CN219364013U - Automatic thread breaking device for sewing machine - Google Patents

Abstract

The utility model discloses an automatic wire breaking device for a sewing machine, which comprises a fixed frame, a fixed cutter group, a movable cutter group, a driving mechanism, a first adjusting device and the like, wherein the fixed cutter group and the movable cutter group are arranged on the fixed frame arranged on the lower plane of a needle plate, the movable cutter group is driven to move back and forth along the fixed cutter group by the driving mechanism, after a wire end is hooked by a groove on a movable cutter, the fixed cutter group can be matched with the fixed cutter in time to realize accurate wire breaking, and the fixed cutter group is also provided with the first adjusting device capable of adjusting the relative distance between a cutter head and a needle hole, so that the relative distance between the cutter head and the needle hole can be adjusted by the first adjusting device according to actual requirements, the length of the trimmed wire end is controllable, the wire breaking device can be further suitable for trimming long wire ends, the sewing requirements in special occasions are met, and the wire breaking device also has the characteristics of simple and compact structure, easiness in operation and the like.

Description

Automatic thread breaking device for sewing machine

Technical Field

The utility model relates to the technical field of sewing machines, in particular to an automatic thread breaking device for a sewing machine.

Background

A sewing machine is a machine that interweaves or sews one or more layers of stitching material by forming one or more stitches on the stitching material with one or more stitching threads. The sewing machine can sew cotton, hemp, silk, wool, artificial fiber and other fabrics, leather, plastic, paper and other products, and the sewn stitch is neat, beautiful, flat, firm, fast in sewing speed and simple and convenient to use. The existing thread cutting device of the sewing machine is complex in structure, the sewing thread of the needle needs to be picked out by the thread hooking structure, then the sewing thread is clamped to the cutter through the thread clamping structure to be cut, and the whole thread cutting device is complex. In view of this situation, some improved wire cutting devices are also on the market.

For example, chinese patent application No. CN201821379419.2 (issued to the public No. CN 209340555U) discloses an automatic thread end cutting device of a sewing machine, which comprises a fixed knife, a movable knife and a driving piece, wherein the fixed knife, the movable knife and the driving piece are fixedly arranged below a needle plate, the fixed knife and the movable knife are arranged between the needle plate and a rotating shuttle, the cutting edge of the fixed knife is close to a needle hole, the movable knife is arranged below the fixed knife, the driving piece is connected with the tail end of the movable knife through a thread cutting swing rod and can drive the movable knife to reciprocate to cut threads, the distance between a thread hooking groove on the movable knife and the knife tip of the movable knife determines the length of thread end left on a needle, the device also installs the fixed knife at a position close to the needle hole, the distance between the fixed knife and the needle hole determines the length of thread end left on the sewing material, therefore, the thread end left on the sewing material can be very short due to structural limitation, the length of the thread end is not easy to adjust, which is good for maintaining the beautiful appearance of the sewing material if the thread end is needed to be cut off manually in the later period, one procedure can be saved, but the leather material needs to be sewn, or leather bags or leather boxes which imitate the high-grade one of the manual sewing, car seat sleeves which are special one of the sewing, and the like are sewn, if the thread end is too short at the tail end of the thread end, when the leather of two layers of the material or other better materials are touched, as the materials generally have very strong elasticity, the thread end is once tightened, the thread end which is too short can lead to disconnection, the end needle is not wired, the whole sewing effect is greatly discounted, even the phenomenon of seam disconnection occurs, so the thread end needs to be left long, and then the bottom thread and the upper thread are manually sewn, the threads are fastened together, so that the threads are not scattered, are firm, and are more similar to the effect of manual sewing.

Therefore, how to provide a wire breaking device with simple and reasonable structure, controllable length of the trimmed wire ends and especially suitable for trimming the long wire ends is a problem to be solved by the person skilled in the art.

Disclosure of Invention

The utility model aims to solve the technical problem of providing an automatic thread breaking device for a sewing machine, which has a simple structure, is convenient to adjust and can be suitable for cutting long thread ends.

