CN214572639U - Sewing machine and bobbin rotation preventing device thereof - Google Patents

Abstract

The utility model relates to a sewing machine technical field especially relates to a sewing machine prevent shuttle peg rotation device and one kind including this prevent sewing machine of shuttle peg rotation device. The shuttle peg rotation preventing device comprises a motor, a driving cam and a transmission mechanism, wherein the motor drives a thread cutting mechanism to act and drives the driving cam to rotate, the profile surface of the driving cam comprises a first driving profile surface and a second driving profile surface which are connected and symmetrically arranged, one end of the transmission mechanism is provided with a driving roller which is in contact fit with the profile surface of the driving cam, and the other end of the transmission mechanism is provided with a contact piece which is opposite to the shuttle peg at intervals; when the motor drives the thread trimming mechanism in a forward rotation mode to perform thread trimming action or drives the thread trimming mechanism in a reverse rotation mode to perform idle stroke, the driving cam acts on the driving roller through the first driving contour surface or the second driving contour surface to drive the transmission mechanism to act, the contact piece is driven to move towards the bobbin, and the contact piece is in pressure contact with the bobbin. The automatic thread cutting is realized through one motor, and the shuttle peg is prevented from continuously rotating during thread cutting and sudden stop.

Description

Sewing machine and bobbin rotation preventing device thereof

Technical Field

The utility model relates to a sewing machine technical field especially relates to a sewing machine prevent shuttle peg rotation device and one kind including this prevent sewing machine of shuttle peg rotation device.

Background

The clothing industry has seen a great deal of use of lock stitch sewing machines, the bottom thread of which is provided by a bobbin inside a rotating shuttle. During sewing, the bobbin rotates to release the thread wound on the bobbin winding post, after the thread trimming is completed during sewing or when the sewing machine is suddenly stopped, the bobbin continues to rotate due to inertia, and the bobbin automatically rotates to cause the change of the length of the thread head of the bottom thread and the tension of the bottom thread, so that the subsequent sewing belt is not provided with the bottom thread or the sewing effect is influenced.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a sewing machine prevent shuttle peg rotation device can both prevent the shuttle peg because of inertia continuation rotation when sewing machine trimming and scram to overcome prior art's above-mentioned defect.

In order to solve the technical problem, the utility model discloses a following technical scheme:

the utility model provides a sewing machine prevent cop latch rotation device, including motor, drive cam and drive mechanism, motor drive trimming mechanism action and drive cam rotate, drive cam's profile face is including connecting and the first drive profile face and the second drive profile face that set up symmetrically, one end of drive mechanism is equipped with the drive gyro wheel that contacts the cooperation with drive cam's profile face, and the other end is equipped with the contact piece opposite with the cop latch interval; when the motor drives the thread trimming mechanism to perform thread trimming action in a forward rotation mode or drives the thread trimming mechanism to perform idle stroke in a reverse rotation mode, the driving cam acts on the driving roller through the first driving contour surface or the second driving contour surface to drive the transmission mechanism to act, and the transmission mechanism drives the contact piece to move towards the shuttle peg and enables the contact piece to be in pressure contact with the shuttle peg.

Preferably, the transmission mechanism comprises a rotating lever, a pull wire and a rotating block, the rotating lever and the rotating block are both rotatably arranged on a bottom plate of the sewing machine, the driving roller is arranged at one end of the rotating lever, the other end of the rotating lever is hinged with one end of the pull wire, the other end of the pull wire is hinged with the rotating block, and the contact element is arranged on the rotating block.

Preferably, the transmission mechanism further comprises a tension spring, two ends of the tension spring are respectively connected with the bottom plate and the rotating lever, and the tension spring applies tension to the rotating lever and enables the driving roller to be kept in contact with the profile surface of the driving cam.

Preferably, the middle portion of the turning lever is rotatably mounted on the base plate by a first pin shaft.

Preferably, the turning block is rotatably installed on the bottom plate through a second pin shaft, a torsion spring is sleeved on the second pin shaft, and two ends of the torsion spring respectively abut against the turning block and the bottom plate.

Preferably, the contact member includes a connecting member having one end connected to the transmission mechanism and the other end facing the bobbin, and a contact sleeve disposed on one end of the connecting member facing the bobbin.

