CN114318698A - Thread trimming mechanism of 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 sewing machine and sewing machine

Technical Field

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

Background

In the existing sewing machine, the thread cutting mechanism can use the thread separating piece to separate threads when cutting threads, however, referring to fig. 1, the upper thread loop may cover the existing thread separating piece 01 or be entirely arranged on one side of the bevel edge of the existing thread separating piece 01, which causes the length of the thread end of the upper thread 9 on the right side of the needle after thread cutting to be unstable. The length of the thread end of the upper thread 9 on the right side of the needle is unstable, and the length may be too short to form an upper thread loop, so that the probability that the seam starting belt cannot be covered by the lower thread 10 is further increased, and even the phenomenon that the seam is separated from the needle hole during seam starting occurs.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a trimming mechanism of a sewing machine and a sewing machine, which can limit the position of a thread loop in a needle thread loop during trimming, improve the stability of the needle thread loop during trimming, and make the length of the thread end of the needle thread after trimming substantially uniform.

In order to achieve the above object, the present invention provides a thread trimming mechanism of a sewing machine, configured to trim thread at a rotating shuttle assembly of the sewing machine, where the thread trimming mechanism includes a first thread trimming blade and a second thread trimming blade, the first thread trimming blade is fixedly installed at an outer peripheral side of the rotating shuttle assembly, the second thread trimming blade is installed at the outer peripheral side of the rotating shuttle assembly and can rotate around the rotating shuttle assembly to engage with or separate from the second thread trimming blade, the second thread trimming blade is provided with a thread trimming hook for hooking a bottom thread and a top thread to move towards the first thread trimming blade, the thread trimming mechanism further includes a fixedly installed thread trimming catching member, the thread trimming catching member is provided with a first constraint structure, and the second thread trimming blade is provided with a second constraint structure; 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.

Furthermore, the trimming hook of the second trimming knife comprises a hook bevel edge and a hook flange, the hook bevel edge extends obliquely rightwards from the left side of the second trimming knife, the hook flange is arranged on the right side of the hook bevel edge, and the second constraint structure comprises the trimming hook; the thread trimming catching piece comprises an arc catching piece arranged along the outer peripheral side of the rotating shuttle assembly, the arc catching piece is positioned between the rotating shuttle assembly and the first thread trimming knife, one end, facing the second thread trimming knife, of the arc catching piece is an A side end, the other end of the arc catching piece is a B side end, the first constraint structure comprises a constraint side edge which is arranged on the right side of the A side end of the arc catching piece and inclines to the right, the constraint side edge is opposite to the thread trimming hook, and one side, close to the A side end, of the constraint side edge extends to the left side of the thread hooking bevel edge; when the second thread trimmer cutter rotates towards the first thread trimmer cutter, the thread trimming hook and the constraint side edge are intersected to form a closed area.

Further, when the second thread trimmer cutter rotates to be meshed with the first thread trimmer cutter for trimming threads, a closed area formed by the intersection of the thread trimming hook and the constraint side edge still exists.

Further, when the second thread trimmer cutter rotates to engage with the first thread trimmer cutter for trimming threads, the thread trimming hook crosses the constraint side edge so that the closed area disappears.

Furthermore, collude the slope setting about the line flange, and be close to the trimming and catch one end and be located the left side, keep away from trimming and catch one end and be located the right side.

Further, be equipped with on the second thread trimmer cutter and be used for inserting the separated time point portion that carries out the separated time between the facial line wire loop, separated time point portion left side limit is for colluding the line flange, separated time point portion right side limit has the first separated time hypotenuse that the slope set up right.

Furthermore, a second line-dividing oblique edge opposite to the first line-dividing oblique edge is arranged on the right side edge of the arc-shaped catching sheet, and the first line-dividing oblique edge and the second line-dividing oblique edge are intersected when the second line-cutting knife rotates towards the first line-cutting knife; the second constraining structure further includes a first hypotenuse, and the first constraining structure further includes a second hypotenuse.

