TW201814099A - Thread trimmer of post-bed sewing machine - Google Patents

Abstract

A thread trimmer of post-bed sewing machine which is assembled to a feed wheel post with a needle eye, comprising a knife assembly, a transmission device, and a lower shaft. The knife assembly includes a fixed knife which is behind the needle eye, and a movable knife which is assembled to the feed wheel post. Wherein, the transmission device is assembled to the movable knife and may bring the movable knife to swing back and forth in between a thread hooking position, and a cutting position where the movable knife cuts the thread. Further, the movable knife loops around a rotating axis which is parallel to the lower shaft. The fixed knife is behind the needle eye, and the movable knife may swing back and forth in between the thread hooking position and the cutting position. With the aforementioned two features, the movable knife may cut the longer thread at the cutting position, and the shorter thread will be left on the sawn material.

Description

Thread cutting device of cylindrical sewing machine

The invention relates to a thread cutting device of a column-type sewing machine, in particular to a thread cutting device which can leave a short-length thread end on a sewing object after cutting a thread.

The sewing machine mainly combines several layers of stitched objects through stitching, and with the continuous evolution of technology, there are many types of sewing machines on the market, and different types of sewing machines can be applied to different cars. Sewing operation of sewing products. Among them, there is currently a cylindrical sewing machine suitable for sewing shoes, bags or tubes.

However, when the cylindrical sewing machine finishes sewing, in order to facilitate the cutting of the thread, a conventional thread cutting device 1 for cutting the thread is provided on the cylindrical sewing machine. Please refer to FIG. 1, the conventional thread cutting device 1 The utility model mainly has a fixed knife 10 and a movable knife 11, the fixed knife 10 is disposed on a fixed knife seat 13 in a rotary hook seat 12, and the movable knife 11 is pivotally connected to the above by a pivot 14 At the upper end of the hook base 12, a swing arm 15 is assembled from the lower end of the pivot shaft 14, the swing arm 15 is connected to a driver (not shown), so that the driver (not shown) can pass through the swing arm 15 and The pivot 14 can drive the movable knife 11 to swing around the pivot 14 (the z-axis in the figure) to perform thread hooking and thread trimming operations.

However, since both the fixed knife 10 and the movable knife 11 are disposed on the rotary hook base 12, the blade edges of the fixed knife 10 and the movable knife 11 are far away from the needle hole, thereby causing the movable knife 11 to stitch When cutting, a long length of thread will remain on the surface of the sewing object, even if the thread is cut by the movable knife 11 above, in some applications, it is still necessary to manually cut the long length of thread .

In view of the aforementioned shortcomings of the thread cutting device currently used in the cylindrical sewing machine, it is necessary to innovate and improve the thread cutting device so that after the thread cutting device cuts the thread, a shorter thread end can remain on the surface of the sewing object.

The main purpose of the present invention is to allow thread ends with a shorter length to remain on the surface of the sewn objects after cutting the sutures, so as to avoid the sewing person needing to trim the thread ends a second time, thereby shortening the working time, To increase production.

The secondary object of the present invention is to adjust the swing distance between the hooking position and the cutting position of the movable cutter according to the material characteristics of the suture, thereby shortening or lengthening the time difference for cutting the suture, thereby increasing practicality.

To achieve the above object, the thread cutting device of the column sewing machine of the present invention is provided on a side seat assembled on a base, the side seat has a side seat cylinder extending along a longitudinal axis and a lower shaft capable of rotating, the above The side seat cylinder has a feed table, a needle plate seat assembled on the feed table and a movable knife seat assembled on the feed table, the needle plate seat is assembled with a pin hole plate having a pin hole, the pin hole plate The needle hole is used for passing a machine needle and a suture, and the movable knife holder is provided with an arc track, wherein the thread cutting device is mainly composed of all knife groups and a transmission device.

