CN107916506A - Thread cutting device for column type sewing machine - Google Patents

Abstract

The invention provides a thread cutting device of a column-shaped sewing machine, which is assembled on a side seat with a pinhole and mainly comprises a cutter group, a transmission device and a lower shaft, wherein a fixed cutter of the cutter group is positioned behind the pinhole, and a movable cutter of the cutter group is movably assembled on the side seat, wherein the transmission device is assembled on the movable cutter and can drive the movable cutter to swing from a thread hooking position positioned at one side of the pinhole to a cutting position for cutting a thread around a rotating shaft center parallel to the lower shaft. Therefore, the fixed cutter is positioned behind the needle hole, and the movable cutter can swing back and forth between the thread hooking position and the cutting position around the rotating shaft center, so that when the movable cutter cuts off the thread at the cutting position, the thread end with shorter length can be remained on the surface of the sewing object.

Description

Thread cutting device for column type sewing machine

technical field

The invention relates to a thread cutting device of a column type sewing machine, in particular to a thread cutting device capable of leaving a relatively short thread end on a sewing object after cutting the thread.

Background technique

The sewing machine is mainly to combine several layers of sewing materials with each other through sewing, and, with the continuous evolution of technology, there are many types of sewing machines on the market, and different styles of sewing machines can be applied to different cars. The sewing operation of sewing thing, wherein, existing a kind of column type sewing machine that is applicable to sewing shoes, bag shape thing or cylindrical thing on the market at present.

However, when the column type sewing machine is finished sewing, in order to cut off the sutures conveniently, an existing thread cutting device 1 for cutting the sutures will be set on the column type sewing machine. Please refer to Fig. 1, the existing thread cutting device 1 mainly There is a fixed knife 10 and a movable knife 11, the fixed knife 10 is arranged on a fixed knife seat 13 in a hook seat 12, and the movable knife 11 is pivotally connected to the The upper end of the hook seat 12 is assembled with a swing arm 15 from the lower end of the pivot 14, and 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 shaft 14 can drive the movable knife 11 to swing around the pivot shaft 14 (z-axis in the figure) to perform thread hooking and thread cutting operations.

However, since both the fixed knife 10 and the movable knife 11 are arranged on the hook seat 12, the blade edges of the fixed knife 10 and the movable knife 11 are far away from the pinhole, so that the movable knife 11. When the suture is cut off, there will be a longer length of thread remaining on the surface of the sewing object, so that even if the suture is cut off by the movable knife 11, it is still necessary to manually cut the longer length of the thread in some applications. short.

In view of the aforesaid deficiency of the thread trimming device currently used in the cylindrical sewing machine, it is necessary to innovate and improve the thread trimming device so that after the thread trimming device cuts off the suture, a relatively short thread remains on the surface of the sewing object.

Contents of the invention

The main purpose of the present invention is that after the suture is cut off, the thread end with a shorter length can be left on the surface of the sewing object, so as to avoid the need for the sewing person to trim the thread end for the second time, so as to shorten the working time and improve the quality of the thread. Production.

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

To achieve the stated purpose, the present invention provides a thread cutting device of a cylindrical sewing machine, which is assembled on a side seat, and the side seat has a side seat cylinder extending along the longitudinal axis and a lower shaft capable of rotating. The side seat cylinder is provided with a pinhole for a suture to pass through, and it is characterized in that the thread cutting device includes:

A cutter 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 is located behind the pinhole; and

A transmission device, assembled on the movable cutter, and capable of driving the movable cutter to swing along a direction parallel to the rotation axis of the lower shaft, so that the movable cutter is sequentially positioned at a It swings between an initial position on one side of the needle hole, a hooking position away from the initial position, and a cutting position for cutting off the suture.

The thread cutting device of the cylindrical sewing machine, wherein: the side seat cylinder contains:

a feeding table;

A needle plate seat is assembled between the feeding table and the fixed cutter, and a needle hole plate with the needle holes is assembled;

A movable knife seat is assembled on the feeding table, and forms an arc track for accommodating the movable cutter, so that the movable cutter can swing along the arc track.

