Sewing Machine

Abstract

The present invention determines the spring type of a replaceable presser foot spring. The sewing machine includes a cloth presser that presses a workpiece to be sewn from above, a presser bar that holds the cloth presser at its lower end, a presser spring that urges the cloth presser via the presser bar, a presser motor, and control device that performs the following control operation: a presser motor is controlled to change and regulate presser pressure of the cloth presser, the presser spring is changed into a plurality of types of presser foot springs having different spring constants, and the control device controls the presser foot motor so that the cloth presser is lowered downwardly upward in a state that the cloth presser is moving away from an upper part relative to a needle plate, the control device has a spring type recognition function, which of the plurality of types of the presser foot springs different in spring constant is the presser foot spring can be identified based on the reaction force received from the presser foot spring during descending of the cloth presser.

Description

technical field [0001] The invention relates to a sewing machine capable of controlling the pressure of the presser foot of the cloth presser. Background technique [0002] Current sewing machines have a presser foot mechanism consisting of a presser bar that holds the material presser foot, and a presser spring that applies downward presser pressure to the material presser foot via the presser bar. a rod that applies a rising motion to the presser bar against the presser spring; and a solenoid that applies a rising motion to the rod via a plurality of link bodies. [0003] In addition, when the material presser foot is lowered, the solenoid is not driven or the thrust is minimized, and the material is pressed by the spring pressure of the presser foot spring, and when the material presser foot is raised, the solenoid is driven to raise it. action (for example, refer to Patent Document 1). [0004] Patent Document 1: Japanese Unexamined Patent Publication No. 2011-092523 ...

AI Technical Summary

Problems solved by technology

[0005] However, in the conventional sewing machine mentioned above, since a solenoid is used as a driving source for the lifting movement of the cloth presser foot, it is difficult to arbitrarily adjust the presser foot pressure of the cloth presser foot through control.

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