Blockierschutzgeraet

摘要

1304049 Anti-skid systems ROBERT BOSCH GmbH 26 March 1970 [27 March 1969] 14632/70 Heading F2F A compressed air, vacuum or hydraulic pressure fluid system for preventing a vehicle brake 3 from locking an associated vehicle wheel comprises a master cylinder 1 from which fluid can be transmitted through a brake line 2 for actuating the brake, a floating piston 71 provided in the line 2 and actuable by a servomechanism to relieve the pressure in the brake line in response to the associated wheel commencing to lock, the servomechanism including a two-way valve which, in a first position, connects the working chamber 91 of the servomechanism to atmosphere and which, when actuated by a signal issued from a wheel lock sensing device, moves to a second position in which the chamber 91 is connected to a source 20 of pressure medium and the piston 71, and flow control means, including a throttle, for varying the rate of flow of pressure medium to and/or from the chamber 91. As shown, the sensing device transmits a signal to solenoid 21 of the two-way valve whereby the closure member of the valve engages valve seat 14 so that pressure medium flows to the chamber, the pressure difference between the source 20 and the chamber being such as to raise the valve closure member 18 and as the pressure in the chamber approaches that of the source the member 18 is seated so that pressure medium now flows through throttling hole 15. The piston 9 and rod 8 are displaced so that the rod closes the bore 6 of the piston 71 whereby the pressure from the master cylinder 1 is reduced. Upon cessation of the signal from the sensing device the solenoid of the two-way valve is deenergized and the closure member of the valve engages the seat 13 so that pressure medium flows from the chamber 91 to atmosphere at 211. In a modification, the inlets of the two-way valve are connected to the pressure source 20 and atmosphere via an accumulator and a throttling aperture.