Platform type feeding industrial sewing machine and thread trimming method

Abstract

The invention belongs to the technical field of sewing machines, and particularly relates to a platform type feeding industrial sewing machine and a thread trimming method, the platform type feeding industrial sewing machine comprises a rack, a thread sweeping mechanism, a presser foot lifting mechanism and a thread trimming mechanism, and the thread trimming mechanism comprises a fixed cutter assembly, a movable cutter assembly and a thread clamping assembly; the fixed cutter assembly comprises a first driving motor, a first transmission assembly and a fixed cutter; the movable cutter assembly comprises a second driving motor, a second transmission assembly and a movable cutter; the thread clamping assembly is used for clamping thread ends on the surface of the movable cutter; one side of the movable cutter is hinged to the second transmission assembly, and the other side of the movable cutter is provided with a lead part; the head part of the lead part is a convex tip part, the tail part of the lead part is a thread hooking part, and a guide curved surface is arranged between the two parts; the lead part is provided with a movable blade part and a movable blade threading hole; the movable blade part is matched with the fixed blade and cuts off a sewing thread; in the rotating process of the movable cutter, the movable cutter threading hole passes through the position under the machine needle, in the sewing starting stage, the machine needle penetrates through the movable cutter threading hole and drives a sewing thread to move towards the thread clamping piece, and the thread clamping piece tightly presses a thread end penetrating through the movable cutter threading hole.

Description

Technical Field

[0001] This application relates to the field of sewing machine technology, and in particular to an industrial sewing machine with platform feeding and a thread cutting method. Background Technology

[0002] Platform-feed industrial sewing machines refer to sewing equipment where the work panel and the sewing machine table are on the same plane. They often include various types of sewing machinery such as pattern sewing machines, bartacking machines, and button sewing machines. They are suitable for flat sewing operations in fields such as clothing and bags, providing high-efficiency, high-quality, and standardized production.

[0003] CN202422597332.4 discloses a bartacking machine, which includes a thread sweeping mechanism, a presser foot lifting mechanism, and a thread cutting mechanism. The core of the thread cutting mechanism is the shearing pair of a moving blade and a fixed blade. A thread cutting motor, in conjunction with a cam or electromagnet, drives a linkage transmission, which in turn drives the moving blade and the fixed blade to automatically cut the top and bottom threads after sewing. For some high-end fabrics, the thread ends left on the fabric during sewing must be short and free of bird's nest-like defects. Therefore, the industry is constantly researching and improving the thread cutting mechanism for bartacking machines, seeking to obtain a more stable thread cutting mechanism that leaves shorter thread ends. Summary of the Invention

[0004] The purpose of this patent application is to provide an industrial sewing machine with platform feeding and a thread cutting method.

[0005] The purpose of this technical solution is achieved as follows: A platform-type feeding industrial sewing machine includes a frame, on which a thread sweeping mechanism, a presser foot lifting mechanism, and a thread cutting mechanism are provided. The thread cutting mechanism includes a fixed blade assembly, a moving blade assembly, and a thread clamping assembly. The fixed blade assembly includes a first drive motor, a first transmission assembly, and a fixed blade; The moving blade assembly includes a second drive motor, a second transmission assembly, and a moving blade; The wire clamping assembly includes a wire clamping plate, which is used to clamp the wire end on the surface of the moving blade; The moving blade is rotatably mounted on the frame. One side of the moving blade is hinged to the second transmission assembly, and the other side of the moving blade is provided with a thread guide. The head of the thread guide is a pointed tip, and the tail of the thread guide is a hooking tip. A smooth guide surface is provided between the head and the tail. The head is used to pass the thread loop through the sewing thread at the end of the sewing stage. The guide surface is used to guide the thread loop to slide from the head to the tail of the thread guide. The tail is used to hook the thread loop and prevent it from coming off. The thread guide also has a moving blade edge and a moving blade thread hole. The moving blade edge is adjacent to the head and cooperates with the fixed blade to cut the sewing thread. The moving blade thread hole is adjacent to the tail. During the rotation of the moving blade, the moving blade thread hole passes directly below the needle. The moving-blade thread hole is used to allow the needle to pass through during the initial sewing stage and to move the sewing thread toward the position of the thread clamping plate, which can press the thread end passing through the moving-blade thread hole.