Further, the right side limit of arc catching piece is provided with an arc arch, and the arc arch is located colludes line flange left side, the one end that the restraint side is close to the B side extends to arc protruding department.

Furthermore, a first catching part is arranged on the side surface of the first thread trimmer cutter facing the rotating shuttle assembly, and a second catching part abutted against the first catching part is arranged on the outer arc surface of the arc catching sheet; during thread cutting, the second thread cutter rotates towards the first thread cutter and enables the thread cutting hook to drive the bottom thread to stretch into the space between the first catching part and the second catching part.

Furthermore, collude the slope setting about the line flange, and be close to the one end that the trimming caught the piece and be located the left side, keep away from the one end that the trimming caught the piece and be located the right side, collude the line flange and be close to the right side that the trimming caught one end and be located the second and catch the portion.

Furthermore, the inclination angle of the line-hooking flange relative to the front-back direction is 2-4 degrees.

Furthermore, the inclination angle of the line hooking rib relative to the front and back direction is 3 degrees.

Furthermore, a lifting part is arranged on the first thread trimmer, a lifting part which inclines towards the side where the rotating shuttle component is arranged on the second thread trimmer, and the lifting part is inserted into the lower side surface of the lifting part which faces the rotating shuttle component when the second thread trimmer rotates towards the first thread trimmer.

Furthermore, the trimming catching piece is provided with an installation section connected with the arc catching piece, parts used for fixedly installing the trimming catching piece in the sewing machine are a catching piece installation foundation, and the installation section is fixedly connected with the catching piece installation foundation.

Furthermore, the mounting section is fixedly mounted on the mounting foundation of the capturing part by utilizing a fastening screw, a strip-shaped connecting hole extending along the front-back direction is formed in the mounting section, and the fastening screw penetrates through the strip-shaped connecting hole and is screwed into the mounting foundation of the capturing part.

The invention also provides a sewing machine which comprises the rotating shuttle assembly and the thread trimming mechanism, wherein the thread trimming mechanism is arranged at the rotating shuttle assembly for trimming threads.

As described above, the thread trimming mechanism and the sewing machine according to the present invention have the following advantageous effects:

by arranging the thread cutting catching piece, the first constraint structure on the arc-shaped catching piece and the second constraint structure on the second thread cutting knife are utilized to constrain the upper thread, when cutting thread, the second thread trimming cutter is driven to rotate towards the first thread trimming cutter, the thread trimming hook can hook the bottom thread and the selvage thread in the surface thread ring, then the bottom thread and the upper thread are driven to be close to the first thread cutting knife, simultaneously the upper thread wire loop is close to the first constraint structure on the thread cutting catching piece, the second constraint structure is also close to the first constraint structure, before the clipping is occluded, the second constraint structure is matched with the first constraint structure to constrain the cloth edge line in the surface line loop at a fixed and unchangeable clipping constraint position, then the thread cutting is occluded, so that the upper thread wire ring can be limited at a stable position during each thread cutting, the stability of the upper thread wire ring during the thread cutting is improved, and the length of the thread end behind the thread cutting is basically consistent.

Drawings

Fig. 1 is a schematic diagram of the position of the upper thread loop on the branching piece in the prior art.

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

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

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

Fig. 5 is a schematic structural view of one embodiment of the thread cutting catching member of the present invention.

Fig. 6 is a schematic structural view of another embodiment of the thread cutting catching member of the present invention.

FIG. 7 is a schematic view showing the operation of the thread trimming mechanism of the present invention in normal sewing and bobbin thread catching.

Fig. 8 is a schematic diagram of the thread trimming mechanism of the present invention in operation during thread trimming.

Fig. 9 is a schematic view of the first thread trimmer and the first thread trimmer catching member of the present invention in a first state during thread trimming.