The technical scheme adopted for solving the technical problems is as follows: the automatic thread breaking device for the sewing machine comprises: comprising

The fixing frame is arranged on the lower plane of a needle plate of the sewing machine;

the fixed knife group is arranged on the fixed frame, a knife head of the fixed knife blade is adjacent to a needle hole of the needle plate, and a first adjusting device capable of adjusting the relative distance between the knife head and the needle hole is arranged;

the movable knife set is transversely arranged on the fixed frame in a moving way and is matched with the fixed knife set, a groove capable of hooking a thread end below the pinhole is arranged on the movable knife blade, and the groove retracts after hooking the thread end and contacts with a knife head of the fixed knife blade to finish the thread breaking action; and

and the driving mechanism drives the movable knife group to move.

In order to optimize the mounting structure of the fixed cutter group so as to facilitate processing and assembly, preferably, the fixed cutter group further comprises a first bracket, the fixed cutter group comprises an upper cutter and a lower cutter, the upper cutter and the lower cutter are both arranged on the first bracket, a gap for the movable cutter to pass through is reserved between the upper cutter and the lower cutter, the cutter head of the fixed cutter is arranged on the upper cutter, and the first adjusting device is arranged on the first bracket.

In order to enable the movable blade to better hook the thread end and realize seamless matching with the fixed blade, preferably, the movable blade is integrally long and narrow, one end of the movable blade matched with the cutter head of the fixed blade is designed to be in a sharp blade shape, and an inclined plane forming an included angle with the upper end face of the upper blade is further arranged at the end part of the sharp blade shape.

In order to quickly realize the adjustment of the relative distance between the tool bit and the pinhole, preferably, the first adjusting device comprises a first strip-shaped hole and a first fastener which are arranged on the first bracket, a first positioning hole corresponding to the first strip-shaped hole is further formed in the fixing frame, the first fastener penetrates through the first strip-shaped hole and then fixes the first bracket on the first positioning hole, and the position of the fixing frame is moved, so that the first fastener can relatively slide along the first strip-shaped hole to realize the position adjustment of the fixing frame, and the relative distance between the tool bit and the pinhole is changed.

In order to enable an operator to more intuitively feel the relative distance between the cutter head and the pinhole in the whole adjusting process, further, a first scale is further arranged on the fixing frame, and correspondingly, a first positioning mark which can correspond to the first scale is arranged on the first support.

In order to optimize the mounting structure of moving the knife tackle in order to make things convenient for subsequent assembly to make and move the knife tackle and remove more steady accurate, preferably, move the knife tackle still include the second support, move the blade and locate on this second support, the second support is equipped with the spout, be equipped with on the mount with spout looks adaptation's slide rail, actuating mechanism drive is connected on the second support order to move the blade along slide rail round trip movement.

In order to facilitate the driving mechanism to drive the movable cutter group to move, preferably, the driving mechanism comprises a motor, a driving wheel connected with the output end of the motor, a driven wheel connected with the driving wheel in a driving way and a driving belt connected between the driving wheel and the driven wheel in a driving way, the driving belt is connected with the second bracket, and the motor drives the driving belt to move back and forth so as to drive the second bracket to move and then to move to the movable cutter.

In order to facilitate the connection between the driving belt and the second bracket, preferably, a connecting seat is further arranged between the second bracket and the driving belt, one end of the connecting seat is fixed on the driving belt, the other end of the connecting seat is connected with the second bracket, and a second adjusting device capable of adjusting the relative position between the driving belt and the second bracket is further arranged on the connecting seat.

In order to facilitate the adjustment of the second adjusting device, preferably, the second adjusting device comprises a second bar-shaped hole and a second fastener which are arranged on the connecting seat, a second positioning hole corresponding to the second bar-shaped hole is arranged on the second bracket, the second fastener passes through the second bar-shaped hole and then fixes the connecting seat on the second positioning hole, a second graduated scale is further arranged on the connecting seat, and correspondingly, a second positioning mark which can correspond to the second graduated scale is arranged on the second bracket.

In order to realize the detachable connection of the transmission belt and the connecting seat and adjust the relative position at any time, preferably, the connecting seat further comprises a bottom plate arranged at the bottom of the connecting seat, the bottom plate and the connecting seat are detachably connected through bolts, and a belt of the transmission belt is embedded between the bottom plate and the connecting seat and is fixed.