The cutter group is adjacent to the pinhole, wherein the cutter group has a fixed cutter, a movable cutter and a thread clamping spring, and the fixed cutter is fixed to the needle plate seat of the side seat cylinder so that the above The fixed cutter is located behind the pinhole of the pinhole plate, and the pinboard seat is located between the feed table and the fixed cutter, and the movable cutter is rotatably connected to the side seat cylinder and has a housing A hook groove portion of the suture and a guide portion that guides the suture to the hook groove portion, and an end of the hook groove portion is provided with a movable blade corresponding to the fixed cutter, wherein the thread clamping spring One end is assembled to the movable knife seat of the side seat cylinder, and the other end is pushed against the movable cutter. In a preferred embodiment, the movable cutter is accommodated in the arc-shaped track, so that the movable cutter swings along the arc-shaped track.

The transmission device is assembled between the movable cutter and the lower shaft, and drives the movable cutter to swing longitudinally along a rotation axis parallel to the lower shaft through the rotation of the lower shaft, so that the movable cutter is sequentially Swinging between an initial position on the side of the pinhole, a hook position away from the initial position, and a cutting position to cut the suture, wherein the transmission device has a cam group and a swing arm , A return spring and a driver, the cam group is disposed on the lower shaft and can rotate synchronously with the lower shaft, and the cam group has a drive that drives the movable cutter to swing from the hook line position to the cutting position The lift path and a return path that drives the movable cutter to swing from the initial position to the hook position.

In this preferred embodiment, the cam set has a first cam and a second cam, the first cam can rotate relative to the lower shaft, so that the relative position between the first cam and the second cam Adjustments can be made, and the relative position between the lift path and the return path can be changed, thereby adjusting the swing time difference of the movable cutter swinging from the hook position to the cutting position.

In addition, one end of the swing arm of the transmission device is assembled to the movable cutter by a connecting rod, and the other end is pivotally connected to the side seat, and the swing arm can be separated from the above at a contact position contacting the cam group The cam group moves back and forth between the separated positions.

In this preferred embodiment, the connecting rod has a first rod body and a second rod body assembled to the first rod body, and a An adjusting device for the relative position between the first rod body and the second rod body, and further the adjusting device can adjust the length of the connecting rod by changing the relative position between the first rod body and the second rod body, wherein The adjusting device has a plurality of screw holes formed in the first rod body and a plurality of long slot holes formed in the second rod body. The plurality of screw holes are located in the plurality of long slot holes by at least one screw pair.

Furthermore, the return spring is installed between the swing arm and the side seat, and can ensure that the roller is continuously located at the separated position, and the driver has a telescopic rod that extends movably toward the swing arm, so that the roller can be The separation position moves to the above-mentioned contact position.

The feature of the present invention is that the fixed cutter of the cutter group is located behind the needle hole and the movable cutter of the cutter group can swing back and forth between the initial position, the hook position and the cutting position around the rotation axis parallel to the lower shaft , So that when the movable cutter cuts the suture at the cutting position, a short thread can be left on the surface of the sewing object to avoid the sewing person needing to trim the thread for the second time.

In addition, the first cam of the cam group can selectively change the relative position between the second cam and the relative position between the lift path and the return path, so that the movable cutter can be adjusted to swing from the hook line position The swing time to the cutoff position is different.

Furthermore, the adjusting device of the connecting rod can change the relative distance between the first rod body and the second rod body, and thus the length of the connecting rod can be lengthened or shortened, so that the movable cutter can be adjusted relative to the above-mentioned needle at the initial position The distance between holes.

In order to facilitate a deeper and more clear and detailed understanding and understanding of the structure, use and characteristics of the present invention, the preferred embodiment is cited, and the detailed description in conjunction with the drawings is as follows:

Please refer to FIG. 2, the thread cutting device 2 of the present invention is mainly applied to a cylindrical sewing machine 20. The cylindrical sewing machine 20 has a head (not shown), a support (not shown) and a base 21. The base 21 forms a work surface 211, and the work surface 211 is installed with a kettle shaft seat 22 which can be moved and adjusted along the X-axis direction and a side seat 23 on the side of the kettle shaft seat 22. The kettle shaft seat 22 can Selectively change the relative position with the needle located in the head.

