A thread take-up structure for preventing thread breakage in a sewing machine, and a sewing machine

Abstract

The application provides a sewing machine thread starting and preventing thread dropping structure and a sewing machine. The sewing machine thread starting and preventing thread dropping structure is used for cooperating with a thread cutting mechanism of the sewing machine to prevent thread dropping when starting sewing. The thread cutting mechanism has a first thread cutting knife for hooking thread movement and cutting thread. The sewing machine thread starting and preventing thread dropping structure comprises a clamping assembly, a thread passing notch and a first clamping part provided on the first thread cutting knife. The thread passing notch is used for the needle to pass through when the first thread cutting knife moves to a thread starting initial position of the lower side of the needle of the sewing machine. The first clamping part is provided on the side of the thread passing notch. The clamping assembly is provided with a second clamping part. The second clamping part is located on the path of the thread passing notch and the first clamping part when the first thread cutting knife moves. When the first thread cutting knife moves from the thread starting initial position to the clamping assembly, the thread passing notch can drive the thread in the thread passing notch to the second clamping part, and the thread is clamped between the first clamping part and the second clamping part.

Description

Technical Field

[0001] This invention relates to the field of sewing equipment technology, and in particular to a sewing machine start-up anti-slip structure, and a sewing machine. Background Technology

[0002] Lockstitch, the most commonly used stitch type in pattern sewing machines, is widely used in the sewing of clothing, bags, leather goods, and other products due to its advantages of simple structure, strong stitching, and low thread consumption. The stitch formation principle is as follows: after the needle drives the top thread to pierce the fabric, the rotary hook hooks the top thread to form a loop. Then, the take-up lever mechanism tightens the loop and pulls the bottom thread into the back of the fabric, causing the top and bottom threads to intertwine and lock together, thus completing the stitch formation.

[0003] However, lockstitch has inherent structural limitations: after the first needle pierces the fabric, an effective loop cannot be formed directly during the rotary hooking process. It relies on the first needle to embed the top thread into the fabric, providing a foundation for the loop formation of the second needle. With the diversification of fabric materials in industrial production (such as lightweight synthetic fibers, high-elasticity fabrics, and multi-layered composite fabrics) and the increasing complexity of sewing conditions (high-speed sewing, variable thickness sewing), the stability of existing lockstitch formation faces severe challenges. The top thread embedded in the fabric is easily pulled out under the traction of the second needle take-up lever due to the loose fiber structure and insufficient frictional resistance on the back of the fabric. This results in the second needle failing to form a complete loop, ultimately causing a thread slippage problem. Such thread slippage significantly increases the rework rate, severely impacting production efficiency, especially in mass production scenarios, and has become a key bottleneck restricting the improvement of sewing processing quality and capacity.

[0004] To address the issue of thread slippage at the start of lockstitch stitches, various solutions have been proposed in existing technologies, but each has its own drawbacks:

[0005] Parameter adjustment solutions: These solutions enhance the thread retention by enabling backstitching, setting a slow starting stitch, or extending the initial stitch length. While easy to operate, these solutions have the following drawbacks: backstitching increases stitch density, potentially leading to dense needle holes and fiber breakage in the fabric; a slow starting stitch directly reduces sewing efficiency; and the adaptability of parameter adjustments is extremely poor, failing to simultaneously meet the sewing requirements of fabrics of different thicknesses and materials.

[0006] Mechanism Improvement Solutions: Some technologies optimize the presser foot mechanism by using an independent stepper motor to drive its lifting and lowering, allowing the presser foot to pre-press the fabric during the start-up stage and reducing top thread displacement. While this solution can improve start-up stability to some extent, the structural modification is complex, requiring additional drive motors and control systems, leading to increased equipment costs. Furthermore, it only addresses fabric loosening and cannot fundamentally improve the first stitch's resistance to pull-out, and it remains ineffective for high-smoothness fabrics.

[0007] Operational adjustment solutions: These involve manually optimizing the thread tension by adjusting the pressure of the high-pressure foot, cleaning impurities from the bobbin case, and adjusting the tension of the thread clamp. These methods rely on operator experience, have poor stability, and are prone to failure during high-speed sewing due to fabric displacement and thread tension fluctuations, making them unsuitable for automated production lines. Summary of the Invention

[0008] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a sewing machine start-up anti-slip structure and a sewing machine that can stably clamp the top thread by utilizing the action of the thread cutting mechanism during sewing start-up to prevent the sewing start-up problem from slipping.

