Thread monitor and a slubbing clamping device for draw frames of spinning machines equipped with double upper rollers

摘要

A bearing rail is provided extending along each side of the draw frame and spaced laterally from the outer edges of the double upper rollers. At the end of the each rail, in the area when the thread exits from the exit rollers, each rail is provided with two carriers, one of which is provided with a light source and the other which with a light receiving photo-cell. The light source on one side of the drawing frame is arranged in association with the thread being drawn adjacent the photo-cell on the other side so that the light source causes this remote thread to cast a shadow on the photo-cell adjacent to it. Similarly the light source on the other side, the thread remote from it and the photo-cell opposite it are also aligned. The shadow on each photo-cell produces an alternating current which is then independently fed to a circuit and switch means, housed at the inlet end of the bearing rail. The switch means, such as a solenoid operates a clamping or arresting device which is movable between the lower inlet roller and the associated upper inlet roller, to clamp the slubbing between it and the upper roller thus preventing its continued feed into the draw frame.