Double-blade driving device of sewing machine and thread trimming equipment

Abstract

The invention provides a sewing machine double-blade driving device and thread trimming equipment, the sewing machine double-blade driving device comprises a transmission mechanism B, a transmission mechanism A, a motion control piece and a driving source, the driving source is connected with the motion control piece and drives the motion control piece to move, the transmission mechanism B is in transmission connection with the motion control piece and is used for connecting a thread trimming movable blade B, and the transmission mechanism A is used for driving the thread trimming movable blade B to move. The transmission mechanism A is in transmission connection with the motion control piece and is used for being connected with the thread trimming movable cutter A; the operation stroke of the motion control piece comprises the working stroke range of the movable cutter B and the working stroke range of the movable cutter A. When the motion control piece moves in the working stroke range of the movable cutter A, the transmission mechanism A moves and drives the thread trimming movable cutter A. When the motion control piece moves in the working stroke range of the movable cutter B, the transmission mechanism B moves and drives the thread trimming movable cutter B.

Description

Technical Field

[0001] This invention relates to the field of sewing technology, and in particular to a double-blade drive device for a sewing machine and a thread-cutting device. Background Technology

[0002] In the field of pattern sewing machines, the process of making the first stitch on the sewing material is called the starting stitch. During the starting stitch, a free thread end at one end of the top thread can lead to failure. There are two possible causes for starting stitch failure: 1. The top thread end is too short to catch the bobbin thread, causing subsequent stitches to fail and severely impacting sewing production. 2. The top thread end is too long, causing it to tangle with the bobbin thread, forming a bird's nest-like defect. This defect affects the appearance and requires manual repair by the sewing worker, making the work tedious.

[0003] Existing pattern sewing machines require the bottom and top threads to be trimmed after one round of sewing. See attached document. Figure 1 As shown, this is a conventional drive device for driving a wire-cutting blade. The drive device uses the attraction action of an electromagnet 001 to drive the first linkage assembly 002 to move, which in turn drives the connecting plate 003 to move. The roller 004 is fixedly connected to the connecting plate 003. When the machine needs to cut the wire, the electromagnet 001 is energized, causing the roller 004 to mesh with the cam 005. The cam 005 rotates under the drive of the main shaft, causing the second linkage assembly 006 to move up and down. The second linkage assembly 006 converts the up and down movement into a back and forth movement, which drives the third linkage assembly 007 and the moving blade linkage 008 to move back and forth, causing the moving blade to move and cut the bottom and top wires short.

[0004] Existing mechanical structures for shortening bottom seams have drawbacks such as complex structures and numerous specialized parts. Furthermore, there are currently no mechanical structures or drive devices on the market that can solve the aforementioned seam-starting failure. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a double-blade drive device and a thread-cutting device for a sewing machine, which drives two thread-cutting blades through a drive source, and can realize the prevention of slippage at the start of sewing and the cutting of threads after sewing.

[0006] To achieve the above objectives, the present invention provides a dual-blade drive device for a sewing machine, comprising a transmission mechanism B, a transmission mechanism A, a motion control component, and a drive source. The drive source is connected to the motion control component and drives the motion control component to move. The transmission mechanism B is driven by the motion control component and is used to connect the thread-cutting blade B. The transmission mechanism A is driven by the motion control component and is used to connect the thread-cutting blade A. The operating stroke of the motion control component includes the working stroke range of the blade B and the working stroke range of the blade A. When the motion control component moves within the working stroke range of the blade A, the transmission mechanism A moves and drives the thread-cutting blade A. When the motion control component moves within the working stroke range of the blade B, the transmission mechanism B moves and drives the thread-cutting blade B.

[0007] Furthermore, the motion control component includes a cam, the drive source drives the cam to rotate, and the working surface of the cam is provided with a working area for a moving blade A and a working area for a moving blade B. The working area for moving blade A includes a stroke area for moving blade A, and the working area for moving blade B includes a stroke area for moving blade B. The transmission mechanism A includes a transmission block A and a connecting component A for connecting the transmission block A and the wire-cutting moving blade A. The transmission mechanism B includes a transmission block B and a connecting component B for connecting the transmission block B and the wire-cutting moving blade B. When the cam rotates to the stroke area of ​​moving blade A and contacts the transmission block A, the transmission mechanism A moves; when the cam rotates to the stroke area of ​​moving blade B and contacts the transmission block B, the transmission mechanism B moves.

[0008] Furthermore, the working area of ​​the moving tool A includes a no-go area located in the stroke area of ​​the moving tool A along the clockwise rotation direction of the cam, and the connecting shaft A remains stationary when the no-go area of ​​the moving tool A abuts against the transmission block A; the working area of ​​the moving tool B includes a no-go area located in the stroke area of ​​the moving tool B along the counterclockwise rotation direction of the cam, and the connecting shaft B remains stationary when the no-go area of ​​the moving tool B abuts against the transmission block B; when the cam rotates to the point where the stroke area of ​​the moving tool A contacts the transmission block A, the no-go area of ​​the moving tool B contacts the transmission block B; when the cam rotates to the point where the stroke area of ​​the moving tool B contacts the transmission block B, the no-go area of ​​the moving tool A contacts the transmission block A.

[0009] Furthermore, the working area of ​​the moving tool A also includes a waiting area of ​​the moving tool A located in the stroke area of ​​the moving tool A along the counterclockwise rotation direction of the cam, and the working area of ​​the moving tool B also includes a waiting area of ​​the moving tool B located in the idle area of ​​the moving tool B along the counterclockwise rotation direction of the cam. When the cam rotates to the point where the waiting area of ​​the moving tool A contacts the transmission block A, the waiting area of ​​the moving tool B contacts the transmission block B.

