other end is in contact with the cam surface of the thread trimming cam (14); The tooth adjustment drive assembly comprises a tooth adjustment cam (24) arranged on the rotating shaft of the motor (1); the tooth adjustment eccentric shaft (25) of the tooth adjustment assembly is connected to one end of the tooth adjustment shaft lever (26); the other end of the tooth adjustment shaft lever (26) is provided with a tooth adjustment cam follower (27); the tooth adjustment cam follower (27) is in contact with the cam surface of the tooth adjustment cam (24); The needle distance adjustment drive assembly comprises a needle distance cam drive member (33) and a needle distance cam (34) arranged on a needle distance differential adjustment drive shaft (32); the needle distance cam (34) is connected to the needle distance differential adjustment drive shaft (32) via a first one-way bearing (35); the needle distance cam drive member (33) is connected to the first one-way bearing (35); a cloth feed shaft (36) of the needle distance adjustment assembly is connected via a cloth feed crank (37), a second needle distance adjustment connecting rod (38), and a cloth feed group (36) connected in sequence A connecting rod (39) is connected to a cloth feeding assembly (40); the connecting rod (39) of the cloth feeding assembly is further connected to a needle distance adjustment shaft (43) through a first needle distance adjustment connecting rod (41) and a second needle distance adjustment lever (42) which are connected in sequence; a first needle distance adjustment lever (44) is arranged on the needle distance adjustment shaft (43); a needle distance cam follower (45) is arranged on the first needle distance adjustment lever (44); and the needle distance cam follower (45) is in contact with a cam surface of the needle distance cam (34); The differential ratio adjustment drive assembly comprises a differential cam drive member (52) arranged on a needle distance differential adjustment drive shaft (32) and a differential adjustment shaft (53) located on one side of the differential cam drive member (52); a first differential adjustment lever (54) and a differential cam (55) are arranged on the differential adjustment shaft (53); a differential drive cam follower (56) is arranged on the first differential adjustment lever (54); the differential drive cam follower (56) is in contact with the cam surface of the differential cam drive member (52); the differential cam (55) is connected to the differential adjustment shaft (53) via a second one-way bearing (61); a second differential adjustment lever (57) is connected to the differential shaft (58) of the differential ratio adjustment assembly; a differential cam follower (59) is arranged on the second differential adjustment lever (57); the differential cam follower (59) is in contact with the cam surface of the differential cam (55); The rotating shaft of the motor (1) is connected to the needle distance differential adjustment driving shaft (32) and drives the same to rotate.

2. The thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism for a sewing machine according to claim 1, characterized in that: The presser foot lifting shaft (3) is rotatably connected to the housing (7) via a presser foot lifting shaft sleeve (6); one end of the presser foot lifting lever (4) is sleeved on the presser foot lifting shaft (3); a limit retaining ring (8) is also sleeved on the presser foot lifting shaft (3); the presser foot lifting lever (4) is axially limited between the limit retaining ring (8) and the presser foot lifting shaft sleeve (6); and the limit retaining ring (8) is fixedly connected to the presser foot lifting shaft (3).

3. The thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism for a sewing machine according to claim 2, characterized in that: A top block (9) is arranged at one end of the presser foot lifting lever (4), and a convex block (10) is arranged on the limit retaining ring (8). The convex block (10) abuts against the top block (9). When the presser foot lifting lever (4) rotates counterclockwise, the top block (9) acts on the convex block (10) to drive the limit retaining ring (8) and the presser foot lifting shaft (3) to rotate counterclockwise.

4. The thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism for a sewing machine according to claim 1, characterized in that: A notch (48) is provided at the lower end of the needle distance cam driving member (33), and a limit block (49) is provided on the housing (7) below the needle distance cam driving member (33), and the upper end of the limit block (49) extends into the notch (48).

5. The thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism for a sewing machine according to claim 1, characterized in that: The presser foot lifting cam (2), the thread trimming cam (14), the thread adjusting cam (24), the stitch length cam, the differential driving cam, and the differential cam all include a driving section and a base circle section.

6. The thread trimming, stitch length, tooth height, presser foot lifting and differential ratio adjustment mechanism for a sewing machine according to claim 1, characterized in that: The rear side surface of the casing (7) is provided with a recess in the opposite direction to the front side surface, and the motor (1), the thread trimming drive assembly, the stitch length adjustment drive assembly, and the presser foot lifting drive assembly are arranged in the recess; the stitch length differential adjustment drive shaft (32) is rotatably arranged on the casing (7) and extends out of the left side surface of the casing (7); the stitch length cam (34), the differential cam driving member (52), and the differential cam (55) are located outside the left side surface of the casing (7) and are covered by the sewing platform (69).

Images