Dual-moving-blade thread trimming device and method of sewing machine

Abstract

The invention provides a dual-moving-blade thread trimming device and method of a sewing machine. The dual-moving-blade thread trimming device of the sewing machine comprises a first moving blade, a second moving blade, an electronic control module, a detecting sensor, a sensed piece which is fixed to the second moving blade and can be sensed by the detecting sensor, a first driving source, a second driving source, a first driving assembly and a second driving assembly. The first driving source is connected with the first moving blade through the first driving assembly. The second driving source is connected with the second moving blade through the second driving assembly. The detecting sensor, the first driving source and the second driving source are connected with the electronic controlmodule. The electronic control module precisely controls the action stopping time point of the second driving source according to the changes of output signals of the detecting sensor when the secondmoving blade moves forwards so as to precisely control the second limit position of the second moving blade moving forwards and make the second moving blade move forwards to a thread cutting point, and the thread cutting effect of short thread residues can be stably realized; no linkage exists in the movements between the first moving blade and the second moving blade, and the device is easy to obtain.

Description

technical field [0001] The present invention relates to a sewing machine. [0002] The invention particularly relates to a sewing machine double-action knife thread cutting device and a sewing machine double-action knife thread cutting method performed by using the sewing machine double-action knife thread cutting device. Background technique [0003] 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 th...

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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