Stitch length adjusting and presser foot lifting device of sewing machine

Abstract

The invention belongs to the technical field of sewing machine equipment, particularly relates to a stitch length adjusting and presser foot lifting device of a sewing machine, and solves the problems that the stitch length adjusting precision is not high and the like while the presser foot lifting function and the stitch length adjusting function of an existing sewing machine are controlled through one driving device. The stitch length adjusting and presser foot lifting device of the sewing machine comprises a rotary driving source, a feeding swing plate seat and a presser foot lifting lever, wherein a rotary shaft is sleeved with a stitch length adjusting eccentric wheel and a presser foot lifting cam; a stitch length connecting rod is arranged between the stitch length adjusting eccentric wheel and the feeding swing plate seat; the stitch length adjusting eccentric wheel rotates to drive the feeding swing plate seat to swing up and down; the presser foot lifting lever is provided with a presser foot lifting rolling piece abutting against the end face of the presser foot lifting cam; a presser foot lifting face is arranged on the end face of the presser foot lifting cam in a protruding mode; and a presser foot is lifted when the presser foot lifting rolling piece abuts against the presser foot lifting face. According to the invention, the influence on the stitch length adjustment precision is reduced, and stitch length adjusting and presser foot lifting are facilitated.

Description

technical field [0001] The invention belongs to the technical field of sewing machine equipment, and in particular relates to a stitch length adjustment and presser foot lifting device of a sewing machine. Background technique [0002] A sewing machine is a machine that uses one or more sewing threads to form one or more stitches on the cloth to interweave or sew one or more layers of sewing materials. The sewing machine usually consists of four parts: feeding device, base, transmission and accessories. The movement of each mechanism is reasonably coordinated, and the cycle works to sew the sewing materials together. [0003] At present, the sewing machine will use the functions of automatic presser foot lifting and automatic stitch distance adjustment during the sewing process. Commonly, an electromagnet alone drives the presser foot lifting mechanism to realize the automatic presser foot lifting function, and a stepping motor drives the needle distance adjustment mechanis...

AI Technical Summary

Problems solved by technology

And this extrusion force will be transmitted to the motor shaft through the cam, which will affect the circular runout error of the motor shaft, resulting in poor contact between the needle distance contour surface on the cam and the needle distance ball

However, the adjustment amount of the needle distance is small, and the required adjustment accuracy is high. Therefore, when there is a poor contact between the needle distance adjustment contour surface and the needle distance adjustment ball, it will eventually be reflected on the needle distance adjustment, resulting in poor adjustment accuracy of the needle distance. high

[0005] In the above-mentioned patents, the stitch length adjustment and presser foot lifting functions are integrated on a cam. During the long-term operation of the sewing machine, due to the circular runout error of the motor shaft, the relevant contour surface on the cam will be worn. Need to adjust

However, the sewing machine may have a problem that the stitch length is adjusted normally, but the function of the presser foot is abnormal; or the stitch length is not adjusted normally, but the function of the presser foot is normal.

If the above cam is used, it will make it more difficult to adjust the contour surface of the stitch adjustment and presser foot function on this cam

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