JP2023123066A - Sewing machine thread cutting base device capable of cutting thread into extremely short thread - Google Patents

Abstract

To provide a sewing machine thread cutting base device, which can be applied to a driving member of any sewing machine model number of any manufacturer to perform linear drive and cut a thread into an extremely short thread that significantly improves sewing quality.SOLUTION: A sewing machine thread cutting base device capable of cutting a thread to an extremely short thread includes a thread cutting base 10, a joint rod cutter set 20, a fixing blade member 30, and a cover spring piece 40. An elastic pressing end 442 is formed on an elastic bending step 441 of a front end of a spring area 44 so as to press and deal with a spring energy accumulated at a pressing section 293 of a movable blade member 27 and form appropriate cutting force by laterally moving a movable blade 29 toward a fixing blade 34. Thickness of a hole table 12 in vertical direction at a position corresponding to a thread insertion hole 13 is 0.5 mm, enabling a section between a sewing machine thread 70 and a cutting part 71 to be cut into an extremely short thread. The extremely short thread shrinks to inside of a fabric body due to resilience preliminarily held thereby so that excellent flatness is formed on a surface after cutting the thread of a sewn product and an extremely long thread is not left on the surface of the sewn fabric.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a sewing machine thread cutting board device capable of cutting very short threads. In particular, the movable blade of the movable blade member faces the thread insertion hole, and also performs linear slide cutting with the fixed blade. An elastic restraining end is formed at the end of the elastic bending step at the front end of the spring area to hold and respond to the spring energy accumulated in the pushing section of the movable blade member, so that when the movable blade moves laterally toward the fixed blade, A good cutting force is formed. At the same time, the vertical thickness (H) of the position corresponding to the thread insertion hole of the perforating board is 0.5 mm. It shrinks inside, forms good flatness on the surface of the sewn product after thread cutting, and does not leave too long threads on the surface of the sewn fabric. Furthermore, linear drive is performed by applying to the drive member installed in any manufacturer's sewing machine model number.

Known sewing machine technology is that of sewing equipment, which is used to sew fabrics with sewing thread. The sewing machine is arranged with a thread cutting structure for cutting the sewing thread, when the user cuts the sewing thread, it controls the needle of the sewing machine to leave the fabric, then the sewing machine drives the thread cutting structure to cut the sewing thread. cut.

The main object of the present invention is to provide a sewing machine thread cutting board device that can be applied to the drive member of any manufacturer's sewing machine model number, linearly driven, and cut into extremely short threads that greatly improve the quality of sewing. be.

A sewing machine thread cutting board device capable of cutting into very short threads includes:
The thread cutting board has a slide groove section, and a perforation board is provided at a predetermined position of the slide groove section. A thread inserting hole is drilled at a predetermined position in the perforator, and a plurality of assembling holes are drilled at a predetermined position in the slide groove section. A first pivot base and a second pivot base are formed at one end of the slide groove section. The first pivot base and the second pivot base respectively install the first elastic assembly member and the second elastic assembly member.
The joint rod cutter set is linearly slidably arranged in the slide groove section of the thread cutting board, and the joint rod cutter set includes a driving knob and a movable blade. The movable blade linearly slides in the thread insertion hole of the thread cutting board, the connecting rod cutter set forms an engaging groove corresponding to the second elastic assembly member, and the connecting rod cutter set corresponds to the first elastic assembly member. The pressing surface is formed, the engaging groove is fitted on the first elastic assembly member, and the pressing surface presses the second elastic assembly member. The drive knob drives the joint rod cutter set by an external force, the movable blade linearly slides in the direction of the surface of the thread insertion hole, and the joint rod cutter set is driven by the first elastic assembly member and the second elastic assembly member. elastically restores the
The cover spring pieces correspond to the through holes corresponding to the plurality of assembly holes of the thread cutting board, and the through holes and the assembly holes are screw-fixed with connecting members, and the cover spring pieces cover the joint rod cutter set. Further, the driving knob and the thread insertion hole are exposed, and the cover spring piece has a limiting block surface at a position corresponding to the driving knob.