Preferably, the thread trimming mechanism includes a thread trimming cam driven by the motor to rotate, a thread trimming roller in contact fit with a contour surface of the thread trimming cam, and a thread trimming assembly connected to the thread trimming roller, the contour surface of the thread trimming cam includes a thread trimming segment and a base circle segment connected to each other, and the thread trimming segment and the base circle segment respectively act on the thread trimming roller to drive the thread trimming assembly to perform a thread trimming operation and an idle stroke.

The utility model also provides a sewing machine, include as above sewing machine's prevent shuttle peg rotation device.

Compared with the prior art, the utility model discloses the progress that has showing:

when the motor drives the thread cutting mechanism to cut thread in forward rotation or drives the thread cutting mechanism to rotate reversely to execute idle stroke, the driving cam acts on the driving roller through the first driving contour surface or the second driving contour surface to drive the transmission mechanism to act, the contact piece is driven to move towards the shuttle peg by the action of the transmission mechanism and is in pressure contact with the shuttle peg, and therefore the shuttle peg can be pressed and fixed by the contact piece when thread is cut and when the sewing machine is in emergency stop at any time. Therefore, the utility model discloses a motor has realized automatic trimming and can both prevent the shuttle peg because of inertia continuation rotation when sewing machine trimming and any scram condition, has avoided arousing bottom line end of a thread length and bottom line tension to change and lead to follow-up sewing area not to go up the bottom line or influence the sewing effect because of the shuttle peg rotation, can guarantee best sewing effect, and has reduced manufacturing cost.

Drawings

Fig. 1 is a schematic structural view of a view angle of the bobbin rotation preventing device of the sewing machine according to the embodiment of the present invention.

Fig. 2 is a schematic structural view of another view angle of the bobbin rotation preventing device of the sewing machine according to the embodiment of the present invention.

Fig. 3 is a schematic structural view of a thread trimming mechanism in the bobbin rotation preventing device of the sewing machine according to the embodiment of the present invention.

Fig. 4 is a schematic view of a split structure of a rotating shuttle in the sewing machine.

Wherein the reference numerals are as follows:

1. motor 101 and rotating shaft

102. Motor support 2 and driving cam

201. A first drive contour surface 202, a second drive contour surface

3. Transmission 301, rotating lever

302. Stay wire 303 and turning block

304. First pin 305 and second pin

306. Tension spring 307 and torsion spring

4. Trimming mechanism 401 and trimming cam

4011. Shear line segment 4012, base circle segment

402. Trimming roller 403 and front crank

404. Crank axle 405, rear crank

406. Slider 407 and drive shaft

4071. Chute 408 and trimming crank

409. Connecting rod 410, move sword crank

411. Moving knife 412 and fixed knife

413. Shaft sleeve 5 and driving roller

6. Contact 601 and connecting piece

602. Contact sleeve 7 and rotating shuttle

701. Bobbin 702 and bobbin case

703. Shuttle bed

Detailed Description

The following describes the present invention in further detail with reference to the accompanying drawings. These embodiments are provided only for illustrating the present invention and are not intended to limit the present invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

As shown in fig. 1 to 4, the present invention relates to an embodiment of a bobbin rotation preventing device for a sewing machine. The sewing machine is provided with a base plate (not shown in the figure) and a rotating shuttle 7, and the bobbin rotation preventing device of the sewing machine of the embodiment is arranged below the base plate of the sewing machine. Referring to fig. 4, the rotary hook 7 includes a bobbin 701, a bobbin case 702 accommodating the bobbin 701, and a bed 703 externally fitted to the bobbin case 702, the bed 703 is mounted on a shaft provided in a hole in a bottom plate of the sewing machine, a bobbin thread required for sewing by the sewing machine is wound around the bobbin 701, and the bobbin 701 is rotated to release the bobbin thread when in operation. The bobbin rotation preventing device of the sewing machine of the embodiment is used for preventing the bobbin 701 from continuously rotating due to inertia when the sewing machine cuts threads and is in sudden stop.

Referring to fig. 1 and 2, the bobbin rotation preventing device of the sewing machine of the present embodiment includes a motor 1, a driving cam 2, and a transmission mechanism 3.

