Patent US4231396A successfully refreshed from Google Patents.
US4231396A
Expired / Lapsed
US
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Load responsive fluid control valves
Assignee: Individual
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Filing: 1979-01-26
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Granted: 1980-11-04
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Expires: 1999-01-26
Abstract
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.
Inventors
- 👤 Tadeusz Budzich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:48
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/0416; F15B13/0417; F15B11/00; F15B11/02; F15B11/04; F15B11/044; F15B11/0445; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/2053; F15B2211/20546; F15B2211/20553; F15B2211/30; F15B2211/305; F15B2211/30525; F15B2211/3053; F15B2211/30535; F15B2211/50; F15B2211/505; F15B2211/50509; F15B2211/50518; F15B2211/55; F15B2211/555; F15B2211/60; F15B2211/605; F15B2211/6051; F15B2211/6057; F15B2211/70; F15B2211/705; F15B2211/7051; F15B2211/7053; F15B2211/71; F15B2211/76; F15B2211/761; F15B2211/80; F15B2211/86; F15B2211/8609; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87169; Y10T137/87177; Y10T137/87185
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
203 words
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.
Claim 2
Dependent Claim
203 words
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.
Claim 3
Dependent Claim
46 words
A valve assembly as set forth in claim 1 wherein said housing has positive load pressure sensing means selectively communicable with said load chambers by said first valve means, said positive load pressure sensing means having means operable to transmit control pressure signal to said pump.
Claim 4
Dependent Claim
48 words
A valve assembly as set forth in claim 1 wherein said second valve means has force generating means responsive to pressure in said negative load pressure sensing means operable to move said fluid isolating means towards position to close communication between said inlet chamber and said supply chamber.
Claim 5
Dependent Claim
56 words
A valve assembly as set forth in claim 1 wherein said second valve means is interposed between said negative load pressure sensing means and said fluid exhaust means and spring biasing means to bias said fluid isolating means of said first valve means towards position to open communication between said inlet chamber and said supply chamber.
Claim 6
Dependent Claim
27 words
A valve assembly as set forth in claim 1 wherein said fluid replenishing means has check valve means between said fluid exhaust means and said supply chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |