Lucas Industries Public Limited Company

Grau Gmbh

Colin F Ross

Robert D Prescott

Malcolm Brearley

Mark Ian Phillips

William S Broome

Denis J McCann

A vehicle braking system comprising a controller responsive to wheel speed signals from at least two wheel speed sensors for sensing skid conditions of at least two wheels and for generating skid control instructions; a plurality of wheel brakes responsive to fluid pressure, hereinafter referred to as brake pressure, supplied thereto; a supply device, comprising a common supply valve, for supplying brake pressure to the brakes from a fluid pressure supply in accordance with a brake operating signal; and a skid controller controlled by the skid control instructions for controlling the brake pressure in a plurality of cycles each of which comprises a pressure reduction phase and a pressure increase phase, and a first comparitor to compare the co-efficient of friction of the lower friction surface with a predetermined threshold, and/or a second comparitor to compare the relative values of the co-efficients of friction of the surfaces with which at least two of the wheels are engaged and a device to operate the skid controller in a select low mode if the comparitors determine that a) the co-efficient of friction of the lower friction surface is above a predetermined absolute level, and/or b) the co-efficients of friction of the surfaces with which at least two of the wheels are engaged differ by less than a predetermined amount, and in a select high mode if the comparitors determine that a) the co-efficient of friction of a lower friction surface is at or below a predetermined absolute level, and/or b) the co-efficients of friction of the surfaces differ by at least the predetermined amount.

Vehicle braking system

Multi-channel vehicle braking system with multiple supply valves and

An anti-skid braking system for a vehicle comprising a supply of fluid for actuating a plurality of wheel brakes, a skid control unit interposed between the fluid supply and the brakes, sensors to detect the skidding of a plurality of wheels and actuating means responsive to skid signals from the sensors and adapted to actuate the skid control unit to relive the fluid pressure at the brake of the wheel at impending lock by means of a plurality of successive first brake release periods. In order to reduce yawing, when an impending skid condition is detected at one wheel, the skid control unit is arranged to induce second, shorter brake release periods in one or more of the brakes of the wheels not at impending lock.

Anti-skid braking systems for vehicles

A trailer air braking system has combined spring brake and service brake actuators, and the service brake chambers of the actuators are controlled by a combined emergency relay and modulator valve assembly of known construction. In order to ensure that the spring brake function does not become operative due to a moderate loss in the pressure of the trailer reservoir, such as would occur in the event of an anti-skid test in which the reservoir is isolated from the emergency line and the modulator valve is cycled, a spring brake one-way control valve is inserted into the spring brake circuit leading from the reservoir. The control valve acts in one condition as a one-way valve to prevent air returning from the spring brake actuator chamber to the reservoir, but on a large loss in reservoir pressure, a piston which carries the one-way valve seat and is subjected to reservoir pressure moves under spring biassing such that the one-way poppet valve member is unseated by a control pin to permit a reduction in spring brake pressure.

Vehicle anti-skid air braking systems

Growing community of inventors

Kidderminster, United Kingdom

Colin F Ross