[0006] Through the above technical solution, in normal use, a platform-type feeding industrial sewing machine, during the initial sewing stage, the moving blade first moves below the needle. After the needle pierces the thread hole of the moving blade, a thread end is left. After the moving blade returns to its original position, the thread clamping plate immediately presses the thread end. During the final sewing stage, the moving blade swings downwards from the needle under the drive of the second drive motor. The protruding tip of its thread guide passes through the thread loop. The thread loop slides smoothly along the guide surface until the hook part at the end is firmly hooked. The moving blade continues to move, taking the thread loop away from the sewing area. The fixed blade assembly swings under the drive of the first drive motor. Its fixed blade cooperates with the moving blade edge on the moving blade to complete the thread cutting. By actively capturing, guiding, and constraining the thread loop before cutting, the tension and position of the sewing thread are ensured to be stable during cutting. Combined with the immediate fixation of the thread end by the thread clamping assembly, the stability of the thread cutting process and the effective shortening of the thread end length are achieved.

[0007] Preferably, the lead wire portion is provided with a downwardly recessed wire receiving groove, the front part of the wire receiving groove extends to the moving blade portion and forms a through hole at the moving blade portion, and the rear part of the wire receiving groove extends to the tail of the lead wire portion. The moving knife threading hole is located inside the wire receiving groove.

[0008] Through the above technical solution, the thread loop hooked by the hook part will naturally fall into and conform to the thread groove. The groove wall plays a lateral constraint and limiting role on the thread, preventing it from shifting laterally, jumping out or twisting during the swing of the cutting knife, thereby ensuring that the thread is always guided to the correct cutting position and improving the reliability and accuracy of the cutting action.

[0009] Preferably, the wire cutting mechanism further includes a suction assembly, which is mounted on the frame and located below the moving blade.

[0010] Through the above technical solution, the suction component generates a directional airflow when it is activated, which sucks the cut short thread ends into the collection device, effectively preventing waste thread ends from falling onto the fabric, getting caught on other parts of the machine, or interfering with subsequent sewing operations, keeping the work area clean, and improving the continuity and reliability of automated production.

[0011] Preferably, the guiding surface is an outwardly bulging arc surface.

[0012] With the above technical solution, when the thread loop is passed through the protruding tip and needs to move towards the tail, the arc-shaped guide surface provides a continuous, smooth, and non-sharp transition path. When the sewing thread contacts and slides relative to this surface, the frictional resistance and abrupt changes in direction are reduced, allowing it to slide very smoothly from the head to the tail. This reduces the risk of the thread loop getting stuck, worn, or accidentally dislodging during the transfer process, ensuring the smoothness and high success rate of the thread guiding action.

[0013] Preferably, the first drive motor has a first motor shaft, and the first transmission assembly includes: A swing arm, one end of which is connected to the first motor shaft; One transmission arm has one end hinged to the other end of the swing arm; A crank is rotatably mounted on the frame. The crank has a first swing arm and a second swing arm. The first swing arm is hinged to the other end of the first transmission arm, and the second swing arm is hinged to the first connecting rod. Linkage 1, the other end of which is away from the swing arm 2 is hinged to one side of the fixed blade; When the swing arm swings, it drives the connecting rod to swing through the transmission arm and crank, thereby realizing the swing of the fixed blade.

[0014] Through the above technical solution, the rotational motion of the first drive motor is transmitted to the swing arm through the first motor shaft. The swing of the swing arm is transmitted to the crank through the transmission arm. The crank rotates around its fulcrum. The rotation of the crank is then converted into a swing traction on one side of the fixed tool through the connecting rod. The multi-link mechanism realizes the precise swing of the fixed tool, ensuring the stability and repeatability of the fixed tool's motion trajectory.

[0015] Preferably, the second drive motor has a second motor shaft, and the second transmission assembly includes: A wire-cutting cam is sleeved on the shaft of the second motor. The wire-cutting cam is provided with a limiting groove, and the inner wall of the limiting groove is formed with a driving curved surface and a free-rotating curved surface. The second transmission arm has a transmission block at its upper end, and the transmission block is disposed in the limiting groove. Linkage 2, one end of which is hinged to the lower end of transmission arm 2, and linkage 2 is pushed by transmission arm 2; The wire-cutting arm has one end hinged to one side of the moving blade, and the other end connected to the second connecting rod via a transmission component. The transmission component is rotatably connected to the frame and is used to limit the position of the second connecting rod and the wire-cutting arm. When the transmission block abuts against the drive curved surface, the continued rotation of the wire-cutting cam will push the second transmission arm to swing. Through the cooperation of the second connecting rod and the wire-cutting arm, the swing of the moving blade is realized.

