Thread-trimming device of sewing machine

Abstract

The invention provides a thread-trimming device of a sewing machine, and belongs to the technical field of machinery. According to the technical scheme, the problems that occlusal force of movable cutters and fixed cutters of a thread-trimming device of an existing sewing machine cannot be adjusted, the bottom line clamping force cannot be adjusted, and the thread-trimming performance is unstable are solved. The thread-trimming device of the sewing machine comprises a fixed cutter rest, a movable cutter, a fixed cutter and a needle plate, wherein the movable cutter is installed on a rotating shuttle platform, the fixed cutter rest comprises a connecting part and a mounting part, the mounting part is arranged to be bended relative to the connecting part, the connecting part is provided with a first strip-shaped hole, the connecting part abuts against the side wall of the rotating shuttle platform and penetrates through the first strip-shaped hole to be fixed through a fastener, the fixed cutter is fixed to the mounting part and is located above the movable cutter, both the fixed cutter and the movable cutter are located below the needle plate, a bottom line thread clamping component is further arranged below the movable cutter, and the movable cutter can be matched with the fixed cutter to achieve thread-trimming. In the thread-trimming device of the sewing machine, by adjusting the fixed cutter rest to adjust the offset of screws and control the up-to-down motion amount of the fixed cutter shelf, the occlusal amount of the fixed cutter and the movable cutter is thus controlled, so that good occlusal force is maintained all the time between the fixed cutter and the movable cutter, and thus good thread-trimming performance is guaranteed.

Description

Technical field [0001] The invention belongs to the technical field of sewing machines and relates to a thread trimming device of a sewing machine. Background technique [0002] A sewing machine is a machine that uses one or more sewing threads to form one or more stitches on the sewing material, so that one or more layers of sewing material are interwoven or stitched together. At present, sewing machines are widely used in the garment manufacturing industry, especially large-scale sewing machines used in factories, which are more widely used in mass production enterprises. [0003] In the existing double-needle sewing machine thread trimming device, the movable knife is fixed on the rotary shaft of the movable knife, the fixed knife support spring is riveted on the needle plate, and the fixed knife is installed on the needle plate through the fixed knife fixing screw, wherein the fixed knife support plate passes through Supporting the fixed knife plays the role of increasing the ...

AI Technical Summary

Problems solved by technology

[0005] The thread trimming devices of existing sewing machines all have the following defects: 1. The occlusal force of the fixed knife and the moving knife cannot be adjusted

Although it is supported by the fixed knife support spring, the knife support spring has a certain fatigue limit and its elastic quality is unstable. Once the fixed knife has no support force or the fixed knife is worn out, the thread trimming performance will be affected.

2. The elastic force of the bottom thread clamping spring, that is, the clamping plate, cannot be adjusted

The bottom thread tension spring also has a certain fatigue limit and its elastic quality is unstable. When the bottom thread tension spring loses its elasticity and fails, the bottom thread tension spring cannot clamp the bottom thread after the thread is cut, and the seam will be off the thread when sewing next time. bad phenomenon

3. In the case of thick upper thread and thin bottom thread for sewing, because many existing clamping plates cannot freely adjust the angle, resulting in the moment after thread trimming, before the upper thread comes out of the movable knife and the clamping piece, the bottom thread is not affected The clamping force or clamping force is very small. Under the action of the inertial force of the bobbin, the bottom thread is easy to come out of the clamping piece; 4. The structure of the fixed knife fixed on the needle plate makes it more troublesome to replace the needle position group. It is necessary to re-rotate the rotary hook and reposition and adjust the thread trimming performance, which will bring a lot of inconvenience to production, debugging, and maintenance

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