Thread trimming mechanism and sewing machine

Abstract

The invention provides a thread trimming mechanism, which includes a fixed knife with a fixed knife edge and a movable knife with a movable knife edge. The movable knife can move in a direction approaching or away from the fixed knife. The movable knife is provided with a line dividing groove. The blade of the movable knife and the thread-dividing groove are set opposite to each other in the moving direction of the movable knife; when the thread is trimmed after sewing, the thread-dividing groove of the movable knife allows the bottom thread and the upper thread to enter, and the movable knife drives the bottom thread and the upper thread to approach The fixed knife moves in the direction until the blade of the movable knife engages with the blade of the fixed knife, cutting the bottom thread and the upper thread; when the seam starts, the upper thread end is allowed to enter in the dividing groove of the movable knife, and the movable knife drives the upper thread end to approach and fix Move in the direction of the knife until the blade of the moving knife and the blade of the fixed knife bite and cut the upper thread. This application can cut the upper thread and the lower thread when trimming the thread after sewing, and cut off the end of the upper thread when starting the sewing, and simultaneously solve the problem of the bird's nest in the thread trimming and starting the sewing, and realize the high-quality and stable sewing of the sewing machine.

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 sewing machines are equipped with a thread trimming mechanism, which is used to cut off the suture (comprising upper thread and bottom thread) after sewing. like 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 movable kn...

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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