[0016] Through the above technical solution, the second motor shaft drives the wire-cutting cam to rotate. When the transmission block contacts the driving curved surface, it pushes the second transmission arm to swing. Then, through the linkage system composed of the second linkage, the transmission component and the wire-cutting arm, the moving blade is driven to perform one wire-cutting swing, ensuring that the moving blade only moves when needed within a working cycle. The cam control method precisely sets the timing, speed and stroke of the moving blade's action.

[0017] Preferably, the scanning mechanism includes: A sweeping cam, which is sleeved on the shaft of the second motor; The transmission arm three has a transmission column formed at one end, and the transmission column abuts against the sweeping cam. Linkage three is connected to the other end of the transmission arm three; The line sweeping execution component has a line sweeping hook at its lower end; The sweeping cam pushes the transmission arm three to swing through the curved surface, and through the cooperation of the connecting rod three and the sweeping execution component, it is used to realize the sweeping hook to perform the sweeping action.

[0018] Through the above technical solution, the curved surface of the sweeping cam drives the transmission arm to swing, and then transmits the signal to the sweeping execution component via the connecting rod, which drives the sweeping hook at its lower end to move. The timing of its action is usually after the thread cutting action, sweeping away short thread ends that may be attached to the needle plate or the thread clamp from the working area, further ensuring the cleanliness of the sewing area, so as to facilitate the next round of sewing.

[0019] Preferably, the presser foot lifting mechanism includes: A lifting cam is sleeved on the shaft of the second motor. The transmission arm four is hinged to the frame via a hinge shaft. One side of the transmission arm four abuts against the lifting cam. A buffer spring connects the transmission arm four to the frame. The lifting and pressing foot action assembly is connected to the other end of the transmission arm four; When the lifting cam pushes the transmission arm four to swing through the curved surface, it enables the lifting foot action component to perform the lifting foot action.

[0020] Through the above technical solution, the presser foot lifting mechanism is also driven by the lifting cam on the second drive motor shaft. The curved surface of the lifting cam acts on one end of the transmission arm four, forcing it to overcome the force of the buffer spring and generate a swing. The swing of the transmission arm four directly or indirectly drives the presser foot lifting action component to realize the lifting and pressing of the presser foot. The function of the buffer spring is to provide flexible pressure, so that the presser foot has a certain elasticity when pressing down the fabric, which can adapt to different fabric thicknesses, avoid damaging the fabric, and realize the automatic switching of the presser foot state in the sewing cycle.

[0021] Preferably, a thread-cutting method for a platform-feed industrial sewing machine includes the aforementioned platform-feed industrial sewing machine; the thread-cutting method includes thread cutting at the beginning of the sewing stage and thread cutting at the end of the sewing stage. Step 1, the initial sewing stage: the moving blade moves from its initial position to below the needle, and the moving blade thread hole moves to directly below the needle; the needle inserts downwards into the fabric and the moving blade thread hole, and then withdraws upwards; the sewing thread on the needle remains in the moving blade thread hole. Step 2: Move the moving blade back to its initial position, move it away from directly below the needle, and move the thread hole of the moving blade to the position of the thread clamping plate. The thread clamping plate is pressed tightly against the thread hole of the moving blade and presses the sewing thread firmly. Step 3: The take-up lever of the platform-feed industrial sewing machine swings upward and tightens the sewing thread; Step 4: Continue sewing N stitches in place, or sew N stitches with a small stitch spacing and then return to the position near the first stitch; N is less than 5. Step 5: Swing the stationary blade until it is close to the moving blade, and the blades of the stationary blade and the moving blade work together to cut the sewing thread; Step 6: After cutting the thread at the beginning of the sewing stage, continue sewing; Step 7, the final stage: the moving blade swings directly below the needle, the protruding tip on the moving blade passes through the thread loop, the thread loop moves the tail of the moving blade; the tail of the moving blade hooks the sewing thread and moves back to the initial position; the stationary blade moves towards the moving blade at the same time and cuts the sewing thread.

[0022] The key and beneficial technical effects of this technical solution compared to existing technologies are: This technical solution achieves precision and stability in the thread cutting process by having the moving blade guide the needle to leave a thread end during the initial sewing stage, which is then immediately clamped and fixed by the thread clamping plate. When the sewing ends, the moving blade actively swings, using its thread guide to capture and guide the thread loop to the hook section for fixation, and then works with the fixed blade to complete the thread cutting. This ensures stable thread tension and fixed position during thread cutting, effectively shortens the thread end length, and improves sewing quality and efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this embodiment.

[0024] Figure 2 This is a partial structural diagram of the embodiment with the rack hidden.

