Thread cutting mechanism and sewing machine

Abstract

The invention provides a thread cutting mechanism. The mechanism includes a fixed cutter having a fixed cutting edge and a movable cutter having a movable cutting edge. The movable cutter can move inthe direction close to or away from the fixed cutter, a thread distribution groove is formed in the movable cutter, and the movable cutting edge and the thread distribution groove are opposite to eachother in the movement direction of the movable cutter. After sewing is over, at the time of thread cutting, bottom threads and surface threads are allowed to enter the thread distribution groove of the movable cutter, and the movable cutter drives the bottom threads and the surfaces threads to move in the direction near the fixed cutter until the movable cutting edge and the fixed cutting edge bite and cut the bottom threads and the surface threads; at the time of stitching, surface thread residues are allowed to enter the thread distribution groove of the movable cutter, and the movable cutter drive the surface thread residues to move in the direction close to the fixed cutter until the movable cutting edge and the fixed cutting edge bite and cut the surface thread residues. After sewingis over, at the time of thread cutting, the surface threads and the bottom threads are cut off, the surface thread residues are cut off at the time of stitching, the thread cutting problem and the 'bird's nest' problem during stitching are solved at the same time, and high-quality and stable sewing of a sewing machine is achieved.

Description

technical field [0001] The invention relates to a thread cutting mechanism. [0002] The present invention also relates to a sewing machine comprising the above-mentioned thread trimming mechanism. Background technique [0003] At present, all the sewing machines are equipped with a thread trimming mechanism, which is used to cut off the suture (including upper thread and bottom thread) after sewing. Such as figure 1 As shown, the existing thread trimming mechanism includes a moving knife 100 and a fixed knife 200 arranged oppositely, and the moving knife 100 and the fixed knife 200 are all arranged below the needle plate 300 in the sewing machine and above the rotary shuttle 400 in the sewing machine, wherein, The fixed knife 200 is fixed on the base of the sewing machine, and the movable knife 100 can rotate around the lower shaft of the sewing machine under the action of the driving assembly. When the thread is trimmed after sewing, the driving assembly drives the mova...

AI Technical Summary

Problems solved by technology

Although the above method can solve the problem of sewing bird’s nest, it will affect the operating space after installing a sliding thread clamping device on the machine head, the presser foot with the blade is not universal, the thick upper thread blade will not cut continuously, and the cut upper thread end needs to be sucked. There are a series of problems such as wind collection and treatment, air suction required for air source, upper thread thread remaining on the front of the sewing material due to the cutting of the presser foot, and affecting the appearance of the sewing material.

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