Small nest movable cutter and sewing machine thread trimming mechanism

Abstract

The utility model relates to a small nest movable cutter and a thread trimming mechanism of a sewing machine, and provides the small nest movable cutter and the thread trimming mechanism of the sewing machine. According to the small nest movable cutter, a concave opening which is concave forwards is formed between a cutter lifting wing and a thread cutting and separating tip part, so that the length of a residual thread end of an upper thread after thread cutting is effectively controlled to be about 20mm on the premise of ensuring that thread loosening does not occur, and the phenomenon of a nest is relieved; in addition, the thread trimming cutting edge is designed to be matched with the cutting edge of the fixed cutter, the upper thread and the bottom thread can be cut off at the same time, secondary sewing is facilitated, and sewing efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a small-nest moving knife and a thread trimming mechanism of a sewing machine. Background Art

[0002] A lockstitch sewing machine is a sewing machine that can form a lockstitch and is widely used in various sewing process scenarios to meet the sewing of various fabrics. However, during the process of forming the initial lockstitch, the upper thread is often brought under the sewing material and intertwined with the bobbin thread. Since the lengths of the upper threads brought down are different, the range of intertwining below is different. In the industry, this phenomenon is called a bird's nest. The bird's nest formed at the initial stage of sewing is not beautiful and is not acceptable, especially for the sewing quality of clothing with high requirements.

[0003] However, as Figure 1 , Figure 2 shown in the shape of the moving knife of the existing thread trimming mechanism of a sewing machine, the right side of the thread trimming and separating tip is often designed as an inclined surface. Since the distance between the right side of this inclined surface and the thread trimming edge of the moving knife is relatively large, after thread trimming, there will inevitably be a large amount of redundant upper thread ends, resulting in a certain degree of bird's nest phenomenon during the secondary starting of sewing. Summary of the Invention

[0004] Aiming at the deficiencies in the above problems, the utility model provides a small-nest moving knife and a thread trimming mechanism of a sewing machine.

[0005] To achieve the above object, on the one hand, the utility model provides a small-nest moving knife, including a moving knife body designed in an arc shape, on which a thread trimming edge, a thread trimming and separating tip, a thread separating groove and a knife lifting wing are formed;

[0006] After the small-nest moving knife is positioned and installed, the movement direction of the sewing needle is defined as the up-down direction, the axial direction of the rotary hook is defined as the left-right direction, and the movement direction of the fabric is defined as the front-back direction.

[0007] Then, the thread trimming and separating tip is distributed at the rear of the thread separating groove, the orientation of the thread separating groove is opposite to the feeding direction during normal sewing of the sewing machine, that is, the opening of the thread separating groove faces the rear side. The thread trimming edge is distributed at the front of the thread separating groove, and the thread trimming edge and the thread separating groove are distributed on the same circumferential line of the moving knife body. The knife lifting wing is formed on the right edge of the moving knife body. There is also a recess formed by a forward depression between the knife lifting wing and the thread trimming and separating tip of the moving knife body, so that after thread trimming, the end of the upper thread is effectively shortened.

[0008] Furthermore, the recess is in a V shape or a U shape with a gradually shortening distance from the thread trimming edge.

[0009] Further, a wire groove is provided on the movable blade body, and the front and rear ends of the wire groove are respectively connected to the wire cutting edge and the wire dividing groove.

[0010] Further, a blade bulge and a bulge through hole are formed on the movable blade body, and the wire cutting edge is distributed at the front edge position of the bulge through hole.

[0011] Further, two adjusting mounting holes are machined on the right side of the movable blade body to facilitate fixed installation on the moving tool holder of the sewing machine wire cutting mechanism.

[0012] On the other hand, the present invention provides a sewing machine wire cutting mechanism configured with the above-mentioned small bird's nest movable blade.

[0013] The beneficial effects of the present invention compared with the prior art are as follows:

[0014] Through the design of the recessed opening, since the distance between the recessed opening and the wire cutting edge is effectively shortened, on the premise of ensuring no thread breakage, after wire cutting, the length of the remaining thread end of the surface thread can be effectively controlled at about 20 mm, alleviating the phenomenon of bird's nest; in addition, the design of the wire cutting edge, in cooperation with the edge of the fixed blade, can cut the surface thread and the bottom thread simultaneously, facilitating secondary starting of sewing and improving the sewing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a top view of the existing movable blade;

[0016] Figure 2 is a side view of the existing movable blade;

[0017] Figure 3 is a schematic diagram of the existing wire cutting mechanism;

[0018] Figure 4 is a top view of the small bird's nest movable blade involved;

[0019] Figure 5 is a side view of the small bird's nest movable blade involved.

