Process and device for monitoring the bobbin thread on stitch-forming machines

摘要

A process and device for monitoring the bobbin thread on stitch-forming machines, on the bobbin of which a residual amount of thread is wound in a winding direction opposite the direction of winding of the principal amount of thread, is to ensure that a first control function will be generated at the beginning of consumption of the residual amount of thread, and a second control function is generated nearly without delay in the case of thread end or thread break. To achieve this, two signal patterns are received with a phase shift from a bobbin acting as a signal generator, and the first signal function is generated in the case of a deviation of the actual phase shift from the desired phase shift. If only one signal pattern is received, this first control function is also generated if its signal sequence deviates from a reference signal sequence. The second control function is generated if a stoppage of the bobbin lasts longer than a predeterminable number of stitches. Devices for carrying out this process, as well as a device for winding thread on the bobbin in different directions of rotation for the principal amount of thread and the residual amount of thread are provided.