Sewing machine

Abstract

An object of the present invention is to provide a sewing machine that naturally enables performing normal sewing work, and that enables skipping a stitch during the sewing work, and furthermore, another object is to provide a sewing machine that enables causing a latching portion and an engaging device of the needle bar to be accurately engaged and disengaged when skipping the stitch during the sewing work. An operating member return spring is provided between the operating member and the frame; and the operating member return spring is formed such that, in a process that upon supplying powerto the solenoid the latching portion is being driven from the engaging position to the retreated position, a spring force of the operating member return spring is not, or only weakly exerted on the operating member while the latching portion is located between the engaging position and the vicinity of a departing point where the latching portion starts to be disengaged, and that the spring forceis relatively strongly exerted on the operating member while the latching portion is located between the vicinity of the departing point and the retreated position, so that resilient force is stored in the operating member return spring with the movement of the operating member.

Description

technical field [0001] The invention relates to a sewing machine, in particular to a sewing machine capable of skipping stitches during sewing. Background technique [0002] Conventionally, sewing machines capable of skipping stitches during sewing are widely known. For example, there is a sewing machine shown in Patent Document 1 as such a sewing machine. The sewing machine of patent document 1 has the following structure. [0003] This sewing machine is provided with: the upper part is provided with the needle bar of hooking part (hanging part) and is equipped on the head frame freely up and down, and is driven by the main shaft and is equipped with and is equipped with to move up and down freely toward the direction parallel to the above-mentioned needle bar, The above-mentioned elevating body is equipped with an engaging part (engaging claw), which is always engaged with the engaging part of the above-mentioned needle bar in order to make the needle bar move up and dow...

AI Technical Summary

Problems solved by technology

[0022] However, in the case of increasing the acting force, the following problem will occur on the contrary: that is, the resistance to the driving force of the solenoid when the engaging member is disengaged from the engaging part of the needle bar is enhanced, so that the engaging member The disengagement speed of the hook part from the needle bar is slowed down

In this way, there is a problem that the needle bar repeatedly descends and rises near the top dead center, and it is difficult to stabilize immediately after reaching the top dead center.

[0026] In this way, the needle bar moves up and down repeatedly after reaching the top dead center and is unstable at a certain position of the top dead center. The hooking part is engaged, and the knocking part in the lifting body cannot be correctly engaged with the hanging part of the needle bar after reaching the top dead center and then descending. There is only the lifting body without the needle The rod falls, and the scheduled sewing cannot be carried out, causing the embroidery pattern to be destroyed.

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