Fig. 10 is a schematic view showing the first thread trimmer and the thread trimmer catching member in the second state of trimming according to the present invention.

Fig. 11 is a schematic view showing the first thread trimmer and the thread trimmer catching member in the third state of the present invention during thread trimming.

Fig. 12 is a schematic view showing the position of the upper thread end of the present invention at the thread cutting catching member.

Fig. 13 is a schematic diagram of the thread trimming mechanism of the present invention in operation during thread trimming.

Fig. 14 is a schematic diagram of the thread trimming mechanism of the present invention after trimming.

Description of the element reference numerals

01 branching piece

1 case

2 rotating shuttle assembly

2a rotating shuttle inner container

2b bobbin case 2b

2c shuttle rack wire guide groove

3 rotating shuttle positioning hook

4 machine needle

5 first thread trimmer

5a first knife edge

5b first catching part

5c raised part

6 second thread trimmer

6a second blade

6b thread cutting hook

6c hook bevel edge

6d hook line flange

6e branching tip

6f first line-dividing bevel edge

6g raised part

7 piece is caught to trimming

71 arc catching sheet

711A side end

712B side end

71a bound side

71b second hypotenuse

71c second trap part

71d arc-shaped bulge

72 mounting section

72a strip-shaped connecting hole

8 wire cutting driving assembly

9 noodle line

9a selvedge line

9b needle sideline

10 bottom line

11 fastening screw

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, proportions, and dimensions shown in the drawings and described herein are for illustrative purposes only and are not intended to limit the scope of the present invention, which is defined by the claims, but rather by the claims. In addition, the terms such as "upper", "lower", "left", "right" and "middle" used in the present specification are for convenience of description only, and are not intended to limit the scope of the present invention, and changes or modifications of the relative relationship thereof may be regarded as the scope of the present invention without substantial changes in the technical contents.

Referring to fig. 1 to 14, the present invention provides a thread trimming mechanism for a sewing machine, which is provided at a rotating shuttle assembly 2 of the sewing machine for trimming thread, wherein the rotating shuttle assembly 2 is positioned and installed by a rotating shuttle positioning hook 3, the rotating shuttle positioning hook 3 is fixed on a machine shell 1, and the outermost part of the rotating shuttle assembly 2 is a rotating bobbin case 2 b.

The thread trimming mechanism comprises a first thread trimming cutter 5 and a second thread trimming cutter 6, wherein the first thread trimming cutter 5 and the second thread trimming cutter 6 can be both arc thread blades, the first thread trimming cutter 5 is fixedly arranged at the outer peripheral side of a rotating shuttle component 2, the second thread trimming cutter 6 is arranged at the outer peripheral side of the rotating shuttle component 2 and can rotate around the rotating shuttle component 2 to be meshed with or separated from the second thread trimming cutter 6, namely, the first thread trimming cutter 5 and the second thread trimming cutter 6 are both positioned on a bobbin case 2b and have certain gaps, and the first thread trimming cutter 5 and the second thread trimming cutter 6 cannot be touched when the bobbin case 2b rotates. The rotation of the first thread trimmer 5 is driven by a thread trimmer drive assembly 8. The second thread trimmer 6 is provided with a thread trimming hook 6b for moving the bobbin thread 10 and the upper thread 9 toward the first thread trimmer 5, and referring to fig. 2 and 7, the thread trimming hook 6b is positioned below the needle 4, the second thread trimmer 6 catches the bobbin thread 10 and the selvage thread 9a in the loop of the upper thread when rotating, and pushes both the bobbin thread 10 and the upper thread 9 to the first thread trimmer 5, and then the second blade 6a of the second thread trimmer 6 engages with the first blade 5a of the first thread trimmer 5, where the bobbin thread 10 is cut off, and the selvage thread 9a in the loop of the upper thread is cut off.

