CN107254745B - Sewing anti-falling device of sewing machine - Google Patents

Abstract

The invention provides an anti-sewing device for sewing machines, belonging to the technical field of machinery. The utility model solves the problem that the existing sewing machine is easy to come off the thread at the start of the seam. The sewing machine starting anti-sewing device includes a mounting plate, a thread clamping assembly, a driving part and a thread removing knife. The mounting plate is fixed on the front end of the casing and is located at the rear side of the decorative thread knife assembly, and the driving part is fixed at one end of the mounting plate. , the middle of the thread setting knife is hinged on the other end of the mounting plate, the two ends of the transmission connecting rod are respectively hinged with the thread setting knife and the driving crank, the driving part is connected to the driving crank, and the mounting plate is located below the transmission connecting rod. A mounting plate is detachably connected , the thread clamping assembly is fixed on the mounting plate and is opposite to the thread-removing knife. The needle feeding and threading plate and the threading knife are located on both sides of the installation plate. The hook of the threading knife is not higher than the bottom of the needle feeding and threading plate. There is also a return spring on it. The hook of the thread setting knife of the sewing-starting anti-dropping device is located at the right or lower right side of the needle-feeding and thread-passing plate after returning to its original position.

Description

A sewing machine starting seam anti-sewing device

technical field

The invention belongs to the technical field of machinery, and relates to an anti-sewing device for sewing machines.

Background technique

At present, the operation process of the sewing machine is to thread the stitches first, then press the fabric or clothing to be sewn with the presser foot, and finally use the bur to perform the sewing operation. Among them, when the sewing operation is to be stopped and the fabric or clothing is to be removed, the upper trim thread left on the fabric or clothing must be cut, so that the fabric or clothing can be further removed. However, in the early process of cutting and trimming the thread, the operator had to pull out the seam by hand, and at the same time pull out the seam and reserve a section of seam to facilitate the next sewing operation, and finally use scissors to The sutures are cut. However, the cut thread ends will remain near the needle and appear messy. At the same time, the operator needs to pay special attention to the position of these thread ends in the next sewing operation to avoid the interference of these thread ends in the next sewing operation and cause twisting. line situation. In view of the inconvenience of the next sewing operation caused by the above reserved line segments, some manufacturers have developed a more convenient thread trimming device.

For example, a Chinese patent application (application number: 201520253181.9) discloses a sewing machine with an upper trimming cutter device and an upper thread pulling device, which includes a sewing machine body and a sewing machine arm, which are installed on the sewing machine arm and are opposite to each other. A needle holder for the reciprocating sewing stroke of a sewing machine arm, a bur mounted on the needle holder and threading the needle thread respectively, an upper trim thread guide mounted on the sewing machine arm and guiding the upper trim thread, and a sewing machine mounted on the sewing machine The machine arm has to perform a reciprocating yaw stroke relative to the sewing machine arm to pull the upper decoration thread between the needles, and the upper decoration thread guide and the upper decoration thread looper are separated from each other up and down to form a slit. It also includes an upper trim thread cutter device, which is installed on the sewing machine body, the upper trim thread cutter device includes a fixed thread trimmer, and a movable thread trimmer for hooking the upper trim thread to the fixed thread trimmer, the movable thread trimmer The upper thread is staggered relative to the fixed thread cutting member to cut off the upper decoration thread; it also includes an upper thread removal device, which is installed on the sewing machine body, and the upper thread removal device performs the reciprocating thread hooking stroke of the shuttle slit relative to the sewing machine body to clamp the needle thread, The upper thread pulling device includes a thread hooking member for hooking the needle thread, and a clamping member arranged on the thread hooking member and clamping the needle thread with the thread hooking member. The thread-clamping device of the thread-removing knife of the above-mentioned sewing machine and the thread-removing knife are assembled together and occupy a large space. Due to the large thread pressure angle of the thread path, the thread pressure effect is not good, so it is easy to cause the situation that the upper decorative thread is not on the thread and the stitches are skipped, and the thread clamping force of the thread clamping device in the above-mentioned sewing machine cannot be adjusted.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above-mentioned problems in the prior art, and proposes a sewing machine starting seam anti-dropping device. The technical problem to be solved by the present invention is: how to prevent jumping stitches and falling off due to the lack of thread when starting the seam. Wire.

