Thread trimming mechanism and sewing machine
By designing a thread-cutting mechanism that combines moving and fixed blades, automatic thread cutting is achieved when the sewing machine starts sewing, solving the problem of loose threads in the Bird's Nest stadium, improving sewing efficiency and garment quality, and the structure is simple and low-cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-04-07
AI Technical Summary
Existing sewing machines cannot automatically trim threads at the start of a sewing process, resulting in bird's nest-like thread ends, which affects garment quality, increases the need for manual trimming, and reduces production efficiency.
Design a wire cutting mechanism, including a moving blade, a fixed blade, and a wire clamping plate. The moving blade is provided with a wire-passing hole and a wire-separating groove. Automatic wire cutting is achieved through the cooperation of the first and second cutting edges. The wire clamping plate clamps the wire end in time before cutting to prevent it from moving around and to ensure cutting accuracy.
It achieves automatic thread trimming at the start of the seam, avoiding bird's nest-like thread ends, improving sewing efficiency and garment quality, reducing manual trimming, and has a simple structure and low cost.
Smart Images
Figure CN224092135U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sewing machine technology, and more specifically, to a thread-cutting mechanism and a sewing machine. Background Technology
[0002] Sewing machines typically employ automatic thread cutters, which not only ensure smooth sewing but also reduce thread ends in garments, improving subsequent finishing efficiency. However, existing cutters can only cut the thread after the sewing process is complete, not at the start of a second stitch. Therefore, during the second stitch, a certain length of thread remains on the needle, causing it to form a bird's nest pattern on the garment, affecting overall quality. To maintain garment quality, this thread must be manually trimmed, increasing labor intensity and impacting production efficiency. Utility Model Content
[0003] The main purpose of this invention is to provide a thread-cutting mechanism and a sewing machine to solve the problem of low sewing efficiency caused by manual handling of bird's nest-shaped thread ends in the prior art.
[0004] To achieve the above objectives, according to one aspect of the present invention, a wire cutting mechanism is provided, comprising: a movable blade having a wire-passing hole and a wire-separating groove, the wall of the wire-passing hole away from the wire-separating groove forming a first cutting edge, and the end of the wire-separating groove near the first cutting edge being spaced apart from the wire-passing hole; a fixed blade having a second cutting edge and being disposed above the movable blade; a wire clamping plate disposed above the fixed blade for clamping the wire in the wire-passing hole; the movable blade being reciprocally oscillating about a preset axis, so that it moves through the first cutting edge toward a direction closer to the second cutting edge until the first and second cutting edges engage, thereby cutting the wire in the wire-passing hole, and moves through the first cutting edge toward a direction away from the second cutting edge until the wire to be cut enters the wire-separating groove.
[0005] Furthermore, the moving blade is provided with a wire clamping part, which is located on the side of the wire passage hole away from the wire dividing groove, so that the wire moving through the first cutting edge toward the direction close to the second cutting edge is located between the wire clamping part and the wire clamping plate, so as to clamp the wire in the wire passage hole.
[0006] Furthermore, the moving blade is also provided with a wire receiving groove, which is located between the wire passing hole and the wire dividing groove, and the two ends of the wire receiving groove are respectively connected to the wire passing hole and the wire dividing groove.
[0007] Furthermore, the thread hole is an irregularly shaped through hole, which is used for the thread from the sewing machine needle to pass through.
[0008] Furthermore, the moving blade includes a connecting part and a cutting part that are connected to each other, and the wire passing hole, the wire separating groove and the wire receiving groove are all provided on the cutting part; the wire cutting mechanism also includes a moving blade seat, which is oscillatingly arranged to reciprocate around a preset axis, and the connecting part of the moving blade and the moving blade seat are fastened together.
[0009] Furthermore, the wire cutting mechanism also includes a drive unit, a crank, and a connecting rod. The crank is driven to the output shaft of the drive unit, one end of the connecting rod is hinged to the crank, and the other end of the connecting rod is hinged to the moving blade holder.