[0025] Figure 3 This is a schematic diagram of the overall structure of the fixed blade assembly and the moving blade assembly in this embodiment.

[0026] Figure 4 This embodiment Figure 3 A top-down view diagram.

[0027] Figure 5This is a partial structural diagram of the fixed and moving blades in this embodiment.

[0028] Figure 6 This is a partial exploded view of the fixed and moving blades in this embodiment.

[0029] Figure 7 This is a schematic diagram of the fixed and moving blades from another perspective in this embodiment.

[0030] Reference numerals: 1. Frame; 2. Fixed blade assembly; 21. First drive motor; 22. First transmission assembly; 221. Swing arm; 222. Transmission arm one; 223. Crank; 224. Connecting rod one; 23. Fixed blade; 3. Moving blade assembly; 31. Second drive motor; 32. Second transmission assembly; 321. Wire cutting cam; 322. Transmission arm two; 323. Connecting rod two; 324. Wire cutting arm; 33. Moving blade; 4. Wire clamping assembly; 41. Wire clamping plate; 5. Wire guide part; 51. Protruding tip; 52. Wire hooking part; 6. Guide surface; 7. Moving blade edge; 8. 9. Wire insertion hole; 10. Wire receiving groove; 11. Through hole; 12. Suction assembly; 13. First motor shaft; 14. Second motor shaft; 15. Swing arm part one; 16. Swing arm part two; 17. Limiting groove; 18. Drive surface; 19. Idle surface; 10. Transmission block; 11. Transmission component; 12. Wire sweeping cam; 13. Transmission arm three; 14. Connecting rod three; 15. Wire sweeping execution assembly; 16. Transmission column; 17. Wire sweeping hook; 20. Lifting cam; 20. Transmission arm four; 24. Buffer spring; 25. Hinge shaft; 100. Needle. Detailed Implementation

[0031] This patent application will now be further described with reference to the accompanying drawings and specific embodiments. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0032] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0033] Example: See Figure 1 and Figure 2A platform-type feeding industrial sewing machine includes a frame 1. A needle 100 is movably mounted at the head end of the frame 1. The frame 1 is equipped with a thread sweeping mechanism, a presser foot lifting mechanism, and a thread cutting mechanism. The thread sweeping mechanism is existing technology and will not be described in detail here. The thread sweeping mechanism includes a thread sweeping cam 171, a transmission arm 172, a connecting rod 173, and a thread sweeping execution assembly 174. A second drive motor 31 is installed inside the frame 1. A second motor shaft 13 is provided at the output end of the second drive motor 31. The second motor shaft 13 rotates relative to the frame 1 in approximately the same direction. It is arranged horizontally; the sweeping cam 171 is coaxially fixed on the second motor shaft 13 to achieve synchronous drive. The sweeping cam 171 is a cam structure, that is, its outer wall has a curved surface for driving. One end of the transmission arm 172 extends to the upper side of the sweeping cam 171 and is formed with a transmission column 18. The transmission column 18 abuts against the sweeping cam 171. The other end of the transmission arm 172 is connected to one end of the connecting rod 173. The connecting rod 173 extends toward the machine head and is connected to the sweeping execution component 174. The lower end of the sweeping execution component 174 is provided with a sweeping hook 19.

[0034] When the second drive motor 31 drives the sweeping cam 171 to rotate synchronously through the second motor shaft 13, the sweeping cam 171 pushes the transmission arm 172 to swing through the curved surface. The transmission arm 172 pulls the connecting rod 173 to move, transmitting power to the sweeping execution component 174. The sweeping execution component 174 drives the sweeping hook 19 at its lower end to perform a sweeping action, so as to sweep the short thread ends near the needle plate of the frame 1 or on the thread clamp away from the working area, further ensuring the cleanliness of the sewing area, so as to facilitate the next round of sewing.

[0035] The lifting foot mechanism is existing technology and will not be described in detail here. It typically includes a lifting cam 201, a transmission arm 202, and a lifting foot actuation assembly. The lifting cam 201 is located on the side of the sweeping cam 171 away from the second drive motor 31 and is coaxially fixed on the second motor shaft 13 to achieve synchronous drive. The lifting cam 201 is a cam structure with a curved surface for driving on its outer wall. The transmission arm 202 is hinged to the frame 1 via a hinge shaft 25. Its hinge axis is located in the middle section of the transmission arm 202. One end of the transmission arm 202 abuts against the upper side of the lifting cam 201, and the other end is connected to the lifting foot actuation assembly. A buffer spring 24 is connected between the transmission arm 202 and the frame 1 to provide flexible pressure and reset capability.