The purpose of the present invention can be achieved by the following technical solutions: a sewing machine starting sewing prevention device, the sewing machine comprises a casing, a decorative thread knife assembly, a needle feeding hook, a needle feeding frame and a needle feeding thread passing plate, The stripping device includes a mounting plate, a wire pulling assembly and a wire clamping assembly. The wire pulling assembly includes a driving member and a wire pulling knife with a hook at one end. It is fixed at the front end of the casing and is located at the rear side of the decorative thread cutter assembly, the driving part is fixed at one end of the installation plate, and the middle part of the thread cutter is hinged to the other end of the installation plate through the rotating shaft. There is also a driving crank and a transmission connecting rod between the wire cutter and the thread setting cutter. One end of the transmission connecting rod is hinged with the other end of the thread setting cutter, and the other end is hinged with the driving crank. The driving member can drive the driving crank to swing. , the mounting plate can also be detachably connected with a mounting piece, the mounting piece is located between the drive crank and the thread setting knife and is arranged close to the thread setting knife, the mounting sheet is located below the transmission link and has one end downward It extends to the bottom of the mounting plate, the thread clamping assembly is fixed on the extension end and is opposite to the thread setting knife, and the needle feeding and thread passing plate is fixed on the mounting plate and is installed separately from the thread setting knife. On both sides of the plate, the height of the hook of the thread-removing knife in the horizontal direction is not higher than the bottom of the needle-feeding thread-passing plate. For the thread-passing gap through which the thread-removing knife swings, the mounting plate is also provided with a return spring capable of driving the thread-removing knife to return.

When the sewing machine finishes the sewing action, the thread is trimmed and clamped by the automatic thread trimming device on the sewing machine. First, the lower thread cutter cuts the needle thread and clamps the lower thread, and then the decorative thread cutter assembly on the sewing machine moves to complete the cutting of the decorative thread. After clamping, the thread setting device operates, the driving part drives the drive crank to swing, drives the transmission link to move, and the transmission link drives the thread setting knife to swing. The return spring is stretched, the hook on the thread setting knife hooks the needle thread, and then the driving part stops running. The components cooperate to clamp the needle thread of the machine. When sewing next time, the decorative thread forms a stable stitch under the action of the needle thread force, and it is not easy to jump the thread. The sewing machine start-up anti-sewing device adopts the split design of the thread setting knife and the thread clamping assembly, and cooperates with the design of the unique transmission structure. , the space layout is reasonable, and the space is small. At the same time, the needle feeding and threading plate is installed on the installation plate and is located on both sides of the installation plate. The height of the hook is not higher than the bottom of the needle feeding and threading plate. The mutual cooperation of the transmission parts makes the thread-removing knife return to its position and cooperate with the thread clamping assembly to clamp the needle thread. The decorative thread cutter components cooperate with each other, making the seam start more stable, and it is not easy to skip the needle and fall off the thread.

In the above-mentioned sewing machine starting-sewing prevention device, the mounting piece includes a sheet-shaped body, a strip-shaped connecting portion and a sheet-shaped mounting portion, the body is abutted and fixed on the mounting plate, and the connecting portion is formed by the body One side of the cable extends downward out of the mounting plate, the mounting portion is bent relative to the connecting portion and is located below the mounting plate, the mounting portion is inclined, and the wire clamping assembly is fixed on the mounting portion. The unique structural design of the mounting plate makes the thread clamping assembly located under the mounting plate after installation, so that it will not occupy the space in the horizontal direction. At the same time, it is designed with the position of the needle feeding and thread passing plate, so that after the thread setting knife is returned to its position and the thread clamping assembly is used to clamp the needle thread, the hook of the thread setting knife is just located on the right or lower right side of the needle, and the sewing starts. More stable and not easy to jump wires.