As shown in FIGS. 2 and 3, the base 21 is provided with a lower shaft 24 and a lower feeding shaft 25. Both the lower shaft 24 and the lower feeding shaft 25 can rotate along the X axis, and the kettle shaft seat 22 extends along the Z axis to form a kettle shaft cylinder 221, the kettle shaft cylinder 221 is provided with a kettle shaft 222 driven by the lower shaft 24 and capable of rotating along the Z axis, and the kettle shaft 222 drives an assembly The rotary hook 26 on the kettle shaft cylinder 221 rotates.

As shown in the figure, the side seat 23 extends along the Z axis to form a side seat cylinder 231, the side seat cylinder 231 has a feed table 231a, a needle plate seat 231b and a movable knife seat 231c, the feed table 231a The top end is assembled with the needle plate holder 231b and a pinhole plate 27 assembled with the needle plate holder 231b. The pinhole plate 27 is provided with a pinhole 271 communicating with the inside of the feeding table 231a, and the pinhole 271 is provided for the machine A needle (not shown) passes through the Z axis in a reciprocating manner, and the movable knife holder 231c is bolted to the feed table 231a of the side seat cylinder 231, and has an arc-shaped track 231d , The opening direction of the arc-shaped track 231d is parallel to the X axis, so that the arc-shaped track 231d faces the rotary hook 26, wherein the side seat cylinder 231 of the side seat 23 is provided with a driven by the lower feed shaft 25 A lower transmission element 232 capable of rotation. The lower transmission element 232 drives a lower feed wheel 28 assembled to the needle plate base 231b to rotate along the X axis through a gear set, and a part of the outer periphery of the lower feed wheel 28 is convex Out of the top surface of the needle plate seat 231b, the lower feed wheel 28 is used to sew the stitched objects during the sewing operation.

Please refer to FIG. 4 and FIG. 5. In order to clearly show the structure of the thread cutting device 2, the drawing of the base 21, the kettle shaft seat 22, the kettle shaft 222, the lower feed shaft 25, the rotary hook 26 and the lower feed wheel are omitted. The structure of 28, as shown in the figure, the thread cutting device 2 is mainly assembled on the side seat 23, and is mainly composed of all knife sets 30 and a transmission device 40.

The cutter set 30 is adjacent to the pinhole 271 of the pinhole plate 27, and is located between the rotary hook 26 and the lower feed wheel 28, wherein the cutter set 30 has a fixed cutter 31 and a movable cutter 32 And a thread clamping spring 33, the fixed cutter 31 is mounted on the needle plate base 231b and is located below the pinhole plate 27, and the fixed cutter 31 has a fixed blade 311 close to the pinhole 271.

As shown in the figure, the movable cutter 32 of the cutter set 30 is located below the needle hole 271, so that the movable cutter 32 and the fixed cutter 31 are arranged longitudinally, and the movable cutter 32 has a connecting pin 321 , A hook groove portion 322 at the end, a guide portion 323 at the end side, and a movable blade 324 formed behind the hook groove portion 322, wherein the movable cutter 32 is movably assembled to the movable blade In the arc-shaped track 231d of the seat 231c, the movable cutter 32 can swing in the arc-shaped track 231d along a rotation axis 231e parallel to the lower shaft 24. In this embodiment, the movable knife holder 231c is provided with two pressing plates 34, and a partial section of the pressing plate 34 covers the arc-shaped track 231d, so that the two pressing plates 34 can prevent the movable cutter 32 from separating from the arc-shaped track 231d.

