Patent ID: 6540307
Filing Date: 2003-04-01
Classification: B60T

Abstract:
A braking system for a road vehicle, comprising:a primary electronic braking circuit; a back-up braking circuit having a source of back-up braking pressure which varies in accordance with braking demand as initiated by a driver; a braking actuator for braking a wheel on a vehicle axle; a changeover valve which is biased into a back-up position in which the back-up braking circuit is connected to the braking actuator and is actuable to a normal braking position during correct operation of the braking system to apply the primary electronic braking circuit to the braking actuator; and a regulating valve located in the back-up braking circuit between the source of back-up braking pressure and the changeover valve and being operable as a function of axle loading and back-up braking pressure to regulate the supply of back-up braking pressure to the changeover valve.