In the above-mentioned sewing machine starting and anti-sewing device, the mounting portion is provided with a mounting stud, and the thread clamping assembly includes a first elastic thread clamping piece, and the first elastic thread clamping piece is in the shape of a bent plate, and the elastic clamp One end of the wire piece is fixed on the installation part by screws, and the middle part is sleeved on the installation stud. The stud is also sleeved with a wire clamping plate, and the shape of the clamping plate is matched with the elastic wire clamping plate 1. and abuts on the upper side of the elastic wire clip 1, the installation stud is also provided with an adjusting nut, and the adjustment nut abuts on the wire clip pressing plate to elastically press the elastic wire clip 1 on the installation part. superior. The design of the adjusting nut, by rotating the position of the adjusting nut on the mounting stud, the pressing force of the wire clamping plate on the elastic wire clamping piece 1 can be adjusted, so as to realize the adjustment of the elastic pressing force of the elastic wire clamping piece 1, and the adjustment can be realized. The function of the tensioning force of the clamping line ensures that it is not easy to come off the line. The thread-removing knife and the elastic thread-clamping piece can realize the thread-clamping effect, that is, the thread-removing knife and the elastic thread-clamping piece form a thread-clamping component.

In the above-mentioned sewing machine starting anti-sewing device, the installation stud is also sleeved with an elastic abutting block and a second elastic thread clamping piece, and the lower side of the first elastic thread clamping piece abuts against the elastic abutting piece On the block, one end of the second elastic wire clamping piece is fixedly sleeved on the mounting stud and located below the mounting portion, and the other end is elastically abutted against the other end of the elastic wire clamping piece 1. The provision of the elastic abutting block has the functions of supporting and buffering, so as to ensure better realization of the tensioning force on the wire of the wire clamping assembly. The second elastic wire clipping piece and the first elastic wire clipping piece can realize the wire clipping effect, that is, the second elastic wire clipping piece and the first elastic wire clipping piece form a wire clipping component.

In the above-mentioned sewing machine starting anti-sewing device, an intermediate nut and an anti-loosening nut are arranged above the adjusting nut in sequence, and both the intermediate nut and the anti-loosening nut are threadedly connected with the mounting stud. The design of the middle nut and the anti-loosening nut can ensure that the adjusting nut can be better fixed after the adjustment is completed, and it will not loosen, ensuring that it always has a suitable tensioning force for the wire.

In the above-mentioned sewing machine starting-sewing preventing device, the driving member is a rotating electromagnet, the rotating electromagnet is fixed on one side of the mounting plate, and the iron core passes through the mounting plate and is fixedly connected with the driving crank. When it is necessary to dial the wire, the iron core of the rotating electromagnet rotates to drive the driving crank to swing, and the transmission connecting rod drives the wire dialing knife to swing under the driving of the driving crank. Contact, the thread setting knife moves to the limit position, the rotating electromagnet is powered off, and under the action of the return spring, the thread setting knife hooks the thread back to the original position. Using the design of the rotating electromagnet, the rotating electromagnet can be directly fixed on one side of the mounting plate, only the iron core can be directly connected to the driving crank through the mounting plate, eliminating the need for the hinged structure of the driving crank on the mounting plate, and further improving the The structure is compact and the space occupied is reduced.

In the above-mentioned sewing machine sewing machine anti-sewing device, one end of the driving crank has a clamping opening, the side wall of the clamping opening is provided with an arc-shaped installation groove, and the iron core of the rotating electromagnet passes through the arc-shaped installation groove. Mounted in the slot and secured by tightening the clips with fasteners. The arc-shaped installation groove is used to match the iron core of the rotating electromagnet, and at the same time, it is clamped in accordance with the design of the clip, which is convenient for installation.

In the above-mentioned sewing machine starting anti-sewing device, two eccentric shafts are also fixed on the mounting plate, and the end of the transmission connecting rod hinged with the driving crank is bent downward to form a baffle plate, and the transmission The middle of the connecting rod has a protruding limit rod, the baffle and the limit rod are located between the two eccentric shafts, and the baffle can abut against one of the eccentric shafts when the rotating electromagnet drives the drive crank to swing, so The limit rod can abut against another eccentric shaft when the drive crank returns. The matching structure design of the two eccentric shafts with the baffle plate and the limit rod respectively can limit the movement and return stroke of the transmission link respectively, so as to realize the limit of the swing angle of the thread setting knife, so as to ensure the accurate realization Thread hooking and return thread clamping, the hook of the thread setting knife is just located on the right or lower right of the needle feeding and thread passing plate, and the starting seam is more stable, and it is not easy to skip the needle and fall off the thread.

