A sewing machine double-acting knife thread trimming device

Abstract

The invention provides a double-movable blade thread cutting device of a sewing machine. The double-movable blade thread cutting device comprises a first movable blade and a second movable blade bothmovably mounted on a needle plate, and further comprises a first drive source, a second drive source, a first drive assembly and a second drive assembly, wherein the a first cutting edge of the firstmovable blade is engaged with a second cutting edge of the second movable blade, the first drive source is connected with the first movable blade through the first drive assembly to drive the first movable blade to move, and the second drive source is connected with the second movable blade through the second drive assembly to drive the second movable blade to move. Two independent drive sources respectively drive the first movable blade and the second movable blade to move, and no linkage exists between motions of the first movable blade and the second movable blade, so that the device can achieve good adjustability and controllability and can cut short thread ends stably.

Description

technical field [0001] The invention relates to a sewing machine, in particular to a double-action knife thread cutting device for the sewing machine. Background technique [0002] At present, customers have higher and higher requirements on the thread ends of clothes, and the length of the thread ends directly affects the appearance of the clothes. In addition, if the thread ends are too long, it is easy to pull the thread ends and cause the hidden danger of loose threads. In order to solve the problem of too long thread ends, the common practice of garment factories is to add a process of manually trimming the thread ends, but this method increases the labor cost of garment making and reduces the production efficiency of garment making; or, some sewing machine manufacturers also Make improvements on the thread trimming device of the sewing machine to achieve the effect of trimming the short thread ends. In the prior art, there are mainly two types of thread trimmers in se...

AI Technical Summary

Problems solved by technology

The double-moving knife thread-cutting device has two moving knives, such as: the double-moving knife thread-cutting mechanism of a sewing machine disclosed in the Chinese Utility Model Patent Specification of Application No. 201520727456.8, the double-moving knife thread-cutting mechanism uses a drive The source simultaneously drives the first moving knife and the second moving knife to realize thread trimming; however, the double-moving knife thread-cutting mechanism has the following defects: 1. The two moving knives are connected to the same driving rod through a mechanical structure, so The two moving knives are in a linkage structure and act at the same time, and there is a certain mutual limitation between them; 2. The double-moving knife thread trimming mechanism is connected by multiple linkage mechanisms, and the cooperation between the parts is required to realize the needle drop. The ideal thread trimming position, the limit of each component, and the flexible movement of each component are realized at the hole, which leads to the strong correlation and poor adjustability of the double-moving knife thread-cutting mechanism; 3. Two moving knives move at the same time , cooperate to achieve thread trimming, so the thread trimming effect is affected by the two moving knives, and the thread trimming stability is poor; 4. It realizes thread trimming at the needle drop hole, so it is necessary to ensure that the two moving knives are sharpened separately during the return process. The mouths meet and bite at the needle drop hole, and it is necessary to ensure that the limit forward position of the second movable knife is located directly below the needle drop hole. However, due to the correlation between the movements of the two movable knives, there is an adjustment to achieve the above ideal thread trimming position. Greater difficulty, resulting in unsatisfactory thread cutting effect

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