REIBUNGSKUPPLUNG MIT WEGSENSOR

A friction clutch (1, Fig. 1) for a motor vehicle is actuable via a system comprising a hydraulic master cylinder (2, Fig. 1) and slave cylinder (3, 4, 5; Fig 1) having a displacement sensor, which determines the clutches state of wear, combined with the slave cylinder to form a unit. The slave cylinder may be arranged outside the clutch and connected by a release rod (7, Fig. 1). Alternatively the slave cylinder may 46 be combined with the release bearing 6 to form a unit arranged around gear shaft 1b. The displacement sensors may be a mechanical/electrical limit switch 22, 29, a hydraulic pressure-operated switch (23, Fig. 5) or a displacement sensor, eg variable resistor (37, 38; Fig. 7). Both arrangements of slave cylinder may be provided with a limit arrangement may be provided with the pressure switch (23, Fig. 5). A displacement sensor of this type does not necessitate constructional modifications to the clutch and is only slightly affected by tolerances of the release system.