[0010] Furthermore, the connecting assembly A further includes a transmission block constraining transmission member A, wherein the transmission block A is mounted on the transmission block constraining transmission member A, and the transmission block constraining transmission member A can constrain the movement trajectory of the transmission block A to keep the transmission block A in contact with the working area of ​​the moving tool A, and transmit the movement of the transmission block A to the connecting assembly A; the connecting assembly B further includes a transmission block constraining transmission member B, wherein the transmission block B is mounted on the transmission block constraining transmission member B, and the transmission block constraining transmission member B can constrain the movement trajectory of the transmission block B to keep the transmission block B in contact with the working area of ​​the moving tool B, and transmit the movement of the transmission block B to the connecting assembly B.

[0011] Furthermore, the transmission block constrains the transmission component A as an axially movable connecting shaft A. When the cam rotates to the stroke area of ​​the moving tool A and contacts the transmission block A, the transmission block A drives the connecting shaft A to move axially. The transmission block constrains the transmission component B as an axially movable connecting shaft B. When the cam rotates to the stroke area of ​​the moving tool B and contacts the transmission block B, the transmission block B drives the connecting shaft B to move axially.

[0012] Furthermore, the transmission block constrains the transmission component A as a rotatably mounted swing plate A. When the cam rotates to the stroke area of ​​the moving tool A and contacts the transmission block A, the transmission block A drives the swing plate A to rotate. The transmission block constrains the transmission component B as a rotatably mounted swing plate B. When the cam rotates to the stroke area of ​​the moving tool B and contacts the transmission block B, the transmission block B drives the swing plate B to rotate.

[0013] Furthermore, the transmission mechanism B also includes an elastic structure B, which directly or indirectly applies a spring force to the transmission block B to bring the transmission block B closer to the cam working surface; the transmission mechanism A also includes an elastic structure A, which directly or indirectly applies a spring force to the transmission block A to bring the transmission block A closer to the cam working surface.

[0014] Furthermore, the transmission block B is a roller and is rotatably mounted on the transmission block constraining transmission component B; the transmission block A is a roller and is rotatably mounted on the transmission block constraining transmission component A.

[0015] Furthermore, it also includes a limiting plate, which has a limiting groove. The cam is fixed in the limiting groove, and a limiting channel is formed between the working surface of the cam and the side wall of the limiting groove. Both the transmission block B and the transmission block A are located in the limiting channel.

[0016] Furthermore, the limiting plate is provided with limiting part A and limiting part B. When the cam rotates counterclockwise to the end of the idle travel area of ​​the moving blade A and contacts the transmission block A, the transmission block B abuts against the limiting part B and the transmission block A abuts against the limiting part A.

[0017] Furthermore, the transmission mechanism A also includes a guide seat A, and the connecting shaft A is mounted on the guide seat A and is axially movable relative to the guide seat B; the transmission mechanism B also includes a guide seat B, and the connecting shaft B is mounted on the guide seat B and is axially movable relative to the guide seat B.

[0018] Further, the connecting component B of the transmission mechanism B includes a rotating rod B, a first swing arm B, a second swing arm B, and a moving blade connecting rod B. The first swing arm B is fixedly connected to the rotating rod B and is connected to the transmission block constraining transmission member B. The second swing arm B is fixedly connected to the rotating rod B, and its other end is hinged to one end of the moving blade connecting rod B. The other end of the moving blade connecting rod B is used to connect to the wire-cutting moving blade B. Alternatively, the connecting component A of the transmission mechanism A includes a rotating rod A, a first swing arm A, a second swing arm A, and a moving blade connecting rod A. The first swing arm A is connected to the transmission block constraining transmission member A and is fixedly connected to the rotating rod A. One end of the second swing arm A is fixedly connected to the rotating rod A, and its other end is hinged to one end of the moving blade connecting rod A. The other end of the moving blade connecting rod A is used to connect to the wire-cutting moving blade A.

[0019] The present invention also provides a thread-cutting device for a sewing machine, including a thread-cutting blade B and a thread-cutting blade A, and further including the aforementioned double-blade drive device. The transmission mechanism A is connected to the thread-cutting blade A, and the transmission mechanism B is connected to the thread-cutting blade B. The thread-cutting blade A is used to perform the sewing start and anti-slipping action of the sewing machine, and the thread-cutting blade B is used to perform the thread-cutting action after the sewing machine has finished sewing.

[0020] As described above, the dual-blade drive device and wire cutting device of the present invention have the following beneficial effects:

[0021] 1. A single drive source drives the motion control component, which in turn drives the thread-cutting blade A and thread-cutting blade B through transmission mechanisms A and B4 respectively. This allows the two blades to move independently, performing the sewing start-up and anti-slipping actions and the thread-cutting action after sewing, respectively. This reduces the number of drive sources and simplifies the mechanism.

[0022] 2. The original electromagnet structure can be removed. By adopting the design structure of this invention, the number of special parts used can be greatly reduced, the cost can be reduced, and assembly and after-sales maintenance can be facilitated.

[0023] 3. Enhancement of core competitiveness: Currently, there is a high demand for anti-seam slippage machines in the pattern making machine market, but there are no large-scale machines with anti-seam slippage function on the market. Therefore, pattern making machines equipped with this thread cutting device can enhance their competitiveness.

[0024] 4. High versatility: This thread-cutting device can be modularized by mounting the components on the mounting plate, making it suitable for various sewing machines and increasing its versatility with other models. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the drive unit for an existing wire-cutting mechanism.

[0026] Figure 2 This is a schematic diagram of the structure of a first embodiment of the dual-blade drive device of the present invention.

[0027] Figure 3 This is a schematic diagram of the motion control component and drive source in Embodiment 1 of the present invention.

[0028] Figure 4 This is a schematic diagram of the transmission mechanism B and transmission mechanism A in Embodiment 1 of the present invention.

[0029] Figure 5 This is an assembly diagram of the cam, limiting disk, transmission block B and transmission block A in Embodiment 1 of the present invention.

[0030] Figure 6 for Figure 5 Top view.

[0031] Figure 7 This is a schematic diagram of the cam and limiting plate in Embodiment 1 of the present invention.

[0032] Figure 8 This is a schematic diagram of the structure of a second embodiment of the dual-blade drive device of the present invention.

