CN114318698A - Thread trimming mechanism of a sewing machine, and sewing machine - Google Patents

Abstract

The invention relates to a thread trimming mechanism of a sewing machine and the sewing machine, wherein the thread trimming mechanism comprises a first thread trimming cutter and a second thread trimming cutter, the first thread trimming cutter is fixedly arranged at the outer peripheral side of a rotating shuttle assembly, the second thread trimming cutter is arranged at the outer peripheral side of the rotating shuttle assembly and can rotate around the rotating shuttle assembly to be meshed with or separated from the second thread trimming cutter, a thread trimming hook used for hooking a bottom thread and an upper thread to move towards the first thread trimming cutter is arranged on the second thread trimming cutter, the thread trimming mechanism further comprises a fixedly arranged thread trimming catching piece, a first constraint structure is arranged on the thread trimming catching piece, and a second constraint structure is arranged on the second thread trimming cutter; when the thread cutting is started, the second thread cutting knife rotates towards the first thread cutting knife, the thread cutting hook drives the surface thread to be close to the first constraint structure, and the second constraint structure is matched with the first constraint structure before the second thread cutting knife is meshed with the first thread cutting knife for thread cutting, and the selvage thread in the surface thread loop is constrained at a fixed thread cutting constraint position.

Description

Thread trimming mechanism of a sewing machine, and sewing machine

technical field

The invention relates to the field of sewing equipment, in particular to a thread trimming mechanism of a sewing machine and a sewing machine.

Background technique

In the existing sewing machine, the thread trimming mechanism will use the thread dividing piece to divide the thread when cutting the thread. However, referring to FIG. 1, the upper thread loop may cover the existing thread dividing piece 01, or it may be completely in the existing thread dividing piece 01. The side of the oblique edge of the thread piece 01, this will cause the thread length of the upper thread 9 on the right side of the needle after trimming, which is very unstable. The thread length of the upper thread 9, which is very unstable on the right side of the needle, may be too short to form an upper thread loop, which further increases the probability that the bottom thread 10 will not reach the bottom thread 10 at the start of the seam. phenomenon of escape.

SUMMARY OF THE INVENTION

In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a thread trimming mechanism for a sewing machine and a sewing machine, which can limit the position of the edge thread in the upper thread loop during thread trimming and improve the upper thread The stability of the thread loop during thread trimming ensures that the length of the thread end after thread trimming is basically the same.

In order to achieve the above purpose, the present invention provides a thread trimming mechanism for a sewing machine, which is used for trimming the thread at the rotary hook assembly of the sewing machine. The thread trimming mechanism includes a first thread trimmer and a second thread trimmer. The first thread trimmer is fixedly installed at the outer peripheral side of the hook assembly, and the second thread trimmer is arranged at the outer peripheral side of the hook assembly and can rotate around the hook assembly to engage with or separate from the second thread trimmer, so The second thread trimmer is provided with a thread trimmer hook for hooking the lower thread and the upper thread toward the first thread trimmer, and the thread trimming mechanism also includes a fixedly installed thread trimmer catcher, the thread trimmer A first constraining structure is arranged on the catching piece, and a second constraining structure is arranged on the second thread trimmer; when thread trimming starts, the second thread trimmer rotates toward the first thread trimmer and the thread trimmer hook drives the surface The thread is close to the first restraint structure, and before the second thread cutter engages with the first thread cutter to cut the thread, the second restraint structure cooperates with the first restraint structure and constrains the selvedge line in the upper thread loop to a fixed at the position of the trimming constraint.

Further, the thread-cutting hook of the second thread trimmer is composed of a thread-hook hypotenuse and a thread-hook rib, and the thread-hook hypotenuse extends from the left side of the second thread trimmer to the right obliquely, and the hook The thread rib is arranged on the right side of the oblique side of the hook thread, and the second restraining structure includes a thread trimmer hook; the thread trimmer capturing member includes an arc-shaped capturing piece arranged along the outer peripheral side of the rotary hook assembly, and the arc-shaped capturing sheet is located at Between the hook assembly and the first thread trimmer, one end of the arc-shaped catch piece facing the second thread trimmer is the A side end, and the other end is the B side end, and the first constraining structure includes a The right side of the A side end of the sheet and the rightward inclined restraint side, the restraint side is opposite to the thread trimmer hook, and the side of the restraint side close to the A side end extends to the left side of the hook line hypotenuse; the first When the second thread trimmer rotates toward the first thread trimmer, the thread trimmer hook and the restraining side meet to form a closed area.

Further, when the second thread trimmer rotates to engage with the first thread trimmer for thread trimming, a closed area formed by the intersection of the thread trimmer hook and the constraining side edge still exists.

Further, when the second thread trimmer rotates to engage with the first thread trimmer for thread trimming, the thread trimmer hook straddles the constraining side edge so that the closed area disappears.

Further, the thread hooking ribs are arranged obliquely from left to right, and one end close to the thread trimming catcher is located on the left side, and one end away from the thread trimmer catcher is located on the right side.