The motor 1 is a driving source of a thread cutting mechanism 4 of the sewing machine, namely, the motor 1 drives the thread cutting mechanism 4 to act. The motor 1 is provided with a rotating shaft 101, when the motor 1 works, the rotating shaft 101 rotates forwards around the axis of the rotating shaft 101 in one direction (such as clockwise direction) or rotates backwards in the other direction (such as anticlockwise direction), and the rotating shaft 101 of the motor 1 drives the trimming mechanism 4 to execute trimming action when rotating forwards from an initial zero position; when the rotating shaft 101 of the motor 1 rotates reversely from the initial zero position, the thread trimming mechanism 4 is driven to execute an idle stroke, namely when the rotating shaft 101 of the motor 1 rotates reversely from the initial zero position, the thread trimming mechanism 4 does not act. The driving cam 2 is fixedly arranged on a rotating shaft 101 of the motor 1, and the driving cam 2 is driven to rotate forwards or backwards synchronously by the forward rotation or reverse rotation of the rotating shaft 101 of the motor 1. Preferably, the motor 1 can be a stepping motor, and can realize the precise control of the rotation direction and rotation angle of the driving cam 2 and the action of the thread cutting mechanism 4. Preferably, the motor 1 is fixedly mounted on a bed plate of the sewing machine through a motor bracket 102.

The profile surface of the drive cam 2 comprises a first drive profile surface 201 and a second drive profile surface 202, and the first drive profile surface 201 and the second drive profile surface 202 are connected and symmetrically arranged. Preferably, the drive cam 2 may employ an end cam.

One end of the transmission mechanism 3 is provided with a driving roller 5, and the driving roller 5 is contacted and matched with the contour surface of the driving cam 2. The other end of the transmission mechanism 3 is provided with a contact piece 6, the contact piece 6 is opposite to the bobbin 701 in the rotating shuttle 7 in a spaced mode, and the contact piece 6 can move towards the bobbin 701 and penetrate through the notch of the bobbin case 702 to be in contact with the bobbin 701.

When the motor 1 drives the thread trimming mechanism 4 in a forward rotation mode to perform thread trimming actions or drives the thread trimming mechanism 4 in a reverse rotation mode to perform idle strokes, the driving cam 2 acts on the driving roller 5 through the first driving contour surface 201 or the second driving contour surface 202 to drive the transmission mechanism 3 to act, and the transmission mechanism 3 drives the contact piece 6 to move towards the bobbin 701 and enables the contact piece 6 to be in pressure contact with the bobbin 701. When the rotating shaft 101 of the motor 1 is located at the initial zero position, the driving roller 5 is located at the connecting point of the first driving contour surface 201 and the second driving contour surface 202 on the contour surface of the driving cam 2, and because the first driving contour surface 201 and the second driving contour surface 202 are symmetrically arranged, the rotating shaft 101 of the motor 1 rotates forward or backward from the initial zero position, so that the driving roller 5 performs the same action when moving along the first driving contour surface 201 or the second driving contour surface 202 from the connecting point of the first driving contour surface 201 and the second driving contour surface 202. Specifically, when the rotating shaft 101 of the motor 1 rotates forward from the initial zero position to drive the thread trimming mechanism 4 to perform a thread trimming operation, the driving cam 2 acts on the driving roller 5 through the first driving contour surface 201 to drive the transmission mechanism 3 to operate, the contact element 6 is driven to move towards the bobbin 701 by the operation of the transmission mechanism 3, and the contact element 6 penetrates through the notch of the bobbin case 702 to be in pressure contact with the bobbin 701, so that the bobbin 701 is pressed and fixed by the contact element 6 during thread trimming, the bobbin 701 can be prevented from pulling the cut bobbin thread end back into the bobbin case 702 due to continuous self-rotation of inertia during thread trimming, and the situation that the bobbin thread end cannot be taken up due to shortening of the bobbin thread end during subsequent sewing is avoided. When the motor 1 rotating shaft 101 reversely rotates from the initial zero position to drive the thread cutting mechanism 4 to execute the idle stroke, the driving cam 2 acts on the driving roller 5 through the second driving contour surface 202 to drive the transmission mechanism 3 to act, the action of the transmission mechanism 3 drives the contact element 6 to move towards the bobbin 701, and the contact element 6 penetrates through the gap of the bobbin case 702 to be in pressure contact with the bobbin 701, so that the bobbin 701 is pressed and fixed by the contact element 6 through the reverse rotation of the motor 1 rotating shaft 101 when the sewing machine suddenly stops at any time, the bobbin 701 is prevented from continuously rotating due to inertia to change of the length of a bobbin thread head and the tension of the bobbin thread when the sewing machine suddenly stops, the sewing effect is prevented from being influenced, and the thread cutting mechanism 4 executes the idle stroke without executing the thread cutting action.

