Movable thread trimmer with thread sweeping function, thread trimming mechanism and sewing machine

Abstract

The invention relates to a movable thread trimmer with a thread sweeping function, a thread trimming mechanism and a sewing machine, the movable thread trimmer is used for trimming in the sewing machine, the movable thread trimmer is provided with a thread dividing sharp part used for being inserted into an upper thread ring, and the right side of the thread dividing sharp part is provided with a thread dividing side edge; the movable thread trimmer can move relative to the matched thread trimmer until the movable thread trimmer and the thread trimmer are meshed to trim threads or separated, a thread sweeping structure is further arranged on the thread dividing tip and comprises a thread sweeping hole and a thread sweeping opening connected with the thread sweeping hole and the thread dividing side edge, and the thread sweeping hole forms a thread sweeping flange on at least one of the left side and the right side of the thread sweeping opening.

Description

Technical Field

[0001] The invention relates to the technical field of sewing equipment, and in particular to a movable thread trimmer with a thread sweeping function, a thread trimming mechanism, and a sewing machine. Background Art

[0002] After a sewing machine completes one sewing, when it trims the thread for the next sewing, it needs to move the fabric from the original sewing position to the next sewing position. After trimming the thread, the upper thread usually has several bends and bends under the needle plate. When the upper thread is too long, the worker will encounter certain resistance when moving the fabric. A Japanese patent with publication number JP2013123297 proposes a sewing machine thread sweeping mechanism, which sweeps the thread by driving an object through an electromagnet after trimming the thread. After trimming the thread, the upper thread end can be pulled out from the fabric and the needle plate hole. However, this design will occupy the worker's operating space, and its high-speed thread sweeping action is also dangerous. The utility model patent with application number CN202321401978.X discloses a thread cutting mechanism capable of separating the upper thread and the lower thread, and a sewing machine, wherein the movable thread cutter is provided with structures such as an upper thread hooking part and a lower thread hooking part, which can separate the upper thread from the lower thread when cutting the thread, and push the last interweaving of the upper thread and the lower thread of the last stitch of the current stitch outside the first thread cutter and the movable thread cutter, so that the upper thread and the lower thread are no longer intertwined with each other after the cutting. However, this design can separate the upper thread and the lower thread to a certain extent when cutting the thread, but after the thread is cut and the second thread cutting is carried out to the reset process, the upper thread is still located between the first thread cutter and the movable thread cutter, and multiple bends and curved shapes will be formed under the needle plate, which is prone to thread jamming problems. Summary of the invention

[0003] In view of the shortcomings of the prior art mentioned above, the technical problem to be solved by the present invention is to provide a movable thread trimmer, a thread trimming mechanism, and a sewing machine with a thread sweeping function, which can pull out the upper thread during the thread trimming process to avoid affecting the lower thread and causing thread jamming problems, and have a simple structure and low cost.

[0004] To achieve the above-mentioned purpose, the present invention provides a movable thread trimmer with a thread sweeping function, which is used to be installed in a sewing machine to perform thread cutting work. The movable thread trimmer is provided with a thread dividing tip portion for inserting into a surface thread loop, and the right side of the thread dividing tip portion has a thread dividing side edge. The thread dividing tip portion is also provided with a thread sweeping structure, and the thread sweeping structure includes a thread sweeping hole, and a thread sweeping opening connecting the thread sweeping hole and the thread sweeping side edge, and the thread sweeping hole forms a thread sweeping retaining edge on at least one of the left and right sides of the thread sweeping opening.

[0005] Furthermore, the wire sweeping hole forms a wire sweeping rib on the right side of the wire sweeping opening.

[0006] Furthermore, the line sweeping hole forms line sweeping ribs on both right sides of the line sweeping opening.

[0007] Furthermore, the projection of the thread-wiping opening on the horizontal plane extends along a straight line, and an angle θ1 with the front direction of the sewing machine is less than or equal to 45°.

[0008] Furthermore, the width of the scanning line opening in the left-right direction is 0.1-1.0 mm.

[0009] Furthermore, the sweeping edge has a straight line segment near one side of the sweeping opening, and an angle θ2 between the projection of the straight line segment on the horizontal plane and the left and right directions is less than or equal to 20°.

[0010] Furthermore, the width of the thread-wiping rib in the left-right direction of the sewing machine is 1 to 10 mm.

[0011] Furthermore, there is a smooth transition between the dividing line side and the sweep line opening side, and there is a smooth transition between the sweep line opening side and the sweep line retaining edge.