[0009] To achieve the above objectives, the present invention provides a sewing machine start-up anti-slip structure for cooperating with the sewing machine's thread-cutting mechanism to prevent the top thread from slipping during the start-up process. The thread-cutting mechanism has a first thread-cutting blade for hooking the top thread and cutting it. The start-up anti-slip structure includes a clamping assembly, a thread-passing groove and a first clamping part disposed on the first thread-cutting blade. The thread-passing groove is used for the needle to pass through when the first thread-cutting blade moves to the initial start-up position below the sewing needle. The first clamping part is disposed on the side of the thread-passing groove. The clamping assembly has a second clamping part, which is located on the path of the thread-passing groove and the first clamping part as the first thread-cutting blade moves. When the first thread-cutting blade moves from the initial start-up position toward the clamping assembly, the thread-passing groove can drive the top thread located in the thread-passing groove to the second clamping part, and the top thread is clamped between the first clamping part and the second clamping part.

[0010] Furthermore, the first clamping part is disposed on the upper surface of the first wire cutter, and the first wire cutter is inserted below the second clamping part of the clamping assembly.

[0011] Furthermore, the first clamping part includes a clamping protrusion on the upper surface of the first wire cutter.

[0012] Furthermore, the direction of movement of the first thread cutter when it hooks the thread and cuts it is the thread cutting direction, and the direction of movement from the initial sewing position toward the clamping component is the anti-derailment direction. The anti-derailment direction is opposite to the thread cutting direction, and the first clamping part is located on the side of the thread groove where the thread cutting direction is located.

[0013] Furthermore, the direction of movement of the first thread cutter when it hooks the thread and cuts it is the thread cutting direction, and the direction of movement from the initial sewing position toward the clamping assembly is the anti-slipping direction. The thread passage includes a needle groove and a guide groove. The needle groove is for the sewing machine needle to pass through. The first end of the guide groove is connected to the needle groove, and the second end extends toward the thread cutting direction. The width of the guide groove gradually decreases from the first end to the second end. The first clamping part is located on the side of the second end of the guide groove in the thread cutting direction.

[0014] Furthermore, the first wire cutter has a first blade and a hook groove, and the first clamping part is located outside the movement path of the first blade and the hook groove when the first wire cutter moves along the wire cutting direction.

[0015] Furthermore, the direction of movement of the first wire cutter when it hooks the thread and cuts the thread is the direction of thread cutting. The first wire cutter has a first blade and a hook groove. The first clamping part is located outside the movement path of the first blade and the hook groove when the first wire cutter moves along the direction of thread cutting.

[0016] Furthermore, the clamping assembly is provided with a V-shaped groove, and the second clamping part is located at the bottom of the V-shaped groove. When the first thread cutter moves from the initial sewing position toward the clamping assembly, the movement path of the thread through the groove is within the range of the V-shaped groove, so that the surface thread in the thread through the groove enters the V-shaped groove and can move along the two sides of the V-shaped groove to the bottom of the groove.

[0017] Furthermore, the clamping assembly includes a pressure plate and a wire plate. The pressure plate has a first guide bevel, and the wire plate has a second guide bevel. The wire plate presses against the upper side of the pressure plate, and the first guide bevel and the second guide bevel intersect to form a V-shaped groove. The second clamping part is located on the lower side of the pressure plate.

[0018] Furthermore, the pressure plate includes an arc-shaped portion, which is arranged along the outer periphery of the sewing machine's shuttle, with the inner arc surface of the pressure plate facing the shuttle. The second clamping portion is located on the inner arc surface of the pressure plate, and the first thread cutter is inserted between the inner arc surface of the pressure plate and the shuttle when it moves from the initial sewing position toward the clamping assembly.

[0019] Furthermore, the clamping assembly also includes an adjusting part for adjusting the gap between the second clamping part and the first wire cutter.

[0020] The present invention also provides a sewing machine, including a thread cutting mechanism, the thread cutting mechanism including a first thread cutter for hooking the top thread and cutting the thread, and also including the above-mentioned anti-slipping structure for starting the sewing.

[0021] As described above, the anti-slipping structure for the seam opening and the sewing machine of the present invention have the following beneficial effects:

[0022] 1. By utilizing the action of the first thread cutter of the thread-cutting mechanism, the top thread can be stably clamped during the start-up of the sewing, so that the top thread will not be pulled out of the back of the fabric due to the thread-taking force, thus avoiding the problem of thread detachment. The start-up anti-detachment structure can be improved based on the existing first thread cutter 1, with minimal changes to the structure and operation of the sewing machine, simple structure, and low cost.

