TWI835049B - Automatic thread trimming device of sewing machine - Google Patents

Abstract

An automatic thread trimming device of a sewing machine contains: a holding disc, a cutter assembly, a fixed cutter, and a protective sheet. The automatic thread trimming device further contains an abutting segment formed on a distal portion of a curved section of a front end of an elastic extension and corresponding to a contact zone of a movable cutter, such that the movable cutter moves to the fixed cutter horizontally to produce cutting force. In the meantime, a longitudinal thickness of a protrusion corresponding to a receiving orifice is 0.5 mm so that a short thread end is cut between a thread and a cut portion of the thread, and the short thread end retracts inward because of a woven fabric, thus obtaining a flatness of a sewing product. Preferably, the automatic thread trimming device is capable of being driven by drive elements of any sewing machines.

Description

Automatic thread cutting tray device for sewing machines that can cut extremely short threads

The present invention relates to an automatic thread trimming disc seat device for a sewing machine that can cut extremely short thread ends, and in particular, to a device that cuts linearly with the movable blade of the movable blade toward the thread hole and with the fixed blade. An elastic pressing end is formed at the end of the elastic bending section at the front end of the elastic piece section, and an elastic energy accumulated in the pressing section corresponding to pressing against the movable blade can cause the movable blade to be laterally displaced toward the fixed blade. The better shearing force, and the longitudinal thickness (H) of the hole seat corresponding to the thread hole position is 0.5mm, can make a very short thread end be cut between the suture and the cutting part, and the extremely short thread end will be cut due to the The preset elasticity of the woven fabric itself shrinks inward, so that the surface of the sewn product can have better smoothness after shearing, and no excessively long thread ends will be left on the surface of the sewn fabric. Furthermore, the present invention can improve the customary use of the fabric. The innovative inventor is the innovative inventor of linear drive that can be used as a linear drive for any brand of sewing machine model.

According to conventional sewing machine technology, a sewing machine is a machine used for sewing stitches on fabrics. The sewing machine is equipped with a cutting structure for cutting the stitches. When the user wants to cut the stitches, the sewing machine is controlled. The needle leaves the fabric, and the sewing machine drives the cutting structure to cut the suture. However, the problems with the cutting structure of the conventional sewing machine are as follows: It is a common problem that the cutters of different brands cannot be shared because each brand has a different drive design.

That is, the main purpose of the present invention is to provide an automatic thread trimming disc seat device for a sewing machine that can cut extremely short thread ends; the problem it intends to solve is to solve the problem that is commonly used because each brand has a different drive design. Improvements and breakthroughs have been made to solve the missing problems that cannot be shared among cutters of various brands; The technical features of the solution to the problem are that it mainly includes a cutting plate seat, which is provided with a chute area. A hole seat is provided at a predetermined position in the chute area. A line hole is provided at a predetermined position inside the hole seat. Inside the chute area A plurality of sets of holes are provided at a predetermined position, and a first pivot seat and a second pivot seat are provided at one end of the chute area, wherein the first pivot seat and the second pivot seat are respectively pivoted with a first elastic pivot component. and a second elastic pivot component; a connecting rod knife set, which is linearly slidably arranged in the chute area of the tangent disk seat. The connecting rod knife set includes a driving handle and a movable blade, wherein the movable blade is linear The connecting rod knife set is slidably aligned with the thread hole of the tangent disk seat, and the connecting rod knife set is provided with a buckle groove corresponding to the second elastic pivot component, and the connecting rod knife set is provided with a push surface corresponding to the first elastic pivot component, so that The buckle groove is engaged with the first elastic pivot component, and causes the pushing surface to press against the second elastic pivot component, and the driving handle can drive the connecting rod knife set through external force, so that the movable blade moves toward the The surface of the thread hole performs shear linear sliding, and the connecting rod knife assembly is elastically reset through the first elastic pivot component and a second elastic pivot component; a protective cover elastic piece corresponds to the plurality of holes of the tangent plate base Corresponding through-holes are provided respectively, so that each through-hole and the group of holes are respectively screwed and locked together by a coupling member, and the protective cover elastic piece can just cover the connecting rod knife set, and make the driving handle and The thread hole is exposed, and the protective cover elastic piece is provided with a limiting stop surface corresponding to the position of the driving handle; thereby, the automatic thread cutting disk seat device of the sewing machine of the present invention that can cut extremely short thread ends is driven by the movement of the movable knife. The blade slides linearly towards the wire hole and with the fixed blade, and an elastic pressing end is formed by the end of the elastic bending section at the front end of the elastic piece section, corresponding to the accumulation of the pressing section against the movable blade. An elastic energy can produce better shearing force when the movable blade is laterally displaced toward the fixed blade. At the same time, the longitudinal thickness (H) of the hole seat corresponding to the position of the thread hole is 0.5mm, so that the suture can be A very short thread is cut between the cutting part and the cutting part. The extremely short thread will shrink due to the preset elasticity of the woven fabric itself, so that the surface of the sewn product can have better smoothness after shearing. Excessive thread ends are reserved on the surface of the sewing cloth. Furthermore, the present invention can improve the conventional shortcomings and is suitable for linear driving with the driving element provided in the sewing machine model of any brand.