The thread trimming mechanism further comprises a thread trimming catching piece 7 which is fixedly installed, the thread trimming catching piece 7 can be specifically installed on a machine shell 1 or a rotating shuttle positioning hook 3 and other parts which are fixed with the machine shell 1, a first constraint structure is arranged on the thread trimming catching piece 7, the first constraint structure is arranged at the position of a first thread trimming cutter 5, and a second constraint structure is arranged on a second thread trimming cutter 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 9a in the thread ring of the upper thread at a fixed thread cutting constraint position before the second thread cutting knife 6 is meshed with the first thread cutting knife 5 for thread cutting.

When the thread trimming mechanism provided by the invention normally works, referring to fig. 7, the second thread trimming cutter 6 is not moved and is far away from the first thread trimming cutter 5, and the rotating shuttle component 2 can normally rotate. When the thread cutting is needed, the thread cutting driving assembly 8 is used for driving the second thread cutting knife 6 to rotate towards the first thread cutting knife 5, the thread cutting hook 6b can hook the bottom thread 10 and the selvage threads 9a in the surface thread loop, then the bottom thread 10 and the upper thread 9 are driven to be close to the first thread cutting knife 5, meanwhile, the upper thread loop can be close to the first constraint structure on the thread cutting catching piece 7, the second constraint structure is also close to the first constraint structure, before the thread cutting is occluded, the second constraint structure is matched with the first constraint structure, the selvage threads 9a in the surface thread loop are constrained at a fixed thread cutting constraint position, then the thread cutting is occluded, and the selvage threads 9a of the upper thread loop are cut at the first cutting opening 5a, and fig. 13 and fig. 14 are shown. In the present invention, the fixed trimming restraining position means that the trimming restraining position is fixed and unchanged relative to the fixed first trimming blade 5, the trimming restraining position may be a position having a certain range, and the selvedge thread 9a is located at the trimming restraining position during each trimming, so that the selvedge thread 9a is limited at a stable position during each trimming, the stability of the upper thread loop during trimming is improved, and the lengths of the thread ends of the upper thread 9 after trimming are substantially consistent.

Referring to fig. 1-14, the thread trimming mechanism of the present invention is further described in the following embodiment.

