Abstract: An hydraulic braking system is disclosed which comprises a fluid source and brake actuators, wherein a first master control valve is provided to supply substantially equal pressures to all brake actuators and additional control valves are provided to regulate pressures applied to respective ones of said brake actuators. The first control valve and the additional control valves are provided in series between the fluid source and the brake actuators so that operation of the master control valve allows equal hydraulic pressures to be applied to each actuator while the additional control valves allow individual brake regulation and in an emergency operation of the master control valve allows for automatic operation of all the actuators.

Abstract: A compound disc brake comprises a pair of pressure plates with a ball and ramp camming mechanism, one of the plates comprises a driven plate keyed to a rotating axle shaft to be braked, and the other plate comprises a servo plate carried from the driven plate by the camming mechanism. The servo plate has a torque-transmitting structure in the form of a separate annular disc keyed to the outer peripheral edge of the servo plate. The torque-transmitting structure transmits torque applied to that region by a primary braking apparatus to the central region of the servo plate. Retardation of the servo plate by the primary braking apparatus causes the pressure plates to separate axially and move into engagement with relatively stationary braking surfaces in the brake housing whereafter servo braking occurs.

Abstract: In a power assistance system for a vehicle steering mechanism fluid pressure providing the assistance is supplied from a pump driven intermittently by an infinitely-variable electric motor. For a rack and pinion mechanism fluid pressure chambers are formed by sealing boots at each end of the rack, and are connected through the pump, which is operative to create a pressure differential between the chambers, and thus across the rack to provide power assistance. The electric motor is energized as required to drive the pump in the appropriate direction, and when the motor and pump are inoperative fluid is allowed to flow freely between the chambers to accommodate fluid displacement as a result of unassisted operation of the steering. The pump is preferably a turbine pump, which allows fluid flow when inoperative. The system provides power assistance efficiently, and relatively cheaply.

Abstract: An hydraulic pump and motor assembly for a vehicle hydraulic system has a housing accommodating the pump and motor, the pump having one or more spring-loaded pistons working in complementary bores to pump hydaulic fluid from a reservoir port to a delivery port, and the pistons being operated from an eccentric on a rotary output shaft of the motor through a cam bearing assembly. The assembly includes a retaining device for the pistons to limit their radially inwards movement, when the motor output shaft is removed, to an amount which is insufficient to break the hydraulic circuit containing the pistons. This enables the motor to be removed, while ensuring that the pistons are retained in their bores so that the hydraulic circuit remains intact. The cam bearing assembly may be mounted on the shaft without being retained on it, with the engagement between the pistons and the cam bearing assembly arranged so that they are all retained in the housing on withdrawal of the output shaft.

Abstract: A fuel injection nozzle of the inwardly opening type has a valve member which is movable against the action of a spring by fuel under pressure to allow fuel flow through an outlet. The valve member is coupled to a piston which is slidable within a cylinder formed in a part. The cylinder forms a damping chamber from which there is a leakage path and the part is axially adjustable to determine the degree of restriction.