[0010] Furthermore, the moving cutter holder includes a main body, which has a cavity structure for fitting onto the shaft of the sewing machine so that the moving cutter holder is rotatably mounted around the shaft. The circumferential edge of the main body is provided with a first protrusion extending in the radial direction of the shaft, and the first protrusion is provided with a first connecting hole for connecting with a connecting rod.
[0011] Furthermore, the circumferential edge of the main body is provided with a second protrusion extending in the axial direction of the shaft, the second protrusion is provided with a second connecting hole, and the connecting part of the moving tool is provided with a through hole, so that a fastener can pass through the second connecting hole and the through hole to securely connect the connecting part of the moving tool and the moving tool holder.
[0012] Furthermore, the through hole includes a first hole segment and a second hole segment that are interconnected. The end of the first hole segment away from the second hole segment is used to form a closed end of the through hole. The second hole segment extends to the edge of the connecting portion to form an open end of the through hole. The diameter of the second hole segment is smaller than the diameter of the first hole segment.
[0013] According to another aspect of the present invention, a sewing machine is provided, including a machine body, a shaft, a needle, and the aforementioned thread-cutting mechanism.
[0014] The thread-cutting mechanism of this utility model includes a moving blade, a fixed blade, and a thread clamping plate. The moving blade is provided with a thread-passing hole and a thread-separating groove. The wall of the thread-passing hole away from the thread-separating groove forms a first cutting edge, and the fixed blade has a second cutting edge. When starting the first stitch, the first cutting edge moves away from the second cutting edge until the thread-passing hole is directly below the needle, so that the thread in the needle can enter the thread-passing hole. Then, it moves towards the second cutting edge through the first cutting edge and the thread-passing hole, so that the thread in the thread-passing hole is guided by the moving blade towards the first cutting edge and the thread clamping plate. Before the first cutting edge and the second cutting edge are fully engaged, the thread clamping plate clamps the thread in the thread-passing hole in time, preventing the thread end from moving around before cutting and ensuring the accuracy of the cutting operation. Then, the first cutting edge and the thread guide hole continue to move towards the second cutting edge until they engage. The thread in the thread guide hole is cut, achieving a stable start-up without tangled threads, ensuring a neat stitch, reducing manual trimming of thread ends, and thus solving the problem of low sewing efficiency caused by manual handling of tangled thread ends in existing technologies. Furthermore, this application features a single-acting blade structure, which is simple to implement and low in cost. Attached Figure Description
[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:
[0016] Figure 1 A schematic diagram of an embodiment of a sewing machine according to the present invention is shown;
[0017] Figure 2 A schematic diagram of the moving blade, fixed blade, and wire clamping plate of the wire cutting mechanism according to the present invention is shown;
[0018] Figure 3 A schematic diagram of an embodiment of the wire-cutting mechanism according to the present invention is shown;
[0019] Figure 4 A schematic diagram of the moving blade of the wire-cutting mechanism according to the present invention is shown;
[0020] Figure 5 A schematic diagram of the moving blade holder of the wire cutting mechanism according to the present invention is shown;
[0021] Figure 6 A structural schematic diagram of an embodiment of a sewing machine (without the machine body) according to the present invention is shown.
[0022] The above figures include the following reference numerals:
[0023] 1. Moving blade; 11. Wire guide hole; 12. First cutting edge; 13. Wire separating groove; 15. Wire receiving groove; 14. Connecting part; 142. Through hole; 143. First hole section; 144. Second hole section; 2. Fixed blade; 21. Second cutting edge; 3. Wire clamping plate; 31. Wire clamping part; 7. Moving blade holder; 71. Main body; 73. Cavity; 72. First protrusion; 74. First connecting hole; 75. Second protrusion; 66. Second connecting hole; 4. Driving component; 5. Crank; 6. Connecting rod; 8. Shaft; 10. Machine body. Detailed Implementation
[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0025] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.
[0026] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.