[0036] When the second drive motor 31 drives the lifting cam 201 to rotate through the second motor shaft 13, the lifting cam 201 pushes the transmission arm 202 to swing around the hinge axis through the curved surface, so that the transmission arm 202 can pull the lifting foot action component to perform the lifting foot action.

[0037] See Figure 3The wire-cutting mechanism includes a moving blade assembly 3, which comprises a second drive motor 31, a second transmission assembly 32, and a moving blade 33. The second transmission assembly 32 includes a wire-cutting cam 321, a second transmission arm 322, a second connecting rod 323, and a wire-cutting arm 324. The wire-cutting cam 321 is located on the outer side of the lifting cam 201 away from the sweeping cam 171 and is coaxially fixed to the second motor shaft 13 for synchronous drive. The wire-cutting cam 321 is provided with a limiting groove 14, which is an arc-shaped groove located on the end face of the wire-cutting cam 321 away from the lifting cam 201. The inner wall of the limiting groove 14 is formed with a driving curved surface 141 and a free-rotating curved surface 142, the principle of which is similar to that of a convex... The wheel structure is similar; the upper end of the transmission arm 322 is provided with a transmission block 15, which is set in a matching limiting groove 14; the lower end of the transmission arm 322 is hinged to the rear end of the connecting rod 323, the front end of the connecting rod 323 extends toward the head side, the wire cutting arm 324 is provided with a transmission component 16, which is rotatably connected to the frame 1, the front end of the connecting rod 323 is hinged to the extension arm on the lower side of the transmission component 16, the rear end of the wire cutting arm 324 is hinged to the extension arm on the upper side of the transmission component 16, the transmission component 16 is used to limit the position of the connecting rod 323 and the wire cutting arm 324, and the other end of the wire cutting arm 324 is hinged to one side of the moving blade 33, which is rotatably mounted on the frame 1.

[0038] The driving method of the moving blade 33 is as follows: the second drive motor 31 drives the second motor shaft 13 to rotate around the axis. The second motor shaft 13 drives the wire-cutting cam 321 to rotate. When the transmission block 15 contacts the drive curved surface 141, it pushes the transmission arm 322 to swing. The transmission arm 322 drives the connecting rod 323. The connecting rod 323, in conjunction with the transmission component 16, drives the wire-cutting arm 324 to move. The movement drives the moving blade 33 to swing, so that it performs one wire-cutting swing. This ensures that the moving blade 33 only moves when needed within one working cycle. When the transmission block 15 contacts the idle curved surface 142, it does not perform any action. The precise swing of the moving blade 33 is achieved precisely through the cam control method.

[0039] See Figure 5 and Figure 6 On the other side of the moving blade 33 away from the thread cutting arm 324, there is a thread guide 5. The head of the thread guide 5 is a pointed part 51, and the tail of the thread guide 5 is a hook part 52. A smooth guide surface 6 is provided between the head and the tail, and the guide surface 6 is an outwardly bulging arc surface. The head of the thread guide 5 is used to pass the thread loop through the sewing thread at the end of the sewing stage. The guide surface 6 is used to guide the thread loop to slide from the head of the thread guide 5 to the tail. The tail is used to hook the thread loop and prevent it from coming off.

[0040] The thread guide section 5 is also provided with a moving blade section 7 and a moving blade thread hole 8. The thread guide section 5 is provided with a downwardly recessed thread receiving groove 9, which is opened on the upper end surface of the thread guide section 5. The moving blade section 7 is located near the head. The thread receiving groove 9 extends forward along the groove direction to the moving blade section 7 and forms a through hole 10 at the moving blade section 7. The moving blade section 7 cooperates with the fixed blade 23 to cut the sewing thread. The moving blade thread hole 8 is located near the tail. The rear part of the thread receiving groove 9 extends to the tail of the thread guide section 5, so that the moving blade thread hole 8 is located in the thread receiving groove 9. During the rotation of the moving blade 33 around the rotation axis, the moving blade thread hole 8 can pass directly below the needle 100.

