Patent ID: 7170278

Claim:
A device for sensing the axial position, in relation to the other component, of one of two components mobile relative to each other, namely a piston in relation to a cylinder housing of a master or slave cylinder for a hydraulic clutch control for motor vehicles, with a magnetic signal element arranged on the one component, said magnetic signal element being a permanent ring magnet having a north pole facing the one component and a south pole facing away from the one component or vice versa, and at least one magnetic-flux-sensitive sensor arranged on the other component, by means of which the axial relative position of the signal element to the sensor can be detected, and only one flux guide element allocated to the sensor and stationary in relation thereto which on the other component extends on one side of the one component only at least over the area to be detected of axial relative positions of the signal element to the sensor and comprises a plate section of a suitable magnetizable material such as a dynamo core sheet section, wherein the sensor is arranged at one of the longitudinal ends of the flux guide element outside the area to be detected of axial relative positions of the signal element to the sensor, such that a magnetic flux density detected by means of the sensor increases steadily the further the signal element comes to the sensor, and falls steadily the further the signal element moves away from the sensor.