Compared with the prior art, the utility model has the advantages that: through setting up stationary knife group and moving the knife group on the mount of installing on the faller lower plane to through setting up actuating mechanism and order about moving the knife group and can follow stationary knife group round trip movement, make the slot on the movable blade collude behind the thread end, can in time realize accurate broken string with stationary blade mutually support, because still be provided with on the stationary knife group and can adjust the relative distance between tool bit and the pinhole first adjusting device, consequently, can also be according to actual demand, adjust the relative distance between tool bit and the pinhole through this first adjusting device, thereby make the thread end length that prunes controllable, and then can be applicable to shearing long thread end, satisfied the sewing requirement at special occasion, and this broken string device still has simple structure compactness, characteristics such as very easy control.

Drawings

FIG. 1 is a schematic perspective view of an embodiment of the present utility model;

FIG. 2 is a schematic perspective view of another angle of the embodiment of the present utility model;

FIG. 3 is an exploded view of an embodiment of the present utility model;

FIG. 4 is a schematic diagram of a stationary knife assembly in an embodiment of the utility model;

FIG. 5 is a schematic diagram showing the disassembled state of the movable blade assembly according to the embodiment of the utility model;

fig. 6 is a schematic perspective view showing a structure in which a wire breaking device according to an embodiment of the present utility model is mounted on a needle plate.

Detailed Description

The utility model is described in further detail below with reference to the embodiments of the drawings.

Fig. 1 to 6 are schematic views of the present embodiment, and the automatic thread breaking device for a sewing machine of the present embodiment mainly includes a fixing frame 1, a fixed knife set 2, a movable knife set 4, a driving mechanism 5, a first adjusting device 3, a second adjusting device 6, and the like.

As shown in fig. 1 and 6, the fixing frame 1 is disposed on a lower plane of a needle plate a of the sewing machine, a needle hole b for a needle of the sewing machine to pass through is disposed on the needle plate a, the fixed knife set 2 is disposed on the fixing frame 1, a knife head 211 of a fixed knife blade 21 is adjacent to the needle hole b of the needle plate a, the first adjusting device 3 is disposed on the fixed knife set 2 and is used for adjusting a relative distance between the knife head 211 and the needle hole b, the movable knife set 4 is disposed on the fixing frame 1 in a transversely moving manner and is matched with the fixed knife set 2, a groove 411 capable of hooking a thread head located below the needle hole b is disposed on a movable knife blade 41, the groove 411 is retracted after hooking the thread head and contacts the knife head 211 of the fixed knife blade 21 to complete a thread breaking action, and the driving mechanism 5 is disposed on the fixing frame 1 and is used for driving the movable knife set 4 to move.

As shown in fig. 4, in this embodiment, the fixed blade set 2 mainly includes a fixed blade 21 and a first support 22, the fixed blade 21 includes an upper blade 21a and a lower blade 21b, the upper blade 21a and the lower blade 21b are both disposed on the first support 22, a gap for passing the driving blade 41 is left between the upper blade 21a and the lower blade 21b, the blade head 211 of the fixed blade 21 is disposed on the upper blade 21a, and the first adjusting device 3 is disposed on the first support 22. The movable blade 41 is long and narrow as a whole, one end of the movable blade 41, which is matched with the cutter head 211 of the fixed blade 21, is designed to be an end part with a sharp blade shape, an inclined surface 412 forming an included angle with the upper end surface of the upper blade is arranged at the sharp blade shape end part, and the movable blade can better hook the thread end based on the arrangement of the sharp blade shape and the inclined surface 412 and realize seamless matching with the fixed blade.

As shown in fig. 1, in this embodiment, the first adjusting device 3 mainly includes a first bar hole 31 and a first fastening member 33 provided on the first bracket 22, the fixing frame 1 is further provided with a first positioning hole 32 corresponding to the first bar hole 31, the first fastening member 33 passes through the first bar hole 31 and then fixes the first bracket 22 on the first positioning hole 32, and by moving the position of the fixing frame 1, the first fastening member 33 can slide relatively along the first bar hole 31 to realize the position adjustment of the fixing frame 1, so as to change the relative distance between the cutter head 211 and the pinhole b. The first scale 11 is also arranged on the fixing frame 1, and correspondingly, the first positioning mark 221 which can correspond to the first scale 11 is arranged on the first bracket 22.

As shown in fig. 5, in the present embodiment, the movable blade set 4 mainly includes a movable blade 41 and a second support 42, the movable blade 41 is disposed on the second support 42, a sliding slot 43 is further disposed below the second support 42, a sliding rail 12 adapted to the sliding slot 43 is disposed on the fixing frame 1, and the driving mechanism 5 is connected to the second support 42 to drive the movable blade 41 to move back and forth along the sliding rail 12.