In the above-mentioned sewing machine starting-sewing prevention device, the mounting plate further has a fixing column, one end of the return spring is fixedly sleeved on the fixing column, and the other end is fixedly penetrated on the baffle plate.

In the above-mentioned sewing machine starting and anti-sewing device, the driving member is a linear electromagnet, the linear electromagnet is fixed on the mounting plate, the iron core of the linear electromagnet is fixed with a connecting pin, and one end of the driving crank is A long sliding hole is opened, the connecting pin is slidably inserted in the sliding hole, the middle part of the driving crank is hinged on the mounting plate, and the other end of the driving crank is hinged with the transmission connecting rod. The movement of the iron core of the linear electromagnet drives the connecting pin, the connecting pin slides in the sliding hole of the driving crank, and drives the driving crank to swing, and the driving crank drives the movement of the transmission connecting rod, which pulls the thread-picking knife to swing. The abutting step and the adjusting plate are in contact with each other, the thread-removing knife moves to the limit position, the linear electromagnet is powered off, and under the action of the return spring, the thread-removing knife hooks the thread back to its original position.

In the above-mentioned sewing machine starting anti-sewing device, two eccentric shafts are also fixed on the mounting plate, and the two eccentric shafts are respectively located on both sides of the driving crank. After returning to the position under the action of the elastic force of the positioning spring, it can abut against the two eccentric shafts respectively. The two eccentric shafts can abut against the two sides of the drive crank respectively, and can limit the swing stroke of the drive crank, so as to realize the limit of the swing angle of the thread setting knife, thus ensuring that the thread hooking and return thread clamping can be accurately realized. , the hook of the thread-pulling knife is just located on the right or lower right of the needle-feeding and thread-passing plate, and the starting seam is more stable, and it is not easy to skip the needle.

In the above-mentioned sewing machine starting-sewing prevention device, the mounting plate further has a fixing column, one end of the return spring is fixedly sleeved on the fixing column, and the other end is fixedly penetrated on the driving crank.

Compared with the prior art, the sewing machine sewing machine anti-sewing device has the following advantages: 1. By adopting a separate design for the thread-removing knife and the thread clamping assembly, and with the design of the unique transmission structure, the thread clamping assembly is directly located in the thread-removing knife. Between the drive crank and the drive crank, and below the transmission connecting rod, the space is arranged reasonably and occupies a small space. 2. The needle feeding and threading plate is installed on the installation plate and is located on both sides of the installation plate with the thread-removing knife, and through the unique structural design of the thread-removing device, the thread-removing knife can be clamped with the thread clamping assembly after returning to its position. After sewing the needle thread, the hook of the thread setting knife is just located on the right or lower right side of the needle feeding and threading plate, and in conjunction with the structural design of the decorative thread knife assembly, the starting seam is more stable, and it is not easy to skip the needle and fall off the thread. 3. The design of the eccentric shaft can limit the swing angle of the thread-pulling knife, so as to ensure that the hooking and return clamping can be accurately realized. At the same time, the eccentric shaft can easily adjust the limit position, just rotate the eccentric The shaft can adjust the limit position, and the adjustment range is continuous and uninterrupted. The hook of the thread-pulling knife is just located on the right or lower right of the needle-feeding and thread-passing plate. 4. The design of the adjusting nut, by rotating the position of the adjusting nut on the installation stud, the pressing force of the wire clamping plate on the elastic wire clamping sheet can be adjusted, so as to realize the adjustment of the elastic deformation force of the elastic wire clamping sheet after being compressed. , can realize the function of adjusting the tension of the clamping line to ensure that it is not easy to be off the line.

Description of drawings

Fig. 1 is a structural diagram of the sewing machine starting-sewing preventing device.

FIG. 2 is an enlarged view of A in FIG. 1 .

Fig. 3 is the connection structure diagram of the wire pulling assembly and the wire clamping assembly in the first embodiment.

FIG. 4 is an enlarged view of B in FIG. 3 .

Fig. 5 is the connection structure diagram of the wire pulling assembly and the wire clamping assembly in the second embodiment.