[0027] Please refer to Figures 1 to 6This utility model provides a wire cutting mechanism, comprising: a movable blade 1, which has a wire-passing hole 11 and a wire-separating groove 13, wherein the wall of the wire-passing hole 11 away from the wire-separating groove 13 forms a first cutting edge 12, and the end of the wire-separating groove 13 near the first cutting edge 12 is spaced apart from the wire-passing hole 11; a fixed blade 2, which has a second cutting edge 21, and is disposed above the movable blade 1; and a wire clamping plate 3, disposed above the fixed blade 2, for clamping the wire in the wire-passing hole 11; the movable blade 1 is oscillatingly reciprocated around a preset axis, so that it moves through the first cutting edge 12 toward the direction of approaching the second cutting edge 21 until the first cutting edge 12 and the second cutting edge 21 engage, thereby cutting the wire in the wire-passing hole 11, and moves through the first cutting edge 12 toward the direction of away from the second cutting edge 21 until the wire to be cut enters the wire-separating groove 13.
[0028] The thread-cutting mechanism of this utility model includes a moving blade 1, a fixed blade 2, and a thread clamping plate 3. The moving blade 1 is provided with a thread-passing hole 11 and a thread-separating groove 13. The hole wall of the thread-passing hole 11 away from the thread-separating groove 13 forms a first cutting edge 12. The fixed blade 2 has a second cutting edge 21. When starting the first stitch, the first cutting edge 12 first moves away from the second cutting edge 21 until the thread-passing hole 11 is directly below the needle, so that the thread in the needle can enter the thread-passing hole 11. Then, through the first cutting edge 12 and the thread-passing hole 11, it moves towards the second cutting edge 21, so that the thread in the thread-passing hole 11 is guided by the moving blade 1 towards the first cutting edge 12 and the thread clamping plate 3. Before the first cutting edge 12 and the second cutting edge 21 are fully engaged, the thread clamping plate 3 clamps the thread in the thread-passing hole 11 in time, preventing the thread end from moving around before cutting and ensuring the accuracy of the cutting operation. Then, the first cutting edge 12 and the thread guide hole 11 continue to move towards the second cutting edge 21 until the first cutting edge 12 and the second cutting edge 21 engage, and the thread in the thread guide hole 11 is cut. This achieves a stable starting effect without tangled threads, ensuring a neat and aesthetically pleasing stitch and reducing the need for manual thread trimming. This solves the problem of low sewing efficiency caused by manual handling of tangled thread ends in existing technologies. Furthermore, this application features a single-acting blade structure, which is simple to implement and low in cost.
[0029] In addition, when the sewing machine needs to cut the thread after normal sewing, the first cutting edge 12 moves away from the second cutting edge 21 to the thread to be cut (top thread and bottom thread) and enters the thread separating groove 13; then the first cutting edge 12 moves towards the second cutting edge 21 until the first cutting edge 12 and the second cutting edge 21 engage, so that the thread to be cut in the thread separating groove 13 is cut, thus realizing automatic thread cutting at the end of sewing.
[0030] In this embodiment, the wire cutting mechanism of the present invention also includes a suction component. The suction port of the suction component is arranged facing the second cutting edge 21 of the fixed blade 2. When the wire in the wire hole 11 is cut, or the wire to be cut in the wire dividing groove 13 is cut, the suction component sucks away the cut wire end.
[0031] In this embodiment, the moving blade 1 is provided with a wire clamping part 31, which is located on the side of the wire passage hole 11 away from the wire dividing groove 13. The wire passes through the first cutting edge 12 towards the direction close to the second cutting edge 21 until the wire in the wire passage hole 11 is located between the wire clamping part 31 and the wire clamping plate 3, so as to clamp the wire in the wire passage hole 11.