The thread cutting device of the cylindrical sewing machine, wherein: the movable cutting tool has a groove part for accommodating the suture and a guide part for guiding the thread to the groove part, and the The end of the hook groove is provided with a movable blade corresponding to the fixed cutter.

The thread cutting device of the cylindrical sewing machine, wherein: the cutter set also has a thread clamping elastic piece, one end of the thread clamping elastic piece is assembled on the side seat cylinder, and the other end is pushed against the movable cutter.

The thread cutting device of the cylindrical sewing machine, wherein the transmission device includes:

a cam group assembled on the lower shaft and capable of synchronously rotating with the lower shaft;

a swing arm, one end is assembled to the movable cutter by a connecting rod, and the other end is pivotally connected to the side seat; and

A driver, with a telescopic rod extending toward the swing arm, so that the swing arm is pushed by the telescopic rod and swings from a separated position separated from the cam group to a position in contact with the cam group contact position.

The thread cutting device of the cylindrical sewing machine, wherein: the cam set has a first cam and a second cam, and the first cam can rotate relative to the lower shaft, so that the first cam can select change the relative position with the second cam.

The thread cutting device of the cylindrical sewing machine, wherein: the connecting rod has a first rod body and a second rod body assembled on the first rod body, and a device is arranged between the first rod body and the second rod body The adjustment device for changing the relative position between the first rod body and the second rod body can further adjust the length of the connecting rod.

The thread cutting device of the cylindrical sewing machine, wherein: the transmission device also 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 connecting rod, and can Make sure that the rollers remain in the disengaged position.

The present invention is characterized in that the fixed cutter of the cutter group is located behind the pinhole and the movable cutter of the cutter group can swing back and forth between the initial position, the line-drawing position and the cutting position around the rotation axis parallel to the lower shaft, When the movable cutter cuts off the suture at the cutting position, a shorter length of thread ends can remain on the surface of the sewing object, so that the sewing person needs to trim the thread ends for the second time.

In addition, the relative position between the first cam of the cam group and the second cam can be selectively changed, and then the relative position between the lift path and the return path can be changed, so that the movable cutter can be adjusted to swing from the hook line position Swing time difference to cut-off position.

Moreover, the adjusting device of the connecting rod can change the relative distance between the first rod body and the second rod body, and then the length of the connecting rod can be elongated or shortened, so that the movable cutter can be adjusted relative to the needle hole when it is in the initial position. the distance between.

Description of drawings

Fig. 1 is the schematic diagram of existing thread cutting device;

Fig. 2 is the schematic diagram of column type sewing machine of the present invention;

Fig. 3 is the perspective view of the partial mechanism of the column type sewing machine of the present invention;

Fig. 4 is a schematic diagram of the assembly of the thread cutting device of the present invention on the side seat;

Fig. 5 is an exploded view of the thread cutting device of the present invention;

Fig. 6A is a schematic diagram of the movable cutter in the initial position of the present invention;

Fig. 6B is a schematic diagram of the movable cutter of the present invention at the hook line position;

Fig. 6C is a schematic diagram of the movable cutter in the cutting position of the present invention;

Fig. 7A and Fig. 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 rollers in the separation position of the present invention;

Fig. 8B is a schematic diagram of the roller in the contact position of the present invention;

Fig. 9A and Fig. 9B are schematic diagrams showing the changing length of the connecting rod of the present invention;

Fig. 10 is a schematic diagram of the return spring pulling the swing arm;

Figure 11 is a schematic diagram of the driver pushing the swing arm;

Fig. 12A is a schematic diagram of the thread cutting device of the present invention without thread cutting;

Fig. 12B is a schematic diagram of the thread cutting device hooking the suture according to the present invention;

Fig. 12C is a schematic diagram of thread cutting by the thread cutting device of the present invention.

Explanation of reference signs: 1-existing thread cutting device; 10-fixed knife; 11-movable knife; 12-rotating hook seat; 13-fixed knife seat; 14-pivot; 15-swing arm; 2-thread cutting device; -column type sewing machine; 21-base; 211-working table; 22-kettle shaft seat; 221-kettle shaft cylinder; 222-kettle shaft; -needle plate seat; 231c-movable knife seat; 231d-arc track; 231e-rotation axis; 232-lower transmission assembly; 24-lower shaft; 25-lower feeding shaft; ;271-pinhole; 28-bottom feeding wheel; 30-cutter group; 31-fixed cutter; 311-fixed blade; 32-movable cutter; 321-connecting pin; 324-movable blade; 325-initial position; 326-hook line position; 327-cutting position; 33-clamp shrapnel; 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-connection Rod; 431-first rod body; 432-second rod body; 433-connecting rod pin; 434-swing arm; 435-roller; 435a-separation position; 435b-contact position; 436-adjustment device; - slotted hole; 436c - screw; 44 - return spring; 45 - driver; 451 - telescopic rod; 46 - connection plate; L - suture.

Detailed ways

The present invention will be further described below in combination with specific embodiments and accompanying drawings, and the advantages and characteristics of the present invention will become clearer along with the description.

Please refer to FIG. 2, the thread cutting device 2 of the present invention is mainly applied to a column type sewing machine 20, and the column type sewing machine 20 has three parts: a head (not shown), a pillar (not shown) and a base 21, Wherein, the base 21 forms a worktable 211, and the worktable 211 is equipped with a kettle shaft seat 22 that can be moved and adjusted along the X-axis direction and a side seat 23 located on one side of the kettle shaft seat 22. The still shaft seat 22 can selectively change its relative position with the machine needles located at the headstock.

Please refer to Fig. 2 and Fig. 3, the base 21 is provided with a lower shaft 24 and a lower feeding shaft 25, both of the lower shaft 24 and the lower feeding shaft 25 can rotate along the X axis, and the The kettle shaft seat 22 extends along the Z axis to form a kettle shaft cylinder 221, and the inside of the kettle shaft cylinder 221 is provided with a kettle shaft 222 that is driven by the lower shaft 24 and can rotate along the Z axis. The kettle shaft 222 drives a rotary hook 26 assembled on the kettle shaft cylinder 221 to rotate.

As shown in the figure, the side seat 23 extends along the Z axis to form a side seat cylinder 231, and the side seat cylinder 231 has a feeding platform 231a, a needle plate seat 231b and a movable knife seat 231c. The top of the platform 231a is assembled with the needle plate base 231b and a pinhole plate 27 assembled on the needle plate base 231b. The pinhole plate 27 is provided with a pinhole 271 communicating with the inside of the feeding table 231a, and the The needle hole 271 is used for the machine needle (not shown) to pass through in a reciprocating motion along the Z axis, and the movable knife seat 231c is fixedly connected to the feeding material of the side seat cylinder 231 by bolts. platform 231a, and has an arc track 231d, the opening direction of the arc track 231d is parallel to the X axis, so that the arc track 231d faces the rotary hook 26, wherein the side seat of the side seat 23 Inside the cylinder 231 is provided a lower transmission assembly 232 which is driven by the lower feeding shaft 25 and can rotate. Rotate along the X-axis, and part of the periphery of the lower feeding wheel 28 protrudes outside the top surface of the needle plate seat 231b, so that the lower feeding wheel 28 drives the sewing object during the sewing operation.

Please refer to Figures 4 and 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 feeding shaft 25, the rotary hook 26 and the lower shaft are omitted. The structure of the feeding wheel 28 is as shown in the figure, the thread cutting device 2 is mainly assembled on the side seat 23 , and is mainly composed of a cutter set 30 and a transmission device 40 .

The cutter group 30 is adjacent to the pinhole 271 of the pinhole plate 27, and is located between the hook 26 and the lower feeding wheel 28, wherein the cutter group 30 has a fixed cutter 31, a The movable cutter 32 and a clamping elastic piece 33, the fixed cutter 31 is installed on the needle plate seat 231b, and is located below the needle hole plate 27, and the fixed cutter 31 has a The fixed blade 311 of the pinhole 271 .

As shown in the figure, the movable cutter 32 of the cutter group 30 is located below the pinhole 271, so that both 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 322 at the end, a guide 323 at one side of the end, and a movable blade 324 formed behind the hook groove 322, wherein the movable cutter 32 It is movably assembled in the arc track 231d of the movable knife seat 231c, so that the movable cutter 32 can swing along a rotation axis 231e parallel to the lower shaft 24 in the arc track 231d, In this embodiment, the movable knife seat 231c is provided with two pressure plates 34, and a partial section of the pressure plates 34 covers the arc-shaped track 231d, so that the two pressure plates 34 can prevent the movable cutter 32 from separating on the arc track 231d.

Please refer to FIG. 6A to FIG. 6C, the movable cutter 32 is located in the arc track 231d at an initial position 325 on one side of the pinhole 271, and a hook line away from the initial position 325. Position 326 and a cutting position 327 close to the pinhole 271 swing along the rotation axis 231e, wherein, when the movable cutter 32 swings from the hooking position 326 to the cutting When the position is 327, the groove part 322 of the movable cutter 32 will pass directly under the pinhole 271, so that the movable blade 324 contacts the fixed blade 311 to cut a suture L (as shown in FIG. 12C ). Show).

Referring to Figure 4 and Figure 5 again, the clamping elastic piece 33 of the cutter set 30 is provided with an assembly part 331 assembled on the movable knife seat 231c and a clip located on the side of the assembly part 331. Thread part 332, wherein, the thread clamping elastic piece 33 itself has elastic properties, so that the thread clamping part 332 pushes against the movable cutter 32, and then when the movable cutter 32 cuts the suture L , the thread clamping portion 332 of the thread clamping elastic piece 33 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 group 30 to swing longitudinally along the rotation axis 231e, so that the movable cutter 32 is in the initial position 325, the line-drawing position in sequence. 326 and the cut-off position 327 to swing, as shown in the figure, the transmission device 40 has a fixed seat 41 , a cam set 42 , a connecting rod 43 , a return spring 44 and a driver 45 . The fixing seat 41 is fixedly connected to the side seat 23 , and the cam set 42 is installed on the lower shaft 24 and can rotate in the same direction along the X-axis with the lower shaft 24 synchronously.

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

Please refer to Fig. 7A and Fig. 7B, a plurality of screws pass 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 are in contact with the lower shaft at the same time. 24, so that the first cam 421 is fixed on the lower shaft 24, so that the first cam 421 cannot rotate relative to the lower shaft 24, and the second cam 422 is also composed of multiple Screws are fixed on the lower shaft 24 .

However, the first cam 421 can rotate relative to the lower shaft 24 when the plurality of screws do not interfere with the surface of the lower shaft 24, whereby the first cam 421 and the first cam 421 The relative position between the two cams 422 can be adjusted through rotation, thereby simultaneously changing the relative angular position between the lift path 421b and the return path 422b, so that the movable cutter 32 can be adjusted from the initial position 325 The time difference between swinging to the line hooking position 326 (or swinging from the line hooking position 326 to the cutting position 327 ).

In this preferred embodiment, an included angle is formed between the lift path 421b and the return path 422b, and the relative position between the first cam 421 and the second cam 422 is adjusted through rotation, Make the included angle between the lift path 421b and the return path 422b larger (as shown in FIG. 7B ), and then swing from the initial position 325 to the hook line position 326 earlier (or delay from the hook line Position 326 swings to the swing timing of the cut-off position 327), on the contrary, change the relative position between the first cam 421 and the second cam 422, so that the included angle between the lift path 421b and the return path 422b become smaller, thereby delaying the swinging sequence of the movable cutter 32 swinging from the initial position 325 to the line hooking position 326 (or earlier from the line hooking position 326 to the cutting position 327).