[0041] See Figure 4 and Figure 7 The wire-cutting mechanism includes a fixed blade assembly 2, which includes a first drive motor 21, a first transmission assembly 22, and a fixed blade 23. The first drive motor 21 is fixedly mounted inside the frame 1 and has a first motor shaft 12. The first motor shaft 12 rotates relative to the frame 1 in a direction perpendicular to the rotation direction of the second motor shaft 13. The first transmission assembly 22 includes a swing arm 221, a transmission arm 222, a crank 223, and a connecting rod 224. One end of the swing arm 221 is connected to the first motor shaft 12, and the other end is hinged to one end of the transmission arm 222. 223 is rotatably connected to the frame 1, and its rotation axis is parallel to the rotation direction of the second motor shaft 13. The crank 223 has a first swing arm 131 and a second swing arm 132. The first swing arm 131 and the second swing arm 132 extend to the lower end and the upper end of the crank 223, respectively. The other end of the transmission arm 222 away from the swing arm 221 is hinged to the lower end of the first swing arm 131. The second swing arm 132 is hinged to one end of the connecting rod 224. The other end of the connecting rod 224 is hinged to one side of the fixed blade 23. The fixed blade 23 is rotatably mounted on the frame 1, and its position is offset from that of the moving blade 33.

[0042] The driving method of the fixed blade 23 is as follows: the first drive motor 21 drives the first motor shaft 12 to rotate around the axis, the first motor shaft drives the swing arm 221 to swing, the swing arm 221 transmits to the crank 223 through the transmission arm 1 222, the crank 223 rotates around its fulcrum, and the rotation of the crank 223 drives the connecting rod 1 224 to swing through the transmission arm 2 322, so that the connecting rod 1 224 swings and pulls on one side of the fixed blade 23. The multi-link mechanism realizes the precise swing of the fixed blade 23.

[0043] See Figure 2 The wire clamping assembly 4 is installed on the head side of the frame 1. The wire clamping assembly 4 includes a wire clamping piece 41, which is movably arranged relative to the frame 1. The wire clamping piece 41 is driven by a driving component, and the wire clamping piece 41 can clamp the wire end on the surface of the moving blade 33.

[0044] The thread cutting mechanism includes a suction assembly 11, which is mounted on the frame 1 and located below the moving knife 33. The suction assembly 11 is existing technology and will not be described in detail here. It is aligned with the moving knife 33 through the inlet end of the suction pipe. The suction assembly 11 is activated when the first needle clamps the thread, and it generates a directional airflow that can suck the cut short thread end into the collection device and keep the bobbin thread at the position of the suction nozzle, which can prevent instability when taking the thread in the next section.

[0045] The specific work process of this plan is as follows: This technical solution involves the following steps: During the initial sewing stage, the moving blade 33 first moves below the needle 100. After the needle 100 inserts into the moving blade's thread hole 8, a thread end is left. After the moving blade 33 returns to its original position, the thread clamping plate 41 immediately presses down on the thread end. During the final sewing stage, the moving blade 33 swings downwards from the needle 100 under the drive of the second drive motor 31. The protruding tip 51 of its thread guide 5 passes through the thread loop. The thread loop slides smoothly along the guide surface 6 until the hook part 52 at the end is firmly hooked. The moving blade 33 continues to move, taking the thread loop away from the sewing area. The fixed blade assembly 2 swings under the drive of the first drive motor 21. Its fixed blade 23 cooperates with the moving blade edge 7 on the moving blade 33 to complete the thread cutting. By actively capturing, guiding, and constraining the thread loop before cutting, the tension and position of the sewing thread are ensured to be stable during cutting. Combined with the immediate fixation of the starting thread end by the thread clamping assembly 4, the thread cutting process is stabilized and the thread end length is effectively shortened.