[0023] 2. The clamping components can be flexibly adjusted according to actual needs. The gap between the clamping components and the first wire cutter can be adjusted, thereby adjusting the gap between the first clamping part and the second clamping part in the clamping working state to meet the needs of different sizes of face wires. The relative positional relationship between the clamping components and the first clamping part can also be adjusted to better stabilize the face wires.

[0024] 3. The movement of the first wire cutter can be controlled by a motor to clamp and release the opposite wire. The whole process can be completed automatically without manual operation, eliminating tedious operation and debugging. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the anti-loosening stitch structure of the present invention.

[0026] Figure 2 for Figure 1 Top view.

[0027] Figure 3 for Figure 1 The left-side view.

[0028] Figure 4 This is a schematic diagram of the structure of the first wire cutter, its wire-passing groove, and the first clamping part in this invention.

[0029] Figure 5 This is a schematic diagram of the pressure plate in this invention.

[0030] Figure 6 This is a schematic diagram of the conductor plate in this invention.

[0031] Figure 7 for Figure 6 The left-side view.

[0032] Explanation of icon numbers:

[0033] 1-First wire cutter, 11-First blade, 12-Hook groove, 2-Second wire cutter, 21-Second blade, 3-Clamping assembly, 301-Second clamping part, 302-V-shaped groove, 31-Pressure plate, 311-First guide bevel, 312-Pressure plate arc part, 313-Pressure plate mounting part, 314-First waist-shaped groove, 32-Wire guide plate, 321-Second guide bevel, 322-Wire guide plate arc part, 323-Bending connection part, 324-Wire guide plate mounting part, 325-Second waist-shaped groove, 33-Adjusting plate, 34-Adjusting bolt, 35-Fixed mounting block, 36-Fastening bolt, 4-Wire passage groove, 41-Needle threading groove, 42-Guide groove, 5-First clamping part, 6-Needle, 7-Rotary hook, 8-Moving knife drive component. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] See Figures 1 to 7 This invention provides a sewing machine start-up anti-slip structure, which is used to cooperate with the sewing machine's thread cutting mechanism to prevent the top thread from slipping during the start-up process. The thread cutting mechanism is an existing mechanism of the sewing machine, including a first thread cutter 1 for hooking the top thread and cutting it, and a second thread cutter 2 that cooperates with the first thread cutter 1. The first thread cutter 1 is a movable blade that moves toward the second thread cutter 2 when thread cutting is required. It hooks the top thread and bottom thread with its hook groove 12 and brings them close to the second thread cutter 2. Then, the engagement of the first blade 11 on the first thread cutter 1 and the first blade 21 on the second thread cutter 2 cuts the top thread and bottom thread.

[0039] The anti-loosening sewing structure of the present invention includes a clamping assembly 3, a thread passage slot 4 and a first clamping part 5 disposed on the first thread cutter 1. The thread passage slot 4 is used for the needle 6 to pass through when the first thread cutter 1 moves to the initial sewing position below the needle 6 of the sewing machine. The first clamping part 5 is disposed around the thread passage slot 4. The clamping assembly 3 is provided with a second clamping part 301, and the second clamping part 301 is located on the path of the thread passage slot 4 and the first clamping part 5 as the first thread cutter 1 moves. That is, when the first thread cutter 1 moves, the thread passage slot 4 and the first clamping part 5 pass through the second clamping part 301. When the first thread cutter 1 moves from the initial sewing position toward the clamping assembly 3, the thread passage slot 4 can drive the top thread located in the thread passage slot 4 to the second clamping part 301, and the first clamping part 5 is close to the second clamping part 301, so that the top thread is clamped between the first clamping part 5 and the second clamping part 301.