In the sewing machine thread cutting board device capable of cutting into very short threads according to the present invention, the movable blade of the movable blade member faces the thread insertion hole and performs linear slide cutting with the fixed blade. An elastic depressing end is formed at the end of the elastic curved step at the front end of the spring area to hold down the spring energy accumulated in the pressing section of the movable blade member, so that when the movable blade is laterally moved toward the fixed blade, it is good. cutting force is created. The vertical thickness (H) of the position corresponding to the thread insertion hole of the perforation board is 0.5 mm, and the space between the sewing thread and the cut portion is cut out with a very short thread, and the very short thread is pulled by the elasticity of the fabric body. It shrinks inward, forms good flatness on the surface of the sewn product after thread cutting, and does not leave too long threads on the surface of the sewn fabric. By improving the shortcomings of the known technology, the linear drive can be applied to the drive member installed in any manufacturer's sewing machine model number.

1 is an example of a three-dimensional view of a sewing machine thread cutting board device capable of cutting very short threads according to an embodiment of the present invention; FIG. 1 is an example of an exploded view of a sewing machine thread cutting board device capable of cutting very short threads according to an embodiment of the present invention; FIG. 1 is an example of a bird's-eye view of a sewing machine thread cutting board device capable of cutting very short threads according to an embodiment of the present invention; FIG. 10 is an example of a three-dimensional view of the sewing machine thread cutting board device capable of cutting into ultra-short yarns according to an embodiment of the present invention, in which the joint rod cutter set faces the thread cutting board after removing the cover spring piece; FIG. 10 is an example of another stereoscopic view from another angle in which the joint rod cutter set that appears after removing the cover spring piece is opposed to the thread cutting board in the embodiment of the present invention; FIG. 10 is an example of a three-dimensional view of operation of the joint rod cutter set after removing the lid spring piece according to an embodiment of the present invention, which is operated by an external force; FIG. 10 is an example of an operating bird's-eye view in which the joint rod cutter set, which appears after removing the lid spring piece, is operated by an external force in an embodiment of the present invention; FIG. 10 is an example of a diagram of a drive knob for a joint rod cutter set according to an embodiment of the present invention that linearly drives the drive member of any manufacturer's sewing machine model number; FIG. 10 is an example of a partial cross-sectional view of the joint rod cutter set before actuation according to one embodiment of the present invention, in which the movable blade is cut relative to the sewing thread inside the thread insertion hole; FIG. 10 is an example of a partial cross-sectional view after driving of the joint rod cutter set according to one embodiment of the present invention, in which the movable blade is cut relative to the sewing thread inside the thread insertion hole; It is an example of the figure which shows another one Example of this invention. It is an example of the still another embodiment drawing of the present invention. 1 is an example structural block diagram of some embodiments of the present invention;

(First embodiment)
As shown in FIGS. 1-11, a sewing machine thread cutting board device capable of cutting into very short threads includes: a.

The thread cutting board 10 is provided with a slide groove section 11, and a hole base 12 is provided at a predetermined position of the slide groove section 11. - 特許庁A thread insertion hole 13 is provided at a predetermined position inside the perforation base 12, and the longitudinal thickness (H) of the position corresponding to the thread insertion hole 13 of the perforation base 12 is 0.5 mm. A fixed cutter base 101 is installed on one side of the thread insertion hole 13, and a joint part 102 is installed on one side of the fixed cutter base 101, and the position surface of the hole board 12 corresponding to the thread insertion hole 13 is a curved surface. 121, a first assembly hole 14 and a second assembly hole 15 are respectively drilled at predetermined positions in the slide groove section 11, and a first pivot base 16 and a second pivot base 16 are formed at one end of the slide groove section 11. Two pivot bases 17 are molded.