[0046] A thread-cutting method for a platform-feed industrial sewing machine includes thread cutting at the beginning and end of the sewing stage. Step 1, the initial sewing stage: The moving blade 33 moves from its initial position downwards towards the needle 100, and the moving blade thread hole 8 moves directly below the needle 100; the needle 100 inserts downwards into the fabric, then through the needle plate, then through the moving blade thread hole 8, and then into the rotary hook mechanism; the rotary hook mechanism rotates and hooks the sewing thread (i.e., top thread) on the needle, and the sewing thread on the needle 100 combines with the sewing thread (i.e., bottom thread) in the rotary hook mechanism; the needle 100 then exits upwards out of the fabric; the sewing thread on the needle 100 remains in the moving blade thread hole 8; Step 2: The moving blade 33 moves to the initial position and moves away from directly below the needle 100. The moving blade thread hole 8 moves and drives the sewing thread to move towards the position of the thread clamping plate 41. The driving component drives the thread clamping plate 41 to stick tightly to the moving blade thread hole 8 and press the sewing thread. Step 3: The take-up lever of the platform-feed industrial sewing machine swings upward and tightens the sewing thread; Step 4: Continue sewing N stitches in place, or N stitches with a small stitch spacing; set the feed dog in the electronic control program to move forward and backward slightly, so that the position of the Nth stitch is as close as possible to the position of the 1st stitch; the needle and the rotary hook mechanism work together to lock the bobbin thread and the top thread onto the fabric; N is less than 5; when the program is set to N=4, that is, sewing 4 stitches, the 1st and 2nd stitches move forward, and the 3rd and 4th stitches move backward; when the program is set to N=3, that is, sewing 3 stitches, the 1st and 2nd stitches move forward, and the 3rd stitch moves backward, and so on. Those skilled in the art can adjust the forward or backward movement of the feed dog themselves, as long as the position of the Nth stitch is as close as possible to the position of the 1st stitch; Step 5: The fixed blade 23 swings to be close to the moving blade 33, and the blades of the fixed blade 23 and the moving blade 33 cooperate to cut the sewing thread; Step 6: After cutting the thread at the beginning of the sewing stage, continue sewing; Step 7, End Stage: The moving blade 33 swings directly below the needle 100, and the protruding tip 51 on the moving blade 33 passes through the thread loop of the sewing thread. The thread loop moves the tail of the moving blade 33. The tail of the moving blade 33 hooks the sewing thread and moves back to the initial position. At the same time, the fixed blade 23 moves toward the moving blade 33 and cuts the sewing thread.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of this technical solution. Those skilled in the art should understand that this technical solution is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this technical solution. Various changes and modifications can be made to this technical solution without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed technical solution. The scope of protection of this technical solution is defined by the appended claims and their equivalents.

Claims

1. A platform-type feeding industrial sewing machine, comprising a frame (1), wherein a needle and a needle plate are provided on the frame (1); a rotary hook mechanism and a thread-cutting mechanism are provided below the needle plate, characterized in that: The wire cutting mechanism includes a fixed blade assembly (2), a moving blade assembly (3), and a wire clamping assembly (4); The fixed blade assembly (2) includes a first drive motor (21), a first transmission assembly (22), and a fixed blade (23); The moving blade assembly (3) includes a second drive motor (31), a second transmission assembly (32), and a moving blade (33); The wire clamping assembly (4) includes a wire clamping piece (41) for clamping the wire end on the surface of the moving blade (33); The moving blade (33) is rotatably mounted on the frame (1). One side of the moving blade (33) is hinged to the second transmission assembly (32), and the other side of the moving blade (33) is provided with a thread guide (5). The head of the thread guide (5) is a pointed tip (51), and the tail of the thread guide (5) is a hooked tip (52). A smooth guide surface (6) is provided between the head and the tail. The head is used to pass the thread loop through the sewing thread at the end of the sewing stage. The guide surface (6) The guide loop is used to slide from the head to the tail of the guide part (5), and the tail is used to hook the guide loop and prevent it from coming off; the guide part (5) is also provided with a moving blade part (7) and a moving blade thread hole (8); the moving blade part (7) is close to the head, and the moving blade part (7) cooperates with the fixed blade (23) to cut the sewing thread, and the moving blade thread hole (8) is close to the tail; during the rotation of the moving blade (33), the moving blade thread hole (8) passes directly below the needle; The moving knife thread hole (8) is used to allow the needle (100) to pass through during the starting stage of sewing and to move the sewing thread toward the position of the clamping plate (41), which can press the thread end passing through the moving knife thread hole (8).

2. The industrial sewing machine with platform feeding according to claim 1, characterized in that: The lead wire portion (5) is provided with a downwardly recessed wire receiving groove (9), the front part of the wire receiving groove (9) extends to the moving blade portion (7) and forms a through hole (10) at the moving blade portion (7), and the rear part of the wire receiving groove (9) extends to the tail of the lead wire portion (5). The moving knife thread hole (8) is located inside the wire groove (9).

3. The industrial sewing machine with platform feeding according to claim 1, characterized in that, The wire cutting mechanism also includes a suction assembly (11), which is mounted on the frame (1) and located below the moving blade (33).

4. The industrial sewing machine with platform feeding according to claim 1, characterized in that, The guiding surface (6) is an outwardly bulging arc surface.

5. The industrial sewing machine with platform feeding according to claim 1, characterized in that: The first drive motor (21) has a first motor shaft (12), and the first transmission assembly (22) includes: A swing arm (221) is connected at one end to the first motor shaft (12); Transmission arm 1 (222), one end of which is hinged to the other end of the swing arm (221); A crank (223) is rotatably mounted on the frame (1). The crank (223) has a first swing arm (131) and a second swing arm (132). The first swing arm (131) is hinged to the other end of the first transmission arm (222), and the second swing arm (132) is hinged to the first connecting rod. Linkage 1 (224), the other end of which is away from the swing arm 2 (132) is hinged to one side of the fixed blade (23); When the swing arm (221) swings, it drives the connecting rod (224) to swing through the transmission arm (222) and the crank (223) to realize the swing of the fixed blade (23).

