Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A fluid pressure relief valve comprising a housing (1) provided with a pressure inlet (3) and a relief outlet (4), a chamber (6) in communication with the relief outlet, a valve member (5) for controlling fluid flow between the inlet (3) and the chamber (6), the valve member (5) having a seating portion (9) adapted to close the inlet (3) and an area responsive to pressure in the chamber (6), and resilient means (10) biassing the valve member (5) to close the inlet (3) against the pressure applied to the inlet, characterised in that the valve is so constructed and arranged that on initial opening of the valve pressure builds up in the chamber (6), producing a force to act on the valve member (5) in opposition to the force produced by the resilient means (10).
Claim 2
Dependent Claim
136 words
A fluid pressure relief valve comprising a housing (1) provided with a pressure inlet (3) and a relief outlet (4), a chamber (6) in communication with the relief outlet, a valve member (5) for controlling fluid flow between the inlet (3) and the chamber (6), the valve member (5) having a seating portion (9) adapted to close the inlet (3) and an area responsive to pressure in the chamber (6), and resilient means (10) biassing the valve member (5) to close the inlet (3) against the pressure applied to the inlet, characterised in that the valve is so constructed and arranged that on initial opening of the valve pressure builds up in the chamber (6), producing a force to act on the valve member (5) in opposition to the force produced by the resilient means (10).
Claim 3
Dependent Claim
33 words
A fluid pressure relief valve according to claim 1, characterised in that the valve member (5) has passage means (8, 7) providing a fluid connection between the chamber (6) and the outlet (4).
Claim 4
Dependent Claim
87 words
A fluid pressure relief valve according to claim 2, characterised in that the passage means (8, 7) provides the only connection between the chamber (6) and the outlet (4), so that once the valve has opened fully in response to the pressure in the chamber (6) it remains open, fluid flow to the outlet (4) being through the passage means (8, 7), and the valve being constructed and arranged to allow pressure build-up in the chamber (6), and a suitable relief flow rate from the chamber (6).
Claim 5
Dependent Claim
41 words
A fluid pressure relief valve according to claim 2, characterised in that there is a second fluid connection (14) between the chamber (6) and the outlet (4), fluid flow through the second connection (14) being controlled by the valve member (5).
Claim 6
Dependent Claim
44 words
A fluid pressure relief valve according to claim 4, characterised in that fluid flow through the second connection (14) is controlled by movement of the valve member (5) in response to pressure in the chamber (6) and the force in the resilient means (10).
Claim 7
Dependent Claim
100 words
A fluid pressure relief valve according to claim 5, characterised in that the second connection (14) is closed when the valve member (5) closes the inlet (3), and on initial opening of the valve, and opens as the valve opens fully to relieve the fluid pressure in the chamber (6), the resilient means (10) then acting to return the valve member (5) to close the second connection (14) but not the inlet (3), allowing pressure to build up in the chamber (6) so that the valve member (5) moves to open the valve fully and the second connection (14) again.
Claim 8
Dependent Claim
29 words
A fluid pressure relief valve according to any preceding claim, characterised in that the valve member comprises a spool (5) sliding in a bore (2) in the housing (1).
Claim 9
Dependent Claim
23 words
A fluid pressure relief valve according to any preceding claim, characterised in that the valve member (5) has a conical seating portion (9).
Claim 10
Dependent Claim
36 words
A vehicle hydraulic system comprising a fixed displacement engine-driven pump for supplying an accumulator for a vehicle braking system and an hydraulic suspension system, and incorporating a fluid pressure relief valve according to any preceding claim.