The first pivot base 16 and the second pivot base 17 have a recessed trapezoidal shape and communicate with the sliding groove section 11, and the first pivot base 16 is formed with a first assembly part 161 at a predetermined position to form the first assembly part. A first position limiting part 162 is formed on one side of 161 . Further, a second assembly part 171 is formed at a predetermined position of the second pivot base 17 and a second position limiting part 172 is formed at one side of the second assembly part 171 .

The elastic assembly member 18 and the second elastic assembly member 19 are assembled and installed in the first assembly portion 161 and the second assembly portion 171, respectively. The first elastic assembly member 18 comprises a first assembly member 181 , a first washer 182 and a first spring member 183 . A first pivot hole 184 is provided at the center of the first spring member 183 , and the first assembly member 181 is arranged in the first pivot hole 184 , and then the first assembly member 181 is installed in the first assembly of the thread cutting board 10 . The first washer 182 is sandwiched between the first assembly part 161 and the first spring member 183, and the first spring member 183 has elastic ends at both ends, each of which is a first position limiting end. 185 and a first mating end 186 . The first position limiting end 185 holds the first position limiting portion 162 of the thread cutting board 10 , and the first fitting end 186 holds the holding surface 26 of the joint rod cutter set 20 .

The second elastic assembly member 19 includes a second assembly member 191 , a second washer 192 and a second spring member 193 . The center of the second spring member 193 forms a second pivot hole 194, in which the second assembly member 191 is arranged, and then the second assembly member 191 is installed in the second assembly of the thread cutting board 10. The second washer 192 is sandwiched between the second assembly part 171 and the second spring member 193, and the second spring member 193 has elastic ends at both ends for the second position. It is divided into a limiting end 195 and a second mating end 196 respectively. The second position limiting end 195 limits and holds the second position limiting portion 172 of the thread cutting board 10 , and the second fitting end 196 holds the engaging groove 23 of the joint rod cutter set 20 .
The slide groove section 11 of the thread cutting board 10 includes a first groove path 112, a second groove path 113 and a joint groove portion 111, which are downwardly U-shaped.

The joint rod cutter set 20 is arranged in the slide groove section 11 of the thread cutting board 10 for linear sliding. 291 , the bottom surface of the lateral guide protrusion 291 forms a guide slope 292 , and the uppermost surface of the movable blade 29 forms a pressing section 293 . The movable blade 29 is linearly slidable in the thread insertion hole 13 of the thread cutting board 10 , and the hole base 12 to which the movable blade 29 corresponds is formed with an arc-shaped curved surface 121 for arranging the corresponding cross section. is formed with an engaging groove 23 corresponding to the second elastic assembly member 19 . The joint rod cutter set 20 is further formed with a restraining surface 26 corresponding to the first elastic assembly member 18 , the first elastic assembly member 18 is fitted in the engaging groove 23 , and the restraining surface 26 is formed into the second elastic assembly member 18 . The elastic assembly member 19 is pressed.

A driving surface 25 is provided on the rear end surface of the driving knob 24, and the driving surface 25 drives the joint rod cutter set 20 with an external force. The movable blade 29 is linearly slidably cut in the direction of the surface of the thread insertion hole 13 , and the first elastic assembly member 18 and the second elastic assembly member 19 elastically restore the joint rod cutter set 20 .

The joint rod cutter set 20 further includes an actuation part 21 and a movable blade member 27 . The starting part 21 corresponds to the first channel 112 of the thread cutting board 10 and the movable blade member 27 corresponds to the second channel 113 . At the relative end positions of the actuating part 21 and the movable blade member 27, there is provided a mating assembly end 22 and a mating assembly groove 28 which are interconnected. The mating assembly end 22 and the mating assembly groove 28 are arranged in the joint groove portion 111 , and the movable blade member 27 and the actuating part 21 are separated, disassembled or connected at the fitting assembly end 22 and the mating assembly groove 28 . The movable blade member 27 can be replaced individually when the movable blade 29 wears out.

