Hydraulic control valve assemblies for hydraulic braking systems

A hydraulic control valve assembly comprising:

• a spool valve, wherein said spool valve comprises a spool body, a spool housing having a bore, a spool working in said bore, and said housing in turn being sealingly received in said spool body, wherein biasing means are incorporated for urging said spool housing in a given direction, wherein said biasing means comprise a resilient device acting between said spool body and said spool housing to bias said spool housing relatively away from said spool body.

A hydraulic control valve assembly comprising:

• a spool valve, wherein said spool valve comprises a spool body, a spool housing having a bore, a spool working in said bore, and said housing in turn being sealingly received in said spool body, wherein biasing means are incorporated for urging said spool housing in a given direction, incorporating a solenoid body, and a solenoid contained within said solenoid body for controlling operation of said spool valve, said solenoid having an armature, wherein said spool is of differential outline and said bore in which said spool works is of complementary stepped outline so chosen that, in operation, a feed back force is transmitted to said armature of said solenoid.

A hydraulic control valve assembly comprising:

• a spool valve, wherein said spool valve comprises a spool body, a spool housing having a bore, a spool working in said bore, and said housing in turn being sealingly received in said spool body, wherein biasing means are incorporated for urging said spool housing in a given direction wherein said spool and said housing are each respectively in the form of first and second spool members, which co-operate at adjacent ends, and first and second housing components, also which co-operate at adjacent ends.