A movable thread cutter with a thread-sweeping function, a thread-cutting mechanism, and a sewing machine.

Abstract

This invention relates to a movable thread cutter with a sweeping function, a thread cutting mechanism, and a sewing machine for thread cutting operations in a sewing machine. The movable thread cutter has a thread separating tip for insertion into a thread loop. The right side of the thread separating tip has a thread separating side. The movable thread cutter can move relative to the thread cutter until the two engage to cut the thread or separate. The thread separating tip also has a sweeping structure, which includes a sweeping hole and a sweeping opening connecting the sweeping hole and the thread separating side. The sweeping hole forms a sweeping stop on at least one side of the sweeping opening.

Description

Technical Field

[0001] This invention relates to the field of sewing equipment technology, specifically to a movable thread cutter with a thread sweeping function, a thread cutting mechanism, and a sewing machine. Background Technology

[0002] After a sewing machine completes one stitch, the fabric needs to be moved from the previous stitch to the next stitch before the next stitch is cut. After cutting the thread, the top thread usually has several bends and curves under the needle plate. When the top thread is too long, the worker will encounter some resistance when moving the fabric. Japanese Patent Publication No. JP2013123297 proposes a sewing machine thread sweeping mechanism that uses an electromagnet to drive an object to sweep the thread after cutting. This can pull the thread end out of the fabric and needle plate hole after cutting. However, this design takes up the worker's operating space, and its high-speed sweeping action also poses certain dangers. The utility model patent with application number CN202321401978.X discloses a thread-cutting mechanism and a sewing machine capable of separating the top thread and bottom thread. The movable thread-cutting blade is equipped with structures such as a top thread hook and a bottom thread hook, which can separate the top thread and bottom thread during thread cutting and push the last interlacing of the top and bottom thread in the last stitch of the current stitch outside the first and movable thread-cutting blades, thus preventing the top and bottom threads from interlacing after cutting. However, while this design can separate the top and bottom threads to a certain extent during thread cutting, the top thread remains between the first and movable thread-cutting blades during the second thread cutting and resetting process, still forming multiple bends and curves under the needle plate, easily leading to thread jamming. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the technical problem to be solved by the present invention is to provide a movable thread cutter, a thread cutting mechanism, and a sewing machine with a thread sweeping function, which can pull out the top thread during the thread cutting process, avoiding affecting the bottom thread and causing thread jamming problems, and has a simple structure and low cost.

[0004] To achieve the above objectives, the present invention provides a movable thread cutter with a thread-sweeping function, which is installed in a sewing machine for thread cutting. The movable thread cutter is provided with a thread-separating tip for insertion into the thread loop. The right side of the thread-separating tip has a thread-separating side edge. The thread-separating tip is also provided with a thread-sweeping structure. The thread-sweeping structure includes a thread-sweeping hole and a thread-sweeping opening connecting the thread-sweeping hole and the thread-separating side edge. The thread-sweeping hole forms a thread-sweeping stop edge on at least one side of the left and right sides of the thread-sweeping opening.

[0005] Furthermore, the scanning hole forms a scanning guard edge on the right side of the scanning opening.

[0006] Furthermore, the scanning hole forms scanning guard edges on both the right and right sides of the scanning opening.

[0007] Furthermore, the projection of the sweeping opening on the horizontal plane extends in a straight line, and the angle θ1 between it and the direction in front of the sewing machine is less than or equal to 45°.

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

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

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

[0011] Furthermore, the side of the dividing line and the side of the sweeping line opening are smoothly transitioned, and the side of the sweeping line opening and the sweeping line stop are smoothly transitioned.

[0012] The present invention also provides a thread-cutting mechanism with a thread-sweeping function for thread-cutting work in a sewing machine, including a matching thread-cutting blade and the aforementioned movable thread-cutting blade, wherein the movable thread-cutting blade can move relative to the matching thread-cutting blade in the sewing machine until the two bite together to cut the thread or separate.

[0013] The present invention also provides a sewing machine including the above-described thread-cutting mechanism.

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

[0015] By incorporating a sweeping structure on the movable thread cutter, the top thread is guided through the sweeping opening into the sweeping hole before being cut. After cutting, as the movable thread cutter retracts, the top thread is pulled out through the sweeping hole from the mating thread cutter, the movable thread cutter, and the curved capture plate, separating the top thread from the bottom thread and preventing interference. This significantly improves the sewing machine's thread loading rate, reduces the number of times the top thread bends under the needle plate, lowers the resistance encountered by workers when removing fabric after cutting, reduces worker workload, and prevents the top thread from getting stuck. Furthermore, only minor modifications to the movable thread cutter of the existing thread cutting mechanism are needed to achieve the sweeping action on the top thread. The entire technical solution is simple in structure, easy to use, and low in cost. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the wire cutting mechanism of the present invention during the biting and cutting of wire.