The fixed blade member 30 is provided inside the fixed cutter base 101 of the thread cutting board 10 . A fixed blade member 30 is provided with a guide arc surface 33 corresponding to one end of the thread insertion hole 13, and a fixed blade 34 is provided at one end of the guide arc surface 33. The fixed blade 34 and the movable blade 29 form relative cutting positions. A double-edged cutting operation state is formed at the position of the thread insertion hole 13 facing the fixed blade 34 due to the positional movement of the movable blade 29, and the guide slope 292 of the movable blade 29 is formed on the guide arc surface 33 after the positional movement of the movable blade 29. are opposed to provide guided slide movement. A connecting end 31 is provided at the other end of the stationary blade member 30 . The connecting end 31 corresponds to the connecting portion 102 of the thread cutting board 10 , and the connecting portion 102 and the connecting end 31 are connected by a connecting member 32 by screwing.

A first through hole 41 and a second through hole 42 corresponding to the first assembly hole 14 and the second assembly hole 15 of the thread cutting board 10 are formed in the cover spring piece 40 . A first coupling member 45 and a second coupling member 46 are screwed to face the first assembly hole 14 and the second assembly hole 15 and the first through hole 41 and the second through hole 42, respectively. Cover the joint rod cutter set 20. Furthermore, the drive knob 24 and the thread insertion hole 13 are exposed, and a limit block surface 43 is formed at a position corresponding to the drive knob 24 of the lid spring piece 40, and the drive knob 24 is blocked by the limit block surface 43 in the normal state. ing.
The cover spring piece 40 has a spring area 44 corresponding to the movable blade 29, and the movable blade member 27 is housed between the thread cutting board 10 and the spring area 44 to perform linear sliding. An elastic curved step 441 slightly curved downward is formed at the front end of the spring area 44 . An elastic pressing end 442 is formed at the end of the elastic curved step 441 and corresponds to the pressing section 293 that presses the movable blade member 27 . When the movable blade 29 is elastically pressed in the longitudinal direction through the pressing section 293 and the elastic detent end 442 of the spring area 44, the spring energy is stored in the movable blade 29, and the movable blade 29 is released from the spring detent. , produces a short range impact force and produces a large cutting force with the fixed blade 34 when the movable blade 29 of the movable blade member 27 moves laterally to the fixed blade 34 .

As shown in FIGS. 8 to 10, the drive surface 25 at the rear end of the drive knob 24 is activated by the drive member 50, and the auxiliary thread member 60 presses the thread portion to form a vertically oriented right-hand drive module, which connects the rods in a straight line. Activate cutter set 20; The fitting assembly end 22 of the activating part 21 moves the fitting assembly groove 28 of the movable blade member 27 to linearly slide the movable blade 29 of the movable blade member 27 toward the thread insertion hole 13 and the fixed blade 34 for cutting. By forming an elastic stop end 442 at the end of the elastic curved step 441 at the front end of the spring area 44 , the spring energy accumulated in the pressing section 293 of the movable blade member 27 can be accommodated and the movable blade 29 laterally moves toward the stationary blade 34 . Generates good cutting force when moved in any direction. Furthermore, since the vertical thickness (H) of the position corresponding to the thread insertion hole 13 of the perforating board 12 is 0.5 mm, the space between the sewing thread 70 and the cut portion 71 is cut with a very short thread, and the very short thread The body shrinks inside due to the pre-existing elasticity of the main body, forming good flatness on the surface of the sewn product after the threads are cut, and leaving no excessively long threads on the surface of the sewn fabric.
The present invention adopts the double-reset power design with the first elastic assembly member 18 and the second elastic assembly member 19. After cutting the thread, the joint rod cutter set 20 is immediately returned and restored, so that the cutting and restoring efficiency is greatly improved. is shortened to
(Second embodiment)