Referring to fig. 2 and 3, in this embodiment, the driving mechanism 5 includes a motor 51, a driving wheel 52 connected to an output end of the motor 51, a driven wheel 53 drivingly connected to the driving wheel 52, and a driving belt 54 drivingly connected between the driving wheel 52 and the driven wheel 53, where the driving belt 54 is connected to the second bracket 42, and the motor 51 drives the driving belt 54 to move back and forth to drive the second bracket 42 to move to the moving blade 41, and of course, the driving mechanism 5 is not limited to the motor and the driving belt to move the moving blade 41, and may be replaced by other equivalent driving methods.

In order to facilitate the connection between the driving belt 54 and the second bracket 42, in this embodiment, as shown in fig. 5, a connecting seat 44 is further provided between the second bracket 42 and the driving belt 54, one end of the connecting seat 44 is fixed on the driving belt 54, the other end is connected to the second bracket 42, and a second adjusting device 6 capable of adjusting the relative position between the driving belt 54 and the second bracket 42 is further provided on the connecting seat 44. The connecting seat 44 further comprises a bottom plate 45 arranged at the bottom of the connecting seat 44, the bottom plate 45 and the connecting seat 44 are detachably connected through bolts, and a belt of the driving belt 54 is embedded between the bottom plate 45 and the connecting seat 44 and is fixed.

Referring to fig. 1, in the present embodiment, the second adjusting device 6 mainly includes a second bar hole 61 and a second fastening member 63 disposed on the connecting seat 44, the second bracket 42 is provided with a second positioning hole 62 corresponding to the second bar hole 61, the second fastening member 63 passes through the second bar hole 61 to fix the connecting seat 44 on the second positioning hole 62, the connecting seat 44 is further provided with a second scale 441, correspondingly, the second bracket 42 is provided with a second positioning mark 421 corresponding to the second scale 441, and based on the setting of the second adjusting device 6, the relative position adjustment between the driving belt 54 and the second bracket 42 can be more convenient, more flexible and controllable.

The working principle of the automatic thread breaking device for the sewing machine in the embodiment is as follows:

as shown in fig. 6, the fixing frame 1 is first fixed on the lower plane of the needle board a by a fastener such as a screw, so that the cutter head 211 of the fixed blade 21 of the fixed blade group 2 is adjacent to the needle hole b on the needle board a, and meanwhile, the groove 411 arranged by the movable blade 41 on the movable blade group 5 is aligned with the thread to be trimmed at the position below the needle hole b, so as to facilitate the hooking of the groove 411, and then the driving mechanism 5 is driven to make the movable blade 41 move back and forth to mutually cooperate with the fixed blade 21 to realize thread breakage. In the use process, the relative distance between the cutter head 211 of the fixed blade 21 and the pinhole b can be adjusted through the first adjusting device 3, so that the length of the cut thread end is controllable, and the length can be adjusted at any time according to the needs. In the practical application process, the relative position between the transmission belt 54 and the movable cutter group 4 can be adjusted by adjusting the second adjusting device 6, so that the movable cutter 41 can hook the thread ends to be trimmed at the most appropriate position, and finally the matching connection between the movable cutter group 4 and the fixed cutter group 2 is more optimized, so that the length of the cut thread ends can be controlled more easily while the quick thread breakage is realized, and the movable cutter is more suitable for trimming long thread ends.

It should be noted that, in the description of the present embodiment, the directions or positional relationships indicated by the terms "front, rear", "left, right", "inner, outer", "upper, lower", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. The terms "mounted," "connected," "coupled," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Claims (10)

1. An automatic thread breaking device for a sewing machine, characterized in that: comprising

A fixed frame (1) arranged on the lower plane of a needle plate (a) of the sewing machine;

the fixed knife group (2) is arranged on the fixed frame (1), a knife head (211) of a fixed knife blade (21) is adjacent to a needle hole (b) of the needle plate (a), and a first adjusting device (3) capable of adjusting the relative distance between the knife head (211) and the needle hole (b) is arranged;

the movable knife group (4) is transversely arranged on the fixed frame (1) in a moving way and is matched with the fixed knife group (2), a groove (411) capable of hooking a thread end below the pinhole (b) is arranged on the movable knife blade (41), and the groove (411) retracts after hooking the thread end and contacts with the knife head (211) of the fixed knife blade (21) to finish the thread breaking action; and

and the driving mechanism (5) drives the movable knife group (4) to move.