[0033] Figure 9 for Figure 8 Top view.

[0034] Figure 10 This is a schematic diagram of the cam structure in Embodiment 2 of the present invention.

[0035] Explanation of icon numbers:

[0036] 001-Electromagnet, 002-First link assembly, 003-Connecting plate, 004-Roller, 005-Cam, 006-Second link assembly, 007-Third link assembly, 008-Moving tool link.

[0037] 1-Motor, 2-Mounting plate, 3-Cam, 31-Working area of ​​moving tool A, 311-Stroke area of ​​moving tool A, 312-Idle travel area of ​​moving tool A, 313-Wait area of ​​moving tool A, 32-Working area of ​​moving tool B, 321-Stroke area of ​​moving tool B, 322-Idle travel area of ​​moving tool B, 323-Wait area of ​​moving tool B, 33-Connecting sleeve, 4-Transmission mechanism B, 401-Transmission block B, 402-Connecting shaft B, 403-Guide seat B, 404-Spring structure B, 405-Rotating rod B, 406-First swing arm B, 407-Second swing arm B, 408-Moving tool connecting rod B, 409 - Connecting pin B, 410 Rotating shaft B, 411 Front connecting rod B, 412 Swing plate B, 5 Transmission mechanism A, 501 Transmission block A, 502 Connecting shaft A, 503 Guide seat A, 504 Spring structure A, 505 Rotating rod A, 506 First swing arm A, 507 Second swing arm A, 508 Moving blade connecting rod A, 509 Front connecting rod A, 510 Rotating shaft A, 511 Connecting plate A, 512 Swing plate A, 6 Limiting plate, 61 Limiting groove, 62 Limiting part A, 63 Limiting part B, 7 Wire cutting moving blade B, 8 Wire cutting moving blade A. Detailed Implementation

[0038] 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.

[0039] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and 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.

[0040] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0041] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0042] See Figures 1 to 7 This invention provides a dual-blade drive device for a sewing machine, used to drive a thread-cutting blade B7 and a thread-cutting blade A8. The dual-blade drive device includes a transmission mechanism B4, a transmission mechanism A5, a motion control component, and a drive source. The drive source is connected to the motion control component and drives the motion control component to move. The transmission mechanism B4 is driven by the motion control component and is used to connect the thread-cutting blade B7, wherein the thread-cutting blade B7 can be used to perform the sewing start-up and anti-slipping action of the sewing machine. The transmission mechanism A5 is driven by the motion control component and is used to connect the thread-cutting blade A8, wherein the thread-cutting blade A8 can be used to perform the thread-cutting action after the sewing machine has finished sewing. The operating stroke of the motion control component includes the working stroke range of blade A and the working stroke range of blade B. When the motion control component moves within the working stroke range of blade A, the transmission mechanism A5 drives the thread-cutting blade A8, thereby causing the thread-cutting blade A8 to perform the sewing start-up and anti-slipping action of the sewing machine. When the motion control component moves within the working stroke range of blade B, the transmission mechanism B4 drives the thread-cutting blade B7, thereby causing the thread-cutting blade B7 to perform the thread-cutting action after the sewing machine has finished sewing. The working stroke ranges of moving tool A and moving tool B can partially overlap or not overlap at all.

[0043] The thread-cutting device of this invention uses a motion control component and a drive source to drive the movement of thread-cutting blades B7 and A8. When the sewing machine begins sewing, the drive source drives the motion control component to move within the working stroke range of blade A. At this time, the transmission mechanism A5 drives the thread-cutting blade A8 to perform the corresponding sewing start-up anti-slipping action. For example, after the first stitch, the thread-cutting blade A8 actuates to clamp the free thread end produced by the first stitch. After the second and third stitches sew the thread onto the fabric, the thread-cutting blade A8 actuates to cut the thread end, achieving sewing start-up anti-slipping. The specific movement trajectory of the transmission mechanism A5 driving the thread-cutting blade A8 can be determined according to actual work needs. After the sewing machine finishes sewing, the drive source drives the motion control component to move within the working stroke range of blade B. At this time, the transmission mechanism B4 drives the thread-cutting blade B7 to perform the corresponding action, such as cutting the bottom thread. Depending on actual needs, the working stroke ranges of moving blade A and moving blade B can partially overlap or not overlap at all. Generally, they are separate. That is, when moving blade A8 performs the sewing machine's anti-slipping action, moving blade B7 generally does not move and stays at the initial position. When moving blade B7 performs the thread-cutting action after the sewing machine has finished sewing, moving blade A8 generally does not move and stays at the initial position.

[0044] See Figures 2 to 7 The present invention will be further described below with reference to several specific embodiments:

[0045] Example 1:

[0046] See Figures 2 to 7 The diagram below illustrates the structure of Embodiment 1. In this embodiment, as a preferred design, see [reference needed]. Figure 3 , Figure 5 and Figure 6 The motion control component includes a cam 3, which is driven to rotate by a drive source. The working surface of the cam 3 has a working area 31 for a moving blade A and a working area 32 for a moving blade B. The working area 31 for moving blade A includes a stroke area 311 for moving blade A, and the working area 32 for moving blade B includes a stroke area 321 for moving blade B. The transmission mechanism A5 includes a transmission block A501 and a connecting component A for connecting the transmission block A501 and the wire-cutting moving blade A8. The transmission mechanism B4 includes a transmission block B401 and a connecting component B for connecting the transmission block B401 and the wire-cutting moving blade B7. When the cam 3 rotates to the point where the moving blade A stroke area 311 contacts the transmission block A501, it pushes the transmission block A501 to move. The connecting component A transmits the movement of the transmission block A501 to the wire-cutting moving blade A8, thereby realizing the movement of the transmission mechanism A5 and driving the wire-cutting moving blade A8. When the cam 3 rotates to the stroke area 321 of the moving blade B and contacts the transmission block B401, it will push the transmission block B401. The connecting component B will transmit the motion of the transmission block B401 to the wire-cutting moving blade B7, thereby realizing the movement of the transmission mechanism B4 and driving the wire-cutting moving blade B7.