[0040] The basic working principle of the anti-slipping structure for starting a stitch, as involved in this invention, is as follows: Before the sewing machine starts sewing, the thread cutting mechanism is controlled to move so that the first thread cutter 1 is located at the initial starting position below the needle 6, at which time the thread guide 4 is located directly below the needle 6; then the first stitch is started, the needle 6 carries the top thread through the thread guide 4 and through the fabric, and is then hooked by the rotary hook 7. After the rotary hook 7 completes hooking the thread, the end of the top thread on the back of the fabric is just inside the thread guide 4; then the needle 6 rises above the first thread cutter 1, preferably to the upper stop position of the needle 6, the first thread cutter 1 moves from the initial starting position toward the clamping assembly 3 to the thread clamping working position and stops. During this process, the thread guide 4 will drive the top thread therein to approach the clamping assembly 3 and reach the second clamping part 301, and the first clamping part 5 approaches the second clamping part 301, clamping the top thread between the two. At this time, the top thread in the fabric will be pulled up a short distance but will not come off the fabric. After the top thread is stably clamped between the first clamping part 5 and the second clamping part 301, the second and subsequent stitches are performed. At this time, the top thread will not be pulled out of the back of the fabric due to the thread take-up force, avoiding the inability to form a complete loop during the second stitch, thus preventing the problem of thread detachment and improving production efficiency. After the start-up is completed, the first thread cutter 1 moves away from the clamping assembly 3 and can return to the position where the first thread cutter 1 is when the sewing machine is sewing normally. The first clamping part 5 separates from the second clamping part 301, releasing the clamping of the top thread, so that the sewing work can be carried out smoothly. The thread detachment prevention structure of the present invention can be used for the start-up of lockstitch in pattern sewing machines, and can also be used for the start-up of other types of sewing machines. Among them, when the first thread cutter 1 is in the thread clamping position, the first thread cutter 1 should be lowered to avoid the needle 6, or the first thread cutter 1 is provided with a clearance slot for the needle 6 to pass through, so that the needle 6 can move up and down smoothly to perform the subsequent stitches of the start-up.

[0041] The anti-loosening sewing structure of the present invention utilizes the action of the first thread cutter 1 of the thread cutting mechanism to achieve stable clamping of the top thread during sewing, so that the top thread will not be pulled out of the back of the fabric due to the thread-pulling force, thus avoiding the problem of loosening the thread. The anti-loosening sewing structure can be improved on the existing first thread cutter 1 with minimal changes to the structure and operation of the sewing machine, reducing costs.

[0042] See Figures 1 to 7 The present invention will be further described below with reference to a specific embodiment:

[0043] In this embodiment, see Figure 1 , Figure 2 and Figure 3 As a preferred design, the first clamping part 5 is disposed on the upper surface of the first thread cutter 1, with the lower side of the first thread cutter 1 facing the rotary hook 7 of the sewing machine. The first thread cutter 1 is inserted below the second clamping part 301 of the clamping assembly 3, that is, inserted between the clamping assembly 3 and the rotary hook 7, so that the first clamping part 5 on the upper surface of the first thread cutter 1 is close to the second clamping part 301, thereby better clamping the thread. Preferably, the first clamping part 5 is a clamping protrusion protruding from the upper surface of the first thread cutter 1. The height of the protrusion can be determined according to the actual assembly gap. The clamping protrusion allows for a larger gap between the body of the first thread cutter 1 and the clamping assembly 3, avoiding interference during movement. The clamping protrusion allows for better contact and clamping of the thread with the second clamping part 301 of the clamping assembly 3.

[0044] In this embodiment, see Figure 1 , Figure 2 and Figure 3 As a preferred design, the direction of movement of the first thread cutter 1 when it hooks the thread and cuts it is denoted as the thread cutting direction. The direction of movement of the first thread cutter 1 from the initial position of the sewing towards the clamping component 3 is the anti-slipping direction, and the anti-slipping direction is opposite to the thread cutting direction. The first clamping part 5 is located on the side of the thread passage 4 where the thread cutting direction is located. Specifically, in this embodiment, the first thread cutter 1 preferably rotates. When viewed from the horizontal plane, the first thread cutter 1 moves along the front-back direction when it rotates. When the first thread cutter 1 rotates backward, it engages with the second thread cutter 2 to cut the thread, and when it rotates forward, it approaches the clamping component 3. That is, the thread cutting direction is backward and the anti-slipping direction is forward. At this time, the first clamping part 5 is located on the rear side of the thread passage 4. In this way, when the first thread cutter 1 moves from the initial position of the sewing towards the clamping assembly 3, the thread groove 4 will first pass through the second clamping part 301, and the top thread will contact the second clamping part 301 and fall towards the side where the second clamping part 301 (clamping protrusion) is located, and stick to the clamping protrusion, thereby effectively and stably clamping the top thread.

