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US 5,332,303 AGranted
Anti-lock-controlled brake system
AssigneeAlfred Teves GmbH
InventorHans Wupper
Life of this patent
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AssigneeAlfred Teves GmbH
InventorHans Wupper
Estimating the term…
An anti-lock-controlled hydraulic brake system is described having a pump (9) and a master brake cylinder (1). An arrangement for controlling the pump pressure is integrated in the master brake cylinder ( 1 ) and consists of the combination of a connection of the pump to the master cylinder and reservoir, and a primary seal (30, 34) cooperating with a compensating hole (36) in the master cylinder wall. The seal (30, 34) consists of an elastic ring (37) lying on the inside and of a slide ring (38) lying on the outside. The necessary communication between the storage reservoir ( 7 ) and the brake circuits, which enables the brake circuits to be resupplied via a non-return valve, is effected via the nonreturn valves (10, 11) of the pump (9). The double seal can be backed by a secondary seal (41) which completely seals the working chamber against leakage flow past the primary ring seal.
An anti-lock-controlled brake system including at least one wheel brake, a brake pedal, a master brake cylinder having a housing with an internal bore formed therein, at least one working piston and one working chamber, said working chamber defined in part by one end of said working piston and by said internal bore, said working piston slidably movable in said master cylinder housing, said internal bore of said brake pedal engaged with said working piston, a return spring acting on said working piston in opposition to said brake pedal engagement, said working piston movable towards and away from a retracted position by actuation by said brake pedal and return by said return spring, a storage reservoir, means for communicating said working chamber with said reservoir, including a valve arrangement opening communication when said master brake cylinder is not operated, and closing said communication when said master brake cylinder is operated, a controllably operable pump having a suction side inlet connected to said storage reservoir and a delivery side outlet connected to said working chamber and said at least one wheel brake, a brake line connected to said working chamber and said pump outlet and said wheel brake and a return line connecting said reservoir to said wheel brake, an inlet valve associated with said wheel brake and controlling communication of said wheel brake with said working chamber and pump outlet via said brake line and an outlet valve controlling communication of said reservoir and said wheel brake via said return line and enabling a slip-dependent wheel brake pressure control, said valve arrangement including a primary seal provided on said working piston and retained in an external groove in said working piston adjacent said one end thereof defining said working chamber, said seal comprised of an inner first elastic ring and of an outer second ring of harder material, said outer second ring expanded by said inner first ring to engage said internal bore in said master brake cylinder housing to be in sliding engagement therewith as said working piston is moved in said bore;
An antilock brake system comprising at least one hydraulically operated wheel brake, a brake pedal, a master cylinder having a housing formed with a bore, a piston slidably disposed in said bore defining with one end thereof a working chamber, said piston operatively connected to said brake pedal to be able to be stroked away from a retracted position, said bore to an advanced position, return spring means for returning said piston to said retracted position in said bore, a brake line connecting said master cylinder working chamber to said wheel brake, an inlet valve in said brake line for controlling communication between said working chamber and said wheel brake, a reservoir, a return line extending between said wheel brake and said reservoir for return fluid flow, an outlet valve in said return line controlling communication between said reservoir and said wheel brake, pump means able to be operated to pressurize fluid, said pump means having an inlet connected to said reservoir and an outlet connected to said brake line at a point between said working chamber and said inlet valve, a first one way valve connected to said pump means inlet opening only towards said pump means and a second one way valve connected to said pump means outlet opening only towards said brake line, said first and second one way valves having a negligible opening pressure, a primary seal on said piston adjacent said one end defining said working chamber, said primary seal slidably engaging said master cylinder, a compensating hole entering through said master cylinder bore at an axial location to be just opened directly into said working chamber when said piston moves to said retracted position in which said one end thereof is withdrawn past said compensating hole to allow flow from said reservoir through said compensating hole and past said piston one end and into said working chamber, and a fluid connection between said reservoir and said compensating hole, said pump means open to free fluid flow therethrough in the opening direction of said first and second one way valves when said pump means is not operated and said brake pedal is released, whereby said piston seal and said compensating hole can act to meter flow out of said working chamber to said reservoir when said working chamber is pressurized by said pump means to adjust said pump means pressure to said working chamber pressure level developed by said brake pedal.
Dependencies are inferred from the claim text.