Face yarn holder for sewing machine

Abstract

The present invention relates to a needle thread holding device for sewing machine. The needle thread holding device A is provided with: an insert- holding means D for insert-holding the end of the needle thread; a stepping motor 10 which serves as a single actuator; a related operation means C provided with the insert-holding means D at a front end part; and a connection means 12 for connecting the motor 10 with the related operation means C. When the motor 10 is operated, the connection member 12 is moved forward and backward to transmit the operation of the motor 10 to the related operation means C. Then, the lower thread grasping plate 2 and an upper thread grasping plate 3 of the related operation means C are moved relatively, and the protrusion part 5d of an insert-holding member 5 and the front wall 2i of a through- hole 2b formed at the lower thread grasping plate 2 are abutted on each other to insert-hold the end of the needle thread put through the through hole 2b. Thus, by using the motor 10 which serves as a single actuator, the end of the needle thread is insert-held (held).

Description

technical field [0001] The present invention relates to an upper thread holding device for a sewing machine for stabilizing the length of the upper thread remaining at the needle point at the beginning of sewing. Background technique [0002] In order to reliably form the stitches at the beginning of sewing and to make the end of the upper thread remaining on the inside of the fabric look good at the position where sewing starts, it is necessary to stabilize the length of the upper thread remaining on the needle point at the beginning of sewing. Low-speed control to form the speed of up and down movement of the needle for a specified number of stitches including the first stitch (first stitch) formed at the beginning of sewing, to prevent the end of the upper thread from being pulled out from the stitch hole due to inertia and falling off , or, with the well-known technique of clamping the end of the upper thread of the first needle through the needle on the inside of the ne...

AI Technical Summary

Problems solved by technology

[0007] On the other hand, in the upper thread holding device of Patent No. 2000-325683, since the upper thread is released by pulling the upper thread with the thread take-up lever, there is no problem when processing a thick cloth, but it is not a problem when processing a thin cloth. Sometimes, when the upper thread is released, it is easy to cause wrinkles on the processed fabric due to the tension generated by the thread take-up lever.

[0008] In addition, these conventional needle thread holding devices require at least two actuators (air cylinders, etc.) in order to clamp (hold) the end of the needle thread inside the cloth. The size (dimensions) of the thread holding device itself becomes larger

This is followed by the need for redundant costs in part of the number of actuators used, and, corresponding to the number of actuators, the control of these actuators also becomes complicated

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