Abstract: The disclosure concerns an actuating knob which is particularly useful for the window crank of an automotive vehicle, wherein the actuating knob is adapted to break off in the event of high impact. The knob comprises an outer knob part to be grasped and an inner knob part which serves as a pivot pin for the outer knob part. A tapered thickness region of the pivot pin is adapted to break off upon impact. Detent pins beneath the pivot pin connect with the crank arm. A blocking member installed between the detent pins holds them apart and the blocking member is detent connected to the pivot pins to prevent subsequent removal. The pivot pin has a widened lower borehole for receiving the blocking member and a narrowed diameter upper portion of that serves as the pivot pin for the outer knob part.