Load responsive fluid control valves
OwnerTadeusz Budzichinventor
Life of this patent
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Abstract
A load responsive direction and flow control valve for use in fluid power load responsive system. The system is powered by a single fixed or variable displacement pump. The valve maintains a selected constant flow level during control of positive loads and automatically blocks pump flow to the actuator in presence of a negative load, providing the actuator inlet flow requirement from the valve exhaust manifold. The direction and flow control valve is equipped with a load responsive control which during control of positive load maintains a constant low pressure level at the actuator outlet and retains its control characteristics in a system in which multiple positive loads are simultaneously controlled.
Claims5
A valve assembly supplied with pressure fluid by a pump comprising a housing having a fluid inlet chamber connected to said pump, a fluid supply chamber, first and second load chambers, and fluid exhaust means, first valve means for selectively interconnecting said fluid load chambers with said fluid supply chamber and said fluid exhaust means, first variable fluid metering orifice means responsive to movement of said first valve means between said fluid supply chamber and said load chambers, second variable fluid metering orifice means responsive to movement of said first valve means between said load chambers and said exhaust means, negative load pressure sensing means between said load chambers and said exhaust means selectively communicable with said load chambers by said first valve means, second valve means having fluid isolating means between said inlet chamber and said supply chamber, said inlet chamber being solely communicable with said supply chamber by said second valve means, said fluid isolating means having means operable to isolate said inlet chamber from said supply chamber when pressure in said negative load pressure sensing means exceeds a certain predetermined level, and fluid replenishing means operable to supply fluid flow to said load chamber isolated by said fluid isolating means.
Dependencies are inferred from the claim text.