2. The automatic thread cutting device for a sewing machine of claim 1, wherein: the fixed cutter group (2) also comprises a first support (22), the fixed cutter (21) comprises an upper cutter (21 a) and a lower cutter (21 b), the upper cutter (21 a) and the lower cutter (21 b) are arranged on the first support (22), a gap for the movable cutter (41) to pass through is reserved between the upper cutter (21 a) and the lower cutter (21 b), the cutter head (211) of the fixed cutter (21) is arranged on the upper cutter (21 a), and the first adjusting device (3) is arranged on the first support (22).

3. The automatic thread cutting device for a sewing machine of claim 2, wherein: the movable blade (41) is integrally long and narrow, one end of the movable blade (41) matched with the cutter head (211) of the fixed blade (21) is designed to be in a sharp blade shape, and an inclined plane (412) forming an included angle with the upper end face of the upper blade is further arranged at the end part of the sharp blade shape.

4. The automatic thread cutting device for a sewing machine of claim 2, wherein: the first adjusting device (3) comprises a first strip-shaped hole (31) and a first fastening piece (33) which are arranged on the first support (22), a first positioning hole (32) corresponding to the first strip-shaped hole (31) is further formed in the fixing frame (1), the first fastening piece (33) penetrates through the first strip-shaped hole (31) and then is fixed on the first positioning hole (32), and the position of the fixing frame (1) is moved, so that the first fastening piece (33) can relatively slide along the first strip-shaped hole (31) to achieve position adjustment of the fixing frame (1), and the relative distance between the cutter head (211) and the needle hole (b) is changed.

5. The automatic thread cutting device for a sewing machine of claim 2, wherein: the fixing frame (1) is also provided with a first scale (11), and correspondingly, the first bracket (22) is provided with a first locating mark (221) which can correspond to the first scale (11).

6. The automatic thread cutting device for a sewing machine of claim 1, wherein: the movable knife group (4) further comprises a second support (42), the movable knife blade (41) is arranged on the second support (42), the second support (42) is provided with a sliding groove (43), the fixing frame (1) is provided with a sliding rail (12) matched with the sliding groove (43), and the driving mechanism (5) is connected to the second support (42) in a driving mode to drive the movable knife blade (41) to move back and forth along the sliding rail (12).

7. The automatic thread cutting device for a sewing machine of claim 6, wherein: the driving mechanism (5) comprises a motor (51), a driving wheel (52) connected with the output end of the motor (51), a driven wheel (53) connected with the driving wheel (52) in a driving mode and a driving belt (54) connected between the driving wheel (52) and the driven wheel (53) in a driving mode, the driving belt (54) is connected with the second bracket (42), and the motor (51) drives the driving belt (54) to move back and forth so as to drive the second bracket (42) to move and then drive the movable blade (41) to move.

8. The automatic thread cutting device for a sewing machine of claim 7, wherein: a connecting seat (44) is further arranged between the second support (42) and the driving belt (54), one end of the connecting seat (44) is fixed on the driving belt (54), the other end of the connecting seat is connected with the second support (42), and a second adjusting device (6) capable of adjusting the relative position between the driving belt (54) and the second support (42) is further arranged on the connecting seat (44).

9. The automatic thread cutting device for a sewing machine of claim 8, wherein: the second adjusting device (6) comprises a second strip-shaped hole (61) and a second fastening piece (63) which are arranged on the connecting seat (44), a second positioning hole (62) corresponding to the second strip-shaped hole (61) is arranged on the second bracket (42), the second fastening piece (63) penetrates through the second strip-shaped hole (61) to fix the connecting seat (44) on the second positioning hole (62), a second graduated scale (441) is further arranged on the connecting seat (44), and correspondingly, a second positioning mark (421) which can correspond to the second graduated scale (441) is arranged on the second bracket (42).

10. The automatic thread cutting device for a sewing machine of claim 8, wherein: the connecting seat (44) further comprises a bottom plate (45) arranged at the bottom of the connecting seat (44), the bottom plate (45) is detachably connected with the connecting seat (44) through bolts, and the belt of the driving belt (54) is embedded between the bottom plate (45) and the connecting seat (44) and is fixed.