Short loose threads double-shear mechanism

Abstract

The invention provides a short loose threads double-shear mechanism. An auxiliary tool rest of the mechanism is provided with a limiting lock plate extending towards a main tool rest, the main tool rest is provided with a limiting end and a reset end, and the limiting end and the reset end are positioned respectively on two sides of the limiting lock plate to limit a rotational angle of the limiting lock plate; a reset component is disposed between the auxiliary tool rest and a lower shaft sleeve, the reset component applies a rotation to limit end force towards the auxiliary tool rest; the main tool rest is connected with a shearing drive component, and the shearing drive component drives the main tool rest to rotate around the axis of a lower shaft; a limiting portion is disposed between the auxiliary tool rest and the lower shaft sleeve and can fix the auxiliary tool rest relative to the lower shaft sleeve. The short loose threads double-shear mechanism can ensure a cut-off position of upper and base threads being insusceptible to external factors, tail length of the cut upper thread left on one side of a needle is less than that provided in the prior art, and stich attractiveness can be more effectively guaranteed.

Description

technical field [0001] The invention relates to a short thread end double shearing mechanism. Background technique [0002] The existing sewing machine is provided with a fixed knife and a moving knife under the needle plate and above the rotary shuttle. The upper thread loop, under the action of the driving element, reversely rotates to hook the upper thread and the lower thread, and continues to rotate to overlap with the fixed knife to form a blade overlap, cuts the upper thread and lower thread at the overlapping position, and the tail of the cut upper thread remains on the machine. Needle side, use it next time you sew. [0003] The stitches of the sewing machine are formed by the mutual movement of the needle and the hook. In order not to affect the movement of the needle and the hook, the fixed knife and the moving knife must avoid the range of movement of the needle up and down. Since the position of the fixed knife is fixed As a result, there must be a certain dis...

AI Technical Summary

Problems solved by technology

[0005] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a short-thread double-shear mechanism, which is used to solve the problem in the prior art that the length of the tail of the upper thread after cutting is long and unstable.

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