Abstract:
A movable wall assembly for use in a servomotor having a resilient diaphragm with a bead radially compressed in a groove on a hub by a backing plate to form a seal between a vacuum chamber and a power chamber. The diaphragm correspondingly axially urges the wall assembly into contact with the hub to prevent relative movement therebetween.
Abstract:
A servomotor for use in a power braking system having a pressure ratio changer wherein a first piston and a second concentric piston supply a master cylinder with an operative force. The first piston is connected to a wall within the servomotor which is moved by a pressure differential. The second piston is concentrically positioned within the first piston to transmit an input force which operates a control valve that develops the pressure differential, and also operates a hydraulic lock valve located within a master cylinder. As the first piston and the second piston move together in response to movement of the wall, hydraulic fluid will flow into a locking chamber past the lock valve. When the maximum force output capable of being generated by the pressure differential is reached, the simultaneous movement of the first and second pistons will cease. Further manual force input from the operator will move the second piston within the first piston to close the lock valve and hold the hydraulic fluid within the locking chamber to prevent the first piston from moving.
Abstract:
A metering valve apparatus for transferring a servomotor force from a first piston to a second piston in response to an input force to produce an operational braking force. The first and second pistons are initially simultaneously moved by a differential pressure responsive movable wall to pressurize fluid in interconnected first and second chambers in response to the input force. A predetermined input force will independently move the second piston with respect to the first piston to interrupt the communication between the first chamber and the second chamber and allow pressurized fluid to escape into a third chamber. As the pressurized fluid escapes into the third chamber the wall will move to supply the second piston with the servomotor force to further pressurize the fluid in the second chamber.
Abstract:
A pressure differential controlled valve for use in a two stage servomotor to delay the communication between a second pressurizing chamber and a first pressurizing chamber until compensatory fluid, which is lost from the first pressurizing chamber in the transfer of the development of an operational force from a first diameter on a power piston to a second diameter on the power piston is replaced.
Abstract:
A filtering apparatus for use in a pressure differential operated servomotor to provide a primary flow path during a first rate of input force application and a secondary flow path during a second rate of input force application to effectively establish the pressure differential as a direct function of the rate of application of the input force.
Abstract:
A PRESSURE RATIO CHANGING DEVICE FOR A SERVOMOTOR OF A POWER BRAKING SYSTEM. A FIRST PISTON SECURED TO THE HUB MEMBER OF THE MOVABLE WALL OF THE SERVOMOTOR EXTENDS INTO THE HYDRAULIC CHAMBER OF A MASTER CYLINDER. A SECOND PISTON LOCATED IN A BORE WITHIN THE FIRST PISTON ALSO EXTENDS INTO THE HYDRAULIC CHAMBER. DEPRESSION OF AN ACTUATOR BY AN OPERATOR WILL OPEN A VALVE IN THE HUB MEMBER TO CREATE A PRESSURE DIFFERENTIAL ACROSS THE MOVABLE WALL. AS THE WALL MOVES, THE FIRST PISTON WILL ENERGIZE THE MASTER CYLINDER TO PRESSURIZE THE HYDRAULIC FLUID IN THE BRAKING SYSTEM. FURTHER DEPRESSION OF THE ACTUATOR BY THE OPERATOR WILL MOVE THE SECOND PISTON TO ADD TO THE ENERGIZING FORCE OF THE FIRST PISTON. A REACTION MEMBER ADJACENT THE SECOND PISTON WILL SELECTIVELY POSITION THE MOVABLE WALL AND THE ACTUATOR IN PROPORTION TO AN INTERNAL REACTIVE BACK FORCE TO MAINTAIN EQUILIBRIUM WITHIN THE SYSTEM DURING ACTIVATION.