Further, the second thread trimmer is provided with a line dividing tip for inserting between the upper thread loops and dividing the line. The right side of the tip portion has a first bisector hypotenuse inclined to the right.

Further, the right side of the arc-shaped catching piece is provided with a second parting line oblique edge opposite to the first parting line oblique edge, and the first parting line is oblique when the second cutting knife rotates toward the first cutting knife. The edge meets the hypotenuse of the second dividing line; the second constraining structure further includes the hypotenuse of the first dividing line, and the first constraining structure further comprises the hypotenuse of the second dividing line.

Further, an arc-shaped protrusion is provided on the right side of the arc-shaped catching piece, and the arc-shaped protrusion is located on the left side of the hook line retaining edge, and the end of the restraint side close to the B side end extends to the arc-shaped protrusion. place.

Further, a first catching portion is provided on the side of the first thread trimmer facing the hook assembly, and an outer arc surface of the arc-shaped catching piece is provided with a second catching portion abutting against the first catching portion; During thread trimming, the second thread trimmer rotates toward the first thread trimmer so that the thread trimmer hook drives the lower thread to extend between the first catching portion and the second catching portion.

Further, the thread hooking ribs are arranged obliquely from left to right, and the end close to the thread trimming catcher is located on the left side, and the end away from the thread trimmer catcher is located on the right side. Two catch the right side of the section.

Further, the inclination angle of the hooking rib with respect to the front-rear direction is 2-4°.

Further, the inclination angle of the hooking rib with respect to the front-rear direction is 3°.

Further, the first thread trimmer is provided with a raised portion, the second thread trimmer is provided with a raised portion inclined toward the side where the hook assembly is located, and the second thread trimmer faces the first trimmer. When the thread knife rotates, the raised part is inserted into the lower side of the raised part facing the hook assembly.

Further, the thread trimmer catcher has a mounting section connected with the arc-shaped catch piece, and the component used for the fixed installation of the thread trimmer catcher in the sewing machine is the catcher mounting base, and the mounting segment is connected to the catcher mounting base. Fixed connection.

Further, the installation section is fixedly installed on the installation base of the catcher by means of fastening screws, the installation section is provided with a bar-shaped connection hole extending in the front-rear direction, and the fastening screw is screwed through the bar-shaped connection hole. into the catcher installation base.

The present invention also provides a sewing machine comprising a rotary hook assembly and the above thread trimming mechanism, wherein the thread trimming mechanism is arranged at the rotary hook assembly for thread trimming.

As described above, the thread trimming mechanism and the sewing machine involved in the present invention have the following beneficial effects:

By setting the thread trimmer catcher, the upper thread is restrained by the first restraint structure on the arc catch piece and the second restraint structure on the second thread trimmer. When thread trimming, the second thread trimmer is driven toward the first thread trimmer. When the knife rotates, the thread trimmer hook will hook the lower thread and the selvage thread in the upper thread loop, and then drive the lower thread and the upper thread close to the first thread cutter, and at the same time the upper thread loop will be close to the first constraint on the thread trimmer catcher structure, the second constraining structure is also close to the first constraining structure, the second constraining structure cooperates with the first constraining structure before engaging the trimming line to constrain the selvedge line in the upper thread loop to a fixed trimming constraint The upper thread loop can be limited to a stable position every time the thread is trimmed, and the stability of the upper thread loop during thread trimming can be improved, so that the length of the thread end after the thread trimming is basically the same. .

Description of drawings

FIG. 1 is a schematic diagram of the position of the upper thread loop on the split sheet in the existing design.

FIG. 2 is a schematic structural diagram of the thread trimming mechanism of the present invention.

3 is a schematic structural diagram of a second thread trimmer in the thread trimming mechanism of the present invention.

4 is a schematic structural diagram of a first thread trimmer in the thread trimming mechanism of the present invention.

FIG. 5 is a schematic structural diagram of an embodiment of the thread-cutting catch of the present invention.

FIG. 6 is a schematic structural diagram of another embodiment of the thread trimmer catcher in the present invention.

7 is a schematic view of the work of the thread trimming mechanism of the present invention during normal sewing and bobbin thread capture.

8 is a schematic view of the work of the thread trimming mechanism of the present invention during thread trimming.

FIG. 9 is a schematic diagram of the cooperation of the first thread trimmer and the thread trimmer catcher in state 1 when the thread is trimmed in the present invention.

FIG. 10 is a schematic diagram of the cooperation of the first thread trimmer and the thread trimmer catcher in state 2 when the thread is trimmed in the present invention.

FIG. 11 is a schematic diagram of the cooperation of the first thread trimmer and the thread trimmer catcher in state three when thread trimming in the present invention.

Fig. 12 is a schematic diagram of the position of the thread end of the upper thread at the thread trimmer catcher in the present invention.

13 is a schematic view of the work of the thread trimming mechanism of the present invention when thread trimming.

FIG. 14 is a schematic view of the work of the thread trimming mechanism of the present invention after thread trimming.