[0017] Figure 2 This is a schematic diagram of the operation of the wire cutting mechanism of the present invention when the second wire cutting track is reset after wire cutting.

[0018] Figure 3 This is a schematic diagram of the wire-cutting mechanism of the present invention.

[0019] Figure 4 This is a schematic diagram of the movable wire cutter in this invention.

[0020] Figure 5 for Figure 4 Top view.

[0021] Figure 6 for Figure 5 Enlarged view of circle A in the image.

[0022] Figure 7 This is a schematic diagram of the bottom line capture device in this invention.

[0023] Explanation of icon numbers

[0024] 1. Use with a thread cutter

[0025] 2. Movable Thread Cutter

[0026] 201 Points Tip

[0027] 202 Side of the dividing line

[0028] 203 Sweep Hole

[0029] 204 Scanning Line Opening

[0030] 205 Sweep line edge guard

[0031] 206 Wire Cutting Hook

[0032] 3 Bottom-line capture components

[0033] 301 Installation Department

[0034] 302 Arc-shaped Snap-in Plate

[0035] 303 Second Capture Division

[0036] 304 split line guide side

[0037] 4. Bottom Line

[0038] 5-sided lines

[0039] 501 needle edge thread

[0040] 502 Fabric Selvage Detailed Implementation

[0041] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0042] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0043] See Figures 1 to 7 This invention provides a movable thread cutter with a thread-sweeping function 5, used to be installed in a sewing machine to work in conjunction with a cooperating thread cutter 1 for thread cutting. The cooperating thread cutter 1 and the movable thread cutter 2 are two components of the thread cutting mechanism in the sewing machine. The thread cutting mechanism is located at the shuttle below the needle plate of the sewing machine. In the sewing machine, the axis of the shuttle is along the left-right direction of the sewing machine, and the shuttle is located on the left side of the sewing machine. The thread cutting mechanism includes the cooperating thread cutter 1 and the movable thread cutter 2, and generally also includes a thread divider located below the cooperating thread cutter 1. The movable thread cutter 2 is generally located behind the cooperating thread cutter 1. In some cases, their front and rear positions can be reversed, that is, the movable thread cutter 2 is generally located in front of the cooperating thread cutter 1. After installation, the movable thread cutter 2 can move closer to or further away from the cooperating thread cutter 1. The cooperating thread cutter 1 is generally fixedly installed in the sewing machine, in which case it can be called a fixed thread cutter. In some cases, it can also be movable. The movable thread cutter 2 has a first cutting edge (not shown in the attached diagram) on the thread cutter 1, and a thread separating tip 201 for inserting into the loop of the top thread 5. It also has a second cutting edge and a thread-cutting hook 206, among other conventional structures. The thread-cutting hook 206 hooks the bottom thread 4 and the top thread 5 as they move towards the thread cutter 1. The thread-cutting hook 206 is located to the left of the thread separating tip 201, and a thread separating side 202 is located to the right of the thread separating tip 201. The thread separating side 202 gradually extends to the right in a direction away from the thread cutter 1, causing the thread separating tip 201 to gradually become sharper towards the thread cutter 1. After being installed in the sewing machine, the movable thread cutter 2 can move relative to the thread cutter 1 in the back-and-forth direction of the sewing machine, causing the second cutting edge to engage or disengage with the first cutting edge on the thread cutter 1, thereby cutting the top thread 5 and the bottom thread 4. (See also...) Figure 4 and Figure 5The improvement of the wire cutting mechanism of the present invention is that the wire separating tip 201 is further provided with a wire sweeping structure. 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 separating side 202. The wire sweeping hole 203 forms a wire sweeping guard 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 direction is larger than that of the wire sweeping opening 204, and at least one side extends out of the wire sweeping opening 204.

[0044] The basic working principle of the wire-cutting mechanism involved in this invention is as follows: See Figure 1 and Figure 2 When thread trimming is required, the movable thread cutter 2 moves toward the cooperating thread cutter 1, and the thread-separating tip 201 enters the thread loop of the top thread 5. The section of the top thread 5 near the needle is designated as the needle edge thread 501, and the section near the fabric is designated as the fabric edge thread 502. The fabric edge thread 502 enters the thread-cutting hook 206, which hooks the bottom thread 4 and the fabric edge thread 502, and moves them closer to the cooperating thread cutter 1. The needle edge thread 501 then moves to the right along the thread-separating side 202 to the right of the thread-separating tip 201. During the thread trimming process, under the gradual tightening action of the sewing machine's take-up lever, the needle edge thread 501 is pulled upwards, moving to the right along the thread-separating side 202 to the sweeping opening 204, and then entering the sweeping hole 203 through the sweeping opening 204. (See [reference]). Figure 1 As shown in the diagram, the movable thread cutter 2 engages with the mating thread cutter 1 and cuts the top thread 5 and bottom thread 4. The top thread 5 and bottom thread 4 are typically cut while taut. After the top thread 5 is cut, it is confined within the space of the thread sweeping hole 203. The instantly stretched top thread 5 is pulled out partially between the mating thread cutter 1 and the movable thread cutter 2 due to its own tension, preventing the top thread 5 from intertwining with the bottom thread 4. Then, the movable thread cutter 2 retracts and resets, moving away from the mating thread cutter 1. The top thread 5 (seam thread 502) located in the thread sweeping hole 203 is pulled away from the mating thread cutter 1 by the thread sweeping guard 205, causing the top thread 5 to be further pulled out, ultimately being pulled out below the mating thread cutter 1, that is, between the mating thread cutter 1 and the thread separator. This effectively reduces the bending and twisting of the top thread 5 below the needle, reducing the length of the bottom top thread 5.