[0047] See Figure 3 , Figure 5 and Figure 6 In this embodiment, the connecting component A further includes a transmission block constraint transmission member A. The transmission block A501 is mounted on the transmission block constraint transmission member A. The transmission block constraint transmission member A can constrain the movement trajectory of the transmission block A501, keeping the transmission block A501 in contact with the working area 31 of the moving blade A, and transmitting the movement of the transmission block A501 to the connecting component A, causing the connecting component A to drive the wire-cutting moving blade A8. Since the working area 31 of the moving blade A pushes the transmission block A501 to move, especially when the stroke area 311 of the moving blade A pushes the transmission block A501 to move, the transmission block A501 will have a radial component movement and a tangential component movement. The position of the transmission block A501, especially the tangential position, can be constrained by the transmission block constraint transmission member A to stabilize the movement trajectory of the transmission block A501 and better control the transmission of movement. Similarly, the connecting component B also includes a transmission block constraining transmission component B. The transmission block B401 is installed on the transmission block constraining transmission component B. The transmission block constraining transmission component B can constrain the movement trajectory of the transmission block B401 so that the transmission block B401 keeps in contact with the working area 32 of the moving blade B, and transmit the movement of the transmission block B401 to the connecting component B, so that the connecting component B drives the wire cutting moving blade B7.

[0048] In this embodiment, the transmission block constrains the transmission member A to be an axially movable connecting shaft A502, and the transmission block constrains the transmission member B to be an axially movable connecting shaft B402. When the cam 3 rotates to the stroke area 311 of the moving blade A and contacts the transmission block A501, the movement of the transmission block B401 drives the connecting shaft B402 to move axially, and drives the thread-cutting moving blade B7 through the connecting assembly B. The thread-cutting moving blade B7 performs the sewing machine's anti-slipping action, which corresponds to the working stroke range of the moving blade A. When the cam 3 rotates to the stroke area 321 of the moving blade B and contacts the transmission block B401, the movement of the transmission block B401 drives the connecting shaft B402 to move axially, and drives the thread-cutting moving blade B7 through the connecting assembly B. That is, the movement of the transmission mechanism B4 drives the thread-cutting moving blade B7 to perform the thread-cutting action after the sewing machine has finished its sewing work. In other embodiments, the transmission block constraining the transmission member A can also adopt a suitable structure, or the motion trajectory of the transmission block A501 can also be constrained in other ways. Similarly, the transmission block constraining the transmission member A can also adopt a suitable structure, or the motion trajectory of the transmission block A501 can also be constrained in other ways.

[0049] In this embodiment, see Figure 3 , Figure 5 and Figure 6As a preferred design, the working area 31 of the moving tool A, along the counterclockwise rotation direction of the cam 3, sequentially includes the moving tool A idle travel area 312, the moving tool A stroke area 311, and the moving tool A waiting area 313. The arc lengths of the three areas can be set according to actual needs. When the moving tool A idle travel area 312 abuts against the transmission block A501, the connecting shaft A502 remains stationary. The working area 32 of the moving tool B, along the counterclockwise rotation direction of the cam 3, sequentially includes the moving tool B stroke area 321, the moving tool B idle travel area 322, and the moving tool A waiting area 313. The arc lengths of the three areas can be set according to actual needs, and when the moving tool B idle travel area 322 abuts against the transmission block B401, the connecting shaft B402 remains stationary. When not in operation, the cam 3 remains stationary in the waiting position. At this time, the moving tool A waiting area 313 is in contact with the transmission block A501, and the moving tool B waiting area 323 is in contact with the transmission block B401. During operation, when cam 3 rotates counterclockwise to the point where the moving blade A's stroke area 311 contacts the transmission block A501, the moving blade B's idle travel area 322 contacts the transmission block B401. This means that when the thread-cutting moving blade A8 performs the sewing start-up and anti-slippage action of the sewing machine, the thread-cutting moving blade B7 stops moving. When cam 3 rotates to the point where the moving blade B's stroke area 321 contacts the transmission block B401, the moving blade A's idle travel area 312 contacts the transmission block A501. This means that the thread-cutting moving blade B7 performs the thread-cutting action after the sewing work, while the thread-cutting moving blade A8 stops moving.

[0050] In this embodiment, see Figure 3 , Figure 5 and Figure 6 As a preferred design, the transmission block B401 is a roller and is rotatably mounted on the connecting shaft B402. This reduces rolling when the transmission block B401 moves on the working area 31 of the moving tool A, thus reducing friction. Similarly, the transmission block A501 is also a roller and is rotatably mounted on the connecting shaft A502 to reduce friction.

[0051] In this embodiment, see Figure 3 , Figure 5 and Figure 6 As a preferred design, it also includes a limiting disk 6, which has a limiting groove 61. The cam 3 is fixed in the limiting groove 61, and both are driven to rotate by a drive source. A limiting channel is formed between the working surface of the cam 3 and the side wall of the limiting groove 61. The transmission block B401 and the transmission block A501 are both located in the limiting channel, which can prevent the transmission block B401 and the transmission block A501 from disengaging from the cam 3. Furthermore, the limiting disk 6 has a limiting part A62 and a limiting part B63. When the cam 3 rotates counterclockwise to the end of the idle travel area 312 of the moving tool A and contacts the transmission block A501, the transmission block A501 abuts against the limiting part A62, and the transmission block B401 abuts against the limiting part B63, so that the transmission block B401 and the transmission block A501 will no longer move relative to the cam 3 and the limiting disk 6.

[0052] In this embodiment, see Figure 2 , Figure 3 and Figure 4 As a preferred design, transmission mechanism A5 further includes a guide seat A503, on which the connecting shaft A502 is mounted and axially movable relative to guide seat B403, thereby stabilizing the moving direction and radial position of the connecting shaft A502. Transmission mechanism B4 also includes a guide seat B403, on which the connecting shaft B402 is mounted and axially movable relative to guide seat B403, thereby stabilizing the moving direction and radial position of the connecting shaft B402.