[0012] The present invention also provides a thread trimming mechanism with a thread sweeping function, which is used for thread trimming in a sewing machine, and includes a mating thread trimmer and the above-mentioned movable thread trimmer. The movable thread trimmer can move relative to the mating thread trimmer in the sewing machine until the two are engaged to trim the thread or separated.

[0013] The present invention also provides a sewing machine, comprising the above-mentioned thread trimming mechanism.

[0014] As described above, the movable thread cutter, thread cutting mechanism, and sewing machine according to the present invention have the following beneficial effects:

[0015] By arranging a thread sweeping structure on the movable thread trimmer, the side edge of the dividing line is used to guide the upper thread through the thread sweeping opening and into the thread sweeping hole before the thread is cut; when the movable thread trimmer retreats after the thread trimming is completed, the upper thread is drawn out from the matching thread trimmer, the movable thread trimmer, and the arc-shaped catching piece through the thread sweeping hole, so as to separate the upper thread from the lower thread and prevent the upper thread from interfering with the lower thread. This can greatly improve the thread starting rate of the sewing machine, reduce the number of times the upper thread bends under the needle plate, reduce the resistance encountered by workers when taking out the cloth after thread trimming, reduce the labor intensity of workers, and prevent the upper thread from getting stuck; and only a small change needs to be made to the movable thread trimmer of the existing thread trimming mechanism to realize the thread sweeping action of the upper thread. The entire technical solution has a simple structure, is easy to use, and has a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of the working state of the thread trimming mechanism of the present invention when the thread trimming mechanism is engaged.

[0017] Figure 2 The figure is a working schematic diagram of the thread trimming mechanism of the present invention when the second thread trimming path is reset after thread trimming.

[0018] Figure 3 It is a structural schematic diagram of the thread cutting mechanism of the present invention.

[0019] Figure 4 It is a structural schematic diagram of the movable wire cutter in the present invention.

[0020] Figure 5 for Figure 4 Top view of the .

[0021] Figure 6 for Figure 4 Enlarged view of circle A in .

[0022] Figure 7 It is a schematic diagram of the structure of the bottom line catching member in the present invention.

[0023] Description of Figure Numbers

[0024] 1 With wire cutter

[0025] 2 movable wire cutters

[0026] 201 branch line tip

[0027] 202 branch line side

[0028] 203 Sweep hole

[0029] 204 Sweep Line Opening

[0030] 205 Sweep line retaining edge

[0031] 206 Wire cutter hook

[0032] 3 Bottom line catcher

[0033] 301 Installation Department

[0034] 302 Arc Capture Plate

[0035] 303 Second Capture Department

[0036] 304 Line guide side

[0037] 4 Bottom Line

[0038] 5. Noodles

[0039] 501 Needle Edge

[0040] 502 Selvedge DETAILED DESCRIPTION

[0041] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0042] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0043] See also Figures 1 to 7 The present invention provides a movable thread trimmer with a thread sweeping function 5, which is used to be installed in a sewing machine and cooperate with a matching thread trimmer 1 to perform thread trimming. The matching thread trimmer 1 and the movable thread trimmer 2 are two parts of the thread trimming mechanism in the sewing machine. The thread trimming mechanism is arranged at the rotary hook below the needle plate of the sewing machine. In the sewing machine, the axis of the rotary hook is along the left and right direction of the sewing machine, and the rotary hook is located at the left side of the sewing machine. The thread trimming mechanism includes the matching thread trimmer 1 and the movable thread trimmer 2, and generally also includes a wire dividing sheet located below the matching thread trimmer 1. The movable thread trimmer 2 is generally arranged at the rear side of the matching thread trimmer 1. In some cases, the front and rear positions of the two can also be swapped, that is, the movable thread trimmer 2 is generally arranged at the front side of the matching thread trimmer 1. After the movable thread trimmer 2 is installed, it can move to be close to or away from the matching thread trimmer 1. The matching thread trimmer 1 is generally fixedly installed in the sewing machine, and can be called a fixed thread trimmer at this time. In some cases, it can also be movable. The mating thread cutter 1 is provided with a first cutting edge (not shown in the attached drawings), the movable thread cutter 2 is provided with a wire dividing tip 201 for inserting into the loop of the upper thread 5, and is also provided with conventional structures such as a second cutting edge and a wire cutting hook 206. The wire cutting hook 206 is used to hook the lower thread 4 and the upper thread 5 and moves toward the mating thread cutter 1. The left side of the wire dividing tip 201 is the wire cutting hook 206, and the right side of the wire dividing tip 201 has a wire dividing side edge 202. The wire dividing side edge 202 gradually extends to the right in a direction away from the mating thread cutter 1, so that the wire dividing tip 201 gradually becomes sharper in a direction toward the mating thread cutter 1. After the movable thread cutter 2 is installed in the sewing machine, it can move relative to the mating thread cutter 1 in the front-rear direction of the sewing machine, so that the second cutting edge engages with or separates from the first cutting edge on the mating thread cutter 1, thereby cutting the upper thread 5 and the lower thread 4. See FIG. Figure 4 and Figure 5The improvement of the wire cutting mechanism of the present invention is that a wire sweeping structure is also provided on the wire dividing tip 201, and the wire sweeping structure includes a wire sweeping hole 203 and a wire sweeping opening 204 connecting the wire sweeping hole 203 and the wire dividing side 202. The wire sweeping hole 203 forms a wire sweeping retaining edge 205 on at least one side of the left and right sides of the wire sweeping opening 204, that is, the size of the wire sweeping hole 203 in the left and right directions is larger than the wire sweeping opening 204, and at least one side protrudes from the wire sweeping opening 204.