Shown in FIG. 11 is another embodiment of the present invention. Among them, the driving member 50A and the auxiliary thread member 60A are rotary arm driving modules arranged vertically on the thread cutting board 10, respectively, and move the movable blade 29 of the movable blade member 27 laterally toward the fixed blade 34, It applies to any manufacturer's sewing machine.
(Third embodiment)

Shown in FIG. 12 is yet another embodiment of the present invention. Among them, the driving member 50B is a left-side driving module with a bilaterally symmetrical configuration arranged laterally on the thread cutting board 10, which further moves the movable blade 29 of the movable blade member 27 laterally to the stationary blade 34, which can be manufactured by any manufacturer. also applies to sewing machines.

FIG. 13 is an example of a structural block diagram of some embodiments of the present invention, the thread cutting board 10 is mainly driven by the joint rod cutter set 20 and the cover spring piece 40 to achieve good driving.

The sewing machine thread cutting board device capable of cutting ultra-short thread according to the embodiment of the present invention has improved the known defect that the drive design must be different for each manufacturer and cannot be shared. The present invention overcomes the known drawbacks and applies to any manufacturer's sewing machine type drive member 50 to provide a linear drive.

REFERENCE SIGNS LIST 10 Thread cutting board 101 Fixed cutter base 102 Coupling portion 11 Slide groove section 111 Joint groove portion 112 First groove path 113 Second groove path 12 Hole base 121 Arc curved surface 13 Thread insertion hole 14 First assembly hole 15 Second assembly hole 16 first pivot base 161 first assembly part 162 first position limiting part 17 second pivot base 171 second assembly part 172 second position limitation part 18 first elastic assembly member 181 first assembly member 182 first washer 183 First Spring Member 184 First Pivot Hole 185 First Position Limiting End 186 First Fitting End 19 Second Elastic Assembling Member 191 Second Assembling Member 192 Second Washer 193 Second Spring Member 194 Second Pivot Hole 195 Second Two-position limiting end 196 Second mating end 20 Joining rod cutter set 21 Starting part 22 Fitting assembly end 23 Engagement groove 24 Driving knob 25 Driving surface 26 Depressing surface 27 Movable blade member 28 Fitting assembly groove 29 Movable blade 291 Side guiding protrusion 292 Guiding slope 293 Pressing section 30 Fixed blade member 31 Coupling end 32 Coupling member 33 Guiding arc surface 34 Fixed blade 40 Lid spring piece 41 First through hole 42 Second through hole 43 Limiting block surface 44 Spring area 441 Elastic curve step 442 elastic hold-down end 45 first coupling member 46 second coupling member 50 drive member 60 auxiliary thread member 50A drive member 60A auxiliary thread member 50B drive member 70 sewing thread 71 cutting portion

A sewing machine thread cutting board device capable of cutting into very short threads includes:
The thread cutting board has a slide groove section, and a perforation board is provided at a predetermined position of the slide groove section. A thread inserting hole is drilled at a predetermined position in the perforator, and a plurality of assembling holes are drilled at a predetermined position in the slide groove section. A first pivot base and a second pivot base are formed at one end of the slide groove section. The first pivot base and the second pivot base respectively install the first elastic assembly member and the second elastic assembly member.
The joint rod cutter set is linearly slidably arranged in the slide groove section of the thread cutting board, and the joint rod cutter set includes a driving knob and a movable blade. The movable blade linearly slides in the thread insertion hole of the thread cutting board, the connecting rod cutter set forms an engaging groove corresponding to the second elastic assembly member, and the connecting rod cutter set corresponds to the first elastic assembly member. A restraining surface is formed, the engaging groove is fitted to the second elastic assembly member , and the restraining surface is pressed by the first elastic assembly member . The drive knob drives the joint rod cutter set by an external force, the movable blade linearly slides in the direction of the surface of the thread insertion hole, and the joint rod cutter set is driven by the first elastic assembly member and the second elastic assembly member. elastically restores the
The cover spring pieces are made to correspond to the through holes corresponding to the plurality of assembly holes of the thread cutting board, and the through holes and the assembly holes are screwed and fixed by connecting members, and the cover spring pieces cover the joining rod cutter set. . Further, the drive knob and thread insertion hole are exposed, and the cover spring piece has a limit block surface at a position corresponding to the drive knob.