[0032] Specifically, this design ensures that during the initial stitching and thread cutting, the precise movement path of the first cutting edge 12 towards the direction of the second cutting edge 21 effectively guides the thread end in the thread hole 11 between the thread clamping part 31 and the thread clamping plate 3. This allows the thread clamping plate 3 to clamp the thread end immediately before the first cutting edge 12 and the second cutting edge 21 are fully engaged, preventing the thread end from moving around before cutting and ensuring the accuracy of the cutting operation. Especially during the initial stitching, the thread in the thread hole 11 is guided by the cutter 1 towards the first cutting edge 12 and the thread clamping plate 3. The thread clamping plate 3 and the thread clamping part 31 together stably clamp the thread in the thread hole 11. This process not only avoids disorderly movement of the thread end and effectively prevents thread slippage or "bird's nest" phenomena in the early stages of stitching, but also ensures automated thread end management during the initial stitching stage of the sewing machine, improving the stability of stitching and the convenience of operation. The role of the thread clamping plate 3 is equally indispensable when cutting the thread at the end of sewing. As the first cutting edge 12 of the moving blade 1 continues to move toward the second cutting edge 21 of the fixed blade 2, the thread end after cutting is guided to the thread receiving groove 15 through the thread separating groove 13 of the moving blade 1. Then, the thread clamping part 31 and the thread clamping plate 3 jointly fix the thread end, preventing the thread end from scattering after cutting, ensuring the cleanliness of the thread cutting operation, and providing convenience for subsequent thread end cleaning and machine maintenance, thereby improving the operating efficiency of the sewing machine and the user experience.
[0033] In practice, the initial stitch is as follows: Before the sewing machine begins the first stitch, the first cutting edge 12 moves away from the second cutting edge 21 until the thread guide hole 11 is directly below the needle. This causes the needle to move downwards during the initial stitch, carrying the thread through the thread guide hole 11. Under the action of the rotary hook, the thread end on one side of the needle is brought below the moving blade 1. The needle then moves upwards from the thread guide hole 11 away from the moving blade 1, pulling out a portion of the thread end. The thread end is then contained within the thread guide hole 11. The sewing machine moves from the first cutting edge 12 towards the second cutting edge 21. The thread in the thread hole 11 is obstructed by the thread clamping plate 3 and gradually moves towards the thread clamping part 31 until the thread in the thread hole 11 is between the thread clamping plate 3 and the thread clamping part 31. The thread in the thread hole 11 is clamped, and the sewing machine starts sewing the second stitch. The needle moves downward through the space on the side of the moving blade 1 away from the fixed blade 2, and moves down to pierce the material for the second time. The top thread and the bottom thread intertwine to form a knot, and the sewing machine starts sewing the third stitch, and so on, until the set number of stitches is reached. During this process, the first cutting edge 12 and the second cutting edge 21 remain in a non-engaged state, so the thread end is always on the surface of the moving blade 1 and is clamped without being cut, effectively preventing the thread from coming off. Then the first cutting edge 12 continues to move towards the second cutting edge 21 until the first cutting edge 12 and the second cutting edge 21 engage, so that the thread in the thread hole 11 is cut, realizing the prevention of bird nests by cutting the thread during sewing.
[0034] In practice, when sewing ends normally and thread cutting is required, during the process of the sewing machine moving the needle upwards after sewing the last stitch, the first cutting edge 12 moves away from the second cutting edge 21 until the thread to be cut (top thread and bottom thread) enters the thread divider groove 13. Then, the first cutting edge 12 moves towards the second cutting edge 21, causing the thread to be cut in the thread divider groove 13 to be pressed into the thread receiving groove 15 and the thread passage hole 11 by the thread clamping plate 3. The first cutting edge 12 continues to move towards the second cutting edge 21, causing the thread to be cut in the thread divider groove 13 to enter between the thread clamping plate 3 and the thread clamping part 31 and be clamped by the thread clamping plate 3. Then, the first cutting edge 12 continues to move towards the second cutting edge 21 until the first cutting edge 12 and the second cutting edge 21 engage, so that the thread to be cut in the thread divider groove 13 is cut, thus achieving automatic thread cutting at the end of sewing.
[0035] In this embodiment, the moving blade 1 is also provided with a wire receiving groove 15, which is disposed between the wire passing hole 11 and the wire dividing groove 13. The two ends of the wire receiving groove 15 are respectively connected to the wire passing hole 11 and the wire dividing groove 13.