In the sewing machine, the axis of the rotating shuttle assembly 2 is along the left-right direction of the sewing machine, and the rotating shuttle assembly 2 is located at the left side of the sewing machine. In the present embodiment, referring to fig. 3, 5 and 9, as a preferred design, the trimming hook 6b of the second trimming knife 6 is composed of a hook bevel edge 6c and a hook rib 6d, the hook bevel edge 6c extends obliquely from the left side of the second trimming knife 6 to the right, the hook rib 6d is disposed on the right side of the hook bevel edge 6c, and a notch structure is formed between the hook bevel edge 6c and the hook rib 6d, so as to form the trimming hook 6 b; the thread cutting hook 6b forms a part of the second constraint structure besides the thread hooking; the thread cutting catching member 7 includes an arc catching piece 71 disposed along an outer peripheral side of the rotating shuttle assembly 2, the arc catching piece 71 is located between the rotating shuttle assembly 2 and the first thread cutting blade 5, one end of the arc catching piece 71 facing the second thread cutting blade 6 is an a-side end 711, and the other end is a B-side end 712, in this embodiment, the first thread cutting blade 5 and the second thread cutting blade 6 are respectively located at a front side and a rear side of the sewing machine, when the thread cutting catching member 7 is mounted, the a-side end 711 of the arc catching piece 71 faces the rear side of the sewing machine, at this time, the a-side end 711 is a front-side end, the B-side end 712 of the arc catching piece 71 faces the front side, at this time, the B-side end 712 is a rear-side end. The first restricting structure includes a restricting side 71a disposed on the right side of the a-side end 711 of the arc-shaped catching piece 71 and inclined to the right, the restricting side 71a being opposite to the trimming hook 6b, and a side of the restricting side 71a near the a-side end 711 extending to the left of the hook sloping side 6 c. By adopting the structure, when trimming, the second trimming blade 6 rotates towards the first trimming blade 5, the trimming hook 6b hooks the bottom thread 10 and the cloth edge line 9a in the surface thread ring, and as the constraint side edge 71a extends to the left side of the trimming hook 6b, the bottom thread 10 and the surface thread 9 can not be arranged on the left side of the arc-shaped catching sheet 71, namely the phenomenon of being sleeved on the arc-shaped catching sheet 71 can not occur, and only the bottom thread 10 and the surface thread 9 can be arranged on the right side of the constraint side edge 71a, as shown in fig. 12; then the trimming hook 6b meets the constraint side 71a to form a closed area, see fig. 9, that is, the hook bevel edge 6c, the hook rib 6d and the constraint side 71a enclose a closed area, at this time, the base line 10 and the selvage line 9a are both located in the closed area, and during the rotation of the second trimming knife 6, the closed area gradually becomes smaller to constrain the selvage line 9a, and finally, when the second knife edge 6a is engaged with the first knife edge 5a, the selvage line 9a is stable, see fig. 10 and fig. 11. In this embodiment, when the second blade 6a and the first blade 5a engage in thread trimming, there are two schemes at this time, one of the schemes is that a closed area formed by the intersection of the thread trimming hook 6b and the constraint side 71a still exists, referring to fig. 11, the closed area becomes a very narrow space, which can constrain the selvedge thread 9a well and avoid the problem of breaking the selvedge thread 9a at the place; the second scheme is that the thread trimming hook 6b completely crosses the constraint side edge 71a, so that the closed area disappears, and at the moment, the cloth edge line 9a can be tensioned and constrained at the bottom of the thread trimming hook 6b, namely, at the joint of the thread hooking bevel edge 6c and the thread hooking rib 6 d. Of course, in another embodiment, under appropriate circumstances, the first thread trimmer 5 and the second thread trimmer 6 may also be switched to the lower position, the first thread trimmer 5 is located at the rear side, the second thread trimmer 6 is located at the front side, and at this time, the a-side end 711 is the rear side end and the B-side end 712 is the front side end, and the principle is the same, but the positions are opposite, and therefore, the description is not repeated.

In the present embodiment, referring to fig. 3 and 9, as a preferred design, the hook rib 6d of the trimming hook 6b is obliquely arranged left and right, the front end (the end close to the trimming catching member 7) is located on the left side, and the rear end (the end far from the trimming catching member 7) is located on the right side, that is, the hook rib 6d extends from the left front to the right rear, the inclination angle of the hook rib 6d is small, and the inclination angle of the hook rib 6d relative to the front-rear direction is selected to be 2-4 °, and is preferably 3 °. With the slightly inclined thread hooking rib 6d, as the second thread trimming knife 6 rotates, the closed area is reduced, and the rightmost position of the closed area gradually deviates to the right, namely, the rightmost position of the bottom thread 10 and the selvage thread 9a in the closed area gradually deviates to the right.

