Pilot operated valve
AssigneeHaldex Brake Products AB
InventorsEdward Shaw, Laurence Potter
Life of this patent
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Abstract
A valve assembly having a fluid switch and a main valve for controlling fluid pressure in a working volume in three control states wherein the main valve has three ports for fluid, flow of fluid through a first port and a second port being controlled by the fluid switch being provided with an electrical signal in a first state or a second state respectively, and flow of fluid through the third port being controlled by alternating said signal, preferably rapidly, between said first and second states.
Claims43
A fluid switch giving three outputs from a three port, two position structure, actuated by an electrical supply which may be high or low to provide two of said outputs or switched, preferably rapidly, therebetween to provide the third output.
A fluid switch substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
A valve assembly having a fluid switch and a main valve for controlling fluid pressure in a working volume in three control states wherein the main valve has three ports for fluid, flow of fluid through a first port and a second port being controlled by the fluid switch being provided with an electrical signal in a first state or a second state respectively, and flow of fluid through the third port being controlled by alternating said signal, preferably rapidly, between said first and second states.
A valve assembly having an electrically operated fluid switch control device having two seats and a switch member movable alternatively into sealing engagement with the seats to connect a control chamber of a main valve to a supply of fluid under pressure when the switch member is in a first position and in engagement with one seat and to a low pressure region when the switch member is in a second position and in engagement with the other seat, a body of the main valve having a first chamber in which a first piston is mounted for movement under the influence of fluid pressure in the control chamber, a second piston movable in a second chamber provided in the first piston under the influence of fluid pressure in a supply port, the second piston being movable into engagement with a third seat provided on the first piston to control passage of fluid from a delivery to an exhaust and being movable into engagement with a fourth seat provided on said body to control passage of fluid from a supply to the delivery and a control means to energise the fluid switch to position said switch member
- a. in said first position
- b. in said second position
- c. to alternate the position of the valve member between said first and second positions.
A valve assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
Any novel feature or novel combination of features described herein and/or in the accompanying drawings.
Dependencies are inferred from the claim text.