In the figure, 1. the casing; 2. the decorative thread knife assembly; 3. the needle feeding and threading plate; 4. the mounting plate; 7b, sliding hole; 8, transmission link; 8a, limit rod; 8b baffle; 9, mounting piece; 9a, body; 9b, connecting part; 9c, mounting part; 10, return spring; 11, mounting screw Column; 12. Elastic clamping piece 1; 13. Elastic clamping piece 2; 14. Clamping plate; 15. Adjusting nut; 16. Elastic abutting block; 17. Intermediate nut; 18. Anti-loosening nut; 19. Eccentric Shaft; 20. Linear electromagnet; 21. Connecting pin; 22. Needle feeding frame; 23. Fixed column.

Detailed ways

The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

Example 1

As shown in FIGS. 1 and 2 , the sewing machine includes a casing 1 , a decorative thread cutter assembly 2 , a needle feeding hook, a needle feeding frame 22 and a needle feeding thread passing plate 3 . The seam-starting anti-dropping device includes a mounting plate 4, a wire pulling assembly and a thread clamping assembly. The mounting plate 4 is in the shape of a long strip, and the mounting plate 4 is fitted and fixed to the front end of the casing 1 and is located at the edge of the decorative thread cutter assembly 2. rear side.

The wire pulling assembly includes a driving member and a wire pulling knife 5 with a hook at one end. The driving member is further provided with a driving crank 7 and a transmission connecting rod 8 between the driving member and the wire pulling knife 5 . As shown in FIG. 3 , in this embodiment, the driving member is a rotating electromagnet 6 , the rotating electromagnet 6 is fixed on one end of the mounting plate 4 , and the middle part of the thread-pulling knife 5 is hinged on the other end of the mounting plate 4 through the rotating shaft, and the rotating electromagnet 6 is The iron 6 and the wire cutter 5 are located on two sides of the mounting plate 4 respectively, and the iron core of the rotating electromagnet 6 passes through the mounting plate 4 . One end of the driving crank 7 has a clamping opening 7a, and the side wall of the clamping opening 7a has an arc-shaped installation groove. One end of the transmission connecting rod 8 is hinged with the other end of the thread setting knife 5 , and the other end is hinged with the other end of the driving crank 7 . There are also two eccentric shafts 19 fixed on the mounting plate 4, one end of the transmission connecting rod 8 hinged with the driving crank 7 has a downwardly bent baffle plate 8b, and the middle of the transmission connecting rod 8 has a protruding limit rod 8a, The baffle 8b and the limit rod 8a are located between the two eccentric shafts 19. The baffle 8b can abut against one of the eccentric shafts 19 when the rotating electromagnet 6 drives the drive crank 7 to swing, and the limit rod 8a returns to the drive crank 7. It can abut against the other eccentric shaft 19 at the time.

The mounting plate 4 can also be detachably connected with a mounting piece 9 . The mounting piece 9 is located between the driving crank 7 and the thread setting knife 5 and is arranged close to the thread setting knife 5 , and the mounting sheet 9 is located below the transmission connecting rod 8 . The mounting piece 9 includes a sheet-shaped body 9a, a strip-shaped connecting portion 9b and a sheet-shaped mounting portion 9c. The body 9a is abutted and fixed on the mounting plate 4, and the connecting portion 9b extends downward from the mounting plate from one side of the body 9a. In addition, the mounting portion 9c is bent relative to the connecting portion 9b and is located below the mounting plate 4, the mounting portion 9c is inclined, and the thread clamping assembly is fixed on the mounting portion 9c and is opposite to the thread-pulling knife 5. The thread-removing knife 5 and the thread-clamping assembly adopt a split design, with the design of the unique transmission structure, the thread-clamping assembly is directly located between the thread-removing knife 5 and the drive crank 7, and is located under the transmission connecting rod 8, and the space arrangement is reasonable. Small footprint.

The needle feeding and thread passing plate 3 is fixed on the mounting plate 4 and is located on both sides of the mounting plate 4 with the thread removing knife 5. The height of the hook of the thread removing knife 5 in the horizontal direction is not higher than the bottom of the needle feeding thread passing plate 3. , a thread-passing gap for the thread-pulling knife 5 to swing through is formed between the needle-feeding hook, the needle-feeding frame 22 and the needle-feeding thread-passing plate 3 . The mounting plate 4 is also provided with a return spring 10, and the mounting plate 4 also has a fixing column 23. One end of the return spring 10 is fixedly sleeved on the fixing column 23, and the other end is fixedly penetrated on the baffle plate 8b.

