Sewing machine

Abstract

Parameters, such as the amount of up-and-down sending after a to-be-sewed objects detect a step which becomes thick, press pin pressure and thread tension, can be changed. A sewing machine includes: a cloth press pin (71), which presses a sewed object from above; a press pin height detection unit (76), which detects the height of the cloth press pin (71); and a control device (90), which plays a control role if the press pin height detection unit (76) detects that the cloth press pin (71) jumps on the step thicked by the sewed object so as to change parameters associated with sewing. For instance, if the press pin height detection unit (76) detects that the cloth press pin (71) jumps on the step, the control device (90) controls an up-and-down feeding motor (66) applying upward and downward reciprocating movement to feeding teeth (31) to raise the feeding teeth (31) in a feeding interval.

Description

technical field [0001] The invention relates to a sewing machine with feed adjustment. Background technique [0002] In the sewing machine that uses the presser foot and the feed teeth to sandwich the cloth and feed the cloth, the following feed mechanism is currently used. The feed mechanism uses the feed teeth that are mechanically connected to the main shaft to operate (see patent Literature 1). [0003] In addition, the sewing machine has a presser foot lifting mechanism. The presser foot lifting mechanism is composed of a presser bar that holds the material presser foot, and a presser spring that applies downward pressure to the material presser via the presser bar. a presser foot pressure; a rod that applies a rising motion to the presser bar against a presser spring; and a solenoid that applies a rising motion to the rod via a plurality of link bodies. [0004] In addition, when the material presser foot is lowered, the solenoid is not driven or the thrust is minimi...

AI Technical Summary

Problems solved by technology

[0007] However, in the conventional sewing machine in which the cloth is fed by sandwiching the cloth with the presser foot and the feed teeth, there is a problem that the presser foot rises and the pressure of the presser foot decreases at the step where the cloth becomes thicker.

[0008] At this time, if the height of the feed tooth is further increased, the gap between the presser foot and the presser foot becomes smaller, so the decrease in the pressure of the presser foot can be compensated. In the feed mechanism of the moving feed teeth, it is difficult to change the height of the feed teeth during the rotation of the main shaft

[0009] In addition, in the presser foot lifting mechanism such as Patent Document 2, since a solenoid is used as a driving source for the raising motion of the cloth presser foot, it is difficult to arbitrarily adjust the presser foot pressure of the cloth presser foot through control.

[0010] In addition, if the presser foot jumps up the step, there is also a problem of thread slack

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