[0045] The thread-cutting mechanism of the present invention can separate the top thread 5 from the bottom thread 4 after thread cutting, and pull the top thread 5 out from the thread-cutting blade 1, the movable thread-cutting blade 2, and the thread-separating plate, so as to prevent the top thread 5 from interfering with the bottom thread 4, greatly improving the sewing machine's thread-taking rate. Moreover, the structure is simple, requiring only minor modifications to the existing mechanism, and the thread-sweeping action of the top thread 5 can be achieved without adding any extra parts.

[0046] See Figures 1 to 7 The present invention will be further described below with reference to a specific embodiment:

[0047] In this embodiment, see Figure 4 , Figure 5 and Figure 6 As a preferred design, the sweeping hole 203 forms a sweeping guard 205 on at least one side of the sweeping opening 204. More preferably, the sweeping hole 203 forms a sweeping guard 205 on the right side of the sweeping opening 204, so that the movable wire cutter 2 can pull out the face wire 5 when it retracts.

[0048] In this embodiment, see Figure 4 , Figure 5 and Figure 6 As a preferred design, the projection of the thread-sweeping opening 204 on the horizontal plane extends in a straight line. The extension length of the thread-sweeping 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 edge 202 extends in a straight line near the thread-sweeping opening 204, and the angle α between it and the straight extension direction of the thread-sweeping opening 204 is 60° to 150°. Furthermore, the width of the thread-sweeping opening 204 in the left-to-right direction is 0.1 to 0.5 mm, which can ensure that the top thread 5 can enter the thread-sweeping opening 204 along the dividing edge 202 before the top thread 5 is cut (at which time the top thread 5 is in a stretched state), and can also effectively prevent the top thread 5 from running out of the thread-sweeping opening 204 after it is cut (at which time the top thread 5 is in a relaxed state).

[0049] In this embodiment, see Figure 4 , Figure 5 and Figure 6As a preferred design, the scanning hole 203 is an oblong hole, the length of which can be set according to actual needs. The resulting scanning guard 205 is arc-shaped near both ends of the scanning hole 203, and preferably has a straight segment near the scanning opening 204. That is, the scanning guard 205 is composed of an arc segment and a straight segment, and the angle θ2 between the projection of the straight segment on the horizontal plane and the left and right direction is less than or equal to 20°, that is, it can be offset forward or backward within 20°. The angle β between the projection of the straight segment on the horizontal plane and the straight extension direction of the scanning opening 204 on the horizontal plane is 30 to 150°, more preferably θ2 is 90°. At this time, the scanning hole 203 is an oblong hole with the length direction along the left and right direction and the angle β is 90°. The scanning hole 203 and the scanning opening 204 form a T-shaped structure. The width of the scanning guard 205 in the left-right direction is 1-10 mm. Specifically, in this embodiment, the distance between the left side of the scanning opening 204 and the leftmost side of the scanning hole 203 is 1-10 mm. In other embodiments, the scanning opening 204 can also take other shapes, and the scanning hole 203 can also take other shapes such as circular, elliptical, square, trapezoidal, etc. There are no restrictions, as long as it can form the scanning guard 205 and realize the corresponding function.

[0050] In this embodiment, see Figure 4 , Figure 5 and Figure 6 As a preferred design, a rounded corner is used to achieve a smooth transition between the dividing line side 202 and the side of the scanning opening 204. This allows the surface line 5 to enter the scanning opening 204 along the dividing line side 202 and also avoids damage to the surface line 5. Similarly, a rounded corner is also used to achieve a smooth transition between the side of the scanning opening 204 and the scanning guard edge 205.

