Vacuum suspended disc brake

A disc brake and actuator assembly comprising:

• a housing;
• diaphragm means separating said housing into two chambers;
• rotor and stator disc means supported in one chamber of the housing;
• means for producing a differential pressure in said housing including a vacuum and pressure source, said vacuum acting in said one chamber to move the rotor and stator disc means into braking engagement and said pressure source, including atmospheric air received through an intake port, acting in the other of said chambers;
• a double acting valve movable for selectively connecting said chambers either together or the second chamber with the inlet port;
• fluid actuated piston means acting in a cylinder and connected to said valve to provide said movement;
• whereby, in one valve position, the vacuum acts on both said chambers while communication to said inlet port is closed, in a second valve position the vacuum acts on said one chamber while said other chamber communicates with the atmosphere through the inlet port, and in a third valve position the vacuum acts on said one chamber, the inlet port is closed and the atmospheric air trapped in the cylinder between the piston and other chamber is compressed for additional force on the diaphragm area in said other chamber.