When the sewing machine finishes the sewing action, the thread is trimmed and clamped by the automatic thread trimmer on the sewing machine. First, the lower thread cutter cuts the needle thread and clamps the lower thread, and then the decorative thread cutter assembly 2 on the sewing machine moves to complete the trimming of the decorative thread. and clamped, then the wire pulling assembly runs, the rotating electromagnet 6 is energized, the iron core rotates and drives the driving crank 7 to swing, thereby driving the transmission connecting rod 8 to move, the transmission connecting rod 8 drives the wire pulling knife 5 to swing, and the wire pulling knife 5 passes through The thread passing gap formed by the needle feeding hook, the needle feeding frame 22 and the needle feeding thread passing plate 3, the return spring 10 is stretched, when the baffle plate 8b on the transmission link 8 abuts against the corresponding eccentric shaft 19, the thread is pulled The knife 5 swings to the limit position, and the hook on the thread setting knife 5 hooks the needle thread. Then the rotating electromagnet 6 is powered off to stop running, the thread setting knife 5 hooks the needle thread and swings back under the action of the elastic force of the return spring 10, when the limit rod 8a on the transmission link 8 contacts the corresponding eccentric shaft 19 When it is up, the thread setting knife 5 swings back to the limit position and cooperates with the thread clamping assembly to clamp the needle thread of the machine. Because the needle feeding and thread passing plate 3 is installed on the mounting plate 4, and the thread-removing knife 5 is located on both sides of the mounting plate 4, and the height of the hook is not higher than the bottom of the needle feeding and thread passing plate 3, through the mutual interaction of the transmission components In cooperation, after the thread setting knife 5 is returned and the thread clamping assembly cooperates to clamp the needle thread of the machine, the hook of the thread setting knife 5 is just located on the right or lower right side of the needle feeding and thread passing plate 3. When sewing next time, the decorative thread is on the machine. Stable stitches are formed under the action of the needle thread force, and it is not easy to jump the thread.

More specifically, as shown in FIG. 4, the mounting portion 9c is provided with a mounting stud 11, and the wire clamping assembly includes an elastic wire clamping piece 12 and an elastic wire clamping piece 13, an elastic wire clamping piece 12 and an elastic wire clamping piece The second 13 is in the shape of a bent plate, one end of the elastic wire clip is fixed on the mounting part 9c by screws, the middle part is sleeved on the installation stud 11, and one end of the elastic wire clip 2 13 is fixedly sleeved on the installation stud 11 and located below the mounting portion 9c, the other end of which is elastically abutted against the other end of the elastic wire clip one 12. An elastic abutting block 16 is also sleeved on the mounting stud 11 , and the lower side of the elastic clamping piece 1 12 abuts on the elastic abutting block 16 . The stud is also sleeved with a clamping line pressure plate 14, the shape of the clamping line pressure plate 14 is matched with the elastic line clamping piece 1 12 and is attached to the upper side of the elastic line clamping piece 1 12, and the installation stud 11 is also provided. There is an adjusting nut 15 , and the adjusting nut 15 abuts on the wire clamping pressure plate 14 to elastically press the elastic wire clamping piece 1 12 on the elastic wire clamping piece 2 13 . An intermediate nut 17 and a loosening nut 18 are also arranged above the adjusting nut in sequence, and both the intermediate nut 17 and the loosening nut 18 are connected with the mounting stud 11 in a threaded connection. By rotating the position of the adjusting nut 15 on the installation stud 11 , the pressing force of the wire clamping plate 14 on the elastic wire clamping piece 12 can be adjusted, so as to realize the adjustment between the elastic wire clamping piece 1 12 and the elastic wire clamping piece 2 13 The elastic pressing force can realize the function of adjusting the tension of the clamping line. After the adjustment is completed, it is locked by the intermediate nut 17 and the anti-loosening nut 18 and will not loosen, so as to ensure that it always has a suitable tensioning force for the clamping line. Offline.