[0053] In this embodiment, see Figure 2 , Figure 3 and Figure 4 As a preferred design, transmission mechanism B4 further includes an elastic structure B404. The elastic structure B404 directly or indirectly applies a spring force to transmission block B401, bringing transmission block B401 closer to the working surface of cam 3, thereby ensuring stable transmission between transmission block B401 and cam 3. Transmission mechanism A5 also includes an elastic structure A504. The elastic structure A504 directly or indirectly applies a spring force to transmission block A501, bringing transmission block A501 closer to the working surface of cam 3, thereby ensuring stable transmission between transmission block A501 and cam 3.

[0054] In other embodiments, the motion control element may also adopt other designs. The motion control element may be rotating, or it may be in a curve or other motion. The motion elements in transmission mechanisms B4 and A5 that establish a transmission connection with the motion control element may also adopt other suitable structures according to the structure of the motion control element and the motion form.

[0055] In this embodiment, see Figure 2 and Figure 3 As a preferred design, the drive source includes a motor 1, fixed to one side of a mounting plate 2, which is fixedly mounted on the sewing machine. A limiting disc 6 and a cam 3 are located on the other side of the mounting plate 2. A connecting sleeve 33 is fixedly mounted on the cam 3, and the output shaft of the motor 1 is located in and fixedly connected to the connecting sleeve 33. The motor 1 drives the cam 3 and the limiting disc 6 to rotate. Transmission mechanisms B4 and A5 are also mounted on the mounting plate 2, forming a module suitable for various types of sewing machines and occupying minimal space.

[0056] In this embodiment, see Figure 2 , Figure 3 and Figure 4As a preferred design, the connecting component B of the transmission mechanism B4 includes a rotating rod B405, a first swing arm B406, a second swing arm B407, and a moving knife connecting rod B408. The rotating rod B405 is rotatably mounted in the sewing machine via a rotating shaft B410. The first swing arm B406 is fixedly connected to the rotating rod B405 and is drively connected to the connecting shaft B402. Specifically, the first swing arm B406 is provided with a slot, and a connecting pin B409 is installed in the connecting shaft B402. The connecting pin B409 is located in the slot of the first swing arm B406. One end of the second swing arm B407 is fixedly connected to the rotating rod B405, and the other end is hinged to one end of the moving knife connecting rod B408. The other end of the moving knife connecting rod B408 is connected to the thread-cutting moving knife B7 via a screw. When the connecting shaft B402 moves axially, it drives the connecting pin B409. The connecting pin B409 can slide and rotate relative to the first swing arm B406 in the slot, causing the first swing arm B406 to rotate, which in turn causes the rotating rod B405 to rotate. The rotating rod B405 drives the second swing arm B407 to rotate. When the second swing arm B407 swings, it drives the wire-cutting blade B7 through the moving blade connecting rod B408. In this embodiment, the elastic structure B404 includes a tension spring, with its two ends connected to the guide seat B403 and the connecting pin B409, respectively, providing a spring force along the connecting shaft B402 and toward the cam 3. In other embodiments, the connecting assembly B can also adopt other suitable structures that can convert the axial movement of the connecting shaft B402 into the movement of the wire-cutting blade B7.

[0057] In this embodiment, see Figure 2 , Figure 3 and Figure 4As a preferred design, the connecting component A of the transmission mechanism A5 includes a rotating rod A505, a first swing arm A506, a second swing arm A507, and a moving blade connecting rod A508. One end of the first swing arm A506 is fixedly connected to the rotating rod A505. The rotating rod A505 is rotatably mounted in the sewing machine via a rotating shaft A510. One end of the second swing arm A507 is fixedly connected to the rotating rod A505, and the other end is hinged to one end of the moving blade connecting rod A508. The other end of the moving blade connecting rod A508 is connected to the thread-cutting moving blade A8 via a segment screw. The first swing arm A506 is connected to the connecting shaft A502 via a front connecting rod A509 and a connecting plate A511. Specifically, the connecting plate A511 is fixedly connected to the connecting shaft A502, and one end of the front connecting rod A509 is hinged to the connecting plate A511, and the other end is hinged to the first swing arm A506. Preferably, the length of the front connecting rod A509 is adjustable. When the connecting shaft A502 moves axially, it drives the connecting plate A511 to move linearly. The connecting plate A511 drives the front connecting rod A509, which in turn drives the first swing arm A506 to rotate, thereby driving the rotating rod A505 to rotate. The rotating rod A505 drives the second swing arm A507 to rotate. When the second swing arm A507 swings, it drives the wire-cutting blade A8 through the moving blade connecting rod A508. In this embodiment, the elastic structure A504 includes a tension spring, with its two ends connected to the guide seat A503 and the connecting plate A511, respectively, providing a spring force along the connecting shaft A502 and toward the cam 3. In other embodiments, the connecting assembly A can also adopt other suitable structures that can convert the axial movement of the connecting shaft A502 into the movement of the wire-cutting blade A8.

[0058] Example 2;

[0059] Figures 8 to 10 This is a schematic diagram of the structure of Embodiment 2. In both Embodiment 1 and Embodiment 2, the motion control component is a cam 3. Both transmission mechanisms B and A are transmission blocks in the form of rollers that work in conjunction with the cam 3. The difference lies in the result and motion mode of the part between the transmission block and the wire cutter.

