Pressing rod mechanism and sewing machine

Abstract

The invention provides a pressing rod mechanism and a sewing machine. The pressing rod mechanism comprises a supporting column, an elastic assembly, and a pressing rod which are mounted in a machine shell in the sewing machine in sequence from top to bottom, the elastic assembly comprises an upper pressure spring, a balance block and a lower pressure spring, the upper end and the lower end of theupper pressure spring are in abut joint with the supporting column and the balance block correspondingly, the upper end and the lower end of the lower pressure spring are in abut joint with the balance block and the pressing rod correspondingly, due to the fact that when the presser foot height changes to drive the pressing rod to move upwards, the lower pressure spring is extruded, for the balance block in the elastic assembly, the elastic force exerted by the upper pressure spring is smaller than that exerted by the lower pressure spring, the balance block is promoted to move upwards automatically, the stress balance is achieved again, the balance block moves upwards to enable the elastic force of the lower pressure spring to be reduced, the elastic force, exerted to the pressing rod, ofthe lower pressure spring is reduced, the force, exerted to a presser foot, of the elastic assembly is small in conversion, the problems that when thick cloth and stem parts on the cloth are sewn, lines are not attractive, and sewing materials are staggered can be solved to a certain degree, and the sewing quality is improved.

Description

technical field [0001] The invention relates to a sewing machine, in particular to a pressing bar mechanism for the sewing machine. Background technique [0002] At present, all sewing machines are equipped with a pressing bar mechanism, such as a sewing machine pressing bar mechanism disclosed in the Chinese invention patent application with application number 201710353246.0. Generally speaking, the pressing bar mechanism includes a pressing bar and a presser foot arm that cooperate with each other, and a compression spring acting on the pressing bar. It can move up and down with the presser foot, and the pressure spring exerts pressure on the pressure rod, thereby providing the pressure required by the presser foot in the presser foot assembly. Furthermore, when the presser foot is lifted, the presser rod moves up with the presser foot, compressing the compression spring, the elastic force of the compression spring becomes larger, and the pressure fed back to the presser ...

AI Technical Summary

Problems solved by technology

Therefore, when the sewing machine with the above-mentioned pressing rod mechanism is sewing, the height of the presser foot will change with the thickness of the cloth, so that the pressure of the stage spring will also change accordingly; At the stalk part, the height of the presser foot moving up is relatively large, which causes the pressure of the presser foot to change too much. At this time, it is easy to cause the sewing material to be misaligned, and the stitch pitch becomes dense when sewing the stalk material, even when the electromagnet is used as the presser foot lifter. In the sewing machine of the driving source, after a long time, it is easy to cause the electromagnet to lift weakly

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