6A to 6C, the movable cutter 32 is located in the arc-shaped track 231d at an initial position 325 on the side of the pinhole 271, a hook position 326 away from the initial position 325, and a The three cutting positions 327 close to the pinhole 271 swing along the rotation axis 231e. When the movable cutter 32 swings from the hook position 326 to the cutting position 327, the movable cutting The hook groove portion 322 of the knife 32 passes right under the needle hole 271, so that the movable blade 324 contacts the fixed blade 311 to cut a stitch L (as shown in FIG. 12C).

4 and FIG. 5 again, the thread clamping spring 33 of the cutter set 30 is provided with an assembly portion 331 assembled on the movable blade holder 231c and a thread clamping portion 332 on the side of the assembly portion 331 In which, the thread clamping spring 33 itself has elastic characteristics, so that the thread clamping portion 332 is pushed against the movable cutter 32, and then the movable cutter 32 cuts the suture L, the thread clamping spring 33 The thread clamping portion 332 can clamp the suture L released by the rotary hook 26.

The transmission device 40 is used to drive the movable cutter 32 of the cutter set 30 to swing longitudinally along the rotation axis 231e, so that the movable cutter 32 is sequentially in the initial position 325, the hook position 326 and the cutting position Oscillating between 327, as shown in the figure, the transmission device 40 has a fixed seat 41, a cam group 42, a connecting rod 43, a return spring 44 and a driver 45. The fixed seat 41 is fixedly connected to the side seat 23, and the cam group 42 is installed on the lower shaft 24, and can rotate synchronously with the lower shaft 24 along the X axis in the same direction.

In this embodiment, the cam group 42 has a first cam 421 and a second cam 422 located on the side of the first cam 421. The first cam 421 has a first passage for the lower shaft 24 to penetrate A hole 421a and a lift path 421b at the outer edge, and the second cam 422 has a second through hole 422a for the lower shaft 24 to pass through and a return path 422b at the outer edge, wherein the lift path 421b is used to drive the movable cutter 32 to swing from the hook position 326 to the cutting position 327, and the return path 422b is used to drive the movable cutter 32 to swing from the initial position 325 to the hook position 326.

Referring to FIGS. 7A and 7B, a plurality of screws penetrates through the first through hole 421a from the outer edge of the hub of the first cam 421, so that the end surfaces of the plurality of screws simultaneously touch the surface of the lower shaft 24 Furthermore, the first cam 421 is fixed to the lower shaft 24, so that the first cam 421 cannot rotate relative to the lower shaft 24. Similarly, the second cam 422 is also fixed to the lower shaft 24 by a plurality of screws.

However, the first cam 421 can rotate relative to the lower shaft 24 when the plurality of screws are not touching the surface of the lower shaft 24, thereby, between the first cam 421 and the second cam 422 The relative position of can be adjusted by rotation, and at the same time, the relative angular position between the lift path 421b and the return path 422b can be changed, so that the movable cutter 32 can be adjusted to swing from the initial position 325 to the hook position 326 ( Or the swing time from swinging the hook position 326 to the cutting position 327).

In this preferred embodiment, an angle is formed between the lift path 421b and the return path 422b, and the first cam 421 is rotated to adjust the relative position between the second cam 422 and the lift The angle between the path 421b and the return path 422b becomes larger (as shown in FIG. 7B), and then swings from the initial position 325 to the hook position 326 earlier (or delays swinging from the hook position 326 to the cutting position 327) ), On the contrary, change the relative position between the first cam 421 and the second cam 422, so that the angle between the lift path 421b and the return path 422b becomes smaller, thereby delaying the movable cutter 32 from the above The swing timing of the initial position 325 swinging to the hook position 326 (or earlier swinging from the hook position 326 to the cutting position 327).

4 and 5 again, the connecting rod 43 of the transmission device 40 is mainly composed of a first rod body 431 and a second rod body 432 assembled with each other, and the first rod body 431 of the connecting rod 43 Assembled on the connecting pin 321 of the movable cutter 32, and the second rod body 432 is connected to a swing arm 434 through a link pin 433, the swing arm 434 is pivotally connected to the fixing seat 41, and has a The roller 435 selectively contacts the roller 435 of the cam group 42. In this embodiment, the link pin 433 is pivotally connected to the second lever body 432, and the roller 435 can simultaneously contact the first cam 421 and Second cam 422.