[0060] In this embodiment, the transmission block in the connecting assembly A constrains the transmission component A to be a rotatably mounted swing plate A512. Specifically, the swing plate A512 can be a V-shaped plate, which is mounted in a suitable position in the sewing machine via a shaft pin and can rotate smoothly. The transmission block A501 is rotatably mounted on the swing plate A512. The transmission block A501 is constrained to move on a circular trajectory centered on the rotation center of the swing plate A512. When the cam rotates counterclockwise to make the stroke area 311 of the moving blade A contact with the transmission block A501 and push the transmission block A501, the trajectory of the transmission block A501 is stable. Furthermore, in this way, as the cam 3 rotates, the contact position between the stroke area 311 of the moving blade A and the transmission block A501 changes, and the direction of the pushing pressure on the transmission block A501 also changes. Since the swing plate A512 is rotatable, the change in the direction of the pushing pressure can still smoothly push the transmission block A501, and the self-locking jamming problem is not likely to occur. Similarly, in connecting assembly B, the transmission block constrains the transmission component B, which is a rotatably mounted swing plate B412. The swing plate B412 is a V-shaped plate, installed in a suitable position in the sewing machine via a shaft pin, and can rotate smoothly. The transmission block B401 is rotatably mounted on the swing plate B412. When the cam 3 rotates to the stroke area 321 of the moving blade B and contacts the transmission block B401, the transmission block B401 drives the swing plate B412 to rotate. Its working principle is the same as that in connecting assembly A, and will not be described in detail here.

[0061] In this embodiment, see Figure 8 and Figure 9 The connecting component B of the transmission mechanism B4 also includes a rotating rod B405, a first swing arm B406, a second swing arm B407, and a moving blade connecting rod B408. The rotating rod B405 is rotatably mounted in the sewing machine via a rotating shaft B410. One end of the first swing arm B406 is fixedly connected to the rotating rod B405, and the other end of the first swing arm B406 is drive-connected to the swing plate B412. Specifically, the first swing arm B406 is connected to the swing plate B412 via a front connecting rod B411, and both ends of the front connecting rod B411 are hinged to the first swing arm B406 and the swing plate B412, respectively. One end of the second swing arm B407 is fixedly connected to the rotating rod B405, and the other end is hinged to one end of the moving blade connecting rod B408. The other end of the moving blade connecting rod B408 is connected to the thread-cutting moving blade B7 via a segment screw. When the swing plate B412 rotates, it drives the first swing arm B406 to rotate via the front connecting rod B411, which in turn drives the rotating rod B405 to rotate. The rotating rod B405 drives the second swing arm B407 to rotate. When the second swing arm B407 swings, it drives the wire-cutting blade B7 via the moving blade connecting rod B408. In other embodiments, the connecting component B can also adopt other suitable structures that can convert the rotation of the swing plate B412 into the movement of the wire-cutting blade B7.

[0062] In this embodiment, see Figure 8 and Figure 9 As a preferred design, the connecting component A of the transmission mechanism A5 includes a rotating rod A505, a first swing arm A506, a second swing arm A507, and a moving blade connecting rod A508. The rotating rod A505 is rotatably mounted in the sewing machine via a rotating shaft A510. One end of the second swing arm A507 is fixedly connected to the rotating rod A505, and the other end is hinged to one end of the moving blade connecting rod A508. The other end of the moving blade connecting rod A508 is connected to the thread-cutting moving blade A8 via a screw. One end of the first swing arm A506 is fixedly connected to the rotating rod A505, and the other end of the first swing arm A506 is connected to the swing plate A512 via a front connecting rod A509. Specifically, one end of the front connecting rod A509 is hinged to the swing plate A512, and the other end is hinged to the first swing arm A506. Preferably, the length of the front connecting rod A509 is adjustable. When the swing plate A512 rotates, it drives the front connecting rod A509, which in turn drives the first swing arm A506 to rotate, which in turn drives the rotating rod A505 to rotate. The rotating rod A505 drives the second swing arm A507 to rotate, and when the second swing arm A507 swings, it drives the wire-cutting blade A8 through the moving blade connecting rod A508. In other embodiments, the connecting component A can also adopt other suitable structures that can convert the rotation of the swing plate A512 into the movement of the wire-cutting blade A8.

[0063] See Figure 3 In this embodiment, the cam 3 and the limiting disk 6 are basically the same as those in the first embodiment, and the working principle of the cam 3 in cooperation with the transmission block B401 and the transmission block A501 is also basically the same. The difference is that in this embodiment, the limiting part A62 and the limiting part B63 of the limiting disk 6 are connected to the cam 3. When the cam 3 rotates counterclockwise to the end of the idle travel area 312 of the moving tool A and contacts the transmission block A501, the transmission block A501 abuts against the limiting part A62, and the transmission block B401 abuts against the limiting part B63, so that the transmission blocks B401 and A501 will no longer move relative to the cam 3 and the limiting disk 6. When the cam 3 returns to the fixed area 313 of the moving tool A clockwise and contacts the transmission block A501, the transmission block B501 abuts against the limiting part B63, and the transmission block A401 abuts against the limiting part A62, thus successfully resetting. Furthermore, both sides of the limiting part A62 are arc-shaped, so that it can contact and fit well with the cylindrical transmission block B501 and transmission block A401. Similarly, both sides of the limiting part B63 are arc-shaped, so that it can contact and fit well with the cylindrical transmission block B501 and transmission block A401.

[0064] The other parts in this embodiment may be the same as or similar to the corresponding parts in the first embodiment above, and will not be described in detail here.

[0065] In this invention, the transmission mechanism A5 and the transmission mechanism B6 are not limited to the two specific forms mentioned above. In other embodiments, the transmission block constraining the transmission member A and the transmission block constraining the transmission member B can also adopt a suitable structure, or the motion trajectory of the transmission block A501 and the transmission block B401 can also be constrained in other ways.

[0066] The present invention also provides a thread-cutting device for a sewing machine, including a thread-cutting blade B7 and a thread-cutting blade A8, and the aforementioned double-blade drive device. The transmission mechanism A is connected to the thread-cutting blade A, and the transmission mechanism B is connected to the thread-cutting blade B. The thread-cutting blade A8 is used to perform the sewing start and anti-slipping action of the sewing machine, and the thread-cutting blade B7 is used to perform the thread-cutting action after the sewing work is completed.