Therefore, the bobbin rotation preventing device of the sewing machine of the embodiment realizes automatic thread cutting through the motor 1 and can prevent the bobbin 701 from continuously rotating due to inertia when the thread cutting and any sudden stop condition of the sewing machine occur, the phenomenon that the bobbin 701 rotates to cause the change of the thread end length of the bottom thread and the tension of the bottom thread so as to prevent the subsequent sewing belt from not applying the bottom thread or influence the sewing effect is avoided, the best sewing effect can be ensured, and the production cost is reduced.

Referring to fig. 1 and 2, in the present embodiment, the transmission mechanism 3 preferably includes a turning lever 301, a pulling wire 302, and a turning block 303. The rotating lever 301 and the rotating block 303 are both rotatably disposed on the bottom plate of the sewing machine, preferably, the middle portion of the rotating lever 301 is rotatably mounted on the bottom plate through a first pin 304, the rotating block 303 is rotatably mounted on the bottom plate through a second pin 305, and both the first pin 304 and the second pin 305 may be axial screws. The driving roller 5 is provided at one end of the rotating lever 301, and preferably, the driving roller 5 is rotatably mounted on the rotating lever 301. The other end of the rotating lever 301 is hinged with one end of the pull wire 302, the other end of the pull wire 302 is hinged with the rotating block 303, and the contact element 6 is fixedly arranged on the rotating block 303. When the driving cam 2 rotates, the first driving contour 201 or the second driving contour 202 acts on the driving roller 5 to drive the rotating lever 301 to rotate around the first pin 304, the pulling wire 302 is pulled by the rotation of the rotating lever 301, the rotating block 303 is pulled by the pulling wire 302 to rotate around the second pin 305, and the contact member 6 is driven to move towards the bobbin 701 by the rotation of the rotating block 303.

Further, the transmission mechanism 3 in this embodiment may further include a tension spring 306, two ends of the tension spring 306 are respectively connected to the bottom plate of the sewing machine and the rotating lever 301, and the tension spring 306 applies a tensile force to the rotating lever 301 and keeps the driving roller 5 in contact with the contour surface of the driving cam 2. The tension spring 306 can also play a role in assisting the transmission mechanism 3 to reversely act and reset in the process of reversely rotating and resetting the rotating shaft 101 of the motor 1 after the thread cutting is finished or when the sewing machine is restarted after being suddenly stopped.

Further, in this embodiment, a torsion spring 307 may be sleeved on the second pin 305, and two ends of the torsion spring 307 respectively abut against the rotating block 303 and the bottom plate of the sewing machine. After the thread cutting is finished or when the sewing machine is restarted after being suddenly stopped, the torsion spring 307 also plays a role of assisting the transmission mechanism 3 to reversely act and reset in the process of reversely rotating and resetting the rotating shaft 101 of the motor 1.

Therefore, in the bobbin rotation preventing device of the sewing machine of the embodiment, after the thread cutting is finished or when the sewing machine is restarted after being suddenly stopped, the transmission mechanism 3 completes automatic reset under the combined action of the motor 1, the tension spring 306 and the torsion spring 307 in the process of reversely rotating and resetting the rotating shaft 101 of the motor 1.

In this embodiment, the contact member 6 may preferably include a connection member 601 and a contact sleeve 602, one end of the connection member 601 is fixedly connected to the transmission mechanism 3, and the other end of the connection member 601 faces the bobbin 701, and preferably, the connection member 601 may be a bent pipe. The contact sleeve 602 is fixedly provided on the end of the connecting member 601 facing the bobbin 701, and the contact member 6 contacts the bobbin 701 by the contact sleeve 602 when moving toward the bobbin 701. Preferably, the contact sleeve 602 is made of nylon material, which can play a role of buffering, and prevent the contact member 6 from damaging the bobbin 701 when touching the bobbin 701.