Component label description

01 Splitter

1 Chassis

2 hook assembly

2a Hook inner bladder

2b Shuttle skin 2b

2c Shuttle carrier thread guide

3 Hook positioning hook

4 needles

5 First thread cutter

5a First cut

5b The first capture part

5c Elevated part

6 Second thread cutter

6a Second blade

6b Thread trimmer hook

6c Hook line bevel

6d hooking rib

6e branch tip

6f First bisector hypotenuse

6g lift

7 Thread trimmer catches

71 Arc Snap

711 A side end

712 B side end

71a Constrain the sides

71b Second bisector hypotenuse

71c Second Capture Division

71d curved bump

72 Installation section

72a bar connection hole

8 Thread trimmer drive assembly

9 thread

9a Edge line

9b needle edge

10 Bottom Line

11 Fastening screws

Detailed ways

The embodiments of the present invention are described below by specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

It should be noted that the structures, proportions, sizes, etc. drawn in the accompanying drawings of this specification are only used to cooperate with the contents disclosed in the specification, so as to be understood and read by those who are familiar with the technology, and are not used to limit the conditions that the present invention can be implemented. Therefore, without technical substantive significance, any modification of structure, change of proportional relationship or adjustment of size should still fall within the scope disclosed in the present invention without affecting the effect that the present invention can produce and the purpose that can be achieved. within the scope of technical content. At the same time, terms such as "up", "down", "left", "right", "middle", etc. quoted in this specification are only for the convenience of description, and are not used to limit the scope of the present invention. , the change or adjustment of the relative relationship, without substantial change of the technical content, should also be regarded as the scope of the present invention.

Referring to Figures 1 to 14, the present invention provides a thread trimming mechanism for a sewing machine, which is used for thread trimming at the rotary hook assembly 2 of the sewing machine. The rotary hook assembly 2 is positioned and installed by the rotary hook positioning hook 3, and the rotary hook is positioned The hook 3 is fixed on the casing 1 , and the outermost part of the hook assembly 2 is the hook skin 2b that rotates.

The thread trimming mechanism of the present invention includes a first thread trimmer 5 and a second thread trimmer 6. Both the first thread trimmer 5 and the second thread trimmer 6 can be circular arc blades, and the first thread trimmer 5 is fixedly installed. At the outer peripheral side of the hook assembly 2, the second thread trimmer 6 is provided at the outer peripheral side of the hook assembly 2 and can rotate around the hook assembly 2 to engage with or separate from the second thread trimmer 6, that is, the first trimmer Both the thread cutter 5 and the second thread trimmer 6 are located on the hook skin 2b with a certain gap, and the hook skin 2b will not touch the first thread trimmer 5 and the second thread trimmer 6 when the hook skin 2b rotates. The rotation of the first thread cutter 5 is driven by the thread cutter drive assembly 8 . The second thread trimmer 6 is provided with a thread trimmer hook 6b for moving the lower thread 10 and the upper thread 9 toward the first thread trimmer 5. Referring to FIGS. 2 and 7, the thread trimmer hook 6b is located on the needle 4 Below, the second thread trimmer 6 will hook the lower thread 10 and the selvedge thread 9a in the upper thread loop when it rotates, and push both the lower thread 10 and the upper thread 9 to the first thread trimmer 5, and then The second cutting edge 6a on the second thread trimmer 6 is engaged with the first cutting edge 5a on the first thread cutting knife 5, where the lower thread 10 is cut and the selvedge thread 9a in the upper thread loop is cut.

The thread trimming mechanism of the present invention further includes a fixedly installed thread trimming catcher 7. Specifically, the thread trimmer catcher 7 can be installed on the casing 1 or the rotary hook positioning hook 3 and other components that are fixed to the casing 1, and the thread trimmer catches The member 7 is provided with a first restraint structure, the first restraint structure is located at the position of the first thread trimmer 5, and the second thread trimmer 6 is provided with a second restraint structure; when thread trimming starts, the second thread trimmer 6 Rotate toward the first thread trimmer 5, and the thread trimmer hook 6b drives the upper thread 9 to approach the first restraint structure, and before the second thread trimmer 6 and the first thread trimmer 5 engage the thread trimmer, the second restraint structure and the first thread trimmer The restraining structure cooperates and restrains the selvedge 9a in the upper thread loop at a fixed trimming restraint position.

When the thread trimming mechanism involved in the present invention is working normally, referring to FIG. 7 , the second thread trimmer 6 does not move and is far away from the first thread trimmer 5, and the rotary hook assembly 2 can rotate normally. When thread trimming is required, the thread trimming drive assembly 8 is used to drive the second thread trimmer 6 to rotate toward the first thread trimmer 5, and the thread trimmer hook 6b will hook the lower thread 10 and the selvedge thread 9a in the upper thread loop. Then drive the lower thread 10 and the upper thread 9 close to the first thread trimmer 5, and at the same time the upper thread loop will be close to the first restraint structure on the thread trimmer catcher 7, and the second restraint structure will also be close to the first restraint structure. Before, the second restraining structure cooperates with the first restraining structure, constrains the edge line 9a in the upper thread loop at a fixed thread trimming restraint position, and then engages the trimming thread, and cuts the surface at the first cutting edge 5a. The selvedge thread 9a of the thread loop is cut, see FIGS. 13 and 14 . In the present invention, the fixed thread-cutting restraint position means that it is fixed relative to the fixed first thread-cutting knife 5, and the thread-cutting restraint position may be a position with a certain range. The selvage thread 9a will be located at this trimming restraint position, so that the selvage thread 9a is restricted to a stable position every time the thread is trimmed, which improves the stability of the upper thread loop during trimming, so that the thread 9 behind the trimming ends. The length is basically the same.