10:Tangential disc seat

101: Fixed tool holder

102: Joint

11:Chute area

111: Connecting groove part

112:First channel

113:Second channel

12:Hole seat

121: Arc surface

13:Wire hole

14: The first set of holes

15: The second set of holes

16:The first pivot

161:The first central organization department

162: The first limiting part

17:Second Pivot

171:Second Pivot Organization Department

172:Second limiting part

18:First elastic pivot component

181:First pivot component

182:First gasket

183:First elastic member

184:First pivot hole

185: first limit end

186: First nested end

19: Second elastic pivot component

191:Second pivot assembly

192:Second gasket

193:Second elastic member

194:Second pivot hole

195: Second limit end

196:Second nested end

20: Connecting rod cutter set

21:Driving parts

22: Nested end

23:Buckle groove

24:Driving handle

25: Driving surface

26: Noodles

27: Movable cutting tools

28: Nesting slot

29: Movable blade

291:Side guide block

292:Guide slope

293:Forced arrival section

30: Fixed cutter

31:Combining end

32:Combining parts

33: Guide arc surface

34: Fixed blade

40: Cover shrapnel

41: First through hole

42:Second through hole

43:Limited stop surface

44:Shrapnel section

441: Elastic bending section

442: Flexible pressing end

45:First combination piece

46:Second combination piece

50: Drive components

60: patching line components

50A: Drive components

60A: patching line components

50B: Drive components

70: suture

71: Cutting part

Figure 1: is a three-dimensional view of the automatic thread cutting disc seat device of a sewing machine capable of cutting extremely short thread ends according to the present invention.

Figure 2: is an exploded perspective view of the automatic thread cutting disc seat device of the sewing machine according to the present invention which can cut extremely short thread ends.

Figure 3: is a top view of the automatic thread cutting disc seat device of the sewing machine according to the present invention which can cut extremely short thread ends.

Figure 4: is a three-dimensional view of the automatic thread trimming disc seat device of a sewing machine that can cut extremely short threads according to the present invention after the protective cover spring piece is separated, showing the connecting rod knife assembly relative to the thread trimming disc seat.

Figure 5: This is another perspective view of the connecting rod knife assembly relative to the tangent plate seat after the protective cover elastic piece is separated according to the present invention.

Figure 6: is a three-dimensional view of the connecting rod knife assembly being actuated by external force after the protective cover elastic piece is separated according to the present invention.

Figure 7: is a top view showing the action of the connecting rod knife assembly by external force after the protective cover shrapnel is separated according to the present invention.

Figure 8: The driving handle of the connecting rod knife set of the present invention can be linearly driven through the driving element provided in any brand of sewing machine model.

Figure 9: is a partial cross-sectional view of the present invention when the movable blade of the connecting rod cutter set is not driven to cut the suture inside the thread hole.

Figure 10: is a partial cross-sectional view of the present invention when the movable blade of the connecting rod cutter group is driven to cut the suture inside the thread hole.

Figure 11: is another embodiment of the present invention.

Figure 12: is another embodiment of the present invention.

Figure 13: is a structural block diagram of the present invention.

