Bobbin thread detection device for sewing machine

Abstract

The invention relates to the technical field of sewing machines, in particular to a bobbin thread detection device for a sewing machine. The bobbin thread detection device for the sewing machine comprises a bobbin, a bobbin case for accommodating the bobbin, a rotating shuttle arranged on the bobbin case in a sleeving manner and a sensor provided with an emitter and a receiver, wherein the bobbincomprises a wrapping post and shoulders arranged at the two ends of the wrapping post and is provided with at least one light transmitting channel, each light transmitting channel comprises a light transmitting groove and a light transmitting hole which are formed in the two shoulders respectively, bobbin thread allowance corresponding to the position where the light transmitting groove is locatedis set bobbin thread allowance, bobbin thread allowance corresponding to the position where the light transmitting hole is located is not smaller than the set bobbin thread allowance, a light reflecting surface is arranged on the inner side surface of the bobbin case or the inner side surface of the rotating shuttle, the bobbin is located between the light reflecting surface and the sensor, the light transmitting groove is opposite to the light reflecting surface, and signals emitted by the emitter can reach the light reflecting surface through the at least one light transmitting channel andreturn to the receiver through the at least one light transmitting channel after being reflected by the light reflecting surface. The reserved length of a bobbin thread can be controlled, sufficient bobbin thread allowance is guaranteed, and thread connection is avoided.

Description

technical field [0001] The invention relates to the technical field of sewing machines, in particular to a sewing machine bobbin thread detection device. Background technique [0002] A sewing machine is a machine that uses one or more sewing threads to form one or more stitches on the sewing material to interweave or sew one or more layers of sewing material. At present, a large number of lock stitch sewing machines are used in the garment manufacturing industry. It is a sewing device that cooperates with a rotary hook and a machine needle to make the bottom thread and upper thread interlock in the sewing material to realize lock stitch. The upper thread is passed through the needle eye of the machine needle, and the machine needle moves up and down; the bobbin of the hook is accommodated in the bobbin case, and the bottom thread is wound on the bobbin. The upper thread is above the sewing material and is longer, generally up to several kilometers, and the replacement freq...

AI Technical Summary

Problems solved by technology

The bobbin thread monitoring device for the sewing machine cannot control the reserved length of the bobbin thread. Because the bobbin is wound on the bobbin thread, the bobbin thread is not evenly distributed on the bobbin winding post, and the bobbin thread is exhausted and leaks out of the reflective surface during use. Different bobbins are different when detecting the bobbin thread margin, and the reserved bobbin thread length cannot be controlled. Moreover, when the bobbin thread is detected to be insufficient, the bobbin thread length may not be enough to complete a seam, resulting in the need for wiring

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