Referring to FIGS. 1 to 14 , the thread trimming mechanism of the present invention will be further described in the following specific embodiment.

In the sewing machine, the axis of the hook assembly 2 is along the left-right direction of the sewing machine, and the hook assembly 2 is located on the left side of the sewing machine. In this embodiment, referring to FIG. 3 , FIG. 5 and FIG. 9 , as a preferred design, the thread-cutting hook 6b of the second thread-cutting knife 6 is composed of a thread-hook oblique edge 6c and a thread-hook oblique edge 6d , and the thread-hook oblique edge 6c It extends diagonally from the left side of the second thread trimmer 6 to the right, the hooking rib 6d is arranged on the right side of the hooking hypotenuse 6c, and a gap structure is formed between the hooking oblique edge 6c and the hooking rib 6d, so as to This constitutes the thread trimmer hook 6b; in addition to hooking the thread, the thread trimmer hook 6b also constitutes a part of the second restraint structure; The catch piece 71 is located between the hook assembly 2 and the first thread trimmer 5. One end of the arcuate catch piece 71 facing the second thread trimmer 6 is the A side end 711 and the other end is the B side end 712. In this embodiment Among them, the first thread trimmer 5 and the second thread trimmer 6 are located on the front side and the rear side of the sewing machine, respectively. When the thread trimmer catcher 7 is installed, the A-side end 711 of the arc-shaped catch piece 71 is toward the back side of the sewing machine. At this time, the A-side end 711 is the front end, the B-side end 712 of the arc-shaped catching piece 71 faces the front side, and the B-side end 712 is the rear end at this time. The first restraint structure includes a restraint side 71a disposed on the right side of the A-side end 711 of the arc-shaped catch piece 71 and inclined to the right, the restraint side 71a is opposite to the wire-cutting hook 6b, and the restraint side 71a is close to the A-side end One side of 711 extends to the left side of the hook line oblique edge 6c. With the above structure, when the thread is trimmed, the second thread trimmer 6 rotates toward the first thread trimmer 5, and the thread trimmer hook 6b will hook the lower thread 10 and the selvage thread 9a in the upper thread loop. It extends to the left side of the thread trimmer hook 6b, so neither the lower thread 10 nor the upper thread 9 will appear on the left side of the arc-shaped catching piece 71, that is to say, there will be no phenomenon of being caught on the arc-shaped catching piece 71. It is located on the right side of the restraint side 71a, see Figure 12; then the thread trimmer hook 6b meets the restraint side 71a to form a closed area, see Figure 9, that is, the hook line oblique edge 6c, the hook line rib 6d and the restraint side edge 71a The three besieged a closed area. At this time, both the bottom thread 10 and the edge line 9a are located in the closed area. During the rotation of the second thread cutter 6, the closed area gradually becomes smaller, so that the edge line 9a is restrained. When the second cutting edge 6a and the first cutting edge 5a are engaged, the edge line 9a is stable, see FIGS. 10 and 11 . In this embodiment, when the second knife edge 6a and the first knife edge 5a are engaged in the thread trimming, there are two solutions. The first solution is that the closed area formed by the intersection of the thread trimming hook 6b and the constraining side edge 71a still exists. As shown in Figure 11, the closed area has become a very narrow space, which can well restrain the selvedge line 9a and avoid the problem of breaking the selvedge line 9a there; the second option is that the thread-cutting hook 6b completely crosses In order to constrain the side edge 71a, the closed area disappears. At this time, the selvedge line 9a will be tightened and bound at the bottom of the thread trimmer hook 6b, that is, the connection between the hook thread oblique edge 6c and the hook thread rib 6d. The advantage of more stable structure. Of course, in another embodiment, the first thread trimmer 5 and the second thread trimmer 6 can also be exchanged for lower positions under appropriate circumstances, the first thread trimmer 5 is located on the rear side, and the second thread trimmer 6 is located at the rear For the front side, the A side end 711 is the rear side end and the B side end 712 is the front side end.

In this embodiment, referring to FIG. 3 and FIG. 9 , as a preferred design, the thread-hook rib 6d of the thread-cutting hook 6b is inclined left and right, and the front end (the end close to the thread-cutting catch 7 ) is located at the left and rear ends (The end away from the thread-cutting catch 7) is located on the right side, that is, the thread-hook rib 6d extends from the left front to the right rear, and the inclination angle of the thread-hook rib 6d is small, and the thread-hook rib 6d is opposite to the front-rear direction. The inclination angle is 2 to 4°, and 3° is the best. With this slightly inclined thread hooking rib 6d, as the second thread trimmer 6 rotates, the closed area becomes smaller and its rightmost position gradually shifts to the right, that is, the bottom thread 10 and the edge thread 9a The rightmost position that can be reached in a closed area is gradually shifted to the right.