In order for the review committee to have a further in-depth understanding of the present invention, a preferred embodiment is enumerated. Please refer to Figures 1 to 11. The automatic thread cutting tray device of a sewing machine of the present invention that can cut extremely short thread ends includes: The cable tray base 10 is provided with a chute area 11. A hole base 12 is provided at a predetermined position of the chute area 11. A line hole 13 is provided at a predetermined position inside the hole base 12. The hole base 12 corresponds to the position of the line hole 13. The longitudinal thickness (H) is 0.5mm. One side of the wire hole 13 is provided with a fixed knife holder 101. One side of the fixed knife holder 101 is provided with a joint portion 102, and the surface of the hole seat 12 corresponds to the position of the wire hole 13. The arc-shaped surface 121 is provided with a first set of holes 14 and a second set of holes 15 at predetermined positions inside the chute area 11, and a first pivot seat 16 and a second pivot seat are provided at one end of the chute area 11. Seat 17; wherein the first pivot seat 16 and the second pivot seat 17 are respectively in the shape of a concave seat and connected with the chute area 11. The first pivot seat 16 is formed with a first pivot assembly part 161 at a predetermined position. The first pivot assembly part 161 is provided with a first limiting part 162 on one side, and the second pivot base 17 is formed with a second pivot assembly part 171 at a predetermined position. The second pivot assembly part 171 is provided with a second limiter on one side. Position portion 172; wherein the first pivot assembly portion 161 and the second pivot assembly portion 171 respectively pivot to form a first elastic pivot component 18 and a second elastic pivot component 19, wherein the first elastic pivot component 18 includes a first A pivot component 181, a first gasket 182 and a first elastic member 183 are relatively formed. A first pivot hole 184 is provided at the center of the first elastic member 183. The first pivot hole 184 is used to pivot the configuration. The first pivot assembly 181 is then assembled to the first pivot assembly portion 161 of the tangent plate base 10 , and the first gasket 182 is sandwiched between the first pivot assembly portion 161 and the first pivot assembly 161 . Between the elastic members 183, the first elastic member 183 has two elastic ends respectively defined as a first limiting end 185 and a first nesting end 186, wherein the first limiting end 185 is limited and pressed against the The first limiting portion 162 of the tangent disc seat 10 and the first nesting end 186 are in forced contact with the pushing surface 26 of the connecting rod knife set 20; in addition, the second elastic pivot component 19 includes a first Two pivot components 191, a second gasket 192 and a second elastic member 193 are formed oppositely. The second elastic member 193 is provided with a second pivot hole in the center. 194. The second pivot hole 194 is used to pivot the second pivot component 191 so that the second pivot component 191 is assembled on the second pivot assembly part 171 of the tangent plate seat 10. The second gasket 192 is Sandwiched between the second pivot assembly 171 and the second elastic member 193, the second elastic member 193 has two elastic ends respectively defined as a second limiting end 195 and a second nesting end 196, wherein The second limiting end 195 is limited and pressed against the second limiting portion 172 of the tangent disc seat 10 , and the second nesting end 196 is pressed against and contacted with the buckle groove of the connecting rod knife set 20 23; The chute area 11 of the tangent disk base 10 includes a first channel 112, a second channel 113 and a connecting groove portion 111 that are U-shaped to each other; a connecting rod cutter set 20 is arranged in a linear sliding manner. In the chute area 11 of the tangent disk base 10, the connecting rod knife set 20 includes a driving handle 24 and a movable blade 29, in which a side guide block 291 is provided on one side of the movable blade 29. The bottom surface of the block 291 forms a guide slope 292, and the top surface of the movable blade 29 forms a pressing section 293; the movable blade 29 is linearly slid against the line hole 13 of the tangent disk base 10, wherein the movable blade 29 is aligned with The hole seat 12 is provided with an arcuate surface 121 corresponding to the configuration of the cut surface, and the connecting rod knife set 20 is provided with a buckle groove 23 corresponding to the second elastic pivot component 19, and the connecting rod knife set 20 corresponds to the first elastic pivot assembly 19. The pivot component 18 is provided with a push surface 26, so that the buckle groove 23 is engaged with the first elastic pivot component 18, and the push surface 26 is pressed against the second elastic pivot component 19; and the driving handle 24 rear The end surface is provided with a driving surface 25. The driving surface 25 can drive the connecting rod knife set 20 through external force, so that the movable blade 29 can shear linearly slide toward the surface of the wire hole 13, and through the first elastic pivot component 18 And a second elastic pivot component 19 allows the connecting rod knife set 20 to elastically reset; wherein the connecting rod knife set 20 further includes a driving part 21 and a movable knife part 27, the driving part 21 is correspondingly arranged on the thread cutting disk The first channel 112 of the seat 10, and the movable cutter 27 is correspondingly arranged in the second channel 113. The opposite ends of the driving member 21 and the movable cutter 27 are provided with a nesting end that can be connected to each other. 