Patent ID: 7201204

Claim:
A self-centering unit for tire removal machines, comprising a plate having a plurality of angularly equidistant radial slots therein and a clamping jaw in abutting engagement in each of said slots so as to slide in said slot and grip the edge of a wheel rim, said clamping jaws being directly linked together by linking means for moving all of said clamping jaws together always equidistant from the central axis of said plate, at least one of said clamping jaws being operably connected with an actuator which moves said linking means to translate each of said clamping jaws a same distance in a radial direction towards or away from the central axis of the plate, wherein a positioner device is interposed between said at least one of said clamping jaws and said actuator means, the positioner device being arranged to vary a working position of said at least one of said clamping jaws relative to the actuator without modifying the travel stroke of said clamping jaws, the positioner device comprising a crankshaft provided with a crank having a crankpin, said crankpin being received in a bushing rigid with said clamping jaw and the crank being connected to said actuator, and means for locking said crankshaft in different working positions.