In this embodiment, referring to FIG. 3 , FIG. 9 and FIG. 13 , as a preferred design, the second thread cutter 6 is provided with a thread dividing tip 6e for inserting between the upper thread loops and dividing the thread. The left side of the tip portion 6e is the thread hooking rib 6d, that is, the thread hooking rib 6d is shared with the thread trimming hook 6b, and the right side of the branching point 6e has a first branching oblique edge 6f inclined to the right. When starting the thread trimming action, the second thread trimmer 6 rotates, the thread dividing tip 6e is inserted into the upper thread loop, and the upper thread loop is preliminarily separated. That is, in the displacement thread trimming hook 6b, the needle edge thread 9b is located on the right side of the thread parting tip 6e, and moves to the right along the oblique side 6f of the first parting thread when the second thread trimmer 6 rotates, thereby making the upper thread loop Gradually separate. Further, referring to FIG. 5 and FIG. 9 , the right side of the arc-shaped catching piece 71 is provided with a second part-line oblique edge 71b opposite to the first part-line oblique edge 6f, and the second thread trimmer 6 is facing the first thread trimmer. 5. When rotating, the first part line hypotenuse 6f meets the second part line hypotenuse 71b, and the second part line hypotenuse 71b will drive the needle edge line 9b to move along the first part line hypotenuse 6f, and constrain the needle edge line 9b in At this intersection, see FIG. 13 , at this time, the first part line hypotenuse 6f forms a part of the second restraining structure, and the second dividing line hypotenuse 71b forms part of the first restraining structure, so that the upper thread can be better stabilized The ring position, when the second knife edge 6a and the first knife edge 5a are engaged, the position of the intersection point of the hypotenuse 6f of the first dividing line and the hypotenuse 71b of the second dividing line is stable every time the thread is trimmed, that is, the needle The position of the edge thread 9b is stable, so the shape and length of the upper thread loop are stable, and after the thread trimming is completed, the length of the formed thread end of the upper thread 9 is stable. In addition, since the needle edge thread 9b moves a certain distance along the hypotenuse 6f of the first dividing line, that is, the upper thread loop has a certain length, and the thread end of the upper thread 9 formed after thread trimming has a certain length, and there will be no too short thread. question.

In this embodiment, referring to FIG. 4 , FIG. 5 and FIG. 7 , as a preferred design, a first catching portion 5 b is provided on the side of the first thread cutter 5 facing the rotary hook assembly 2 , and the outer arc of the arc-shaped catching piece 71 is The surface is provided with a second catch portion 71c abutting against the first catch portion 5b; when trimming the thread, the second thread trimmer 6 rotates toward the first thread trimmer 5 so that the thread trimmer hook 6b drives the lower thread 10 to extend into the first thread trimmer 5. Between the first catching portion 5b and the second catching portion 71c, the arc-shaped catching piece 71 is arranged in an arc-shaped sheet structure, which can be easily installed in a narrow space there, especially between the rotary hook assembly 2 and the first thread trimmer 5 in a small space (gap is about 0.7mm). During normal operation, referring to FIG. 3 , the second thread trimmer 6 does not move and is far away from the first thread trimmer 5 . The catching parts 5b are in contact with each other, and the two form a bobbin thread catching structure, and the hook assembly 2 can rotate normally to work. When the thread needs to be trimmed, the second thread trimmer 6 rotates toward the first thread trimmer 5, and the second thread trimmer 6 can first contact the first thread trimmer 5 and lift it up, see FIG. 4, the first catch The thread cutting hook 6b will drive the bottom surface and the upper thread 9 to enter between the first catching part 5b and the second catching part 71c, and then continue to rotate to the second cutting edge 6a and the first cutting edge 5a. After the thread trimming is engaged, the lower thread 10 and the selvedge thread 9a complete the thread trimming in the opening of the opened lower thread capturing structure, see Fig. 8 and Fig. 13; after the thread trimming is completed, the second thread trimmer 6 rotates and resets, leaving the first thread trimmer Knife 5, the first catching part 5b and the second catching part 71c are in re-contact to catch the thread end of the lower thread 10, thereby ensuring the position of the thread end of the lower thread 10 after thread trimming is stable. In this application, when the thread end of the lower thread 10 is caught , the thread end of the lower thread 10 can be just sandwiched between the first catching part 5b and the second catching part 71c, or it can be located in the vicinity of the first catching part 5b and the second catching part 71c, as long as the first thread cutter 5 And the arc-shaped catching piece 71 can give a certain clamping force to the thread end of the lower thread 10 so that the thread end will not be separated from it.

