Transmission mechanism for actuating a friction clutch

A transmission mechanism (1) for actuating a friction clutch which can be disengaged against a spring force and is arranged between an internal combustion engine and a manual transmission, the transmission mechanism comprising:

• two lockable elements (11, 16) consisting of a first element and a second element configured to be moved toward one another longitudinally to automatically change a length and to compensate for clutch wear,
• wherein the first element consists of a spindle (16) coupled to a non-rotatable component of a disengagement mechanism of the friction clutch in a rotationally fixed and axially movable manner and has a region with a (18) with a steep-pitch external thread (19),
• in that the second element consists of a nut (11) having a steep-pitch internal thread (15) complementary to the steep-pitch external thread (19) of the spindle (16),
• wherein the internal and external steep-pitch threads (15, 19) have a pitch dimensioned in such a way that no self-locking can occur between the two elements (11, 16),
• wherein the nut (11) is arranged in a hollow casing (2) immovably fixed to a controlling element of a pneumatic, hydraulic or electromechanical clutch actuator,
• wherein the casing (2) has an axially parallel multi-toothed profile (5) directed radially inwards over a length which substantially corresponds to an actuation path (SB) of the friction clutch,
• wherein the nut (11) interacts with the multi-toothed profile (5) in a non-rotatable manner via a polygonal collar (12) which protrudes radially beyond a cylindrical region (14) of the nut (11) when the friction clutch is disengaged,
• wherein the casing (2) has a free region (4) without a multi-toothed profile (5) at an end of the actuation path (SB) which corresponds to an engaged state of the friction clutch,
• wherein the polygonal collar (12) of the nut (11) is freely rotatable in the free region (4) when a spring force is applied to the polygonal collar (12) while the friction clutch is engaged, and is rotatable relative to the spindle (16) toward an end fitting (7) on the casing (2) by an adjustable wear compensation path (SV) corresponding to a change in length as a result of clutch wear that has occurred.