8A and 8B, since the swing arm 434 is pivotally connected to the fixing base 41, the roller 435 can be in contact with the cam group 42 at a separation position 435a separated from the cam group 42 The position 435b moves back and forth along the X axis, while the roller 435 moves back and forth between the separation position 435a and the contact position 435b, the swing arm 434 can drive the link 43 via the link pin 433 mobile. In this embodiment, when the roller 435 is located at the contact position 435b, the roller 435 can contact the lift path 421b or the return path 422b.

9A and 9B, an adjustment device 436 capable of changing the relative position between the first rod 431 and the second rod 432 is provided between the first rod 431 and the second rod 432, and The connecting rod 43 can be extended or shortened by the adjusting device 436. As shown in the figure, the adjusting device 436 has a plurality of screw holes 436a, a plurality of long slot holes 436b, and a plurality of screws 436c, wherein the plurality of screw holes 436a and a plurality of long slot holes 436b are formed in the first rod body 431 and the second rod body 432 respectively, by which the relative position between the first rod body 431 and the second rod body 432 can be finely adjusted to change the above The distance between the connecting pin 321 and the connecting catch 433 can further adjust the distance between the movable cutter 32 and the pinhole 271 when the movable cutter 32 is at the initial position 325.

Please refer to FIG. 4, FIG. 10 and FIG. 11 at the same time, one end of the return spring 44 is hooked on the link pin 433 of the swing arm 434, and the other end is hooked on a connecting plate 46 assembled on the fixing base 41. The return spring 44 is used to ensure that the roller 435 is continuously maintained at the separation position 435a. However, the return spring 44 is hooked to the link pin 433 and the connecting plate 46 at the two ends respectively for illustrative purposes only, that is, the return spring The two ends of 44 can be hooked on the connecting rod 43 and the connecting plate 46 respectively, which can also achieve the effect that the roller 435 can continue to maintain the separation position 435a, and the driver 45 is assembled on the fixing base 41 and has a direction toward the swing The arm 434 moves the telescopic rod 451 so that the telescopic rod 451 can be pushed against the roller 435, and the roller 435 swings from the separation position 435a to the contact position 435b. In this embodiment, the driver 45 is an electromagnet, and the electromagnet can make the telescopic rod 451 move outwards according to the magnetic force generated after the power is applied.

As shown in FIG. 12A, when the column sewing machine 20 performs sewing operation without thread trimming, the driver 45 does not extend the telescopic rod 451 toward the swing arm 434, so that the telescopic rod 451 has no contact The roller 435 and the swing arm 434 are biased downward by the elastic tension of the return spring 44 so that the roller 435 continues to be located at the separation position 435a. At this time, the roller 435 is not in contact with the rotating rotor. The cam group 42 is such that the link 43 of the transmission device 40 can keep the movable cutter 32 at the initial position 325 when the roller 435 is at the separation position 435a.

Referring to FIG. 12B, when the above-mentioned cylindrical sewing machine 20 performs sewing operation to the last stitch and starts thread trimming, the above-mentioned needle passes the above-mentioned sewing thread L through the sewing object along the Z-axis direction, and Disengage the suture L from the pinhole 271, and then activate the driver 45 (the electromagnet is energized), so that the driver 45 drives the telescopic rod 451 to be pushed out, and then the telescopic rod 451 will be pushed against the roller 435 So that the roller 435 deflects from the separation position 435a to the contact position 435b.

Next, the outer diameter of the cam group 42 and the return path 422b sequentially touch the roller 435, so that the swing arm 434 is pushed by the telescopic rod 451 to deflect upward, and then the swing arm 434 passes through the link 43 The movable cutter 32 is driven to swing from the initial position 325 about the rotation axis 231e counterclockwise to the hook position 326. At this time, the guide portion 323 of the movable cutter 32 guides the suture L To the hook groove portion 322, the suture L falls into the hook groove portion 322.

