Vehicle air brake multiple circuit control valve - uses interaction between circuits to prevent brake lock

摘要

The multi-circuit air brake control valve has the brakes of each circuit linked to a separate stepped piston. Part of the brake pressure is derived from the brake control and part from the reaction pressure in the other circuit. If the other circuit fails then the brake force is concentrated on the remaining circuit. Brake lock is prevented because the increase in brake pressure in the remaining circuit is partly compensated for by the loss of brake pressure due to the reaction effect from the other circuit on the stepped piston.