6. The industrial sewing machine with platform feeding according to claim 1, characterized in that: The second drive motor (31) has a second motor shaft (13), and the second transmission assembly (32) includes: A wire-cutting cam (321) is sleeved on the second motor shaft (13). The wire-cutting cam (321) is provided with a limiting groove (14). The inner wall of the limiting groove (14) is formed with a driving curved surface (141) and an idle curved surface (142). The transmission arm 2 (322) has a transmission block (15) at its upper end, and the transmission block (15) is disposed in the limiting groove (14); Linkage 2 (323), one end of which is hinged to the lower end of transmission arm 2 (322), and link 2 (323) is pushed by transmission arm 2 (322); The wire cutting arm (324) has one end hinged to one side of the moving blade (33) and the other end connected to the connecting rod two (323) via a transmission member (16). The transmission member (16) is rotatably connected to the frame (1) and is used to limit the position of the connecting rod two (323) and the wire cutting arm (324). When the transmission block (15) abuts against the drive surface (141), the wire-cutting cam (321) continues to rotate, which will push the transmission arm (322) to swing. Through the cooperation of the connecting rod (323) and the wire-cutting arm (324), the swing of the moving blade (33) is realized.

7. An industrial sewing machine with platform feeding according to claim 6, characterized in that, The frame (1) is also equipped with a wire sweeping mechanism, which includes: A sweeping cam (171) is sleeved on the second motor shaft (13); The transmission arm three (172) has a transmission column (18) formed at one end, and the transmission column (18) abuts against the sweeping cam (171); Linkage three (173) is connected to the other end of the transmission arm three (172); The sweeping execution component (174) has a sweeping hook (19) at its lower end; The sweeping cam (171) pushes the transmission arm three (172) to swing through the curved surface, and is driven by the linkage three (173) and the sweeping execution component (174) to realize the sweeping hook (19) to perform the sweeping action.

8. An industrial sewing machine with platform feeding according to claim 6, characterized in that, The frame (1) is also provided with a pressing foot lifting mechanism, which includes: A lifting cam (201) is sleeved on the second motor shaft (13); The transmission arm four (202) is hinged to the frame (1) via a hinge shaft (25). One end of the transmission arm four (202) abuts against the lifting cam (201). A buffer spring (24) is connected between the transmission arm four (202) and the frame (1). The foot lifting action assembly is connected to the other end of the transmission arm four (202); When the lifting cam (201) pushes the transmission arm four (202) to swing through the curved surface, it is used to realize the lifting foot action component to perform the lifting foot action.

9. A thread-cutting method for an industrial sewing machine with platform feeding, characterized in that, The industrial sewing machine with platform feeding as described in claim 1; the thread trimming method includes thread trimming at the beginning of the sewing stage and thread trimming at the end of the sewing stage. Step 1, starting stage: The moving knife (33) moves from its initial position to below the needle, and the thread hole of the moving knife (33) moves to directly below the needle; the needle inserts downward into the fabric and the thread hole of the moving knife (33), and then pulls back upward; the sewing thread on the needle remains in the thread hole of the moving knife (33); Step 2, the moving knife (33) moves to the initial position, the moving knife (33) moves away from directly below the needle, the thread hole of the moving knife (33) moves to the position of the thread clamping plate (41), the thread clamping plate (41) is close to the thread hole of the moving knife (33) and presses the sewing thread; Step 3: The take-up lever of the platform-feed industrial sewing machine swings upward and tightens the sewing thread; Step 4: Continue sewing N stitches in place, or sew N stitches with a small stitch spacing and then return to the position near the first stitch; N is less than 5. Step 5: The fixed blade (23) swings to be close to the moving blade (33), and the blades of the fixed blade (23) and the moving blade (33) work together to cut the sewing thread; Step 6: After cutting the thread at the beginning of the sewing stage, continue sewing; Step 7, Ending Stage: The moving blade (33) swings directly below the needle, and the protruding tip (51) on the moving blade (33) passes through the loop of the sewing thread. The loop moves the tail of the moving blade (33). The tail of the moving blade (33) hooks the sewing thread and moves back to the initial position. At the same time, the fixed blade (23) moves toward the moving blade (33) and cuts the sewing thread.

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