[0036] Specifically, the thread groove 15 is used to guide the thread to be cut in the thread divider 13 when sewing is finished normally, so as to ensure that the thread to be cut in the thread divider 13 enters between the thread clamping plate 3 and the thread clamping part 31.
[0037] In this embodiment, the thread hole 11 is an irregularly shaped through hole, which is used for the thread on the sewing machine needle to pass through.
[0038] Specifically, the thread guide hole 11 is designed as an irregularly shaped through hole, which ensures that the thread on the needle can pass through the thread guide hole 11 without obstruction when sewing begins, realizing the rapid positioning and guidance of the thread, thereby ensuring the smooth start of sewing.
[0039] In this embodiment, the moving blade 1 includes a connecting part 14 and a cutting part that are connected to each other. The wire through hole 11, the wire separating groove 13 and the wire receiving groove 15 are all provided on the cutting part. The wire cutting mechanism also includes a moving blade seat 7, which is oscillatingly arranged around a preset axis. The connecting part 14 and the moving blade seat 7 are fastened together.
[0040] Specifically, the moving blade 1 consists of a connecting part 14 and a cutting part. The thread passage hole 11, the thread separating groove 13, and the thread receiving groove 15 are all concentrated on the cutting part. This design integrates all key thread cutting and separating functions into a single component, greatly simplifying the structure of the thread cutting mechanism, reducing relative movement and friction between components, thereby reducing energy loss and mechanical wear, and improving the reliability and durability of the thread cutting mechanism. More importantly, the integrated design ensures precise coordination of the thread cutting action, enabling seamless connection of key operations such as the engagement of the first cutting edge 12 and the second cutting edge 21, and the guidance and clamping of the thread end, improving the efficiency of thread cutting and separating, and providing stable support for continuous sewing.
[0041] Specifically, the moving blade holder 7 drives the moving blade 1 to reciprocate around a preset axis. This design provides a flexible and precise swing path for the moving blade 1, ensuring that the first cutting edge 12 on the moving blade 1 can accurately cooperate with the second cutting edge 21 of the fixed blade 2 to complete the cutting action. At the same time, the fastening connection between the connecting part 14 and the moving blade holder 7 enhances the stability and reliability of the moving blade 1's movement. Especially when cutting the thread at the end of sewing, the moving blade 1, driven by the moving blade holder 7, can accurately guide the thread end from the thread separating groove 13 to the thread receiving groove 15 and then to the thread passage hole 11, ensuring the continuity and efficiency of cutting and thread end management.
[0042] In this embodiment, the wire cutting mechanism further includes a drive member 4, a crank 5, and a connecting rod 6. The crank 5 is driven to the output shaft of the drive member 4. One end of the connecting rod 6 is hinged to the crank 5, and the other end of the connecting rod 6 is hinged to the moving blade holder 7.
[0043] Specifically, the drive component 4, acting as the power source, has its output shaft connected to the crank 5, ensuring efficient power transmission and stable motion. The introduction of the crank 5, by converting rotational motion into reciprocating oscillation, provides continuous and precise control over the movement of the moving blade holder 7. This conversion not only enables rapid response and positioning of the moving blade 1 but also precisely controls its amplitude and frequency, ensuring smooth and efficient wire cutting and separating operations. The connecting rod 6 acts as a bridge connecting the crank 5 and the moving blade holder 7. Its hinged design at both ends gives the entire system extremely high flexibility and stability. On one hand, the connecting rod 6 smoothly converts the rotational motion of the crank 5 into the reciprocating oscillation of the moving blade holder 7, driving the moving blade 1 to complete the wire cutting and separating actions. On the other hand, the hinged structure allows each component to remain relatively independent during movement, reducing mechanical interference and energy loss during motion, ensuring efficient power transmission and accurate action execution. Overall, the coordinated work of the drive component 4, crank 5, and connecting rod 6 achieves precise, stable, and efficient movement of the moving blade 1 during the wire cutting process. In particular, the precise engagement of the first cutting edge 12 and the second cutting edge 21 of the moving blade 1, as well as the accurate insertion and clamping of the wire end, all rely on the precise control of this drive system. This design significantly improves the cutting accuracy, wire separating effect, and automation level of the wire cutting mechanism.