Embodiment 2

The structure of this embodiment is basically the same as that of the first embodiment, and the difference lies in that: as shown in FIG. A connecting pin 21 is fixed thereon, a long sliding hole 7b is opened at one end of the driving crank 7, the connecting pin 21 slides through the sliding hole 7b, the middle of the driving crank 7 is hinged on the mounting plate 4, and the driving crank 7 The other end is hinged with the transmission link 8. The mounting plate 4 also has a fixing column 23 , one end of the return spring 10 is fixedly sleeved on the fixing column 23 , and the other end is fixedly penetrated on the driving crank 7 . The movement of the iron core of the linear electromagnet 20 drives the connecting pin 21, and the connecting pin 21 slides in the sliding hole 7b of the driving crank 7, and drives the driving crank 7 to swing, and the driving crank 7 drives the transmission connecting rod 8 to move, and pulls the thread setting knife 5 to swing, After swinging a certain angle, the abutting step on the transmission link 8 and the adjusting plate contact each other, the thread setting knife 5 moves to the limit position, the linear electromagnet 20 is powered off, and under the action of the reset spring, the thread setting knife 5 hooks the thread back. bit.

Two eccentric shafts 19 are also fixed on the mounting plate 4, and the two eccentric shafts 19 are located on both sides of the driving crank 7 respectively. It can abut against the two eccentric shafts 19 respectively, and can limit the swing stroke of the driving crank 7, so as to realize the limit of the swing angle of the thread setting knife 5, so as to ensure that the thread hooking and return thread clamping can be accurately realized. The hook of the thread cutter 5 is just located on the right or lower right side of the needle feeding and thread passing plate 3, so that the starting seam is more stable, and it is not easy to skip the needle and fall off the thread.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention pertains can make various modifications or additions to the described specific embodiments or substitute in similar manners, but will not deviate from the spirit of the present invention or go beyond the definitions of the appended claims range.

Claims (10)

1. The utility model provides a sewing machine plays seam anticreep device, sewing machine include casing (1), ornamental thread cutter unit (2), feed the needle collude, feed needle frame (22) and feed needle line board (3) of crossing, play seam anticreep device includes mounting panel (4), dials line subassembly and thread clamping components, dial line subassembly including driving piece and one end have line sword (5) of dialling of drag hook, its characterized in that, mounting panel (4) are rectangular form, mounting panel (4) laminating is fixed the front end of casing (1) and is located the rear side of ornamental thread cutter unit (2), the driving piece is fixed in the one end of mounting panel (4), the middle part of dialling line sword (5) articulates the other end in mounting panel (4) through the pivot, still be equipped with drive crank (7) and transmission connecting rod (8) between driving piece and the line sword (5), the one end of transmission connecting rod (8) is articulated with the other end of dialling line sword (5), the other end is hinged with a driving crank (7), the driving piece can drive the driving crank (7) to swing, an installation sheet (9) can be detachably connected on the installation plate (4), the installation sheet (9) is positioned between the driving crank (7) and the wire poking knife (5) and is close to the wire poking knife (5), the installation sheet (9) is positioned below a transmission connecting rod (8) and one end of the installation sheet downwardly extends to the lower part of the installation plate (4), a wire clamping component is fixed on the extending end and is arranged opposite to the wire poking knife (5), the wire feeding wire passing plate (3) is fixed on the installation plate (4) and is positioned on two sides of the installation plate (4) respectively with the wire poking knife (5), the height of a drag hook of the wire poking knife (5) in the horizontal direction is not higher than the bottom of the wire feeding wire passing plate (3), a wire passing gap for the wire poking knife (5) to swing to pass is formed between the wire feeding hook, the wire feeding frame (22) and the wire feeding plate (3), the mounting plate (4) is also provided with a return spring (10) which can drive the wire poking knife (5) to return; the wire poking knife (5) is arranged along the vertical direction, and the draw hook is bent along the horizontal direction relative to the wire poking knife (5).

2. The sewing machine seam-lifting and thread-off preventing device of claim 1, wherein the mounting piece (9) comprises a sheet-shaped body (9a), a strip-shaped connecting part (9b) and a sheet-shaped mounting part (9c), the body (9a) is attached to and fixed on the mounting plate (4), the connecting part (9b) extends downwards from one side of the body (9a) to the outside of the mounting plate (4), the mounting part (9c) is bent relative to the connecting part (9b) and located below the mounting plate (4), the mounting part (9c) is arranged in an inclined manner, and the thread clamping assembly is fixed on the mounting part (9 c).