[0045] In this embodiment, see Figure 1 , Figure 2 and Figure 4 As a preferred design, the thread guide 4 includes a needle groove 41 and a guide groove 42. The needle groove 41 is a circular through hole with a radius larger than that of the sewing machine needle 6, through which the sewing machine needle 6 passes. The first end of the guide groove 42 is connected to the needle groove 41, and the second end extends in the direction of thread cutting. The width of the guide groove 42 gradually decreases from the first end to the second end, forming an overall V-shape. The first clamping part 5 is located on the side where the second end of the guide groove 42 is located. Specifically, in this embodiment, the first end of the guide groove 42 is the front end, and the second end is the rear end. The front end of the guide groove 42 is connected to the needle threading groove 41, and the width (the dimension along the left and right direction) gradually decreases from front to back. The first clamping part 5 is located on the rear side of the rear end of the guide groove 42. In this way, when the first thread cutter 1 moves from the initial sewing position toward the clamping assembly 3, the first end of the guide groove 42 reaches the clamping assembly 3 first, and then the second end reaches the clamping assembly 3. The thread in the thread passage 4 will move from the front end to the rear end in the guide groove 42 and be stably constrained at the rear end to avoid its position fluctuation in the left and right direction. This allows the thread to be better aligned with the first clamping part 5, ensuring that the thread is stably clamped by the first clamping part 5 and the second clamping part 301.

[0046] In this embodiment, see Figure 1 , Figure 2 and Figure 4 More preferably, the first clamping part 5 is located outside the movement path of the first blade 11 and the hook groove 12 when the first wire cutter 1 moves along the wire cutting direction. Specifically, the first clamping part 5 is located to the right of the first blade 11 and the hook groove 12, and is a certain distance from the first blade 11 and the hook groove 12 in the left-right direction. At this time, the guide groove part 42 gradually tilts to the right from front to back, so that the second end of the guide groove part 42 is also located to the right of the first blade 11 and the hook groove 12. With this design, the first clamping part 5 will not affect the normal operation of the first blade 11 and the hook groove 12 when the first wire cutter 1 is cutting wire, and the modification to the existing first wire cutter 1 is small.

[0047] In this embodiment, see Figure 1 , Figure 2 and Figure 3The clamping assembly 3 has a V-shaped groove 302 on the side facing the first clamping part 5. The second clamping part 301 is located at the bottom of the V-shaped groove 302. When the first thread cutter 1 moves from the initial sewing position toward the clamping assembly 3, the movement path of the thread passage 4 is within the range of the V-shaped groove 302, so that the top thread in the thread passage 4 enters the V-shaped groove 302 and can move along both sides of the V-shaped groove 302 to the bottom. Specifically, in this embodiment, the V-shaped groove 302 is located on the rear side of the clamping assembly 3, and from... The width gradually narrows from back to front. The bottom position of the V-shaped groove 302 is kept in front-to-back position with the first clamping part 5 (clamping protrusion). In this way, when the first thread cutter 1 moves from the initial position of the sewing to the clamping assembly 3, the surface thread passing through the thread groove 4 will enter the range of the V-shaped groove 302. Under the guidance of the inclined sides on both sides of the V-shaped groove 302, it will smoothly enter the bottom of the V-shaped groove 302, thereby accurately facing the first clamping part 5 (clamping protrusion) and then sticking to the first clamping part 5 (clamping protrusion) to achieve stable clamping.

[0048] In this embodiment, see Figure 1 , Figure 5 and Figure 6 As a preferred design, the clamping assembly 3 includes a pressure plate 31 and a guide plate 32, as well as a fixing block 35 for fixing the pressure plate 31 and the guide plate 32. The fixing block 35 is fixed in the sewing machine, and the pressure plate 31 and the guide plate 32 can be fixed to the fixing block 35 by fastening bolts 36. The pressure plate 31 is provided with a first guide bevel 311, and the guide plate 32 is provided with a second guide bevel 321. The guide plate 32 presses against the upper side of the pressure plate 31, and the first guide bevel 311 and the second guide bevel 321 intersect to form a V-shaped groove 302. That is, the first guide bevel 311 and the second guide bevel 321 constitute the bevels on both sides of the V-shaped groove 302. The second clamping part 301 is located on the lower side of the pressure plate 31. When the first thread cutter 1 moves from the initial sewing position toward the clamping assembly 3, it is inserted into the lower side of the pressure plate 31. The clamping assembly 3, consisting of a pressure plate 31 and a wire guide plate 32, and a V-shaped groove 302, allows adjustment of the size and bottom position of the V-shaped groove 302 by changing the positional relationship between the pressure plate 31 and the wire guide plate 32. This adjustment, in turn, adjusts the relative position with the first clamping part 5 on the first wire cutter 1, better aligning with the clamping surface and making the use more flexible and convenient. In other embodiments, the pressure plate 31 and the wire guide plate 32 can also be an integral structure, i.e., a single plate. In this case, the shape of the V-shaped groove 302 is fixed, and its size can be set appropriately according to actual needs. The clamping assembly 3 can also adopt other suitable shapes and structures.

