Sewing machine and broken stitch detection mechanism thereof

Abstract

The invention provides a broken stitch detection mechanism of a sewing machine. A stitch clamping screw of an existing stitch trapper of a sewing machine body is sleeved with a stitch take-up spring. The stitch take-up spring is sleeved with an insulation cylinder base. A stitch take-up hook of the stitch take-up spring stretches out from a stretching window in the insulation cylinder base through a section of a stretching arm; under the effect of pre-tensioning twisting force of the stitch take-up spring, the stretching arm makes elastic contact with a first detection piece in the stretching window, and the insulation cylinder base is further provided with a second detection piece electrically connected with the stitch take-up spring; when a stitch exists on the stitch take-up hook of the stitch take-up spring, and the stitch take-up hook is pulled so that the stretching arm can deflect to be disconnected with the first detection piece; when the stitch is broken, the stretching arm recovers to make contact with the first detection piece under the effect of the stitch take-up spring. Accordingly, according to the broken stitch detection mechanism of the sewing machine, the stitch take-up spring on the existing stitch trapper of the sewing machine is used for generating broken stitch detection signals, tension of the stitch will not be increased, the broken stitch probability is reduced, and the sewing working fault rate is lowered.

Description

technical field [0001] The invention relates to a thread breakage detection mechanism of a sewing machine and a sewing machine comprising the thread breakage detection mechanism, belonging to the technical field of sewing machine manufacturing. Background technique [0002] Thread breakage will occur during the use of the sewing machine, and an empty needle will be generated during the process from the thread breakage to the operator noticing the thread breakage and stopping the machine. In the sewing process of some special fabrics, such as leather, down jackets and other materials, empty needles are not allowed, which requires the sewing machine to quickly detect thread breakage and stop. Existing thread break detection devices for sewing machines are roughly divided into two categories: one type uses a laser through-beam sensor to detect whether a thread break occurs, and the suture passes between the emitter and receiver of the laser through-beam sensor to block The las...

AI Technical Summary

Problems solved by technology

The problem is: this is an external device, the torsion spring of this device will exert force on the suture, increase the tension of the suture, affect the sewing performance, and increase the probability of thread breakage, thus increasing the sewing work The failure rate; this detection device uses the contact and disconnection of the torsion spring and the detection piece to generate an electrical signal to determine whether a disconnection occurs, but this disconnection detection device connects the casing to the detection circuit, once the electric control short circuit occurs Failure will cause serious consequences, and this method has potential safety hazards

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