Referring to FIG. 12C, the cam group 42 continues to rotate, and the actuator 45 is turned off (the electromagnet is de-energized), so that the telescopic rod 451 loses its thrust, and the lift path 421B of the cam group 42 contacts the roller 435. Then, the swing arm 434 is biased downward by the pressure of the lift path 421B, so that the swing arm 434 drives the movable cutter 32 through the connecting rod 43 from the hook position 326 around the rotation axis The core 231e swings clockwise to the cutting position 327, so that the movable blade 324 and the fixed blade 311 jointly cut the suture L, and the thread clamping portion 332 of the thread clamping spring 33 pushes upward to contact the activity The cutter 32 further allows the suture L released by the rotary hook 26 to be caught when the suture L is cut.

Finally, after the thread trimming operation is completed, the swing arm 434 is pulled by the return spring 44 and continues to maintain the initial position 325.

The above-mentioned embodiments are only for the convenience of describing the present invention and are not limiting. Without departing from the spirit of the present invention, those skilled in the art who are familiar with this industry and applying the patent scope of the present invention and various simple modifications and modifications made by the invention description should still Included in the following patent applications.

1‧‧‧Conventional thread cutting device

10‧‧‧Fixed knife

11‧‧‧ movable knife

12‧‧‧Hook seat

13‧‧‧Fixed knife holder

14‧‧‧Pivot

15‧‧‧ Swing arm

2‧‧‧Thread trimming device

20‧‧‧Column sewing machine

21‧‧‧Base

211‧‧‧Worktop

22‧‧‧ Kettle shaft seat

221‧‧‧ Kettle shaft cylinder

222‧‧‧ Kettle shaft

23‧‧‧Side seat

231‧‧‧Side post

231a‧‧‧Feeding table

231b‧‧‧Needle plate holder

231c‧‧‧movable knife holder

231d‧‧‧Arc track

231e‧‧‧rotation axis

232‧‧‧Lower transmission element

24‧‧‧lower axis

25‧‧‧Lower feeding shaft

26‧‧‧Hook

27‧‧‧Pinhole plate

271‧‧‧Pinhole

28‧‧‧Lower feed wheel

30‧‧‧Cutter set

31‧‧‧Fixed cutter

311‧‧‧Fixed blade

32‧‧‧Mobile cutter

321‧‧‧Connecting pin

322‧‧‧Hook groove part

323‧‧‧Guiding Department

324‧‧‧Mobile Blade

325‧‧‧Initial position

326‧‧‧Hook position

327‧‧‧cut off position

33‧‧‧clamp shrapnel

331‧‧‧Assembly Department

332‧‧‧Thread clamping department

34‧‧‧Press plate

40‧‧‧ Transmission

41‧‧‧Fixed seat

42‧‧‧Cam group

421‧‧‧ First cam

421a‧‧‧First through hole

421b‧‧‧lift path

422‧‧‧Second cam

422a‧‧‧Second through hole

422b‧‧‧Return path

43‧‧‧Link

431‧‧‧The first rod

432‧‧‧Second rod

433‧‧‧Link pin

434‧‧‧ Swing arm

435‧‧‧wheel

435a‧‧‧ Separation position

435b‧‧‧Contact position

436‧‧‧Adjustment device

436a‧‧‧screw hole

436b‧‧‧Long slot

436c‧‧‧screw

44‧‧‧Return spring

45‧‧‧Drive

451‧‧‧ Telescopic pole

46‧‧‧Connecting board

L‧‧‧Suture

1 is a schematic view of a conventional thread cutting device; FIG. 2 is a schematic view of a cylindrical sewing machine of the present invention; FIG. 3 is a perspective view of a partial mechanism of a cylindrical sewing machine of the present invention; FIG. 4 is a schematic view of the thread cutting device of the present invention assembled on a side seat; It is an exploded view of the thread cutting device of the present invention; FIG. 6A is a schematic view of the movable cutter of the present invention at the initial position; FIG. 6B is a schematic view of the movable cutter of the present invention at the hook line position; FIG. 6C is a movable cutter of the present invention at the cutting position 7A and 7B are schematic diagrams of the relative position between the first cam and the second cam of the present invention; FIG. 8A is a schematic diagram of the roller of the present invention in a separated position; FIG. 8B is a schematic diagram of the roller of the present invention in a contact position; 9A and 9B are schematic diagrams of the connecting rod of the present invention to change the length; FIG. 10 is a schematic diagram of the return spring pulling the swing arm; FIG. 11 is a schematic diagram of the driver pushing the swing arm; FIG. 12A is a schematic diagram of the thread trimming device of the present invention without thread trimming; FIG. 12C is a schematic diagram of the thread cutting device of the present invention hooking a suture; and FIG. 12C is a schematic diagram of the thread cutting device of the present invention performing thread cutting.