22 and a nesting groove 28. The nesting end 22 and the nesting groove 28 are arranged in the connecting groove portion 111. The movable knife 27 and the driving member 21 pass through the nesting end 22 and the nesting groove 28. group slot 28 can be separated and disassembled or connected and assembled, so that the movable blade 27 can be replaced individually according to the degree of wear of the movable blade 29; a fixed blade 30 is located in the fixed blade holder 101 of the tangent disc base 10, The fixed blade 30 is provided with a guide surface 33 at one end corresponding to the wire hole 13, and a fixed blade 34 is provided at one end of the guide surface 33, wherein the fixed blade 34 and the movable blade 29 are in relative shearing positions with each other. 29 is in a double-edged shearing action state relative to the position of the hole 13 of the fixed blade 34 through displacement. After the movable blade 29 is displaced, the guide arc surface 33 provides relative guide sliding contact displacement of the guide slope 292 of the movable blade 29 The other end of the fixed blade 30 is provided with a coupling end 31. The coupling end 31 corresponds to the coupling portion 102 of the tangent disk base 10. The coupling portion 102 and the coupling end 31 are passed through a coupling member 32 relative to each other. The screws are locked together; a protective cover spring piece 40 is provided with a first through hole 41 and a second through hole 42 corresponding to the first set of holes 14 and the second set of holes 15 of the tangent disk base 10, so that the first through hole 41 and the second through hole 42 are provided. The set of holes 14 and the second set of holes 15 and the first through-hole 41 and the second through-hole 42 are assembled by relatively screw-locking through a first coupling member 45 and a second coupling member 46, and the protective cover The elastic piece 40 can just cover the connecting rod knife set 20 and expose the driving handle 24 and the wire hole 13. The protective elastic piece 40 is provided with a limiting stop surface 43 corresponding to the position of the driving handle 24, so that the driving handle 24 and the wire hole 13 are exposed. Under normal conditions, the handle 24 is limited to the limiting stop surface 43; the protective cover elastic piece 40 is extended with a elastic piece section 44 corresponding to the movable blade 29, and the movable knife piece 27 is built in the tangent plate seat 10 The elastic piece section 44 linearly slides with the elastic piece section 44. The front end of the elastic piece section 44 is formed with an elastic bending section 441 that is slightly bent downwards. The end of the elastic bending section 441 is formed with an elastic urging end 442. The elastic urging end 442 is formed at the end. The resisting end 442 corresponds to the urging section 293 of the movable blade 27. The movable blade 29 is longitudinally elastically pressed through the urging section 293 and the elastic urging end 442 of the elastic piece section 44. The elasticity Suppression will cause the movable blade 29 to accumulate an elastic energy, which can cause the movable blade 29 to have a short-range impulse after breaking away from the elastic suppression. When the movable blade 29 of the movable blade 27 is laterally displaced toward the fixed blade 34, it can A large shearing force is generated with the fixed blade 34; Please refer to Figures 8 to 10. The driving surface 25 at the rear end of the driving handle 24 can be driven by a driving element 50, and a line-filling element 60 is used to resist the line segment in a vertically positioned right-side driving mode. Activate the connecting rod cutter set 20 linearly, so that the driving member 21 drives the nesting slot 28 of the movable cutter 27 through the nesting end 22, so that the movable blade 29 of the movable cutter 27 faces the wire hole. 13 and performs shear linear sliding with the fixed blade 34. An elastic urging end 442 is formed at the end of the elastic bending section 441 at the front end of the elastic piece section 44, corresponding to the urging section 293 of the movable blade 27. The accumulated elastic energy can produce a better shearing force when the movable blade 29 is laterally displaced toward the fixed blade 34. At the same time, the longitudinal thickness (H) of the hole seat 12 corresponding to the position of the wire hole 13 is 0.5 mm, a very short thread can be cut between the suture 70 and the cutting part 71. The extremely short thread will shrink due to the preset elasticity of the woven fabric itself, so that the surface of the sewn product can be produced after shearing. Better flatness, without leaving too long thread ends on the surface of the sewing cloth; furthermore, the present invention has a dual-reset power design of a first elastic pivot component 18 and a second elastic pivot component 19, which can cut the thread ends. After cutting, the connecting rod cutter unit 20 is quickly rebounded and reset, so as to greatly shorten the efficiency of shearing reset.