Referring to Figure 4 and Figure 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 is assembled The connecting pin 321 of the movable cutter 32, and the second rod body 432 is connected to a swing arm 434 through a connecting rod pin 433, and the swing arm 434 is pivotally connected to the fixed seat 41, and has a The roller 435 for selectively resisting the cam set 42, in this embodiment, the link pin 433 is pivotally connected to the second rod 432, and the roller 435 can simultaneously resist the first A cam 421 and a second cam 422 .

Please refer to FIG. 8A and FIG. 8B, since the swing arm 434 is pivotally connected to the fixed base 41, the roller 435 can be in contact with the cam group 42 at a separate position 435a. The contact position 435b of the cam group 42 moves back and forth along the X axis, and during the process of the roller 435 moving back and forth between the separation position 435a and the contact position 435b, the swing arm 434 can pass through the connecting rod The pin 433 drives the connecting rod 43 to move. In this embodiment, when the roller 435 is located at the contact position 435b, the roller 435 can interfere with the lift path 421b or the return path 422b.

Please refer to FIG. 9A and FIG. 9B, an adjustment device 436 capable of changing the relative position between the first rod body 431 and the second rod body 432 is provided between the first rod body 431 and the second rod body 432, and the The connecting rod 43 can be extended or shortened by the adjustment device 436. As shown in the figure, the adjustment device 436 has a plurality of screw holes 436a, a plurality of slotted holes 436b and a plurality of screws 436c, wherein the plurality of A screw hole 436a and a plurality of slotted holes 436b are respectively formed in the first rod body 431 and the second rod body 432, whereby the relative position between the first rod body 431 and the second rod body 432 can be fine-tuned to change the The distance between the connecting pin 321 and the driving pin 433 can be adjusted, and then the distance between the movable cutter 32 and the pinhole 271 can be adjusted when the movable cutter 32 is located 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 to the link pin 433 of the swing arm 434 , and the other end is hooked to a pin assembled on the fixed seat 41. The connection plate 46, the return spring 44 is used to ensure that the roller 435 is continuously maintained at the separation position 435a, however, the two ends of the return spring 44 are respectively hooked on the link pin 433 and the connection plate 46 for convenience only. For the purpose of illustration, that is, the two ends of the return spring 44 can be hooked on the connecting rod 43 and the connecting plate 46 respectively, and the effect that the roller 435 can be continuously kept at the separation position 435a can also be achieved, and the driver 45 is assembled on the fixed seat 41, and has a telescopic rod 451 that moves and expands toward the swing arm 434, so that the telescopic rod 451 can push against the roller 435, so that the roller 435 can move from the separated position 435a swings to said contact position 435b. In this embodiment, the driver 45 is configured as an electromagnet, and the electromagnet can make the telescopic rod 451 move and extend outward according to the magnetic force generated after electrification.

Please refer to FIG. 12A , when the cylindrical sewing machine 20 is sewing but not thread-cutting, the driver 45 does not extend the telescopic rod 451 toward the swing arm 434 , so that the The telescopic rod 451 does not interfere with the roller 435, and the swing arm 434 is biased downward by the elastic tension of the return spring 44, so that the roller 435 is continuously located at the separation position 435a. At this time, the The roller 435 is not in contact with the rotating cam group 42, so that the connecting rod 43 of the transmission device 40 can keep the movable cutter 32 at the disengaged position 435a when the roller 435 is in the separation position 435a. The initial position 325 is described.

Please refer to FIG. 12B , when the cylindrical sewing machine 20 performs the sewing operation to the last stitch and starts to tangentially move, the needle moves upward along the Z-axis to pass the suture L through the sewing. object, and the suture L is separated from the pinhole 271, and then the driver 45 is activated (the electromagnet is energized), so that the driver 45 drives the telescopic rod 451 to push out, and then the telescopic rod 451 will be pushed against the roller 435, so that the roller 435 is deflected from the separation position 435a to the contact position 435b.

