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US 3,984,979 AGranted
Load responsive fluid control valves
OwnerTadeusz Budzichinventor
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OwnerTadeusz Budzichinventor
Estimating the term…
A load responsive direction and flow control valve for use in fluid power load responsive system. The valve maintains a selected constant flow level for control of both positive and negative loads, irrespective of the change in the load magnitude or change in the fluid pressure, supplied to the valve. When controlling positive or negative loads the valve maintains a constant pressure differential across a flow control metering orifice utilizing a single control slide member, first by throttling fluid entering the inlet chamber and then by throttling the fluid leaving the outlet chamber. The valve may be used with fixed displacement pumps, fixed displacement pumps equipped with differential pressure relief valves, with variable displacement pumps equipped with pressure compensators and variable displacement pumps equipped with differential pressure compensators.
A valve assembly comprising a housing having a fluid inlet chamber, a fluid supply chamber, first and second fluid load chambers, a fluid outlet chamber, a fluid exhuast chamber, and fluid exhaust means, first valve means for selectively interconnecting said fluid load chambers with said fluid supply chamber and said fluid outlet chamber, variable fluid metering means between said fluid exhaust chamber and said fluid exhaust means, first throttling means responsive to pressure in said exhaust chamber and operable to control fluid flow from said fluid inlet chamber to said fluid supply chamber to maintain said pressure in said fluid exhaust chamber at a first relatively constant preselected level when one of said fluid load chambers in interconnected with said fluid outlet chamber and when pressure in said outlet chamber is at said first relatively constant preselected level, and second throttling means responsive to pressure in said fluid exhaust chamber and operable to control fluid flow from said fluid outlet chamber to said fluid exhuast chamber to maintain said pressure in said fluid exhaust chamber at a second relatively constant preselected level when one of said fluid chambers is interconnected with said fluid outlet chamber and when pressure in said fluid outlet chamber is higher than said second preselected pressure level.
A valve assembly comprising a housing having a fluid inlet chamber, a fluid supply chamber, first and second fluid load chambers, a fluid outlet chamber, a fluid exhaust chamber and fluid exhaust means, first valve means for selectively interconnecting said fluid load chambers with said fluid supply chamber and said fluid outlet chamber, variable metering orifice means between said fluid exhaust chamber and said fluid exhaust means, and second valve means interconnecting said fluid inlet chamber with said fluid supply chamber and said fluid outlet chamber with said fluid exhaust chamber operable responsive to fluid pressure in said fluid exhuast chamber, said second valve means having first and second throttling means, said first throttling means on said second valve means being operable to throttle fluid flow from said fluid inlet chamber to said fluid supply chamber to maintain pressure in said fluid exhaust chamber at a first relatively constant preselected pressure level when one of said fluid load chambers is interconnected with said fluid outlet chamber and said fluid outlet chamber is at said first relatively constant preselected pressure level, said second throttling means on said second valve means being operable to throttle fluid flow from said fluid outlet chamber to said fluid exhaust chamber to maintain pressure in said fluid exhaust chamber at a second relatively constant preselected pressure level when one of said fluid load chambers is interconnected with said fluid outlet chamber and when pressure in said fluid outlet chamber is higher than said second relatively constant preselected pressure level.
A valve assembly comprising a housing having a fluid inlet chamber, a fluid supply chamber, first and second fluid load chambers, a fluid outlet chamber, a fluid exhaust chamber and fluid exhaust means, first valve means for selectively interconnecting said fluid load chambers with said fluid supply chamber and said fluid outlet chamber, variable metering orifice means between said fluid exhaust chamber and said fluid exhaust means, and second valve means interconnecting said fluid inlet chamber with said fluid supply chamber and said fluid outlet chamber with said fluid exhaust chamber operable responsive to fluid pressure in said fluid exhaust chamber, said second valve means having first and second throttling means, said first throttling means on said second valve means being operable to throttle fluid flow from said fluid inlet chamber to said fluid supply chamber to maintain pressure in said fluid exhaust chamber at a first relatively constant preselected pressure level when one of said fluid load chambers is interconnected with said fluid outlet chamber and said fluid outlet chamber is at said first relatively constant preselected pressure level, said second throttling means on said second valve means being operable to throttle fluid flow from said fluid outlet chamber to said fluid exhaust chamber to maintain pressure in said fluid exhuast chamber at a second relatively constant preselected pressure level when one of said fluid load chambers is interconnected with said fluid outlet chamber and when pressure in said fluid outlet chamber is higher than said second relatively constant preselected pressure level, and differential relief valve means interconnecting said fluid inlet chamber and said fluid exhaust means and operable to maintain pressure in said fluid inlet chamber at a level higher by a relatively constant pressure differential than pressure in said fluid load chamber when said fluid load chamber and said fluid supply chamber are interconnected by said first valve means.
A valve assembly comprising a housing having a fluid inlet chamber, a fluid bypass chamber, a fluid supply chamber, first and second fluid load chambers, a fluid outlet chamber, a fluid exhaust chamber and fluid exhaust means, first valve means for selectively interconnecting said fluid load chambers with said fluid supply chamber and said fluid outlet chamber, variable metering orifice means between said fluid exhaust chamber and said fluid exhaust means operable responsive to movement of said first valve means, and second valve means interconnecting said fluid outlet chamber and said fluid exhaust chamber, said fluid inlet chamber and said fluid supply chamber and selectively interconnecting said fluid supply chamber and said fluid bypass chamber responsive to pressure in said fluid exhaust chamber when one of said fluid load chambers is connected to said fluid outlet chamber by said first valve means, said second valve means operable to connect said fluid supply chamber to said fluid bypass chamber and to isolate said fluid supply chamber from said fluid inlet chamber and to throttle fluid flow from said fluid outlet chamber to said fluid exhaust chamber to maintain said fluid exhaust chamber at a relatively constant preselected first and second pressure level.
A load responsive control system comprising in combination a variable flow pump having volume output control responsive to a pressure load signal, a fluid motor operating a load, and a valve assembly between said pump and said motor, said valve assembly comprising a housing having a fluid inlet chamber, a fluid supply chamber, first and second fluid load chambers, a fluid outlet chamber, a fluid exhaust chamber, and fluid exhaust means, first valve means for selectively interconnecting said fluid load chambers with said fluid supply chamber and said fluid outlet chamber, variable fluid metering means between said fluid exhaust chamber and said fluid exhaust means, first throttling means responsive to pressure in said exhaust chamber and operable to control fluid flow from said fluid inlet chamber to said fluid supply chamber to maintain said pressure in said fluid exhaust chamber at a first relatively constant preselected level when one of said fluid load chamber is interconnected with said fluid outlet chamber and when pressure in said outlet chamber is at said first relatively constant preselected level, and a second throttling means responsive to pressure in said fluid exhaust chamber and operable to control fluid flow from said fluid outlet chamber to said fluid exhaust chamber to maintain said pressure in said fluid exhaust chamber at a second relatively constant preselected level when one of said fluid chambers is interconnected with said fluid outlet chamber and when pressure in said fluid outlet chamber is higher than said second preselected pressure level, and a load pressure signal line for transmitting a control signal from said load chamber to said volume output control of said variable flow pump, said control being operable to maintain a constant pressure differential between said inlet chamber and said load chamber.
Dependencies are inferred from the claim text.