[0067] See Figure 2 , Figure 4 and Figure 7 The working process of the wire cutting device driven by the double-blade drive mechanism of the present invention is as follows:

[0068] (a) Before working, in the initial stage, the motor 1 stops, and the transmission block A501 and transmission block B401 are respectively located at the corresponding positions of the waiting area 313 of the moving blade A and the waiting area 323 of the moving blade B on the cam 3. At this time, the wire cutting moving blade A8 and the wire cutting moving blade B7 are respectively located in various waiting areas.

[0069] (b) When motor 1 rotates and drives cam 3 to rotate counterclockwise, transmission block A501 of transmission mechanism A5 enters the stroke area 311 of moving blade A and moves relative to it along the stroke area 311. Connecting shaft A502 moves, driving the thread-cutting moving blade A8 through transmission mechanism A5 to complete the start-up and anti-slipping action. At this time, transmission block B401 of transmission mechanism B4 enters the idle travel area 322 of moving blade B. Transmission mechanism B4 is stationary, and thread-cutting moving blade B7 is stationary, which does not affect the start-up and anti-slipping action. After the start-up and anti-slipping action is completed, motor 1 stops operating and waits for one round of sewing work to be completed.

[0070] (c) After one round of sewing is completed, motor 1 rotates and continues to drive cam 3 to rotate counterclockwise. At this time, transmission block A501 of transmission mechanism A5 enters the idle travel area 312 of moving knife A. Transmission mechanism A5 is stationary, and the thread-cutting moving knife A8 will not rotate. Transmission block B401 of transmission mechanism B4 enters the travel area 321 of moving knife B. Transmission mechanism B4 moves and drives the thread-cutting moving knife B7 to move. When it reaches the end of the travel, motor 1 will reverse and drive cam 3 to rotate clockwise. At this time, the bottom thread cutting action is completed. At this time, cam 3 rotates to a position where transmission block A501 is near the idle travel area 322 of moving knife B. Motor 1 continues to reverse and drives cam 3 to rotate clockwise until transmission block B401 enters the waiting area of ​​moving knife B. Transmission block A501 enters the waiting area of ​​moving knife A. Thread-cutting moving knives B7 and A8 return to their respective waiting areas and complete the reset, realizing the driving action of one round of sewing start-up anti-slip and bottom thread cutting.

[0071] As can be seen from the above, the dual-blade drive device and the wire cutting device of the present invention have the following beneficial effects:

[0072] 1. The motion control component is driven by a single drive source, and the thread-cutting blades A8 and B7 are driven by transmission mechanisms A5 and B4 respectively, so that the two blades can move separately to perform the sewing machine's start-up anti-slip action and the thread-cutting action after sewing. This reduces the number of drive sources and simplifies the mechanism.

[0073] 2. The original electromagnet structure can be removed. By adopting the design structure of this invention, the number of special parts used can be greatly reduced, the cost can be reduced, and assembly and after-sales maintenance can be facilitated.

[0074] 3. Enhancement of core competitiveness: Currently, there is a high demand for anti-seam slippage machines in the pattern making machine market, but there are no large-scale machines with anti-seam slippage function on the market. Therefore, pattern making machines equipped with this thread cutting device can enhance their competitiveness.

[0075] 4. High versatility: This thread-cutting device can be easily modularized by mounting the components on the mounting plate 2, making it suitable for various sewing machines and increasing its versatility with other models.

[0076] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0077] 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 double-blade drive device for a sewing machine, characterized in that: It includes a transmission mechanism B (4), a transmission mechanism A (5), a motion control component, and a drive source. The drive source is connected to the motion control component and drives the motion control component to move. The transmission mechanism B (4) is connected to the motion control component and is used to connect the wire-cutting blade B (7). The transmission mechanism A (5) is connected to the motion control component and is used to connect the wire-cutting blade A (8). The running stroke of the motion control component includes the working stroke range of the blade B and the working stroke range of the blade A. When the motion control component moves within the working stroke range of the blade A, the transmission mechanism A (5) moves and drives the wire-cutting blade A (8). When the motion control component moves within the working stroke range of the blade B, the transmission mechanism B (4) moves and drives the wire-cutting blade B (7).

2. The dual-blade drive device according to claim 1, characterized in that: The motion control component includes a cam (3), and the drive source drives the cam (3) to rotate. The working surface of the cam (3) is provided with a working area (31) for moving blade A and a working area (32) for moving blade B. The working area (31) for moving blade A includes a stroke area (311) for moving blade A, and the working area (32) for moving blade B includes a stroke area (321) for moving blade B. The transmission mechanism A (5) includes a transmission block A (501) and a connecting component A for connecting the transmission block A (501) and the wire cutting moving blade A (8). The transmission mechanism B (4) includes a transmission block B (401) and a connecting component B for connecting the transmission block B (401) and the wire cutting moving blade B (7). When the cam (3) rotates to the point where the stroke area (311) for moving blade A contacts the transmission block A (501), the transmission mechanism A (5) moves. When the cam (3) rotates to the point where the stroke area (321) for moving blade B contacts the transmission block B (401), the transmission mechanism B (4) moves.

3. The dual-blade drive device according to claim 2, characterized in that: The working area (31) of the moving tool A includes the idle travel area (312) of the moving tool A located in the stroke area (311) along the clockwise rotation direction of the cam (3), and the connecting shaft A (502) remains stationary when the idle travel area (312) of the moving tool A abuts against the transmission block A (501); the working area (32) of the moving tool B includes the idle travel area (322) of the moving tool B located in the stroke area (321) along the counterclockwise rotation direction of the cam (3), and the moving tool When the idle travel area (322) of B abuts against the transmission block B (401), the connecting shaft B (402) remains stationary; when the cam (3) rotates to the point where the travel area (311) of the moving blade A contacts the transmission block A (501), the idle travel area (322) of the moving blade B contacts the transmission block B (401); when the cam (3) rotates to the point where the travel area (321) of the moving blade B contacts the transmission block B (401), the idle travel area (312) of the moving blade A contacts the transmission block A (501).