Referring to fig. 3, in the present embodiment, the thread trimming mechanism 4 preferably includes a thread trimming cam 401, a thread trimming roller 402, and a thread trimming assembly connected to the thread trimming roller 402. The trimming cam 401 is fixedly arranged on the rotating shaft 101 of the motor 1, and the trimming cam 401 is driven to rotate forwards or backwards synchronously by the forward rotation or reverse rotation of the rotating shaft 101 of the motor 1. Preferably, the motor 1 is a motor with double output shafts, and the trimming cam 401 and the driving cam 2 are respectively installed on the output shafts at both ends of the motor 1. The trimming roller 402 is in contact fit with the profile surface of the trimming cam 401. The contour surface of the trimming cam 401 comprises a trimming segment 4011 and a base circle segment 4012 which are connected, wherein the trimming segment 4011 acts on the trimming roller 402 to drive the trimming assembly to perform a trimming action, and the base circle segment 4012 acts on the trimming roller 402 to drive the trimming assembly to perform an idle stroke. When the motor 1 rotating shaft 101 drives the trimming cam 401 to rotate, the rotation center of the trimming cam 401 is the axis of the motor 1 rotating shaft 101, the base circle segment 4012 of the contour surface of the trimming cam 401 is an arc concentrically arranged with the rotation center of the trimming cam 401, and the distance between the trimming segment 4011 and the rotation center of the trimming cam 401 gradually increases, so that the trimming segment 4011 has a highest point farthest from the rotation center of the trimming cam 401, and the highest point is the tail end of the trimming, and when the trimming roller 402 moves to the highest point along the trimming segment 4011, the trimming mechanism trims the bottom line to complete the trimming action. When the rotating shaft 101 of the motor 1 is located at an initial zero position, the trimming roller 402 is located at a connecting point of the trimming section 4011 and the base circle section 4012 on the contour surface of the trimming cam 401; when the rotating shaft 101 of the motor 1 rotates forwards from the initial zero position, the trimming roller 402 moves along the trimming section 4011 from the connecting point of the trimming section 4011 and the base circle section 4012 to drive the trimming assembly to perform trimming action; when the rotating shaft 101 of the motor 1 is reversely rotated from the initial zero position, the trimming roller 402 moves along the base circle segment 4012 from the connecting point of the trimming segment 4011 and the base circle segment 4012 to drive the trimming assembly to execute an idle stroke.

In this embodiment, the structure of the thread trimming assembly is not limited, as long as the thread trimming operation can be completed under the driving of the motor 1, the thread trimming cam 401 and the thread trimming roller 402. For example, referring to fig. 3, the thread trimming assembly may include a front crank 403, a crank shaft 404, a rear crank 405, a slider 406, a drive shaft 407, the thread cutting machine comprises a thread cutting crank 408, a connecting rod 409, a movable knife crank 410, a movable knife 411 and a fixed knife 412, wherein one end of a front crank 403 is fixedly installed at one end of a crank shaft 404, a thread cutting roller 402 is rotatably installed at the other end of the front crank 403, one end of a rear crank 405 is fixedly installed at the other end of the crank shaft 404, a sliding block 406 is hinged to the other end of the rear crank 405, one end of a driving shaft 407 is provided with a sliding groove 4071, the sliding block 406 is slidably inserted into the sliding groove 4071, one end of the thread cutting crank 408 is fixedly installed at the other end of the driving shaft 407, the other end of the thread cutting crank 408 is hinged to one end of the connecting rod 409, the other end of the connecting rod 409 is hinged to one end of the movable knife crank 410, the movable knife 411 is installed at the other end of the movable knife crank 410, and the fixed knife 412 is installed on a bottom plate of the sewing machine. When the rotating shaft 101 of the motor 1 rotates forwards from the initial zero position, the thread trimming roller 402 moves along the thread trimming section 4011 to drive the front crank 403 to rotate, and drives the crank shaft 404, the rear crank 405, the driving shaft 407, the thread trimming crank 408, the connecting rod 409 and the movable knife crank 410 to rotate, so that the movable knife 411 moves towards the fixed knife 412, and thread trimming is completed through engagement of the movable knife 411 and the fixed knife 412. The driving shaft 407 can be sleeved with a shaft sleeve 413, the driving shaft 407 rotatably penetrates through the shaft sleeve 413, the shaft sleeve 413 is fixedly installed on a bottom plate of the sewing machine, the shaft sleeve 413 is sleeved with a reset torsion spring (not shown in the figure), two ends of the reset torsion spring respectively abut against the bottom plate of the thread trimming crank 408 and the sewing machine, and the reset torsion spring is used for driving the thread trimming mechanism to reset after thread trimming is completed.

