Thread-free alarming device and sewing machine

Abstract

The invention belongs to the technical field of sewing devices and particularly relates to a thread-free alarming device and a sewing machine. The thread-free alarming device comprises a main body and more than one thread through hole and is characterized in that a switch device controlled to be opened or closed by a sewing thread is arranged at each thread through hole; the switch devices are in parallel connection or in series connection with each other; when a thread is supplied, the sewing thread applies force action to the switch devices, then the switch devices are in an open state, and a circuit is in an off state; when the thread is not supplied or the thread is broken, the switch devices are not stressed, the switch devices are in a closed state, the circuit is in an on state, and an alarm generates alarm. The thread-free alarming device is capable of detecting a plurality of threads, and is simple in structure and low in production cost and use cost; the position of a thread rack is far away from the sewing part, so that the probability of rethreading by staff caused by the threads in the thread through holes are used up when the threads are broken or no threads are supplied can be reduced to a great extent.

Description

Technical field: [0001] The invention belongs to the technical field of sewing equipment, in particular to a wireless alarm device and a sewing machine. Background technique: [0002] In the process of sewing, there are often situations where the thread is broken or the thread ball on the thread frame is used up (hereinafter referred to as wireless), which will not only cause damage or waste of the fabric, but also require employees to re-thread each time an abnormality occurs , which greatly increases the labor intensity of employees and seriously affects their production efficiency. [0003] At present, none of the thread racks used in sewing machines has a broken thread or wireless detection and alarm device. The existing wireless detection devices for thread breakage mainly have the following two methods: one is to use sensors for detection, but this detection method is expensive and is not conducive to popularization. . In addition, the notification number CN 1962990 ...

AI Technical Summary

Problems solved by technology

This device is only suitable for detecting sewing threads with obvious tension changes, but it is difficult to detect sewing threads with weak tension and little change, such as looper threads, and the signal it detects is the frequency of circuit on and off. This means that there is a certain hysteresis in the detection. For high-speed machines, such as overlock sewing machines, even if a broken thread or wireless is detected, the damage and waste of the fabric and the embarrassment of the employee re-threading cannot be avoided.

This device is also a single-thread detection device, which cannot detect multiple threads, and is not suitable for multi-thread sewing machines. If each thread is equipped with one set, the cost will be greatly increased

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