Please refer to Figure 11, which is another embodiment of the present invention, in which the driving element 50A and the patching line element 60A can be in a rotary arm driving mode arranged up and down on the tangent disk base 10, and drive the The movable blade 29 of the movable blade 27 is laterally displaced toward the fixed blade 34 to be suitable for any brand of sewing machine model.

Please refer to Figure 12, which is another embodiment of the present invention, in which the driving element 50B can be a left-side driving mode in a bisymmetrical form and is laterally disposed on the tangent disk base 10, and drives the movable knife. The movable blade 29 of 27 is laterally displaced toward the fixed blade 34 to be suitable for any brand of sewing machine model.

Please refer to Figure 13, which is a structural block diagram of the present invention. The tangent disk base 10 of the present invention mainly uses a connecting rod knife assembly 20 and the cover elastic piece 40 to achieve better driving purposes.

Therefore, the automatic thread cutting plate seat device for sewing machines of the present invention that can cut extremely short thread ends is a technology that can improve the conventional technology. The key lies in the fact that each brand has a different drive design, so the cutters of each brand cannot be shared. , the present invention can improve the conventional deficiencies and be applicable to the driving element 50 of any brand of sewing machine model as a linear driver.

According to this, the present invention is indeed a very practical and progressive invention. However, there are no identical products or publications published, so it meets the requirements for an invention patent application and the application must be filed in accordance with the law.

10:Tangential disc seat

13:Wire hole

18: First elastic pivot component

19: Second elastic pivot component

20: Connecting rod cutter set

24:Driving handle

29: Movable blade

30: Fixed cutter

34: Fixed blade

40: Cover shrapnel

Claims (7)