[0044] Optionally, the drive component 4 is a motor.
[0045] In this embodiment, the moving blade holder 7 includes a main body 71, which has a cavity 73. The cavity 73 is used to fit onto the shaft 8 of the sewing machine so that the moving blade holder 7 is rotatably arranged around the shaft 8. The circumferential edge of the main body 71 is provided with a first protrusion 72 extending in the radial direction of the shaft 8. The first protrusion 72 is provided with a first connecting hole 74 for connecting with the connecting rod 6.
[0046] Specifically, the cavity 73 design of the main body 71 allows the moving blade holder 7 to be tightly and flexibly fitted onto the shaft 8 of the sewing machine. This structure not only ensures the free rotation of the moving blade holder 7 around the shaft 8, but also provides precise guidance and support for the rotation of the moving blade holder 7 through the cooperation between the cavity 73 and the shaft 8, reducing swaying and shaking during rotation and improving the stability of the movement and the accuracy of thread cutting. The first protrusion 72, located on the circumferential edge of the main body 71, extends radially along the shaft 8, providing a stable platform for the connection of the connecting rod 6. The first connecting hole 74 on the first protrusion 72 serves as the connection point between the connecting rod 6 and the moving blade holder 7, ensuring a firm and precise connection between the two, while allowing the connecting rod 6 to drive the moving blade holder 7 to perform smooth reciprocating oscillations without causing movement deviation or energy loss due to instability at the connection point. This design enhances the motion coordination of the thread cutting mechanism, ensuring the flexible and accurate movement trajectory of the moving blade 1 during thread cutting and separating, effectively improving the accuracy and efficiency of thread cutting. Overall, the innovative combination of the cavity 73, the first protrusion 72, and the first connecting hole 74 in the main body 71 not only provides a stable rotational foundation for the moving blade holder 7, but also ensures the precise drive of the moving blade holder 7 by the connecting rod 6. This achieves efficient and coordinated movement between the moving blade 1 and the fixed blade 2, avoiding thread cutting errors and tangled thread ends, i.e., the "bird's nest" phenomenon, that may be caused by uncoordinated movement. This effectively improves the thread cutting quality and automation level of the sewing machine.
[0047] Specifically, the central axis of shaft 8 is the preset axis.
[0048] In this embodiment, the circumferential edge of the main body 71 is provided with a second protrusion 75 extending in the axial direction of the shaft 8. The second protrusion 75 is provided with a second connecting hole 66. The connecting part 14 of the moving blade 1 is provided with a through hole 142 so that a fastener can pass through the second connecting hole 66 and the through hole 142 to securely connect the connecting part 14 of the moving blade 1 and the moving blade seat 7.
[0049] Specifically, the design of the second protrusion 75 provides additional support and positioning points, enhancing the stability and reliability of the connection between the moving blade holder 7 and the moving blade 1. Through the fasteners passing through the second connecting hole 66 and the through hole 142, this direct physical connection ensures the stability of the moving blade 1 during the thread cutting process, avoiding movement deviations or inaccurate cutting due to loose connections, thereby improving the stability of thread cutting and the quality of the sewn product. Secondly, this connection method ensures the consistency of movement between the moving blade 1 and the moving blade holder 7. The rotational movement of the moving blade holder 7 can be accurately transmitted to the moving blade 1, allowing the first cutting edge 12 of the moving blade 1 to precisely engage with the second cutting edge 21 of the fixed blade 2 along a preset trajectory, completing the thread cutting action. Simultaneously, the positional changes of the thread separating groove 13 and the thread receiving groove 15 of the moving blade 1 during thread cutting and separating are also precisely controlled, preventing the thread ends from moving erratically during cutting, effectively preventing the "bird's nest" phenomenon, i.e., the tangled and knotted thread ends, and improving the efficiency of automated thread cutting and thread end management. Furthermore, the precise matching of the second protrusion 75 with the through hole 142 simplifies the assembly process of the moving blade 1 and the moving blade holder 7, reduces assembly errors, and improves production efficiency. The use of fasteners not only ensures a stable connection but also allows for easy disassembly and maintenance when needed, reducing maintenance costs and extending the overall service life of the device.
