Fluid-pressure operated braking systems for vehicles
AssigneeLucas Industries public limited company
InventorGlyn P. R. Farr
Life of this patent
Estimating the term…
Abstract
In a fluid-pressure operated braking system for vehicles operating fluid from a supply for actuating a wheel brake is supplied to the brake through a skid control unit interposed in the line between the supply and the brake, and a skid responsive device responsive to a skid signal is incorporated for operating a valve assembly to relieve the pressure of the fluid supplied to the brake at a skid point. The unit incorporates a memory chamber for controlling the rate of brake re-application following correction of a skid, and the memory chamber is charged with air only when the skid signal is received. When separate control units are provided for the brakes of wheels at opposite ends of an axle, the memory chambers are interconnected by a pneumatic connection incorporating a restrictor.
Claims15
A fluid-pressure operated braking system for vehicles comprising a wheel brake, a supply of operating fluid for applying said brake, a line between said supply and said brake, a skid control unit disposed in said line between said supply and said brake, said skid control unit incorporating valve means for relieving pressure of fluid supplied to said brake at a skid point, means responsive to a skid signal for operating said valve means, said skid control unit also incorporating a memory chamber means controlled responsive to a skid signal for storing a memory pressure dependent upon said pressure of said fluid applied to said brake at said skid point, means which is held operated for the duration of said skid signal for maintaining a pressure in the memory chamber which was fixed at the pressure which was prevailing when the skid signal occurs, and means responsive to an end of a skid signal for enabling said pressure in said memory chamber to decay at a controlled rate to control the rate of re-application of said brake following correction of said skid, said memory chamber being charged with air only when said skid signal is received.
A fluid-pressure operated braking system, for vehicles comprising a wheel brake, a supply of operating fluid for applying said brake, a line between said supply and said brake, a skid control unit disposed in said line between said supply and said brake, said skid control unit incorporating valve means for relieving pressure of fluid supplied to said brake at a skid point, and means responsive to a skid signal for operating said valve means, wherein said skid control unit also incorporates a memory chamber for controlling the rate of re-application of said brake following correction of said skid, and said memory chamber is charged with air only when a skid signal is received, and wherein said skid control unit incorporates an application chamber, a main valve assembly for controlling the supply of fluid from said supply to said brake, said application chamber being responsive to a control pressure to generate a force to operate said valve assembly, a main piston for operating said main valve assembly and having a pressure-responsive face responsive to said control pressure to operate said main valve assembly, a second piston having a pressure-responsive face arranged in opposition to said pressure-responsive face of said main piston and defining a wall of said memory chamber, coupling means coupling said main piston and said second piston together, and a valve operable by said means responsive to said skid signal, said valve being movable between a first position to isolate said memory chamber from said application chamber when no skid signal is present and a second position to place said memory chamber in communication with said application chamber when a skid signal is present.
A fluid-pressure operated braking system for vehicles comprising first and second brakes on respective first and second wheels on opposite ends of an axle, a supply of operating fluid for actuating both said first and second brakes, a first line between said supply and said first brake, a second line between said supply and said second brake, a first skid control unit in said first line between said supply and said first brake, a second skid control unit in said second line between said supply and said second brake, first means associated with said first control unit and responsive to a skid signal from said first wheel, first valve means responsive to said first means to relieve the pressure of fluid supplied to said first brake at a skid point, second means associated with said second control unit and responsive to a skid signal from said second wheel, second valve means responsive to said second means to relieve the pressure of fluid supplied to said second brake at a skid point, said first control unit incorporating a first memory chamber for controlling the rate of re-application of said first brake following correction of said skid, and said first memory chamber being charged with air only when a skid signal is recieved, said second control unit incorporating a second memory chamber for controlling the rate of re-application of said second brake following correction of said skid, and said second memory chamber being charged with air only when a skid signal is received, wherein a pneumatic connection incorporating a restrictor interconnects said first and second memory chambers.
Dependencies are inferred from the claim text.