The present invention concerns both a procedure for start-up spinning of a thread in a open-end spinning apparatus and an apparatus for the execution of this procedure.
In accord with a known method, the end of a thread extending from a preparatory position in a thread withdrawal tube of a open-end spinning apparatus is conducted back to a fiber collection surface of an open-end spinning apparatus (DE 27 554 A1) by a sudden reversal of auxiliary rolls. By another reversal of rotation of the auxiliary rolls, the thread, now in its starting spinning operation, is once again withdrawn form the open-end spinning apparatus. The return delivery speed and the lost time up to the initiation of thread withdrawal depend upon the inertia of the auxiliary rolls. Especially, in view of today's customary high speed of rotation of the spin elements, which are designed as spin rotors with small rotor diameters, the dwell time, during which the returned thread end can remain on the fiber collection surface (that is, in the rotor grooving) until the start of the spinning withdrawal, can be measured in very short increments. This time period cannot be controlled by the known apparatus or it can only be maintained by the exercise of considerable effort.