[0051] In this embodiment, see Figure 1 , Figure 3 and Figure 5As a preferred design, the thread cutting mechanism also includes a bobbin catcher 3 (also a thread separator). The bobbin catcher 3 can adopt an existing design, including an arc-shaped catcher 302 arranged along the outer periphery of the rotary hook, and the arc-shaped catcher 302 is located between the rotary hook and the mating thread cutter 1. The bobbin catcher 3 is fixedly installed at a suitable position on the sewing machine by a mounting part 301. The mating thread cutter 1 has a first catcher on its side facing the rotary hook, and a second catcher 303 that mates with the first catcher is provided on the outer arc surface of the arc-shaped catcher 302. At the same time, a thread separator guide side 304 is also provided on the right side of the arc-shaped catcher 302, which gradually tilts to the right in a direction away from the movable thread cutter 2. During thread cutting, the movable thread cutter 2 rotates toward the mating thread cutter 1, causing the thread hook 206 to pull the bobbin 4 into the space between the first catcher and the second catcher 303. When the thread cutting begins, the first and second capturing parts 303 are initially close to or abutting each other. The movable thread cutter 2 moves toward the cooperating thread cutter 1. The movable thread cutter 2 can first contact the cooperating thread cutter 1 and lift it up. If certain dimensions allow, it can also press on the arc-shaped capturing plate 302 to deform it downwards. The first and second capturing parts 303 separate, and the thread cutting hook 206 will drive the bottom thread 4 and the top thread 5 to extend between the first and second capturing parts 303. The thread separating side 202 on the movable thread cutter 2 will form an X-shaped intersection with the thread separating guide side 304 on the arc-shaped capturing plate 302, jointly pushing the needle edge thread 501 of the top thread 5 along the thread separating side 202 into the thread sweeping opening 204. After the movable wire cutter 2 and the mating wire cutter 1 engage and cut the wire, the top wire 5, which expands instantly, will be partially pulled out from between the mating wire cutter 1, the arc-shaped capture plate 302, and the movable wire cutter 2 to prevent the top wire 5 from intertwining with the bottom wire 4. When the movable wire cutter 2 retracts and resets, the top wire 5 is pulled out further, and the first capture part and the second capture part 303 approach and capture the bottom wire 4, without capturing the top wire 5.

[0052] The present invention also provides a sewing machine including the above-mentioned thread-cutting mechanism, which is disposed at the rotary hook of the sewing machine to cut the thread.

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

[0054] 1. By setting a sweeping structure on the movable thread cutter 2, the top thread 5 is guided through the sweeping opening 204 into the sweeping hole 203 by the thread separating side 202 before the thread is cut. After the thread is cut, when the movable thread cutter 2 retracts, the top thread 5 is pulled out from the mating thread cutter 1, the movable thread cutter 2, and the arc-shaped capture plate 302 through the sweeping hole, separating the top thread 5 from the bottom thread 4, preventing the top thread 5 from interfering with the bottom thread 4. This can greatly improve the sewing machine's stitch loading rate, reduce the number of times the top thread 5 bends under the needle plate, reduce the resistance encountered by the worker when taking out the fabric after cutting the thread, reduce the worker's labor intensity, and prevent the top thread 5 from getting stuck.

[0055] 2. Only minor modifications are needed to the movable wire cutter 2 of the existing wire cutting mechanism to achieve the wire sweeping action of the opposite wire 5. The entire technical solution has a simple structure, is easy to use, and has low cost.

[0056] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0057] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can 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 those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A movable thread cutter with a thread-sweeping function, used for installation in a sewing machine for thread cutting, wherein the movable thread cutter (2) is provided with a thread-separating tip (201) for insertion into the thread loop of the face thread (5), and the right side of the thread-separating tip (201) has a thread-separating side edge (202), characterized in that: The tip (201) of the dividing line is also provided with a sweeping structure, which includes a sweeping hole (203) and a sweeping opening (204) connecting the sweeping hole (203) and the side of the dividing line (202). The sweeping hole (203) forms a sweeping guard edge (205) on at least one side of the sweeping opening (204). The sweeping hole (203) is used to accommodate the needle edge thread (501) of the face thread (5) when cutting the thread, and to pull the face thread (5) after cutting the thread.

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

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

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

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

6. The movable wire cutter according to claim 4, characterized in that: The sweeping guard (205) has a straight line segment on the side near the sweeping opening (204), 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°.

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

8. The movable wire cutter according to claim 1, characterized in that: The side of the dividing line (202) and the side of the sweeping opening (204) are smoothly transitioned, and the side of the sweeping opening (204) and the sweeping stop (205) are smoothly transitioned.

9. A thread-cutting mechanism with a thread-sweeping function, used for thread-cutting work in a sewing machine, comprising a thread-cutting blade (1), characterized in that: It also includes a movable thread cutter (2) as described in any one of claims 1 to 8, wherein the movable thread cutter (2) can move relative to the thread cutter (1) in the sewing machine until the two bite together to cut the thread or separate.

10. A sewing machine, characterized in that: Includes the wire-cutting mechanism as described in claim 9.

Images