[0044] The basic working principle of the thread trimming mechanism of the present invention is as follows: Figure 1 and Figure 2 When the thread needs to be trimmed, the movable thread trimmer 2 moves toward the mating thread trimmer 1, and the dividing thread tip 201 enters the thread loop of the upper thread 5. The section of the upper thread 5 close to the needle side is recorded as the needle edge thread 501, and the section close to the fabric side is recorded as the cloth edge thread 502. The cloth edge thread 502 enters the thread trimming hook 206. The thread trimming hook 206 hooks the bottom line 4 and the cloth edge thread 502, and drives the bottom line 4 and the cloth edge thread 502 close to the mating thread trimmer 1. The needle edge thread 501 moves to the right along the dividing line side edge 202 on the right side of the dividing thread tip 201. During the thread trimming process, the needle edge thread 501 will be pulled up as the thread take-up lever of the sewing machine is gradually tightened. The needle edge thread 501 moves to the right along the dividing line side edge 202 to the thread sweeping opening 204, and enters the thread sweeping hole 203 through the thread sweeping opening 204, see Figure 1 In the state shown, the movable thread cutter 2 and the matching thread cutter 1 are engaged and cut the upper thread 5 and the lower thread 4. The upper thread 5 and the lower thread 4 are usually cut in a taut state. After the upper thread 5 is cut, it will be constrained in the space of the thread sweeping hole 203. The upper thread 5 that is stretched out instantly will be pulled out from between the matching thread cutter 1 and the movable thread cutter 2 due to its own tension, preventing the upper thread 5 and the lower thread 4 from interweaving with each other. Then the movable thread cutter 2 retreats and resets, away from the matching thread cutter 1, and the upper thread 5 (seam line 502) located in the thread sweeping hole 203 is pulled by the thread sweeping retaining edge 205 to move away from the matching thread cutter 1, so that the upper thread 5 is further pulled out, and finally pulled out from under the matching thread cutter 1, that is, pulled out from between the matching thread cutter 1 and the wire dividing plate, which can effectively reduce the bending and curvature of the upper thread 5 under the needle and reduce the length of the upper thread 5 below.

[0045] The thread trimming mechanism of the present invention can separate the upper thread 5 from the lower thread 4 after thread trimming, and draw the upper thread 5 out from the matching thread trimmer 1, the movable thread trimmer 2, and the thread dividing piece, so as to prevent the upper thread 5 from interfering with the lower thread 4, thereby greatly improving the sewing thread starting rate of the sewing machine, and the structure is simple, only a small change needs to be made to the existing mechanism, and the thread sweeping action of the upper thread 5 can be realized without adding additional parts.

[0046] See also Figures 1 to 7 The present invention is further described below with a specific embodiment:

[0047] In this embodiment, see Figure 4 , Figure 5 and Figure 6 As a preferred design, the wire sweeping hole 203 forms a wire sweeping retaining edge 205 on at least one side of the left and right sides of the wire sweeping opening 204. More preferably, the wire sweeping hole 203 forms a wire sweeping retaining edge 205 on the right side of the wire sweeping opening 204, so that the movable thread trimmer 2 can pull out the surface thread 5 when retreating.

