Hydraulic master cylinder with integral switch structure

摘要

A master cylinder assembly for controlling a motor vehicle clutch including switches for controlling functions such as enabling the starter motor, disabling the cruise control, or signaling the engine computer. The assembly includes an annular seal disposed in an internal groove in the wall of the cylinder sealingly engaging the piston of the cylinder and dividing the cylinder into a pressurized chamber on one side of the seal and an unpressurized chamber open to atmosphere on the other side of the seal. The plurality of axially spaced pairs of contacts are provided on the inner wall of the cylinder in the unpressurized chamber for coaction with an annular contact carried by a flange structure defined by the piston so that as the piston moves axially within the cylinder in response to depression of the clutch the annular contact on the piston successively closes circuits associated with the successive spaced pairs of contacts on the inner wall of the cylinder whereby to successively enable or disable motor vehicle control devices associated with the pairs of cylinder contacts.