The joint rod cutter set 20 is arranged in the slide groove section 11 of the thread cutting board 10 for linear sliding. 291 , the bottom surface of the lateral guide protrusion 291 forms a guide slope 292 , and the uppermost surface of the movable blade 29 forms a pressing section 293 . The movable blade 29 is linearly slidable in the thread insertion hole 13 of the thread cutting board 10 , and the hole base 12 to which the movable blade 29 corresponds is formed with an arc-shaped curved surface 121 for arranging the corresponding cross section. is formed with an engaging groove 23 corresponding to the second elastic assembly member 19 . The joint rod cutter set 20 is further formed with a restraining surface 26 corresponding to the first elastic assembly member 18, the engaging groove 23 is fitted with the second elastic assembly member 19 , and the restraining surface 26 is formed on the first elastic assembly member 18. It is held down by the elastic assembly member 18 .

Claims (8)

A sewing machine thread cutting board device capable of cutting extremely short threads, comprising a thread cutting board, a joint rod cutter set, a fixed blade member, and a cover spring piece,
The thread cutting board is provided with a slide groove section, a perforation board is provided at a predetermined position of the slide groove section, a thread insertion hole is provided at a predetermined position of the perforation board, and one side of the thread insertion hole is fixed. It has a cutter base, one side of the fixed cutter base has a connecting part, a plurality of assembly holes at predetermined internal positions of the slide groove section, and a first pivot base on one side end of the slide groove section. and a second pivot base, wherein the first pivot base and the second pivot base are respectively provided with a first elastic assembly member and a second elastic assembly member;
Said connecting rod cutter set linearly slides in the sliding groove section of the thread cutting board, the connecting rod cutter set includes a driving knob and a movable blade, of which one side of the movable blade is formed with a side guide protrusion, and a side guide protrusion is formed. A guide slope is formed on the bottom surface, and a pressing section is formed on the uppermost surface of the movable blade,
The movable blade linearly slides in the thread insertion hole of the thread cutting board, the joint rod cutter set forms an engaging groove corresponding to the second elastic assembly member, and the joint rod cutter set forms the first elastic assembly member. The corresponding restraining surface is formed, the engaging groove is fitted in the first elastic assembly member, and the restraining surface presses the second elastic assembly member, and the driving knob drives the joint rod cutter set by external force. the movable blade linearly slides and cuts in the direction of the surface of the thread insertion hole, and the joining rod cutter set is elastically restored by the first elastic assembly member and the second elastic assembly member;
The fixed blade member is installed in the fixed cutter base of the thread cutting board base, the fixed blade member is provided with a guide arc surface corresponding to one end of the thread insertion hole, the one end of the guide arc surface has a fixed blade, of which the fixed blade is fixed. The blade and the movable blade form a relative cutting position, and a double-edged cutting operation state is formed at the position of the thread insertion hole facing the fixed blade according to the positional movement of the movable blade, and the guiding arc surface after the positional movement of the movable blade. The guide slopes of the movable blade face each other to provide a guide slide movement, the fixed blade member is provided with a connecting end at another end, the connecting end corresponds to the connecting part of the thread cutting board, and the connecting part and the connecting end are connected are screwed together by members,
The cover spring piece has a plurality of assembling holes of the thread cutting board corresponding to the through holes, each through hole and the assembling hole is screwed by a connecting member, the cover spring piece covers the joint rod cutter set, and is driven. The knob and the thread insertion hole are exposed, and a limiting block surface is formed at a position corresponding to the driving knob of the lid spring piece. An elastic curved step slightly curved downward is formed at the front end of the spring area, and an elastic pressing end is formed at the end of the elastic curved step, and the elastic pressing end presses the movable blade member. Corresponding to the section, through the pressing section of the movable blade and the elastic restraining end of the spring area, when