Actuating mechanism for axial setting purposes, having a double function

An actuating mechanism for axial setting purposes, comprising three discs which are supported co-axially relative to an axis and of which a central disc is rotatable relative to the two outer discs, between the central disc and each of the outer discs, there are arranged sets of balls, the balls each run in pairs of circumferential grooves in the faces of the central disc and of one of the outer discs facing one another, the circumferential grooves comprise a circumferentially variable depth whose extension is such that, over the entire relative angle of rotation, the first outer disc moves axially from a first end position via a central position into a second end position which deviates from said first end position, and the second outer disc moves axially from a first end position via a second end position deviating therefrom back into the first end position.