Automatic line-tightening mechanism capable of sensing thickness of fabric

Abstract

The invention relates to an industrial flat sewing machine and provides an automatic line-tightening mechanism capable of sensing the thickness of a fabric. The automatic line-tightening mechanism comprises a yarn trapper fixed at the front side of a sewing machine head, a compressor arm provided with a presser foot arranged at the lower end of the compressor arm, a fabric thickness sensor, a follow-up line-tightening frame and two line-tightening pins. The fabric thickness sensor is fixedly arranged on the compressor arm and provided with a vertical curve at one side. A pivot of the follow-up line-tightening frame is pivoted on a vertical shaft inside the sewing machine head, one end of the follow-up line-tightening frame is a follow-up arm tightly adjoined with the curve of the fabric thickness sensor, and a line-tightening surface is formed between the pivot and the follow-up arm. The two line-tightening pins are arranged in guide holes in a wall of a machine shell in a sliding manner, the rear ends of the line-tightening pins are arranged in the sewing machine head and tightly adjoined with the line-tightening surface of the follow-up line-tightening frame, and the front ends of the line-tightening pins are arranged outside the machine head and tightly abuts against the back of a rear yarn bracket of the yarn trapper. According to the automatic line-tightening mechanism of the invention, the sewing pressure can be automatically compensated when the thickness of the fabric changes within a thickness range of 7mm, so that the sewing quality and the sewing efficiency are improved.

Description

technical field [0001] The invention relates to a lockstitch sewing machine for industrial sewing, in particular to a thread tightening mechanism of the locket sewing machine. Background technique [0002] In general lockstitch sewing machines, in order to adjust the tension of the sutures, a thread tensioner is provided at the easy-to-operate position of the machine head, such as a thread clamp on the front side of the machine head, and the operator adjusts the tension of the sutures by adjusting the thread tensioner. Such as figure 1 As shown, the general thread clamping plate 100, from back to front consists of thread clamp seat 101, thread take-up spring 102, thread clamping screw 103, front and rear thread clamping plates 105, 104, thread loosening plate 106, thread pressing spring 107, Limiting plate 108, clamping nut 109 constitutes. The suture is clamped between the front and rear clamping plates 105, 104, and its tension can adjust the pressure of the thread clamp...

AI Technical Summary

Problems solved by technology

However, it is difficult to adapt to sudden and frequent changes in the thickness of the sewing material by manually adjusting the thread tensioner. For example, when sewing multi-layer seams, folding seams, inlaid seams, etc., the manual adjustment cannot keep up with the rhythm of the thickness change of the sewing material, resulting in skipped stitches , Floating thread and other quality problems affect production efficiency and sewing quality, and even cause rework or scrap

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