Pre-take-up roller mechanism for varying the tension on a running thread in a thread processing machine

摘要

A pre-take-up roller mechanism is provided for varying the tractive force and tension on running thread being wound by a take-up mechanism in a thread processing machine. The mechanism includes a variably driven rotating drive shaft carried by the machine, a thread pre-take-up roller rotatably mounted on the drive shaft for receiving the running thread on the surface thereof and for being driven by the running thread through adhesion, and an eddy current clutch or a combination eddy current and hysteresis clutch operatively connecting the drive shaft and the pre-take-up roller for varying the torque on the pre-take-up roller and thus the tractive force and tension on the running thread by varying the driven rotational speed of the drive shaft without affecting the constant winding speed of the running thread being wound by the take-up mechanism.