[0049] In this embodiment, see Figure 1 , Figure 3 and Figure 5As a preferred design, the pressure plate 31 includes a pressure plate arc-shaped portion 312 and a pressure plate mounting portion 313. The pressure plate arc-shaped portion 312 is arranged along the outer periphery of the rotary hook 7 of the sewing machine, and the inner arc surface of the pressure plate arc-shaped portion 312 faces the rotary hook 7. There is an appropriate gap between them, allowing the first thread cutter 1 to be inserted between the pressure plate arc-shaped portion 312 and the rotary hook 7. The rear side of the pressure plate arc-shaped portion 312 faces the first thread cutter 1 and forms a first guide bevel 311. The second clamping portion 301 is located on the inner arc surface of the pressure plate arc-shaped portion 312 and is close to the first guide bevel 311. During the sewing process, the first thread cutter 1 moves from the initial sewing position toward the clamping assembly 3 and inserts between the inner arc surface of the pressure plate arc portion 312 and the rotary hook 7. The first clamping portion 5 (clamping protrusion) on the upper surface of the first thread cutter 1 is close to the second clamping portion 301 on the inner arc surface of the pressure plate arc portion 312, and the gap between them is less than the diameter of the thread, thus clamping the thread. The pressure plate 31 is fixed to the fixed mounting block 35 by the pressure plate mounting portion 313, and preferably, the pressure plate mounting portion 313 is provided with a first waist-shaped groove 314. The length extension direction of the first waist-shaped groove 314 is along the direction of action, that is, perpendicular to the movement direction of the first thread cutter 1. The fastening bolt 36 passes through the first waist-shaped groove 314 and is connected to the fixed mounting block 35 to fix the pressure plate mounting part 313. The position of the pressure plate 31 in the left and right directions can be adjusted through the first waist-shaped groove 314, thereby adjusting the corresponding contact position between the first guide inclined edge 311 and the first clamping part 5 (clamping protrusion). In other words, the position of the second clamping part 301 can be finely adjusted, which facilitates installation and is flexible and convenient to use.

[0050] In this embodiment, see Figure 1 , Figure 3 and Figure 6 As a preferred design, the conductor plate 32 includes an arc-shaped portion 322 and a mounting portion 324. The arc-shaped portion 322 is arranged along the outer arc surface of the pressure plate arc-shaped portion 312 and presses against the outer arc surface. The rear side of the arc-shaped portion 322 faces the first wire cutter 1 and forms a second guide bevel 321. The conductor plate 32 is fixed to the fixing block 35 by the mounting portion 324. Preferably, the mounting portion 324 is provided with a second waist-shaped groove 325. The fastening bolt 36 passes through the second waist-shaped groove 325 and is connected to the fixing block 35 to fix the pressure plate mounting portion 313. The position of the conductor plate 32 can be adjusted by the second waist-shaped groove 325 to facilitate its cooperation with the pressure plate 31 and the first clamping portion 5, making it flexible and convenient to use.

[0051] In this embodiment, see Figure 1 , Figure 3 , Figure 6 and Figure 7As a preferred design, the clamping assembly 3 also includes an adjusting part for adjusting the gap between the second clamping part 301 and the first wire cutter 1, so as to adjust according to the size of the thread and the specific working conditions, ensuring that the thread can be clamped while avoiding cutting the thread. Specifically, the adjusting part includes an adjusting plate 33 fixed to the pressure plate mounting part 313 and an adjusting bolt 34 screwed to the adjusting plate 33. The adjusting bolt 34 is located above the guide plate 32 and is pressed on the guide plate 32. By pressing down, the upper and lower positions of the arc-shaped part 322 of the guide plate and the arc-shaped part 312 of the pressure plate are changed, and the gap between the arc-shaped part 312 of the pressure plate and the rotary hook 7 is adjusted, thereby realizing the adjustment of the gap between the second clamping part 301 and the first wire cutter 1. Preferably, the conductor plate 32 further includes a bent connecting portion 323 connecting the arc-shaped portion 322 of the conductor plate and the conductor plate mounting portion 324. The bent connecting portion 323 is V-shaped. The adjusting bolt 34 presses against the bent connecting portion 323, which can change its deformation state, thereby adjusting the position of the arc-shaped portion 322 of the conductor plate. In other embodiments, the adjusting portion can also adopt other suitable structures, as long as they can achieve the gap adjustment between the second clamping portion 301 and the first wire cutter 1.