In the present embodiment, referring to fig. 3, 9 and 13, as a preferable design, the second thread cutting blade 6 is provided with a thread dividing tip portion 6e for inserting between the upper thread loops to divide thread, the left side of the thread dividing tip portion 6e is a thread hooking rib 6d, that is, a thread hooking rib 6d shared with the thread cutting hook 6b, and the right side of the thread dividing tip portion 6e has a first thread dividing sloping edge 6f inclined to the right. When the thread cutting operation is started, the second thread cutter 6 rotates, the thread dividing tip portion 6e is inserted into the upper thread ring, the upper thread ring is initially separated, the cloth thread line 9a is positioned on the left side of the thread dividing tip portion 6e, namely, in the displacement thread cutting hook 6b, the needle thread line 9b is positioned on the right side of the thread dividing tip portion 6e, and the needle thread line moves rightwards along the first thread dividing inclined edge 6f when the second thread cutter 6 rotates, so that the upper thread ring is gradually separated. Further, referring to fig. 5 and 9, the right side of the arc catching piece 71 is provided with a second hypotenuse 71b opposite to the first hypotenuse 6f, the first hypotenuse 6f meets the second hypotenuse 71b when the second thread trimmer 6 rotates towards the first thread trimmer 5, the second hypotenuse 71b will drive the needle side thread 9b to move along the first hypotenuse 6f and restrain the needle side thread 9b at the meeting position, see fig. 13, at this time, the first hypotenuse 6f forms a part of the second restraining structure, the second hypotenuse 71b forms a part of the first restraining structure, so that the loop position of the facial line can be better stabilized, when the second knife edge 6a is engaged with the first knife edge 5a, because the meeting point position of the first hypotenuse 6f and the second hypotenuse 71b is stable and constant at each thread trimming, that is, the position of the needle side thread 9b is stable and constant, therefore, the shape and length of the upper thread loop are stable, and the length of the thread end of the upper thread 9 formed after the thread cutting is finished is stable. Moreover, the needle side line 9b moves a certain distance along the first line-dividing bevel edge 6f, namely the upper thread line ring has a certain length, and the thread end of the upper thread 9 formed after thread trimming has a certain length, so that the problem of too short thread is avoided.

In the present embodiment, referring to fig. 4, 5 and 7, as a preferable design, a first catching portion 5b is provided on a side surface of the first thread trimmer blade 5 facing the rotary hook assembly 2, and a second catching portion 71c abutting against the first catching portion 5b is provided on an outer arc surface of the arc catching piece 71; during thread trimming, the second thread trimming blade 6 rotates towards the first thread trimming blade 5 and enables the thread trimming hook 6b to drive the bobbin thread 10 to extend into the space between the first catching portion 5b and the second catching portion 71c, the arc catching piece 71 is arranged to be in an arc thin sheet structure, and the installation in a narrow space at the position can be facilitated, particularly in a narrow space (the gap is about 0.7mm) between the rotating shuttle assembly 2 and the first thread trimming blade 5. In normal operation, referring to fig. 3, the second thread trimmer 6 is stationary and away from the first thread trimmer 5, and at this time, the second catching portion 71c of the arc catching piece 71 abuts against the first catching portion 5b of the first thread trimmer 5, so that both of them form a bottom thread catching structure, and the rotating shuttle assembly 2 can normally rotate to operate. When the thread cutting is needed, the second thread cutting knife 6 rotates towards the first thread cutting knife 5, the second thread cutting knife 6 can contact and lift the first thread cutting knife 5, referring to fig. 4, the first catching portion 5b and the second catching portion 71c are separated, the thread cutting hook 6b can drive the bottom surface and the upper thread 9 to enter between the first catching portion 5b and the second catching portion 71c, then the rotation is continued until the second knife edge 6a is meshed with the first knife edge 5a to cut the thread, and the lower thread 10 and the selvage threads 9a finish the thread cutting in the opening of the opened lower thread catching structure, referring to fig. 8 and 13; after the trimming is completed, the second trimming cutter 6 is rotated and reset, the trimming leaves the first trimming cutter 5, the first catching portion 5b and the second catching portion 71c are in contact again, the end of the bobbin thread 10 is caught, and therefore the position of the end of the bobbin thread 10 after trimming is stable.

After the thread trimming is completed, referring to fig. 14, the thread end of the bobbin thread 10 is caught and positioned on the outer arc surface of the arc catching piece 71, that is, on the upper side of the arc catching piece 71, and the bobbin thread 10 extends from the rotating shuttle inner container 2a of the rotating shuttle assembly 2 and then passes through the bobbin carriage thread guiding groove 2c to reach the outer arc surface of the arc catching piece 71, and after being caught by the bobbin thread catching structure, the position of the thread end of the bobbin thread 10 can be ensured to be stable.

