Compressor 1 delivers compressed air into tank 2. Relief valve 3 maintains a constant air pressure in the system. Braking is performed by depressing the pedal of brake valve 5, connected to air tank 2. Valve 5 is connected through rapid-release valve 7 to brake chambers 8 of the front wheels, and through acceleration valve 9 to brake chambers 6 of the rear wheels. In addition, acceleration valve 9 is connected to the air tank. The purpose of rapid-release valve 7 is to discharge the air from the front brake chambers as rapidly as possible to the atmosphere, by-passing brake valve 5. The provision of acceleration valve 9 shortens the path of the compressed air to the brake chambers. Pressure regulator 4 switches the compressor over to idle running.
$4296$CHP,Br$