[0052] The present invention also provides a sewing machine, including a thread-cutting mechanism. The thread-cutting mechanism includes a first thread-cutting blade 1 for hooking the top thread and cutting it, and a second thread-cutting blade 2 that cooperates with the first thread-cutting blade 1. It also includes the aforementioned anti-slipping structure for starting the sewing. The first thread-cutting blade 1 is a movable blade, preferably a thin plate with an arc shape, arranged around the periphery of the rotary hook 7 and coaxial with the rotation. The first thread-cutting blade 1 rotates around the periphery of the rotary hook 7. When thread cutting is required after normal sewing, the first thread-cutting blade 1 moves toward the second thread-cutting blade 2, hooks the top thread and bottom thread through the hook groove 12 on it, and then the first thread-cutting blade 1 and the second thread-cutting blade 2 engage to cut the top thread and bottom thread. After the first stitch during the start of the sewing, the first thread cutter 1 moves toward the clamping assembly 3 of the start-up anti-loosening structure to the thread clamping working position and stops. The thread groove 4 on the first thread cutter 1 drives the top thread to the second clamping part 301, and the first clamping part 5 approaches the second clamping part 301 to clamp the top thread between the two.

[0053] In this embodiment, see Figure 1 and Figure 2The first thread cutter 1 of the thread cutting mechanism is mounted on the moving blade drive 8, which is driven by a thread cutting drive motor. The thread cutting drive motor is controlled by the sewing machine's electronic control system. By setting the motion sequence of the thread cutting drive motor, it coordinates with the movement of the needle 6 to complete the starting stitch. Specifically, when the main shaft rotates, it drives the needle 6 to complete the first stitch, and the first stitch rises to a designated position, preferably the highest position. At this time, the rotation angle of the main shaft reaches the corresponding angle. Based on the feedback of the rotation angle information of the main shaft, the electronic control system automatically controls the movement of the thread cutting drive motor. Through the moving blade drive 8, the first thread cutter 1 is driven from the initial starting position toward the clamping component 3 and reaches the thread clamping working position, where it remains stationary. After completing several stitches of starting stitch, that is, after the main shaft rotates a specific angle, the electronic control system automatically controls the movement of the thread cutting drive motor based on the rotation angle information of the main shaft. Through the moving blade drive 8, the first thread cutter 1 is driven away from the clamping component 3 and returns to the normal working position, releasing the clamping of the opposite thread. The entire starting stitch operation is completed, and the sewing machine can perform normal sewing operations.

[0054] As can be seen from the above, the anti-slipping structure for starting the seam and the sewing machine of the present invention have the following beneficial effects:

[0055] 1. By utilizing the action of the first thread cutter 1 of the thread cutting mechanism, the top thread can be stably clamped during the start-up of the sewing, so that the top thread will not be pulled out of the back of the fabric due to the thread-taking force, thus avoiding the problem of thread detachment. The anti-detachment structure for the start-up of the sewing can be improved based on the existing first thread cutter 1, with minimal changes to the structure and operation of the sewing machine, simple structure, and low cost.

[0056] 2. The clamping component 3 can be flexibly adjusted according to actual needs. The gap between the clamping component 3 and the first wire cutter 1 can be adjusted, thereby adjusting the gap between the first clamping part 5 and the second clamping part 301 in the clamping working state to meet the needs of different sizes of face wires. The relative positional relationship between the clamping component 3 and the first clamping part 5 can also be adjusted to better stabilize the clamping of the face wire.

[0057] 3. The movement of the first wire cutter 1 can be controlled by a motor to clamp and release the opposite wire. The entire process can be completed automatically without manual operation, eliminating tedious operation and debugging. In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0058] 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 sewing machine's anti-slipping structure for starting a sewing process, used in conjunction with the sewing machine's thread-cutting mechanism to prevent the top thread from slipping during sewing, wherein the thread-cutting mechanism has a first thread-cutting blade (1) for hooking the top thread and cutting it, characterized in that: The anti-slipping structure for starting the sewing includes a clamping assembly (3), a thread passage slot (4) and a first clamping part (5) provided on the first thread cutter (1). The thread passage slot (4) is used for the needle (6) to pass through when the first thread cutter (1) moves to the initial position of starting the sewing under the needle (6) of the sewing machine. The first clamping part (5) is provided on the side of the thread passage slot (4). The clamping assembly (3) is provided with a second clamping part (301), and the second clamping part (301) is located on the path of the thread passage slot (4) and the first clamping part (5) when the first thread cutter (1) moves with the first thread cutter (1). When the first thread cutter (1) moves from the initial position of starting the sewing toward the clamping assembly (3), the thread passage slot (4) can drive the top thread located in the thread passage slot (4) to the second clamping part (301), and the top thread is clamped between the first clamping part (5) and the second clamping part (301).