In this embodiment, further referring to fig. 9, as a preferred design, one end of the thread hooking rib 6d close to the thread trimming catching member 7 is located on the right side of the second catching portion 71c, since the thread hooking rib 6d is obliquely arranged left and right, when the thread trimming is completed and the second thread trimming knife 6 rotates backwards, the thread hooking rib 6d will gradually shift the thread end of the bobbin thread 10 to the left by a certain distance to ensure that the thread end of the bobbin thread 10 will be located between the second catching portion 71c and the first catching portion 5b, thereby ensuring that the thread end of the bobbin thread 10 can be stably caught.

In the embodiment, as a preferable design, referring to fig. 3, 4 and 13, a raised portion 5c is provided on the first thread trimmer 5, and a raised portion 6g inclined toward the side where the rotating shuttle assembly 2 is located is provided on the second thread trimmer 6, that is, the raised portion 6g is inclined downward by a certain angle, when the second thread trimmer 6 rotates toward the first thread trimmer 5, the raised portion 6g is first inserted under the lower side surface of the raised portion 5c, and when the second thread trimmer 6 rotates, the raised portion 6g gradually raises the raised portion 5c, and the raised portion 6g functions like a cam, so that the first thread trimmer 5 is separated from the arc catching piece 71 by a certain distance, and the first thread trimmer 5 is conveniently inserted. In other embodiments, when the second thread trimmer 6 enters the arc catching piece 71 and in front of the second thread trimmer 6, the second thread trimmer 6 can also press up on the arc catching piece 71 to deform it downward, if the dimensions allow it.

In this embodiment, the thread trimming mechanism may be an improvement on an existing thread trimming mechanism, and the thread trimming catching member 7 is added to realize the functions of restricting the upper thread 9 and catching the lower thread 10, wherein the thread trimming mechanism may adopt a circular knife single-blade thread trimming mechanism, at this time, the first thread trimming knife 5 and the second thread trimming knife 6 are respectively a fixed knife and a movable knife in the circular knife single-blade thread trimming mechanism and are both arc-shaped blades, the thread trimming mechanism may adopt a circular knife double-blade thread trimming mechanism, and at this time, the first thread trimming knife 5 and the second thread trimming knife 6 are respectively a fixed knife and an auxiliary knife in the circular knife single-blade thread trimming mechanism and are both arc-shaped blades.

In this embodiment, preferably, referring to fig. 5, an arc-shaped protrusion 71d is disposed on the right side of the arc-shaped capturing piece 71, the front end (near the B-side end 712) of the constraining side 71a extends to the arc-shaped protrusion 71d, that is, the side of the arc-shaped protrusion 71d is a part of the constraining side 71a, and the first capturing portion 5B is disposed on the outer arc surface of the arc-shaped protrusion 71d, with this design, on one hand, the closed area formed by the intersection of the trimming hook 6B and the constraining side 71a becomes gradually thinner and thinner as it becomes smaller, referring to fig. 10 and 12, the position of the cloth edge line 9a can be better constrained, on the other hand, the second capturing portion 71c is closer to the trimming rib 6d, and the end of the bobbin thread 10 can be better captured after trimming. The junction of the constraining side edge 71a and the second hypotenuse edge 71b on the right side of the arcuate catch piece 71 may also be concave in shape, with the second catch portion 71c being disposed adjacent the concave protrusion, see fig. 6.