4. The dual-blade drive device according to claim 3, characterized in that: The working area (31) of the moving blade A also includes the moving blade A waiting area (313) located in the moving blade A stroke area (311) along the counterclockwise rotation direction of the cam (3), and the working area (32) of the moving blade B also includes the moving blade B waiting area (323) located in the moving blade B idle area (322) along the counterclockwise rotation direction of the cam (3). When the cam (3) rotates to the point where the moving blade A waiting area (313) contacts the transmission block A (501), the moving blade B waiting area (323) contacts the transmission block B (401).

5. The dual-blade drive device according to any one of claims 2 to 4, characterized in that: The connecting component A further includes a transmission block constraint transmission member A, wherein the transmission block A (501) is mounted on the transmission block constraint transmission member A, and the transmission block constraint transmission member A can constrain the movement trajectory of the transmission block A (501) so that the transmission block A (501) keeps in contact with the working area (31) of the moving tool A, and transmits the movement of the transmission block A (501) to the connecting component A; the connecting component B further includes a transmission block constraint transmission member B, wherein the transmission block B (401) is mounted on the transmission block constraint transmission member B, and the transmission block constraint transmission member B can constrain the movement trajectory of the transmission block B (401) so that the transmission block B (401) keeps in contact with the working area (32) of the moving tool B, and transmits the movement of the transmission block B (401) to the connecting component B.

6. The dual-blade drive device according to any one of claims 5, characterized in that: The transmission block constrains the transmission component A, which is an axially movable connecting shaft A (502). When the cam (3) rotates to the stroke area (311) of the moving tool A and contacts the transmission block A (501), the transmission block A (501) drives the connecting shaft A (502) to move axially. The transmission block constrains the transmission component B, which is an axially movable connecting shaft B (402). When the cam (3) rotates to the stroke area (321) of the moving tool B and contacts the transmission block B (401), the transmission block B (401) drives the connecting shaft B (402) to move axially.

7. The dual-blade drive device according to any one of claims 5, characterized in that: The transmission block constrains the transmission component A, which is a rotatably mounted swing plate A (512). When the cam (3) rotates to the stroke area (311) of the moving tool A and contacts the transmission block A (501), the transmission block A (501) drives the swing plate A (512) to rotate. The transmission block constrains the transmission component B, which is a rotatably mounted swing plate B (412). When the cam (3) rotates to the stroke area (321) of the moving tool B and contacts the transmission block B (401), the transmission block B (401) drives the swing plate B (412) to rotate.

8. The dual-blade drive device according to claim 2 or 5, characterized in that: The transmission mechanism B (4) further includes an elastic structure B, which directly or indirectly applies a spring force to the transmission block B (401) to make the transmission block B (401) approach the working surface of the cam (3); the transmission mechanism A (5) further includes an elastic structure A, which directly or indirectly applies a spring force to the transmission block A (501) to make the transmission block A (501) approach the working surface of the cam (3).

9. The dual-blade drive device according to claim 5, characterized in that: The transmission block B (401) is a roller and is rotatably mounted on the transmission block constraining transmission component B; the transmission block A (501) is a roller and is rotatably mounted on the transmission block constraining transmission component A.

10. The dual-blade drive device according to claim 3, characterized in that: It also includes a limiting plate (6), which has a limiting groove (61). The cam (3) is fixed in the limiting groove (61), and a limiting channel is formed between the working surface of the cam (3) and the side wall of the limiting groove (61). The transmission block B (5401) and the transmission block A (501) are both located in the limiting channel.

11. The dual-blade drive device according to claim 10, characterized in that: The limiting disk (6) is provided with limiting part A (62) and limiting part B (63). When the cam (3) rotates counterclockwise to the end of the idle travel area (312) of the moving blade A and contacts the transmission block A (501), the transmission block B (401) abuts against the limiting part B (63) and the transmission block A (501) abuts against the limiting part A (62).

12. The dual-blade drive device according to claim 6, characterized in that: The transmission mechanism A (5) further includes a guide seat A (503), the connecting shaft A (502) is mounted on the guide seat A (503) and can move axially relative to the guide seat B (403); the transmission mechanism B (4) further includes a guide seat B (403), the connecting shaft B (402) is mounted on the guide seat B (403) and can move axially relative to the guide seat B (403).

13. The dual-blade drive device according to claim 5, characterized in that: The connecting component B of the transmission mechanism B (4) includes a rotating rod B (405), a first swing arm B (406), a second swing arm B (407), and a moving blade connecting rod B (408). The first swing arm B (406) is fixedly connected to the rotating rod B (405) and is connected to the transmission block constraint transmission component B. The second swing arm B (407) is fixedly connected to the rotating rod B (405), and its other end is hinged to one end of the moving blade connecting rod B (408). The other end of the moving blade connecting rod B (408) is used to connect to the wire cutting moving blade B (7), or... The connecting component A of the transmission mechanism A (5) includes a rotating rod A (505), a first swing arm A (506), a second swing arm A (507), and a moving blade connecting rod A (508). The first swing arm A (506) is connected to the transmission block to constrain the transmission component A. The first swing arm A (506) is fixedly connected to the rotating rod A (505). One end of the second swing arm A (507) is fixedly connected to the rotating rod A (505), and the other end is hinged to one end of the moving blade connecting rod A (508). The other end of the moving blade connecting rod A (508) is used to connect to the wire cutting moving blade A (8).

14. A thread-cutting device for a sewing machine, comprising a thread-cutting blade B (7) and a thread-cutting blade A (8), characterized in that: It also includes a double-blade drive device as described in any one of claims 1 to 13, wherein the transmission mechanism A (5) is connected to the thread-cutting blade A (8), the transmission mechanism B (4) is connected to the thread-cutting blade B (7), the thread-cutting blade A (8) is used to perform the sewing start and anti-slip action of the sewing machine, and the thread-cutting blade B (7) is used to perform the thread-cutting action after the sewing machine has finished sewing.

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