[0048] In this embodiment, see Figure 4 , Figure 5 and Figure 6 As a preferred design, the projection of the sweep line opening 204 on the horizontal plane extends in a straight line, and the extension length of the sweep line opening 204 in the front-to-back direction can be set according to actual needs, and the angle θ1 between the straight extension direction and the front-to-back direction of the sewing machine is less than or equal to 45°, that is, it can be offset to the left or right within 45°, and more preferably θ1 is 0°. The dividing line side 202 extends in a straight line near the sweep line opening 204, and the angle α with the straight extension direction of the sweep line opening 204 is 60° to 150°. Furthermore, the width of the sweep line opening 204 in the left-right direction is 0.1 to 0.5 mm, which can ensure that the surface line 5 can enter the sweep line opening 204 along the dividing line side 202 before the surface line 5 is cut (at this time, the surface line 5 is in a stretched state), and can effectively prevent the surface line 5 from running out through the sweep line opening 204 after it is cut (at this time, the surface line 5 is in a relaxed state).

[0049] In this embodiment, see Figure 4 , Figure 5 and Figure 6As a preferred design, the sweeping hole 203 is a waist-shaped hole, and its length can be set according to actual needs. The formed sweeping edge 205 is arc-shaped near the two ends of the sweeping hole 203, and preferably has a straight line segment near the sweeping opening 204, that is, the sweeping edge 205 is composed of an arc segment and a straight line segment, and the angle θ2 between the projection of the straight line segment on the horizontal plane and the left and right directions is less than or equal to 20°, that is, it can be offset forward or backward within 20°, and the angle β between the projection of the straight line segment on the horizontal plane and the straight extension direction of the sweeping opening 204 on the horizontal plane is 30 to 150°, and more preferably θ2 is 90°. At this time, the sweeping hole 203 is a waist-shaped hole with its length direction along the left and right directions, and the angle β is 90°. The sweep line hole 203 and the sweep line opening 204 form a T-shaped structure, wherein the width of the sweep line retaining edge 205 in the left-right direction is 1 to 10 mm, specifically in this embodiment, that is, the distance between the left side of the sweep line opening 204 and the leftmost side of the sweep line hole 203 is 1 to 10 mm. In other embodiments, the sweep line opening 204 may also be in other shapes, and the sweep line hole 203 may also be in other shapes such as circular, elliptical, square, trapezoidal, etc., without limitation, as long as the sweep line retaining edge 205 can be formed and the corresponding function can be achieved.

[0050] In this embodiment, see Figure 4 , Figure 5 and Figure 6 As a preferred design, a rounded corner is provided between the dividing line side edge 202 and the side of the sweeping line opening 204 to achieve a smooth transition, so that the surface line 5 can enter the sweeping line opening 204 along the dividing line side edge 202 better, and damage to the surface line 5 can also be avoided. Similarly, a rounded corner is also provided between the side of the sweeping line opening 204 and the sweeping line retaining edge 205 to achieve a smooth transition.

[0051] In this embodiment, see Figure 1 , Figure 3 and Figure 5As a preferred design, the thread trimming mechanism further includes a bottom line catching member 3 (also a wire splitting piece), which can adopt an existing design, including an arc-shaped catching piece 302 arranged along the outer peripheral side of the rotary hook, and the arc-shaped catching piece 302 is located between the rotary hook and the matching thread trimmer 1, wherein the bottom line catching member 3 is fixedly installed at a suitable position of the sewing machine through a mounting portion 301, and a first catching portion is provided on the side of the matching thread trimmer 1 facing the rotary hook, and a second catching portion 303 matching the first catching portion is provided on the outer arc surface of the arc-shaped catching piece 302. At the same time, a wire splitting guide side edge 304 is also provided on the right side of the arc-shaped catching piece 302, and the wire splitting guide side edge 304 gradually extends to the right along the direction away from the active thread trimmer 2. When trimming the thread, the active thread trimmer 2 rotates toward the matching thread trimmer 1 and causes the thread trimmer hook 206 to drive the bottom line 4 to extend between the first catching portion and the second catching portion 303. When starting to trim the thread, the first catching portion and the second catching portion 303 are first in a close or abutting state, and the movable thread cutter 2 moves toward the matching thread cutter 1. The movable thread cutter 2 can first contact the matching thread cutter 1 and lift it up. Under certain size conditions, it can also be pressed on the arc-shaped capturing piece 302 to deform it downward. The first catching portion and the second catching portion 303 are separated, and the thread cutting hook 206 will drive the bottom line 4 and the surface line 5 to extend between the first catching portion and the second catching portion 303, and the dividing line side edge 202 on the movable thread cutter 2 will form an X-shaped intersection with the dividing line guide side edge 304 on the arc-shaped capturing piece 302, and jointly push the needle edge line 501 of the surface line 5 to move along the dividing line side edge 202 into the line sweeping opening 204. After the movable thread cutter 2 and the matching thread cutter 1 engage to cut the thread, the upper thread 5 that is instantly stretched will be partially pulled out from between the matching thread cutter 1, the arc-shaped capturing piece 302, and the movable thread cutter 2 to prevent the upper thread 5 and the lower thread 4 from being intertwined with each other. When the movable thread cutter 2 retreats and resets, the upper thread 5 is further pulled out, and the first capturing portion and the second capturing portion 303 approach and capture the lower thread 4, and the upper thread 5 will not be captured.

