Abstract: Method for controlling a thread joining process having several thread joining steps and occuring by starting a rotor of an open end rotor spinning machine, which includes choosing a narrow limited rotor speed range for the beginning of a starting process of a specific thread joining step, which occurs after a first thread joining step, and selectively starting and finishing thread joining steps in substantially constant given intervals before and after the beginning of the starting process, and an apparatus for carrying out the method.

Abstract: Method of controlling a thread-joining operation in a rotor-spinning machine having a rotor formed with a fiber-collecting channel, wherein a pulse proportional to the rotary speed of the rotor is applied to control a measure of the material being processed in the spinning operation which includes automatically controlling advance feeding into the rotor of a quantity of fiber required for thread-joining and feeding the fiber beginning with withdrawal of a thread formed for the fiber as well as returning into the rotor the thread end to be joined and withdrawing the joined thread from the rotor during start-up of the rotor, the automatic control being in accordance with a quantity proportional to the peripheral velocity of the fiber-collecting channel of the rotor serving as control input variable for at least one of the fiber feed, the thread withdrawal, the beginning of the advance feeding and the beginning of the returning of the thread end, and device for carrying out the method.