A downward movement structure of a feeding mechanism controlled by a presser foot lifting mechanism and a sewing machine

Abstract

The invention provides a feeding mechanism downward movement structure controlled by a presser foot lifting mechanism and a sewing machine. The feeding mechanism downward movement structure includes a presser foot lifting wrench, an eccentric shaft rotatably installed in a machine housing, a dental articulator having a second swinging supporting point, and a feeding tooth installed at one end of the dental articulator; a sliding groove is formed in the dental articulator, the eccentric shaft has a shaft body part and a shaft eccentric part eccentrically arranged on the shaft body part, the presser foot lifting wrench is connected with the shaft body part of the eccentric shaft through a first transmission mechanism, and the shaft eccentric part of the eccentric shaft can be rotatably installed in the sliding groove of the dental articulator and cooperated with the sliding groove in a sliding mode; when a presser foot is lifted, the presser foot lifting wrench swings around a first swinging supporting point and swings around the second swinging supporting point through a first transmission mechanism and an eccentric shaft driven dental articulator, so that the end, provided with the feeding tooth, of the dental articulator moves downward to the upper surface of a needle plate, the effective height between the presser foot and the needle plate after the presser foot is lifted is ensured, and therefore a to-be-sewed material is easily delivered between the presser foot and the needle plate before sewing is started.

Description

technical field [0001] The invention relates to a downward movement structure of a feeding mechanism controlled by a presser foot lifting mechanism. [0002] The present invention also relates to a sewing machine comprising the above-mentioned structure for the downward movement of the feeding mechanism controlled by the presser foot lifting mechanism. Background technique [0003] The existing overlock sewing machines are equipped with a main feed dog frame and a differential feed dog frame. , The active tooth and the differential tooth together form the feed tooth. Both the main feeding dog and the differential feeding dog are driven by a section of eccentric shaft on the main shaft through the slider. The two ends of the slider are tightened with retaining rings. The angle between the active tooth and the differential tooth and the upper surface of the needle plate is constant. When the overlock sewing machine is in normal use, when the needle bar moves up to the maxim...

AI Technical Summary

Problems solved by technology

When the height of the presser foot is constant, the thickness of the sewing material that can be placed between the presser foot assembly 17 and the needle plate 25 should theoretically be the distance between the lower surface of the presser foot plate in the presser foot assembly and the upper surface of the needle plate, but due to When the presser foot is lifted, the needle bar is at the highest point, and the active teeth and differential teeth are 0.8-1.5mm higher than the needle plate, so that the thickness of the sewing material that can actually be placed between the pressure plate and the needle plate is reduced by 0.8-1.5mm, resulting in It is difficult to feed the sewing material between the presser foot and needle plate before sewing starts

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