After the thread trimming is completed, referring to FIG. 14 , when the thread end of the lower thread 10 is caught, it is located on the outer arc surface of the arc-shaped catching piece 71 , that is, on the upper side of the arc-shaped catching piece 71 . The inner pot 2a protrudes and then passes through the wire slot 2c of the shuttle frame to reach the outer arc surface of the arc-shaped catching piece 71. After being caught by the bobbin thread catching structure, the position of the thread end of the bobbin thread 10 can be guaranteed to be stable.

In this embodiment, further, referring to FIG. 9 , as a preferred design, one end of the thread-hook rib 6d close to the thread-cutting catch 7 is located on the right side of the second capture portion 71c, because the thread-hook rib 6d is inclined left and right. , After the thread trimming is completed, the second thread trimmer 6 rotates backward and the thread hooking rib 6d will gradually move the thread end of the lower thread 10 to the left by a certain distance to ensure that the thread end of the lower thread 10 will be located in the second catching part. 71c and the first catching part 5b, so as to ensure that the thread end of the lower thread 10 can be stably caught.

In the embodiment, as a preferred design, referring to FIG. 3 , FIG. 4 and FIG. 13 , the first thread trimmer 5 is provided with a raised portion 5c , and the second thread trimmer 6 is provided with an inclination toward the side where the hook assembly 2 is located. The raised portion 6g, that is, the raised portion 6g is inclined downward at a certain angle, and when the second thread cutter 6 is rotated toward the first thread cutter 5, the raised portion 6g is first inserted under the lower side of the raised portion 5c. , and the lifting portion 6g gradually lifts the lifting portion 5c when rotating, and the lifting portion 6g is similar to the function of the cam, so that the first thread trimmer 5 is separated from the arc-shaped catching piece 71 by a certain distance, which is convenient for the first thread trimmer. Knife 5 is inserted. In other embodiments, when the second thread cutter 6 enters into the arc-shaped catch piece 71 and the second thread cutter 6 under certain conditions, the second thread cutter 6 can also be pressed up against the arc. The catch piece 71 is deformed downward.

In this embodiment, the thread trimming mechanism can be an improvement on the existing thread trimming mechanism, and the thread trimming catch 7 is added to realize the upper thread 9 constraint and the bottom thread 10 capturing function, wherein the thread trimming mechanism can use a circular knife and a single knife to cut Thread mechanism, at this time, the first thread trimmer 5 and the second thread trimmer 6 are respectively the fixed knife and the movable knife in the circular knife single-knife thread trimming mechanism, both of which are arc-shaped blades. Knife thread trimming mechanism, at this time, the first thread trimmer 5 and the second thread trimmer 6 are respectively the fixed knife and the auxiliary knife in the circular knife single knife thread trimming mechanism, both of which are circular arc blades.

In this embodiment, preferably, referring to FIG. 5 , an arc-shaped protrusion 71 d is provided on the right side of the arc-shaped catching piece 71 , and the front end (near the B-side end 712 ) of the constraining side edge 71 a extends to the arc-shaped The bulge 71d, that is, the side of the arc-shaped bulge 71d, is a part of the constraining side 71a, and the first capturing portion 5b is arranged on the outer arc surface of the arc-shaped bulge 71d. With this design, on the one hand, The closed area formed by the intersection of the thread trimmer hook 6b and the restraining side edge 71a will gradually become more slender as it gradually becomes smaller, see FIG. 10 and FIG. 12, which can better restrain the position of the edge line 9a. On the other hand, the second The catch portion 71c is closer to the thread hooking rib 6d, and can better catch the thread end of the lower thread 10 after the thread trimming is completed. On the right side of the arc-shaped catching piece 71, the junction between the constraining side 71a and the second sub-line hypotenuse 71b may also be concave. Referring to FIG. 6, the second catching portion 71c is disposed near the concave protrusion. place.

In the embodiment, as a preferred design, see FIG. 5 , see FIG. 6 , the wire trimmer catching member 7 mainly includes two parts, an arc-shaped catching piece 71 in the shape of a circular arc, and a mounting section 72 connected with the arc-shaped catching piece 71 . , the inner diameter of the arc-shaped catching piece 71 is slightly larger than the outer diameter of the hook skin 2b, and is arranged coaxially to fit the outer shape of the hook assembly 2 and leave a gap, and the outer diameter of the arc-shaped catching piece 71 is larger than that of the second thread trimmer 6 It is slightly smaller to match the second thread trimmer 6 to ensure that the second thread trimmer 6 can be smoothly inserted into the upper side of the arc-shaped catching piece 71 without interference during thread trimming. The installation section 72 is used for the fixed installation of the thread trimmer catching member 7. In this application, the parts used for the fixed installation of the thread trimmer catching member 7 in the sewing machine are recorded as the catching member installation base, and the installation section 72 is fixedly connected to the catching member installation base. . Wherein, the installation base of the catch can be the casing 1 or other fixed components. In the present embodiment, the mounting section 72 is fixedly mounted on the mounting base of the catcher by means of the fastening screws 11, the mounting section 72 is provided with a bar-shaped connecting hole 72a extending in the front-rear direction, and the fastening screw 11 passes through the bar-shaped connecting hole 72a is screwed into the mounting base of the catching piece, and by tightening or loosening the fastening screw 11, the front and rear positions of the thread trimming catching piece 7 can be adjusted to facilitate assembly, and the arc catching piece 71 can be connected to the first thread trimming knife 5 and the second thread cutting knife 7. The coordination of the second thread trimmer 6 is more flexible. Specifically, the installation section 72 can borrow the installation position of the thread dividing piece 01 in the existing sewing machine, so as to reduce the changes to the existing structure.