Based on the bobbin rotation preventing device of the sewing machine, the embodiment further provides the sewing machine, and the sewing machine of the embodiment comprises the bobbin rotation preventing device of the sewing machine of the embodiment.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and replacements can be made without departing from the technical principle of the present invention, and these modifications and replacements should also be regarded as the protection scope of the present invention.

Claims (8)

1. The bobbin rotation preventing device of the sewing machine is characterized by comprising a motor (1), a driving cam (2) and a transmission mechanism (3), wherein the motor (1) drives a thread cutting mechanism (4) to act and drives the driving cam (2) to rotate, the contour surface of the driving cam (2) comprises a first driving contour surface (201) and a second driving contour surface (202) which are connected and symmetrically arranged, one end of the transmission mechanism (3) is provided with a driving roller (5) which is in contact fit with the contour surface of the driving cam (2), and the other end of the transmission mechanism is provided with a contact piece (6) which is opposite to the bobbin (701) at intervals; when the motor (1) drives the thread trimming mechanism (4) to perform thread trimming action in a forward rotation mode or drives the thread trimming mechanism (4) to perform idle stroke in a reverse rotation mode, the driving cam (2) acts on the driving roller (5) through the first driving contour surface (201) or the second driving contour surface (202) to drive the transmission mechanism (3) to act, and the transmission mechanism (3) drives the contact piece (6) to move towards the shuttle peg (701) and enables the contact piece (6) to be in pressure contact with the shuttle peg (701).

2. The bobbin rotation preventing device of the sewing machine according to claim 1, wherein the transmission mechanism (3) comprises a rotating lever (301), a pulling wire (302) and a rotating block (303), the rotating lever (301) and the rotating block (303) are both rotatably arranged on a bottom plate of the sewing machine, the driving roller (5) is arranged at one end of the rotating lever (301), the other end of the rotating lever (301) is hinged with one end of the pulling wire (302), the other end of the pulling wire (302) is hinged with the rotating block (303), and the contact element (6) is arranged on the rotating block (303).

3. The bobbin rotation preventing device of the sewing machine according to claim 2, wherein the transmission mechanism (3) further comprises a tension spring (306), both ends of the tension spring (306) are respectively connected to the base plate and the rotating lever (301), and the tension spring (306) applies a pulling force to the rotating lever (301) and keeps the driving roller (5) in contact with the profile surface of the driving cam (2).

4. The anti-bobbin rotation device of sewing machine according to claim 2, wherein the middle portion of the rotation lever (301) is rotatably mounted on the base plate by a first pin (304).

5. The bobbin rotation preventing device of the sewing machine according to claim 2, wherein the rotating block (303) is rotatably mounted on the base plate through a second pin (305), a torsion spring (307) is sleeved on the second pin (305), and two ends of the torsion spring (307) respectively abut against the rotating block (303) and the base plate.

6. The device for preventing the rotation of the bobbin of the sewing machine according to claim 1, wherein the contact member (6) comprises a link (601) and a contact sleeve (602), one end of the link (601) is connected to the transmission mechanism (3) and the other end faces the bobbin (701), and the contact sleeve (602) is provided on one end of the link (601) facing the bobbin (701).

7. The bobbin rotation preventing device of the sewing machine according to claim 1, wherein the thread trimming mechanism (4) comprises a thread trimming cam (401) driven by the motor (1) to rotate, a thread trimming roller (402) in contact fit with a profile surface of the thread trimming cam (401), and a thread trimming assembly connected with the thread trimming roller (402), the profile surface of the thread trimming cam (401) comprises a connected thread trimming segment (4011) and a base circle segment (4012), and the thread trimming segment (4011) and the base circle segment (4012) respectively act on the thread trimming roller (402) to drive the thread trimming assembly to perform a thread trimming action and an idle stroke.

8. A sewing machine comprising the bobbin rotation preventing device of the sewing machine according to any one of claims 1 to 7.

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