[0050] Alternatively, the fastener is a bolt.
[0051] In this embodiment, the through hole 142 includes a first hole segment 143 and a second hole segment 144 that are interconnected. The end of the first hole segment 143 that is away from the second hole segment 144 is used to form a closed end of the through hole 142. The second hole segment 144 extends to the edge of the connecting portion 14 to form an open end of the through hole 142. The diameter of the second hole segment 144 is smaller than the diameter of the first hole segment 143.
[0052] Specifically, firstly, the closed-end design of the first hole segment 143 effectively increases the anchoring depth of the fastener within the moving blade 1, thereby significantly enhancing the connection strength and stability between the moving blade 1 and the moving blade holder 7. The closed-end design prevents lateral slippage of the fastener under stress, ensuring the stability of the moving blade 1 during high-speed thread cutting, reducing cutting deviations caused by unstable connections, and improving the accuracy of thread cutting and the quality of the sewn product. Secondly, the open-end design of the second hole segment 144 facilitates quick insertion and removal of the fastener, simplifying the assembly and maintenance process. The gradually decreasing hole diameter ensures precise guidance of the fastener during insertion, avoiding assembly errors, and limits the movement range of the fastener through the smaller hole diameter, improving the tightness and reliability of the connection and reducing the failure rate that may be caused by fastener loosening during thread cutting. Finally, the difference in hole diameter between the first hole segment 143 and the second hole segment 144 achieves a perfect integration of structure and function. While ensuring sufficient connection strength and stability, the precise guidance and restriction of the second hole segment 144 ensures the consistency of movement between the moving blade 1 and the moving blade holder 7, enabling the moving blade 1 to move precisely along a preset trajectory during the cutting and separating of the wire, thus avoiding the random movement of the wire end during the cutting process.
[0053] This utility model also provides a sewing machine, including a body 10, a shaft 8, a needle, and the aforementioned thread-cutting mechanism.
[0054] This utility model includes a body 10, a shaft 8, a needle, and the aforementioned thread-cutting mechanism. Both the shaft 8 and the thread-cutting mechanism are mounted on the body 10, and the needle is movably mounted on the body 10.
[0055] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:
[0056] The thread-cutting mechanism of this utility model includes a moving blade 1, a fixed blade 2, and a thread clamping plate 3. The moving blade 1 is provided with a thread-passing hole 11 and a thread-separating groove 13. The hole wall of the thread-passing hole 11 away from the thread-separating groove 13 forms a first cutting edge 12. The fixed blade 2 has a second cutting edge 21. When starting the first stitch, the first cutting edge 12 first moves away from the second cutting edge 21 until the thread-passing hole 11 is directly below the needle, so that the thread in the needle can enter the thread-passing hole 11. Then, through the first cutting edge 12 and the thread-passing hole 11, it moves towards the second cutting edge 21, so that the thread in the thread-passing hole 11 is guided by the moving blade 1 towards the first cutting edge 12 and the thread clamping plate 3. Before the first cutting edge 12 and the second cutting edge 21 are fully engaged, the thread clamping plate 3 clamps the thread in the thread-passing hole 11 in time, preventing the thread end from moving around before cutting and ensuring the accuracy of the cutting operation. Then, the first cutting edge 12 and the thread guide hole 11 continue to move towards the second cutting edge 21 until the first cutting edge 12 and the second cutting edge 21 engage, and the thread in the thread guide hole 11 is cut. This achieves a stable starting effect without tangled threads, ensuring a neat and aesthetically pleasing stitch and reducing the need for manual thread trimming. This solves the problem of low sewing efficiency caused by manual handling of tangled thread ends in existing technologies. Furthermore, this application features a single-acting blade structure, which is simple to implement and low in cost.
[0057] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0058] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.