2. The anti-loosening structure for seams according to claim 1, characterized in that: The first clamping part (5) is disposed on the upper surface of the first wire cutter (1), and the first wire cutter (1) is inserted below the second clamping part (301) of the clamping assembly (3).

3. The anti-loosening structure for seams according to claim 1 or 2, characterized in that: The first clamping part (5) includes a clamping protrusion on the upper surface of the first wire cutter (1).

4. The anti-loosening structure for seams according to claim 1 or 2, characterized in that: The first thread cutter (1) moves in the direction of thread cutting when it hooks the thread and cuts the thread. The direction of movement from the initial position of the sewing to the clamping component (3) is the anti-derailment movement direction. The anti-derailment movement direction is opposite to the thread cutting movement direction. The first clamping part (5) is located on the side of the thread cutting movement direction of the thread passage slot (4).

5. The anti-loosening structure for seams according to claim 4, characterized in that: The direction of movement of the first thread cutter (1) when it hooks the thread and cuts the thread is the thread cutting direction. The direction of movement from the initial sewing position toward the clamping component (3) is the anti-slipping direction. The thread passage (4) includes a needle groove (41) and a guide groove (42). The needle groove (41) is used for the sewing machine needle (6) to pass through. The first end of the guide groove (42) is connected to the needle groove (41), and the second end extends toward the thread cutting direction. The width of the guide groove (42) gradually decreases from the first end to the second end. The first clamping part (5) is located on the side of the second end of the guide groove (42) in the thread cutting direction.

6. The anti-loosening structure for seams according to claim 1, characterized in that: The first wire cutter (1) moves in the direction of cutting the thread when it hooks the thread and engages to cut the thread. The first wire cutter (1) has a first blade (11) and a hook groove (12). The first clamping part (5) is located outside the movement path of the first blade (11) and the hook groove (12) when the first wire cutter (1) moves along the cutting direction.

7. The anti-loosening structure for seams according to claim 1, characterized in that: The clamping assembly (3) is provided with a V-shaped groove (302). The second clamping part (301) is located at the bottom of the V-shaped groove (302). When the first thread cutter (1) moves from the initial position of the sewing to the clamping assembly (3), the movement path of the thread passage (4) is within the range of the V-shaped groove (302), so that the top thread in the thread passage (4) enters the V-shaped groove (302) and can move along the two sides of the V-shaped groove (302) to the bottom of the groove.

8. The anti-loosening structure for seams according to claim 1, characterized in that: The clamping assembly (3) includes a pressure plate (31) and a wire plate (32). The pressure plate (31) is provided with a first guide bevel (311), and the wire plate (32) is provided with a second guide bevel (321). The wire plate (32) presses against the upper side of the pressure plate (31), and the first guide bevel (311) and the second guide bevel (321) intersect to form a V-shaped groove (302). The second clamping part (301) is located on the lower side of the pressure plate (31).

9. The anti-loosening structure for seams according to claim 8, characterized in that: The pressure plate (31) includes a pressure plate arc-shaped part (312), which is arranged along the outer periphery of the sewing machine's rotary hook (7), and the inner arc surface of the pressure plate arc-shaped part (312) faces the rotary hook (7). The second clamping part (301) is located on the inner arc surface of the pressure plate arc-shaped part (312). When the first thread cutter (1) moves from the initial sewing position toward the clamping assembly (3), it is inserted between the inner arc surface of the pressure plate arc-shaped part (312) and the rotary hook (7).

10. The anti-loosening structure for seams according to claim 1 or 8, characterized in that: The clamping assembly (3) also includes an adjustment part for adjusting the gap between the second clamping part (301) and the first wire cutter (1).

11. A sewing machine comprising a thread-cutting mechanism, said thread-cutting mechanism including a first thread-cutting blade (1) for hooking the thread and cutting it, characterized in that: It also includes the seam-starting anti-loosening structure as described in any one of claims 1 to 9.

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