An automatic thread cutting disc seat device for a sewing machine that can cut extremely short thread ends. It includes: a thread cutting disc seat, which is provided with a chute area. A hole seat is provided at a predetermined position in the chute area, and a thread is provided at a predetermined position inside the hole seat. hole, one side of the line hole is provided with a fixed knife holder, one side of the fixed knife holder is provided with a joint, a plurality of sets of holes are provided at predetermined positions inside the chute area, and one end of the chute area is provided with a first pivot seat and a second pivot seat, wherein the first pivot seat and the second pivot seat respectively pivot to form a first elastic pivot component and a second elastic pivot component; a connecting rod knife set is linearly slidably arranged on the tangent line In the chute area of the tray seat, the connecting rod knife set includes a driving handle and a movable blade, in which a side guide block is provided on one side of the movable blade, and the bottom surface of the side guide block forms a guide slope, and the The top surface of the movable blade forms a pressing section; the movable blade is linearly slid against the line hole of the tangent plate seat; and the connecting rod knife set is provided with a buckle groove corresponding to the second elastic pivot component, and the connecting rod knife set The set is provided with a push surface corresponding to the first elastic pivot component, so that the buckle groove is engaged with the first elastic pivot component, and the push surface is pressed against the second elastic pivot component, and the driving handle can be The connecting rod knife set is driven by an external force, causing the movable blade to shear and slide linearly toward the surface of the wire hole, and the connecting rod knife set is elastically reset by the first elastic pivot component and a second elastic pivot component; A fixed knife piece is installed in the fixed knife holder of the thread cutting disc seat. The fixed knife piece is provided with a guide arc surface at one end corresponding to the thread hole, and a fixed blade is provided at one end of the guide arc surface, wherein the fixed blade and the The movable blades are in relative shearing positions with each other. The movable blades are in a double-edged shearing action state through displacement and the position of the fixed blade relative to the hole. After the movable blades are displaced, the guide arc surface provides the guide slope surface of the movable blades relative to each other. Guide sliding contact displacement, the other end of the fixed blade is provided with a coupling end, the coupling end is corresponding to the coupling portion of the tangent plate seat, the coupling portion and the coupling end are screwed and locked relative to each other by a coupling piece Combining; a protective cover spring piece, corresponding to the plurality of holes of the tangent disk base are respectively provided with corresponding through holes, so that each of the through holes and the group of holes are respectively screwed and locked together by a coupling member, the protective cover spring piece It can just cover the connecting rod cutter set and expose the driving handle and the wire hole. The protective cover elastic piece is provided with a position corresponding to the driving handle. The limit stop surface allows the driving handle to be blocked at the limit stop surface under normal conditions, wherein the protective cover elastic piece is provided with a elastic piece section extending corresponding to the movable blade, and the front end of the elastic piece section is formed with a downward slight A curved elastic bending section has an elastic pressing end formed at the end of the elastic bending section. The elastic pressing end corresponds to the pressing section of the movable blade. The movable blade communicates with the pressing section through the pressing section. The elastic pressing end of the shrapnel segment is longitudinally elastically compressed. This elastic compression will cause the movable blade to accumulate an elastic energy, so that the movable blade will have a short-range impulse after breaking away from the elastic compression. When the movable blade reaches the When the movable blade moves laterally toward the fixed blade, it can generate a large shearing force with the fixed blade. The automatic thread trimming tray device for a sewing machine capable of cutting extremely short threads as described in claim 1, wherein the chute area of the thread trimming tray includes a first channel, a second channel and a U-shaped mutually-shaped channel. A connecting groove part, and the connecting rod cutter set also includes a driving part and a movable cutter part, the driving part is correspondingly arranged in the first channel, and the movable cutter part is correspondingly arranged in the second channel, the The opposite ends of the driving part and the movable knife part are provided with a nesting end and a nesting groove that can be connected to each other. The nesting end and the nesting groove are arranged in the connecting groove part. As claimed in claim 1, the automatic thread trimming disc seat device for a sewing machine capable of cutting extremely short thread ends is provided with a driving surface on the rear end surface of the driving handle of the connecting rod knife set. As claimed in claim 1, the automatic thread trimming tray device for a sewing machine capable of cutting extremely short thread ends, wherein the plurality of holes in the thread trimming tray can include a first group of holes and a second group of holes, and the protective cover The elastic piece is provided with a first through hole and a second through hole corresponding to the first group of holes and the second group of holes, so that the first group of holes and the second group of holes and the first through hole and the second through hole are The holes are assembled by threading screws through a first coupling member and a second coupling member respectively. The automatic thread trimming tray device for a sewing machine that can cut extremely short threads as described in claim 1, wherein the first pivot seat and the second pivot seat of the thread trimming tray are respectively in the shape of a concave base body and are in contact with the slide groove. The areas are connected, wherein the first pivot seat is formed with a first pivot assembly part at a predetermined position, a first limiting part is provided on one side of the first pivot assembly part, and a second pivot assembly part is formed at a predetermined position of the second pivot seat. , the second pivot group A second limiting portion is provided on one side, in which the first elastic pivot component includes a first pivot component, a first gasket and a first elastic member opposite each other. A first elastic member is provided at the center of the first elastic member. The first pivot hole is used to pivot the first pivot component so that the first pivot component is assembled on the first pivot assembly part of the tangent plate seat, and the first gasket is clamped on the third pivot hole. Between a pivot assembly and the first elastic member, the first elastic member has two elastic ends respectively defined as a first limiting end and a first nesting end, wherein the first limiting end is a limiting end. It is against the first limiting part of the tangent disk seat, and the first nesting end is in forced contact with the pushing surface of the connecting rod knife set; and the second elastic pivot component includes a second pivot component , a second gasket and a second elastic member are formed oppositely, and a second pivot hole is provided at the center of the second elastic member. The second pivot hole is used to pivot the second pivot component after the second pivot component is configured. The pivot assembly is assembled on the second pivot assembly part of the tangent plate seat. The second gasket is sandwiched between the second pivot assembly part and the second elastic member. The second elastic member has two elastic ends respectively. It is defined as a second limiting end and a second nesting end, wherein the second limiting end is limited and pressed against the second limiting portion of the tangent disk base, and the second nesting end is forced It is in contact with the buckle groove of the connecting rod cutter set. The automatic thread trimming disc seat device of a sewing machine that can cut extremely short threads as described in claim 1, wherein the hole seat of the thread trimming disc seat corresponds to the position of the thread hole and the surface is generally an arc-shaped surface, and the connecting rod knife set The position of the movable blade corresponding to the arc-shaped surface also forms an arc-shaped surface shape corresponding to the hole seat. The automatic thread trimming disc seat device for a sewing machine capable of cutting extremely short threads as described in claim 1, wherein the longitudinal thickness of the hole seat of the thread trimming disc seat corresponding to the position of the thread hole is 0.5 mm.

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