[0059] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A wire-cutting mechanism, characterized in that, include: A moving blade (1) is provided with a wire hole (11) and a wire dividing groove (13). The wall of the wire hole (11) away from the wire dividing groove (13) forms a first cutting edge (12). The end of the wire dividing groove (13) near the first cutting edge (12) is spaced apart from the wire hole (11). A fixed blade (2) has a second cutting edge (21) and is positioned above the moving blade (1); A wire clamping plate (3) is disposed above the fixed blade (2) and is used to clamp the wire in the wire hole (11); The moving blade (1) is oscillatingly reciprocated around a preset axis so that it moves from the first cutting edge (12) toward the direction of the second cutting edge (21) until the first cutting edge (12) and the second cutting edge (21) engage, so that the wire in the wire hole (11) is cut off, and moves from the first cutting edge (12) toward the direction of the second cutting edge (21) until the wire to be cut enters the wire dividing groove (13).
2. The wire-cutting mechanism according to claim 1, characterized in that, The moving blade (1) is provided with a wire clamping part (31), which is located on the side of the wire passage hole (11) away from the wire dividing groove (13). The wire clamping part (31) moves through the first cutting edge (12) toward the direction close to the second cutting edge (21) until the wire in the wire passage hole (11) is located between the wire clamping part (31) and the wire clamping plate (3) to clamp the wire in the wire passage hole (11).
3. The wire-cutting mechanism according to claim 1, characterized in that, The moving blade (1) is also provided with a wire receiving groove (15), which is located between the wire passing hole (11) and the wire dividing groove (13). The two ends of the wire receiving groove (15) are respectively connected to the wire passing hole (11) and the wire dividing groove (13).
4. The wire-cutting mechanism according to claim 1, characterized in that, The thread hole (11) is an irregularly shaped through hole, which is used for thread from the sewing machine needle to pass through.
5. The wire-cutting mechanism according to claim 3, characterized in that, The moving blade (1) includes a connecting part (14) and a cutting part that are connected to each other. The wire through hole (11), the wire dividing groove (13) and the wire receiving groove (15) are all provided on the cutting part. The wire cutting mechanism also includes a moving blade seat (7). The moving blade seat (7) is oscillatingly arranged around the preset axis. The connecting part (14) of the moving blade (1) and the moving blade seat (7) are fastened together.
6. The wire-cutting mechanism according to claim 5, characterized in that, The wire cutting mechanism also includes a drive member (4), a crank (5) and a connecting rod (6). The crank (5) is driven to the output shaft of the drive member (4). One end of the connecting rod (6) is hinged to the crank (5), and the other end of the connecting rod (6) is hinged to the moving blade holder (7).
7. The wire-cutting mechanism according to claim 6, characterized in that, The moving blade holder (7) includes a main body (71), which has a cavity (73) and is used to be sleeved on the shaft (8) of the sewing machine so that the moving blade holder (7) is rotatably arranged around the shaft (8); The circumferential edge of the main body (71) is provided with a first protrusion (72) extending in the radial direction of the shaft (8), and the first protrusion (72) is provided with a first connecting hole (74) for connecting with the connecting rod (6).
8. The wire-cutting mechanism according to claim 7, characterized in that, The circumferential edge of the main body (71) is provided with a second protrusion (75) extending in the axial direction of the shaft (8). The second protrusion (75) is provided with a second connecting hole (66). The connecting part (14) of the moving blade (1) is provided with a through hole (142) so that a fastener can pass through the second connecting hole (66) and the through hole (142) to securely connect the connecting part (14) of the moving blade (1) and the moving blade seat (7).
9. The wire-cutting mechanism according to claim 8, characterized in that, The through hole (142) includes a first hole segment (143) and a second hole segment (144) that are interconnected. The end of the first hole segment (143) away from the second hole segment (144) is used to form the closed end of the through hole (142). The second hole segment (144) extends to the edge of the connecting portion (14) to form the open end of the through hole (142). The diameter of the second hole segment (144) is smaller than the diameter of the first hole segment (143).
10. A sewing machine, characterized in that, It includes a body (10), a shaft (8), a needle, and a thread-cutting mechanism as described in any one of claims 1 to 9.