Vehicle braking systems
AssigneeGirling Limited
InventorGlyn Phillip Reginald Farr
Life of this patent
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Abstract
In a pressure reducer valve assembly for a vehicle braking system a valve member co-operates with a valve seat of which opposite sides communicate with an inlet connected to a master cylinder and an outlet for connection to a brake, a pressure responsive member controls the position of the valve member in opposition to a spring urging the valve member away from its seat and the position of an abutment member for the spring is controlled in response to a difference in the pressures in two pressure spaces of a master cylinder which supply independent braking circuits.
Claims8
A pressure reducer valve assembly for a vehicle braking system comprising a housing, said housing having means defining first and second inlets for connection to first and second pressure spaces of a master cylinder and means defining an outlet for connection to a rear wheel brake, said housing being provided with a bore, a valve member positioned in said bore, a valve seat of which opposite sides communicate with said first inlet and said outlet, resilient means urging said valve member away from said seat, a pressure responsive member for controlling the position of said valve member, pressure at said first inlet acting on said pressure responsive member so as to urge said valve member towards said seat, abutment means for said resilient means, and means for controlling the position of said abutment means in response to the difference in pressure at said first and second inlets, means being provided for transmitting increase of pressure in said first pressure space up to a threshold value by said reducer valve assembly directly to said outlet to said rear wheel brake, said means transmitting said increases in pressure at pressures above said threshold value at a reduced rate, and said pressure reducer valve being responsive to the difference in pressure between said first and second inlets connected to said pressure spaces and including means for reducing said threshold value upon failure of the pressure at said second inlet.
A pressure reducer valve assembly for a vehicle braking system comprising a housing, said housing having means defining first and second inlets for connection to first and second pressure spaces of a master cylinder and means defining an outlet for connection to a wheel brake, said housing being provided with a bore, a valve member positioned in said bore, a valve seat of which opposite sides communicate with first inlet and said outlet, resilient means urging said valve member away from said seat, a pressure responsive member for controlling the position of said valve member, pressure at said first inlet acting on said pressure responsive member so as to urge said valve member towards said seat, abutment means for said resilient means, and means for controlling the position of said abutment means in response to the difference in pressures at said first and second inlets, and a member adapted to be connected to a part of the vehicle and responsive to changes in the distribution of load on the vehicle wheels during braking, said member being arranged to change the loading of said resilient means said resilient means comprising a spring external to said valve assembly housing.
A pressure reducer valve assembly for a vehicle braking system comprising a housing, said housing having means defining first and second inlets for connection to first and second pressure spaces of a master cylinder and means defining an outlet for connection to a wheel brake, said housing being provided with a bore, a valve member positioned in said bore, a valve seat of which opposite sides communicate with said first inlet and said outlet, resilient means urging said valve member away from said seat, a pressure responsive member for controlling the position of said valve member, pressure at said first inlet acting on said pressure responsive member so as to urge said valve member towards said seat, abutment means for said resilient means, and means for controlling the position of said abutment means in response to the difference in pressures at said first and second inlets, wherein said pressure responsive member comprises a rod, said abutment member being provided at one end with a stepped blind bore, said rod working in said stepped bore, said rod being provided at its inner end with a reduced stem, a radial flange on said rod backing said reduced stem, and an integral valve head on said rod comprising said valve member.
A vehicle hydraulic braking system incorporating a tandem master cylinder in which are defined first and second pressure spaces, first and second actuators on each of a pair of front wheels of a vehicle, and actuators on each of a pair of rear wheels of a vehicle, said first pressure space being connected directly to said first actuators on each of a pair of front wheels of the vehicle, and indirectly through said pressure reducer valve assembly to said actuators on each of a pair of rear wheels of the vehicle, and said second pressure space being connected directly to said second actuators on each of the front wheels, and a pressure reducer assembly, said pressure reducer valve assembly comprising a housing, said housing having means defining first and second inlets for connection to first and second pressure spaces of a master cylinder and means defining an outlet for connection to a wheel brake, said housing being provided with a bore, a valve member positioned in said bore, a valve seat of which opposite sides communicate with said first inlet and said outlet, resilient means urging said valve member away from said seat, a pressure responsive member for controlling the position of said valve member, pressure at said first inlet acting on said pressure responsive member so as to urge said valve member towards said seat, abutment means for said resilient means, and means for controlling the position of said abutment means in response to the difference in pressures at said first and second inlets, means being provided for transmitting increases of pressure in said first pressure space up to a threshold value by said reducer valve assembly directly to said rear wheel actuators, said means transmitting said increases in pressure at pressures above said threshold value to said rear wheel actuators at a reduced rate, and said pressure reducer valve being responsive to the difference in pressure between said first and second pressure spaces and including means for reducing said threshold value upon failure of the pressure in said second pressure space.
Dependencies are inferred from the claim text.