In the embodiment, as a preferred design, referring to fig. 5 and fig. 6, the thread cutting catching member 7 mainly includes two parts, an arc catching piece 71 in an arc shape, and a mounting section 72 connected to the arc catching piece 71, the inner diameter of the arc catching piece 71 is slightly larger than the outer diameter of the bobbin case 2b and is coaxially disposed to fit the outer shape of the rotating shuttle assembly 2 with a gap, and the outer diameter of the arc catching piece 71 is slightly smaller than the outer diameter of the second thread cutting knife 6 to match the second thread cutting knife 6, so as to ensure that the second thread cutting knife 6 can be smoothly inserted into the upper side of the arc catching piece 71 without interference during thread cutting. The mounting section 72 is used for fixedly mounting the trimming catching member 7, in this application, the parts of the sewing machine for fixedly mounting the trimming catching member 7 are recorded as a catching member mounting base, and the mounting section 72 is fixedly connected with the catching member mounting base. Wherein, the catching piece mounting base can be the machine shell 1 or other fixed parts. In this embodiment, the mounting section 72 is fixedly mounted on the catching member mounting base by using the fastening screw 11, the mounting section 72 is provided with a bar-shaped connecting hole 72a extending in the front-rear direction, the fastening screw 11 penetrates through the bar-shaped connecting hole 72a and is screwed into the catching member mounting base, the front-rear position of the trimming catching member 7 can be adjusted by screwing or unscrewing the fastening screw 11, the assembly is convenient, and the arc-shaped catching piece 71 is more flexibly matched with the first trimming cutter 5 and the second trimming cutter 6. The mounting section 72 can specifically use the mounting position of the thread separating sheet 01 in the existing sewing machine, and the change of the existing structure is reduced.

Furthermore, an elastic adjusting hole (not shown in the drawing) can be further formed in the mounting section 72, the elastic adjusting hole is formed in one side, close to the arc-shaped capturing piece 71, and is connected to the capturing piece mounting base in a screwed mode through the elastic adjusting hole by means of an adjusting screw, an adjusting gap is formed between the elastic adjusting hole and the capturing piece mounting base, at the moment, the mounting section 72 can be enabled to deform to a certain extent close to one side of the arc-shaped capturing piece 71 by screwing or unscrewing the adjusting screw, the size of the adjusting gap between the elastic adjusting hole and the capturing piece mounting base is changed, contact pressure between the second capturing portion 71c and the first capturing portion 5b is changed, clamping force on the thread end of the bobbin thread 10 is changed, and the bobbin thread is flexible and convenient to use and can meet different requirements.

The trimming catching member 7 in the present application is in the core area formed by the thread path of the sewing machine, and the distance between the trimming catching member and the rotating shuttle assembly 2 and the first trimming knife 5 is extremely small, so that sharp edge rounding, polishing and quenching treatment are required to be carried out on the outer edge of the whole part to ensure that the shape, toughness, strength and edge of the part cannot generate burrs and the like. The arc catching piece 71 and the mounting section 72 of the trimming catching member 7 are preferably integrated, and the processing mode can be common sheet metal stamping, or other modern part processing technologies such as precision casting, lathe processing and the like.

The invention also provides a sewing machine which comprises the rotating shuttle mechanism and the thread trimming mechanism, wherein the thread trimming mechanism is arranged at the rotating shuttle component 2 in the rotating shuttle mechanism for trimming threads.

From the above, the thread trimming mechanism in the present embodiment has the following beneficial effects:

1. through setting up first restraint structure and second restraint structure, the cooperation is in a fixed position department with the upper thread wire loop restraint when the trimming, improves the stability of upper thread wire loop when the trimming, makes the 9 end of a thread length of upper thread behind the trimming unanimous basically to improve the probability of taking bottom line 10 to form the stitch when starting to sew next time.

2. When the upper thread 9 is restrained, the second catching part 71c is arranged on the arc-shaped catching sheet 71 to form a bottom thread catching structure together with the first catching part 5b of the first thread cutting knife 5, so that the position of the thread end of the bottom thread 10 can be stabilized, the success rate of taking the bottom thread 10 and forming a lock stitch during starting sewing is greatly improved, and the problem of starting sewing of the computer thread cutting sewing machine fed back by a client for a long time is solved;

3. simple structure can be improved in current thread trimming mechanism and is obtained with low costs. In conclusion, the present invention effectively overcomes various disadvantages of the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention 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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