Claims (8)

A thread cutting device for a cylindrical sewing machine is assembled on a side seat. The side seat has a side seat cylinder extending along a longitudinal axis and a lower shaft that can rotate. The side seat cylinder is provided with a thread for threading The thread cutting device includes: a knife set having a fixed cutter fixed to the side seat cylinder and a movable cutter movably connected to the side seat cylinder, the fixed cutter located at the needle Behind the hole; and a transmission device, which is assembled to the movable cutter, and can drive the movable cutter to swing along a rotation axis parallel to the lower shaft, so that the movable cutter is located in the pinhole in sequence The initial position on one side, a hook position away from the initial position, and a cutting position to cut the suture are oscillated. According to the thread cutting device of the column-type sewing machine according to item 1 of the patent application scope, the above-mentioned side seat cylinder includes: a feeding table; a needle plate seat, assembled between the above feeding table and the fixed cutter, and assembling a A pinhole plate with the above-mentioned pinholes; a movable knife seat, assembled on the feeding table, and forming an arc-shaped track accommodating the movable knife, so that the movable knife swings along the arc-shaped track. According to the thread cutting device of the column-type sewing machine according to item 1 of the patent application, wherein the movable cutter has a hook groove portion for accommodating the suture and a guide portion for guiding the suture to the hook groove, The end of the hook groove is provided with a movable blade corresponding to the fixed cutter. According to the thread cutting device of the column sewing machine according to item 1 of the patent application scope, the cutter set further includes a thread clamping spring, one end of the thread clamping spring is assembled to the side seat cylinder, and the other end is pushed against the movable cutting Knife. According to the thread-cutting device of the column-type sewing machine according to item 1 of the patent application scope, the transmission device includes: a cam group assembled on the lower shaft and capable of rotating synchronously with the lower shaft; a swing arm, with one end The connecting rod is assembled to the movable cutter, and the other end is pivotally connected to the side seat; and a driver has a telescopic rod movably extending toward the swing arm, so that the swing arm is pushed against by the telescopic rod and separated by a The separation position of the cam group swings to a contact position that contacts the cam group. According to the thread cutting device of the column sewing machine according to item 5 of the patent application range, the cam group has a first cam and a second cam, the first cam can rotate relative to the lower shaft, so that the first cam The relative position with the above-mentioned second cam can be selectively changed. According to the thread cutting device of the column-type sewing machine according to item 5 of the patent application scope, wherein the connecting rod has a first rod body and a second rod body assembled to the first rod body, the first rod body and the second An adjusting device for changing the relative position between the first rod body and the second rod body is provided between the rod bodies, so that the length of the connecting rod can be adjusted. According to the thread cutting device of the column sewing machine according to item 5 of the patent application range, the transmission device further has a return spring, one end of the return spring is installed on the side seat, and the other end is installed on the swing arm or link, And can ensure that the roller is continuously located at the separation position.