VEHICLE BRAKING SYSTEM

摘要

A braking system comprising a first braking demand signal generator, a modulator which is connected to a source of pressurised fluid via a first fluid flow line, the modulator being connected to and having an input for receipt of a braking demand signal from the braking demand signal generator and further connected to a first braking chamber in a fluid operated brake actuator via a second fluid flow line, the modulator being adapted, on receipt of a braking demand signal from the first braking demand signal generator, to allow pressurised fluid to pass from the source of pressurised fluid to the actuator, the actuator being configured such that passage of pressurised fluid from the modulator into the first chamber causes the actuator to move to a brake apply position, the system further comprising a second braking demand signal generator which is connected to a controller, the controller having an input for receipt of a braking demand signal from the second braking demand signal generator and controlling flow of fluid from the source of pressurised fluid to a second chamber of the brake actuator, the brake actuator being further provided with a mechanical biasing element which biases the actuator into a position which causes the vehicle brake to be applied and being configured such that the passage of pressurised fluid into the second chamber causes the actuator to be moved against the force of the mechanical biasing element out of the position which causes the vehicle brake to be applied, wherein the second chamber is connected to the source of pressurised fluid via at least a portion of the first fluid flow line.