it is elastically pressed in the longitudinal direction, the spring energy is stored in the movable blade, and when the movable blade is released from the elastic pressure, the short distance A sewing machine thread cutting board device capable of cutting very short threads, characterized in that when an impact force is generated and the movable blade of the movable blade member laterally moves to the fixed blade, a large cutting action force is generated together with the fixed blade. The sliding groove section of the thread cutting board includes a downward U-shaped first groove path, a second groove path and a joint groove, the joint rod cutter set includes a starting part and a movable blade member, the starting part being the first The movable blade member is arranged corresponding to the second groove path, and the actuating part and the movable blade member have a mating assembly end and a mating assembly groove that are connected to each other at the relative end positions of the moving part and the movable blade member. 2. A sewing machine thread cutting board device capable of cutting a very short thread according to claim 1, wherein said connecting groove is arranged in said connecting groove. 2. The sewing machine thread cutting board according to claim 1, wherein a drive surface is provided on the rear end surface of the drive knob of said joining rod cutter set. The plurality of assembling holes of the thread cutting board includes first assembling holes and second assembling holes, and the cover spring piece has first through holes and second through holes corresponding to the first assembling holes and second assembling holes. and fixing the first assembly hole and the second assembly hole and the first through hole and the second through hole to each other by the first coupling member and the one second coupling member, respectively. Sewing machine thread cutting board device that can cut into very short threads. The first pivot base and the second pivot base of the thread cutting board base are in the form of recessed bases, respectively communicated with the sliding groove section, and the first pivot base is formed with a first assembly part at a predetermined position, and a second A first position limiting part is formed on one side of the first assembly part, a second position limiting part is formed on the planned position of the second pivot base, and a second position limiting part is formed on one side of the second assembly part. 2. A sewing machine thread cutting board device capable of cutting a very short thread according to claim 1. The first elastic assembly member includes a first assembly member, a first washer and a first spring member, the first spring member central portion having a first pivot hole, the first pivot hole connecting the first assembly member. After mounting, the first assembly member is used to assemble the first assembly portion of the thread cutting board, the first washer is sandwiched between the first assembly portion and the first spring member, and the first spring member is elastic at both ends. an end, which is divided into a first position limiting end and a first mating end, wherein the first position limiting end separates and holds the first position limiting part of the thread cutting board, and the first mating end joins Hold the pressing surface of the rod cutter set,
The second elastic assembly member includes a second assembly member, a second washer and a second spring member, the center of the second spring member forms a second pivot hole, and the second assembly member is installed after the second assembly member is installed. The second washer is sandwiched between the second assembly part and the second spring member, the second spring member has elastic ends at both ends and a second position limiting end. and a second fitting end, wherein the second position limiting end presses the second position limiting portion of the thread cutting board, and the second fitting end presses the engagement groove of the joint rod cutter set. 6. The sewing machine thread cutting board device according to claim 1 or 5, which can cut a very short thread. The position surface corresponding to the thread insertion hole of the perforation board of the thread cutting board forms an arc-shaped curved surface, and the movable blade of the joint rod cutter set corresponds to the arc-shaped curved surface position, and the perforation board and the corresponding arc shape. 2. The sewing machine thread cutting board according to claim 1, wherein a curved surface is formed. 2. The sewing machine thread cutting board device capable of cutting ultra-short threads according to claim 1, wherein the vertical thickness of the position corresponding to the thread insertion hole of the hole board of said thread cutting board is 0.5 mm. .