Further, a tightness adjustment hole (not shown in the drawings) can also be provided on the installation section 72, the tightness adjustment hole is arranged on the side close to the arc-shaped catch piece 71, and an adjusting screw is used to pass through the tightness adjustment hole and screw to In the installation base of the capture piece, there is an adjustment gap between the tightness adjustment hole and the installation base of the capture piece. At this time, by tightening or loosening the adjusting screw, the installation section 72 can be deformed to a certain extent on the side of the arc-shaped catch piece 71, changing the The size of the adjustment gap between the slack adjustment hole and the installation base of the catching piece can change the contact pressure between the second catching part 71c and the first catching part 5b, so as to change the clamping force of the thread end of the lower thread 10, which is flexible and convenient to use , can meet different needs.

The thread trimmer catcher 7 in the present application is located in the core area formed by the thread path of the sewing machine, and the distance between it and the hook assembly 2 and the first thread trimmer 5 is extremely small, so the outer edges of the entire part need to be Sharp edges are rounded, polished, and quenched to ensure that the shape, toughness, strength, and edges will not produce burrs and other problems. The arc-shaped catching piece 71 and the mounting section 72 of the wire-cutting catching member 7 are preferably integrated, and the processing method can be ordinary sheet metal stamping, or other modern parts processing technology such as precision casting and lathe processing.

The present invention also provides a sewing machine, which includes a rotary hook mechanism and the above thread trimming mechanism. The thread trimming mechanism is arranged at the rotary hook assembly 2 in the rotary hook mechanism for thread trimming.

As can be seen from the above, the thread trimming mechanism in this embodiment has the following beneficial effects:

1. By setting the first restraint structure and the second restraint structure, the upper thread loop is constrained to a fixed position when trimming the thread, so as to improve the stability of the upper thread loop during thread trimming, and make the thread trimming easier. The length of the thread ends of the back thread 9 is basically the same, so as to improve the probability of forming a stitch with the lower thread 10 at the next start of sewing.

2. While restraining the upper thread 9, the arc-shaped catching piece 71 is provided with a second catching portion 71c to form a lower thread catching structure with the first catching portion 5b of the first thread trimmer 5, which can stabilize the position of the thread end of the lower thread 10. , which greatly improves the success rate of the bottom thread 10 and the formation of lock stitches when sewing starts, and solves the problem of sewing machine sewing machine with computer thread trimmer feedback from customers for a long time;

3. The structure is simple, can be improved in the existing thread trimming mechanism, and the cost is low. To sum up, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

The above-mentioned embodiments merely illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed in the present invention should still be covered by the claims of the present invention.

Claims (16)

1. The utility model provides a trimming mechanism of sewing machine for set up and carry out the trimming at the rotating shuttle subassembly (2) of sewing machine, trimming mechanism includes first trimming sword (5) and second trimming sword (6), first trimming sword (5) fixed mounting is in rotating shuttle subassembly (2) periphery side department, second trimming sword (6) set up in rotating shuttle subassembly (2) periphery side department and can rotate round rotating shuttle subassembly (2) to interlock or part with second trimming sword (6), be equipped with on second trimming sword (6) and be used for catching on base line (10) and facial suture (9) towards first trimming sword (5) trimming hook (6b) of motion, its characterized in that: the trimming mechanism further comprises a trimming capturing piece (7) fixedly installed, a first constraint structure is arranged on the trimming capturing piece (7), and a second constraint structure is arranged on the second trimming knife (6); when the thread cutting is started, the second thread cutting knife (6) rotates towards the first thread cutting knife (5), the thread cutting hook (6b) drives the upper thread (9) to be close to the first constraint structure, and the second constraint structure is matched with the first constraint structure and constrains the selvage threads in the thread loop of the upper thread at a fixed and unchangeable thread cutting constraint position before the second thread cutting knife (6) and the first thread cutting knife (5) are meshed for thread cutting.

2. The thread trimming mechanism of claim 1, wherein: the trimming hook (6b) of the second trimming knife (6) is composed of a line hooking bevel edge (6c) and a line hooking flange (6d), the line hooking bevel edge (6c) extends from the left side edge of the second trimming knife (6) in a right inclined mode, the line hooking flange (6d) is arranged on the right side of the line hooking bevel edge (6c), and the second constraint structure comprises the trimming hook (6 b); the trimming catching piece (7) comprises an arc catching piece (71) arranged along the outer periphery of the rotating shuttle component (2), the arc catching piece (71) is positioned between the rotating shuttle component (2) and the first trimming knife (5), one end of the arc catching piece (71) facing the second trimming knife (6) is an A side end (711), the other end of the arc catching piece is a B side end (712), the first constraint structure comprises a constraint side edge (71a) which is arranged on the right side of the A side end (711) of the arc catching piece (71) and inclines to the right, the constraint side edge (71a) is opposite to the trimming hook (6B), and one side, close to the A side end (711), of the constraint side edge (71a) extends to the left side of the wire hooking inclined edge (6 c); when the second thread trimmer (6) rotates towards the first thread trimmer (5), the thread trimming hook (6b) and the constraint side edge (71a) are intersected to form a closed area.

