Patent ID: 7997108

Claim:
A disengageable cylinder for a motor vehicle lock mechanism, comprising: a fixed stator; a tubular intermediate sleeve which is mounted in rotation about its axis in the stator and which is fixed axially with respect to the stator; a rotor which is mounted in rotation in the sleeve, which is fixed axially in the sleeve and which comprises tumblers which can move radially under the action of a key intended to be inserted axially into the rotor, the rotor and the intermediate sleeve being blocked against rotation with respect to one another by the tumblers when the key is not appropriate; a driver providing a coupling between the rotor and a cam actuator, when the key is appropriate; and an indexer which can move axially between a rest position and a disengagement position and which is rotationally immovable, under the effect of a rotation of the sleeve with respect to the stator subsequent to the rotor being rotated by means of an inappropriate key, so as to move the driver axially toward a disengaged position, wherein the indexer and the driver are cylindrical parts surrounding the rotor and can move while fitted one inside the other, in that the driver is connected in translation on the rotor, wherein the indexer is connected in translation in the stator, and wherein the rotationally immovable indexer is coupled in rotation with the cam actuator in said disengaged position, thereby blocking the cam actuator from rotation in said disengaged position.