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

Please refer to FIG. 12C , the cam set 42 continues to rotate, and the driver 45 is closed (the electromagnet is powered off), so that the telescopic rod 451 loses thrust, and the lift path 421b of the cam set 42 is in conflict with The roller 435 further causes the swing arm 434 to swing downward due to the pressure of the lift path 421b, so that the swing arm 434 drives the movable cutter 32 through the connecting rod 43. The thread hooking position 326 swings clockwise around the rotation axis 231e to the cutting position 327, so that the movable blade 324 and the fixed blade 311 cut off the suture L together, and the thread clamping elastic piece 33 The clamping portion 332 of the thread clamping portion 332 pushes upwards to contact the movable cutter 32, so that the suture L released by the rotary hook 26 can be clamped when the suture L is cut.

Finally, after the thread cutting operation is completed, the swing arm 434 is pulled by the return spring 44 and remains at the initial position 325 .

The above descriptions and examples are only exemplary and do not constitute any limitation to the scope of the present invention. Those skilled in the art should understand that the details and forms of the technical solutions of the present invention can be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the protection scope of the present invention.

Claims (8)

1. a kind of thread cutter of column type sewing machine, is assembled in a side seat, what the side seat was extended to form with one along the longitudinal axis Side seat column casing and a lower axle that can be rotated, the side seat column casing are equipped with a pin hole penetrated for a suture, its feature exists In the thread cutter includes：

One cutter group, has one to be fixed on the fixed cutting tool of the side seat column casing and one be movably connected on the side seat column casing Moving cutting tool, the fixed cutting tool are located at the pin hole rear；And

One transmission device, is assembled in the moving cutting tool, and can drive the moving cutting tool along one parallel to the lower axle The direction of axis of rotation is swung, make the moving cutting tool sequentially one positioned at the pin hole side initial position, one remote Swung between the off-position of the hooking position of the initial position and a cut-out suture.

2. the thread cutter of column type sewing machine according to claim 1, it is characterised in that：The side seat column casing includes：

One feeding table；

One pin holder, is connected between the feeding table and fixed cutting tool, and assembles a pinhole plate with the pin hole；

One movable tool apron, is assembled in the feeding table, and forms an arc track for housing the moving cutting tool, makes the activity Cutter is swung along the arc track.

3. the thread cutter of column type sewing machine according to claim 1, it is characterised in that：The moving cutting tool has one to hold Put the suture hook groove portion and one by the suture be directed to it is described hook groove portion guidance part, and it is described hook groove portion end Equipped with a mobile blade for corresponding to the fixed cutting tool.

4. the thread cutter of column type sewing machine according to claim 1, it is characterised in that：The cutter group also has a folder Line shrapnel, described Trap shell splinter one end are assembled in the side seat column casing, and the other end is pushed against in the moving cutting tool.

5. the thread cutter of column type sewing machine according to claim 1, it is characterised in that the transmission device includes：

One cam set, is assembled in the lower axle, and synchronous can be rotated with the lower axle；

One swing arm, one end are loaded on the moving cutting tool by a connection rod set, and the other end is pivotally connected to the side seat；And

One driver, has a telescopic rod towards swing arm activity extension, makes the swing arm be subject to the telescopic rod to push against And a contact position for being contacted with the cam set is rocked to by a separation point position for being located away from the cam set.

6. the thread cutter of column type sewing machine according to claim 5, it is characterised in that：The cam set has one first Cam and one second cam, first cam can be rotated relative to the lower axle so that first cam can select Select the relative position sexually revised between second cam.

7. the thread cutter of column type sewing machine according to claim 5, it is characterised in that：The connecting rod has one first bar Body and second body of rod for being assembled in first body of rod, are equipped with one to change between first body of rod and second body of rod The adjusting apparatus of relative position between first body of rod and second body of rod is stated, and then the length of the connecting rod can be adjusted.

8. the thread cutter of column type sewing machine according to claim 5, it is characterised in that：The transmission device also has one Resetting spring, described resetting spring one end are installed in the side seat, and the other end is installed in the swing arm or connecting rod, and can ensure that institute State roller and be continued in the separation point position.