3. The thread trimming mechanism of claim 2, wherein: when the second thread trimmer (6) rotates to be meshed with the first thread trimmer (5) for trimming, a closed area formed by the intersection of the thread trimming hook (6b) and the constraint side edge (71a) still exists.

4. The thread trimming mechanism of claim 2, wherein: when the second thread trimmer (6) rotates to be meshed with the first thread trimmer (5) for trimming, the thread trimming hook (6b) crosses the constraint side edge (71a) to enable the closed area to disappear.

5. The thread trimming mechanism of claim 2, wherein: collude line flange (6d) and control the slope setting, and be close to the trimming and catch one end and be located the left side, keep away from trimming and catch one end of piece (7) and be located the right side of piece (7).

6. The thread trimming mechanism of claim 2, wherein: be equipped with on second thread trimmer (6) and be used for inserting branch line point portion (6e) that carry out the separated time between the facial line wire loop, branch line point portion (6e) left side limit is for colluding line flange (6d), branch line point portion (6e) right side limit has first branch line hypotenuse (6f) that slope right set up.

7. The thread trimming mechanism of claim 6, wherein: a second line-dividing oblique edge (71b) opposite to the first line-dividing oblique edge (6f) is arranged on the right side edge of the arc-shaped catching sheet (71), and the first line-dividing oblique edge (6f) and the second line-dividing oblique edge (71b) are intersected when the second line-cutting knife (6) rotates towards the first line-cutting knife (5); the second constraining structure further comprises a first hypotenuse division edge (6f), and the first constraining structure further comprises a second hypotenuse division edge (71 b).

8. The thread trimming mechanism of claim 2, wherein: the right side edge of the arc-shaped capturing piece (71) is provided with an arc-shaped bulge (71d), the arc-shaped bulge (71d) is positioned on the left side of the line hooking flange (6d), and one end of the constraint side edge (71a) close to the B side end (712) extends to the arc-shaped bulge (71 d).

9. The thread trimming mechanism of claim 2, wherein: a first catching part (5b) is arranged on the side surface of the first thread trimmer (5) facing the rotating shuttle component (2), and a second catching part (71c) abutted against the first catching part (5b) is arranged on the outer arc surface of the arc catching sheet (71); when the thread is cut, the second thread cutter (6) rotates towards the first thread cutter (5) and enables the thread cutting hook (6b) to drive the bottom thread (10) to extend into the space between the first catching part (5b) and the second catching part (71 c).

10. The thread trimming mechanism of claim 9, wherein: collude line flange (6d) and control the slope setting, and be close to the one end that the trimming caught piece (7) and be located the left side, keep away from the one end that the trimming caught piece (7) and be located the right side, collude line flange (6d) and be close to the trimming and catch piece (7) one end and be located the right side that the second caught portion (71 c).

11. The thread trimming mechanism of claim 10, wherein: the inclination angle of the line hooking flange (6d) relative to the front and back direction is 2-4 degrees.

12. The thread trimming mechanism of claim 11, wherein: the inclination angle of the line hooking flange (6d) relative to the front and back direction is 3 degrees.

13. The thread trimming mechanism of claim 9, wherein: the thread trimming device is characterized in that a lifting part (5c) is arranged on the first thread trimming knife (5), a lifting part (6g) which inclines towards the side where the rotating shuttle component (2) is arranged on the second thread trimming knife (6), and the lifting part (6g) is inserted into the lower side surface of the lifting part (5c) towards the rotating shuttle component (2) when the second thread trimming knife (6) rotates towards the first thread trimming knife (5).

14. The thread trimming mechanism according to claim 2 or 9, wherein: the trimming catching piece (7) is provided with an installation section (72) connected with the arc catching piece (71), parts for fixedly installing the trimming catching piece (7) in the sewing machine are a catching piece installation base, and the installation section (72) is fixedly connected with the catching piece installation base.

15. The thread trimming mechanism of claim 14, wherein: the mounting section (72) is fixedly mounted on the catching piece mounting base through a fastening screw (11), a strip-shaped connecting hole (72a) extending in the front-back direction is formed in the mounting section (72), and the fastening screw (11) penetrates through the strip-shaped connecting hole (72a) and is screwed into the catching piece mounting base.

16. A sewing machine comprising a rotating shuttle assembly (2), characterized in that: further comprising a thread trimming mechanism according to any one of claims 1 to 15, arranged at the rotary shuttle assembly (2) for trimming thread.

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