[0052] The present invention also provides a sewing machine, comprising the above-mentioned thread trimming mechanism, wherein the thread trimming mechanism is arranged at the rotary hook of the sewing machine to perform thread trimming.

[0053] As can be seen from the above, the movable thread cutter, the thread cutting mechanism, and the sewing machine of the present invention have the following beneficial effects:

[0054] 1. By arranging a thread sweeping structure on the movable thread trimmer 2, the dividing side 202 is used to guide the upper thread 5 to enter the thread sweeping hole 203 through the thread sweeping opening 204 before the thread is cut. When the movable thread trimmer 2 retreats after the thread trimming is completed, the upper thread 5 is drawn out from the matching thread trimmer 1, the movable thread trimmer 2, and the arc-shaped catching piece 302 through the thread sweeping hole, and the upper thread 5 is separated from the lower thread 4 to prevent the upper thread 5 from interfering with the lower thread 4. This can greatly improve the sewing machine's thread starting rate, reduce the number of times the upper thread 5 bends under the needle plate, reduce the resistance encountered by workers when taking out the cloth after thread trimming, reduce the workers' labor intensity, and prevent the upper thread 5 from getting stuck.

[0055] 2. Only a small modification needs to be made to the movable thread cutting knife 2 of the existing thread cutting mechanism to realize the thread sweeping action of the opposite thread 5. The whole technical solution has a simple structure, is easy to use and has low cost.

[0056] In summary, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0057] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A movable thread trimmer with a thread sweeping function, used for being installed in a sewing machine to perform thread trimming, the movable thread trimmer (2) being provided with a thread dividing tip (201) for inserting into a thread loop of an upper thread (5), the right side of the thread dividing tip (201) being provided with a thread dividing side edge (202), characterized in that: The line-sweeping tip (201) is also provided with a line-sweeping structure, which comprises a line-sweeping hole (203) and a line-sweeping opening (204) connecting the line-sweeping hole (203) and the line-sweeping side edge (202), and the line-sweeping hole (203) forms a line-sweeping retaining edge (205) on at least one side of the left and right sides of the line-sweeping opening (204).

2. The movable thread cutter according to claim 1, characterized in that: The wire sweeping hole (203) forms a wire sweeping retaining edge (205) on the right side of the wire sweeping opening (204).

3. The movable thread cutter according to claim 1 or 2, characterized in that: The wire sweeping hole (203) forms wire sweeping retaining edges (205) on both right sides of the wire sweeping opening (204).

4. The movable thread cutter according to claim 1, characterized in that: The projection of the scanning line opening (204) on the horizontal plane extends along a straight line, and the angle θ1 with the front direction is less than or equal to 45°.

5. The movable thread cutter according to claim 1 or 4, characterized in that: The width of the thread-wiping opening (204) in the left-right direction of the sewing machine is 0.1-1.0 mm.

6. The movable thread cutter according to claim 4, characterized in that: The sweeping edge (205) has a straight line segment on a side close to the sweeping opening (204), and an angle θ2 between a projection of the straight line segment on a horizontal plane and the left and right directions is less than or equal to 20°.

7. The movable thread cutter according to claim 1 or 6, characterized in that: The width of the thread-wiping retaining edge (205) in the left-right direction of the sewing machine is 1 to 10 mm.

8. The movable thread cutter according to claim 1, characterized in that: There is a smooth transition between the line dividing side edge (202) and the line sweeping opening (204) side edge, and there is a smooth transition between the line sweeping opening (204) side edge and the line sweeping retaining edge (205).

9. A thread trimming mechanism with a thread sweeping function, used for thread trimming in a sewing machine, comprising a thread trimming knife (1), characterized in that: It also comprises a movable thread cutter (2) as claimed in any one of claims 1 to 8, wherein the movable thread cutter (2) can move relative to the matching thread cutter (1) in the sewing machine until the two are engaged to cut the thread or separated.

10. A sewing machine, characterized in that: It comprises the thread cutting mechanism as claimed in claim 9.

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