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.
Claims12
A valve assembly supplied with pressure fluid by a pump comprising a housing having a fluid inlet chamber, a fluid supply chamber, first and second load chambers, load pressure sensing port means operable to transmit a control signal to said pump, and fluid exhaust means, first valve means for selectively interconnecting said fluid load chambers with said load pressure sensing port means, said fluid supply chamber and said fluid exhaust means, variable fluid metering orifice means responsive to movement of said first valve means between said load chambers and said exhaust means, second valve means having throttling means and isolating means between said inlet chamber and said supply chamber operable to throttle by said throttling means fluid flow from said inlet chamber to said supply chamber to maintain a relatively constant low pressure level in one of said load chambers connected to said exhaust means by said first valve means and to isolate by said isolating means said inlet chamber from said supply chamber when pressure in one of said load chambers connected to said exhaust means by said first valve means exceeds said relatively constant low pressure level, and connecting means to connect said supply chamber with said exhaust means when said isolating means isolates said inlet chamber from said supply chamber.
A valve assembly supplied with pressure fluid by a pump comprising a housing having a fluid inlet chamber, 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, variable fluid metering orifice means responsive to movement of said first valve means between said load chambers and said exhaust means, second valve means having throttling means and isolating means between said inlet chamber and said supply chamber operable to throttle by said throttling means fluid flow from said inlet chamber to said supply chamber to maintain a relatively constant low pressure level in one of said load chambers connected to said exhaust means by said first valve means and to isolate by said isolating means said inlet chamber from said supply chamber when pressure in one of said load chambers connected to said exhaust means by said first valve means exceeds said relatively constant low pressure level, and connecting means to connect said supply chamber with said exhaust means when said isolating means isolates said inlet chamber from said supply chamber.
Dependencies are inferred from the claim text.