hydraulic geberzylinder with built-in switch

摘要

A master cylinder assembly (10) for controlling a motor vehicle clutch (18) including switches for controlling functions such as enabling the starter motor, disabling the cruise control, or signalling the engine computer. The assembly includes an annular seal assembly (30) disposed in an internal groove (38m,40h) in the wall of the cylinder sealingly engaging the piston (34) of the cylinder and dividing the cylinder into a pressurised chamber on one side of the seal and an unpressurised chamber open to atmosphere on the other side of the seal. A plurality of axially spaced pairs of contacts (50c,50d) are provided on a cartridge (32) on the inner wall of the cylinder in the unpressurised chamber for coaction with an annular contact (50) carried by a flange structure (54g) which forms part of the piston so that as the piston moves axially within the cylinder in response to depression of the clutch pedal (14) annular contact (56) on the piston successively closes circuits associated with the successive spaced pairs of contacts (50c,50d) on the inner wall of the cylinder thus successively enabling or disabling motor vehicle control devices associated with the pairs of cylinder contacts. IMAGE