3. The sewing machine seam starting and thread slipping preventing device according to claim 2, characterized in that an installation stud (11) is arranged on the installation portion (9c), the thread slipping component comprises a first elastic thread slipping piece (12), the first elastic thread slipping piece (12) is in a bent plate shape, one end of the first elastic thread slipping piece is fixed on the installation portion (9c) through a screw, the middle of the first elastic thread slipping piece is sleeved on the installation stud (11), a thread slipping pressing plate (14) is further sleeved on the stud, the shape of the thread slipping pressing plate (14) is matched with the first elastic thread slipping piece (12) and is attached to the upper side of the first elastic thread slipping piece (12), an adjusting nut (15) is further arranged on the installation stud (11), and the adjusting nut (15) is abutted against the thread slipping pressing plate (14) to elastically compress the first elastic thread slipping piece (12) on the installation portion (9 c).

4. The sewing machine seam-starting and thread-off preventing device according to claim 3, wherein the mounting stud (11) is further sleeved with a resilient abutting block (16) and a resilient thread-clamping piece two (13), the lower side of the resilient thread-clamping piece one (12) abuts against the resilient abutting block (16), one end of the resilient thread-clamping piece two (13) is fixedly sleeved on the mounting stud (11) and located below the mounting portion (9c), and the other end of the resilient thread-clamping piece one (12) elastically abuts against the other end of the resilient thread-clamping piece one (12).

5. The sewing machine seam starting and thread falling prevention device according to claim 4, characterized in that a middle nut (17) and a loosening prevention nut (18) are further sequentially arranged above the adjusting nut (15), and the middle nut (17) and the loosening prevention nut (18) are in threaded fit connection with the mounting stud (11).

6. The sewing machine seam thread-off prevention device according to any one of claims 1 to 5, wherein the driving member is a rotary electromagnet (6), the rotary electromagnet (6) is fixed on one side of the mounting plate (4) and an iron core passes through the mounting plate (4) to be fixedly connected with the driving crank (7).

7. The sewing machine seam-up thread-off prevention device according to claim 6, wherein one end of the driving crank (7) is provided with a clamping opening (7a), the side wall of the clamping opening (7a) is provided with an arc-shaped mounting groove, and an iron core of the rotary electromagnet (6) is arranged in the arc-shaped mounting groove in a penetrating manner and is fixed by tightening the clamping opening (7a) through a fastener.

8. Sewing machine seam coming-off prevention device according to claim 7, characterized in that two eccentric shafts (19) are fixed on the mounting plate (4), one end of the transmission connecting rod (8) hinged to the driving crank (7) is provided with a baffle (8b) bent downwards, the middle part of the transmission connecting rod (8) is provided with a convex limiting rod (8a), the baffle (8b) and the limiting rod (8a) are located between the two eccentric shafts (19), the baffle (8b) can abut against one of the eccentric shafts (19) when the driving crank (7) is driven by the rotary electromagnet (6) to swing, and the limiting rod (8a) can abut against the other eccentric shaft (19) when the driving crank (7) is returned.

9. The sewing machine seam thread-up and thread-off prevention device according to any one of claims 1 to 5, wherein the driving member is a linear electromagnet (20), the linear electromagnet (20) is fixed on the mounting plate (4), a connecting pin (21) is fixed on an iron core of the linear electromagnet (20), one end of the driving crank (7) is provided with a long sliding hole (7b), the connecting pin (21) is slidably inserted into the sliding hole (7b), the middle part of the driving crank (7) is hinged on the mounting plate (4), and the other end of the driving crank (7) is hinged with the transmission connecting rod (8).

10. Sewing machine stitch retention prevention device according to claim 9, characterized in that two eccentric shafts (19) are fixed to the mounting plate (4), the two eccentric shafts (19) being located on either side of the drive crank (7), the drive crank (7) being capable of abutting against the two eccentric shafts (19) after being driven to swing by the linear electromagnet (20) and after being returned by the spring force of the return spring (10).

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