Thread hooking apparatus of button-sewing machine

Abstract

The invention provides a catch-thread device for a button sewing machine, wherein a thread trailer capable of being folded and unfolded in a swinging manner is arranged on the open side of the catch-thread part on the front end of the catch-thread device. The thread is reliably caught on the catch-thread part by the movement of the thread trailer together with the catch-thread device along the motion path of a needle under the swing and open state, then the thread trailer draws an atresia and forcibly holds the needle thread between the atresia and the catch-thread device, simultaneously, the thread trailer and the catch-thread device perform the withdrawing motion towards the side direction so as to exert the function of separating the cut needle thread reliably towards the side direction after achieving the button sewing operation, furthermore, by means of maintaining the length of the separated thread in a certain value, the trace of a first stitch for the next sewing can be formed reliably with high quality.

Description

technical field [0001] The invention relates to a thread hooking device of a button sewing machine. The thread hooking device is installed in a button sewing machine for sewing various buttons such as flat buttons, buttons with feet, and marble buttons on fabrics of men's and women's clothing. The needle thread cut off from the fabric at the end of the button is hooked and hooked toward the side such as the rear side separated from the up and down movement path of the needle, and the end of the hooked needle thread is elastically clamped to the next sewing such as a button when production starts. Background technique [0002] The basic structure of the thread hook device of this button sewing machine is shown in Figure 7 and Figure 8, including: a hook thread device cylinder mounting plate 2 fixed on the sewing machine casing 1; On the thread catcher cylinder mounting plate 2, a strip-shaped thread tension spring 6 made of a leaf spring material extends obliquely forward an...

AI Technical Summary

Problems solved by technology

[0007] However, as mentioned above, although the needle thread can be prevented from falling off as long as the groove is formed on the innermost side of the thread hook part and the thread guide is provided, since the elastic clamping force between the thread hook part and the thread clamping spring 6 is set relatively Weak, for the extent that the needle thread can be pulled out with the pulling force at the beginning of the next sewing, therefore, even if the needle thread T is engaged and held by the groove 8c, the needle thread T will not be pulled out from the needle eye 5a of the needle 5 to a predetermined side position. T also tends to slide along its length

In addition, since the sliding amount differs depending on the type of needle thread, the length of the needle thread end portion Ta that is hooked sideways and held varies as shown by the solid line and the broken line in FIG. 8 , and lacks stability. As a result, the stitch formation of the first stitch at the start of the next sewing is unstable, the stitches are deviated and become unstable, and there remains a problem of poor finish quality

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