[0020] In the figure: 10, movable blade body; 101, adjusting mounting hole; 102, lifting wing; 103, recessed opening; 104, wire cutting and dividing tip; 105, wire dividing groove; 106, wire groove; 107, wire cutting edge; 108, blade bulge; 1081, bulge through hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Example 1: As Figure 4 , Figure 5As shown in the figure, a kind of small bird's nest movable knife of the embodiment of the utility model includes a movable knife body 10 designed in an arc shape. A thread-cutting edge 107, a thread-cutting and separating tip 104, a thread separating groove 105 and a knife-lifting wing 102 are formed on the movable knife body 10. After the small bird's nest movable knife is positioned and installed, the movement direction of the sewing needle is defined as the up and down direction, the axial direction of the rotary hook is defined as the left and right direction, and the movement direction of the fabric is defined as the front and back direction. Then, the thread-cutting and separating tip 104 is distributed at the rear of the thread separating groove 105. The orientation of the thread separating groove 105 is opposite to the feeding direction during normal sewing of the sewing machine, that is, the opening of the thread separating groove 105 faces the rear side. The thread-cutting edge 107 is distributed at the front of the thread separating groove 105, and the thread-cutting edge 107 and the thread separating groove 105 are distributed on the same circumferential line of the movable knife body 10. The knife-lifting wing 102 is formed on the right edge of the movable knife body 10. A recessed opening 103 formed by a forward recess is further provided between the knife-lifting wing 102 and the thread-cutting and separating tip 104 of the movable knife body 10, so that after thread cutting, the length of the thread end of the upper thread is effectively shortened. The recessed opening 103 is in a V shape or a U shape with a gradually shortening distance from the thread-cutting edge 107. A thread-containing groove 106 is also provided on the movable knife body 10, and the front and rear ends of the thread-containing groove 106 are respectively connected with the thread-cutting edge 107 and the thread separating groove 105. An edge bulge 108 and a bulge through hole 1081 are further formed on the movable knife body 10, and the thread-cutting edge 107 is distributed at the front edge position of the bulge through hole 1081. Two adjusting mounting holes 101 are machined on the right side of the movable knife body 10 to facilitate fixed installation on the movable knife holder of the thread-cutting mechanism of the sewing machine.

[0022] Embodiment 2: A thread-cutting mechanism of a sewing machine according to an embodiment of the utility model is configured with a kind of small bird's nest movable knife involved in Embodiment 1, and further includes a movable knife holder for installing the movable knife body 10 and driving the movable knife body 10 to rotate, and a fixed knife that cooperates with the movable knife body 10 to realize thread cutting.

[0023] Through the design of the recessed opening, because the distance between the recessed opening and the thread-cutting edge is effectively shortened, on the premise of ensuring no thread breakage, after thread cutting, the length of the remaining thread end of the upper thread can be effectively controlled at about 20 mm, alleviating the phenomenon of bird's nest. In addition, through the design of the thread-cutting edge, in cooperation with the edge of the fixed knife, the upper thread and the bottom thread can be cut simultaneously, facilitating secondary starting of sewing and improving the sewing efficiency.

[0024] During specific use, for the convenience of understanding the utility model, it is described in conjunction with the accompanying drawings.

[0025] When cutting the thread, reference can be made to Figure 3, the tip 104 of the thread cutting and separating part passes through the thread loop of the surface thread. As the movable tool body 10 continues to rotate, the bottom thread and the surface thread on the cut side slide into the thread separating groove 105 and are accommodated in the thread accommodating groove 106. Finally, when the thread cutting edge 107 contacts the edge of the fixed tool, the surface thread and the bottom thread are simultaneously cut. The lifting wing 102 acts on the fixed tool first, so that the thread cutting edge 107 and the edge of the fixed tool can be well engaged.

[0026] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A small bird's nest movable knife, comprising a movable knife body (10) designed in an arc shape, wherein a thread-cutting edge (107), a thread-cutting and separating tip (104), a thread separating groove (105) and a knife-lifting wing (102) are formed on the movable knife body (10); After the small bird's nest movable knife is positioned and installed, the movement direction of the sewing needle is defined as the up-down direction, the axial direction of the rotary hook is defined as the left-right direction, and the movement direction of the fabric is defined as the front-back direction. Then, the thread-cutting and separating tip (104) is distributed at the rear of the thread separating groove (105), the orientation of the thread separating groove (105) is opposite to the feeding direction during normal sewing of the sewing machine, that is, the opening of the thread separating groove (105) faces the rear side, the thread-cutting edge (107) is distributed at the front of the thread separating groove (105), and the thread-cutting edge (107) and the thread separating groove (105) are distributed on the same circumferential line of the movable knife body (10). The knife-lifting wing (102) is formed on the right edge of the movable knife body (10). It is characterized in that: A recessed opening (103) formed by recessing forward is further provided between the knife-lifting wing (102) and the thread-cutting and separating tip (104) of the movable knife body (10), so that after thread cutting, the length of the thread end of the upper thread is effectively shortened.

2. The small bird's nest movable knife according to claim 1, characterized in that: The recessed opening (103) is in a V shape or a U shape with a gradually decreasing distance from the thread-cutting edge (107).

3. The small bird's nest movable knife according to claim 1, characterized in that: A thread storage groove (106) is further provided on the movable knife body (10), and the front and rear ends of the thread storage groove (106) are respectively connected to the thread-cutting edge (107) and the thread separating groove (105).

4. The small bird's nest movable knife according to claim 3, characterized in that: An edge bulge (108) and a bulge through hole (1081) are further formed on the movable knife body (10), and the thread-cutting edge (107) is distributed at the front edge position of the bulge through hole (1081).

5. A small bird's nest movable knife according to claim 1, characterized in that: Two adjusting mounting holes (101) are machined on the right side of the movable knife body (10) for convenient fixed installation on the movable knife holder of the thread-cutting mechanism of the sewing machine.

6. A thread cutting mechanism for a sewing machine, characterized in that: There is a small bird's nest movable knife according to any one of claims 1 to 5 above.

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