Thread monitor, esp. for sewing machine - with brake mounted on vertical path, upper end of path having movable limit stop and brake being loaded so it drops on thread breakage

摘要

A thread monitor, partic. for a sewing machine, incorporates a brake (26) mounted on the path (32) of a vertically -moving component. The path's upper end has a limit stop (38) for the brake (26), which can move to give an increasing gap between the limit stop and the thread roller (18). The thread brake (26) is loaded by a weight (34) so that it drops on a thread break. Typically, a curved slit (32) provides the path for the brake, with its free end further from the thread roller (18) than the end with the limit stop (38). A pivoting arm (34) on an upper horizontal axis (36) acts as the weight, with its free end carrying the thread brake (26), with the centre of arc of the slit (32) lying on the pivoting axis (36). The horizontal axis (30) supporting the brake plate of the brake (26) is secured vertically to the pivoting arm (34) and engaged by the guide slit (32), so that the arm and the brake are on opposite sides of the component (10) with the guide slit. There is a rapid reaction in the event of a thread breakage.