US3675676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power transmission
Assignee: Vickers Inc
•
Filing: 1971-04-09
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Granted: 1972-07-11
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Expires: 1991-04-09
Abstract
Abstract An electrically controlled hydraulic flow control valve has a nozzle and flapper valve acting as a pilot control for a shiftable main throttle valve. A pressure compensating valve responsive to the pressure drop across the main throttle keeps the flow rate constant, independent of inlet and outlet pressures. Pilot control fluid is supplied by a pressure reducing valve which maintains constant pressure on a small area servomotor, biasing the throttle valve toward closed position. The flapper valve receives control fluid from the reducing valve through a fixed orifice and by means of a feedback connection with the throttle valve, maintains the latter in a position corresponding to the energization of the solenoid.
Inventors
- 👤 Maurice J O'connor
- 👤 Donald J Davidson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:12
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0202; F16H61/0251; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/0416; F15B13/0417; F15B21/00; F15B21/08; F16K; F16K31/00; F16K31/12; F16H2061/0258; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7784; Y10T137/7787; Y10T137/7788
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
147 words
An electro-hydraulic flow control valve comprising a body having an inlet and an outlet for pressure fluid, means forming a main flow passageway for fluid flow from the inlet to the outlet, an adjustable orifice valve and a pressure compensating valve effective to maintain a constant but adjustable rate of flow through the main passageway, means forming an auxiliary passageway from the inlet to the outlet, a pressure reducing valve near the upstream end of the auxiliary passageway effective to maintain a constant reduced pressure in the auxiliary passageway, a fixed restriction in the auxiliary passageway, an electrically controlled flapper valve downstream of the fixed restriction, means responsive to the pressure between the fixed restriction and the flapper valve for urging the orifice valve in one direction, means biasing the orifice valve in the opposite direction, and feedback means between the orifice valve and the flapper valve.
Claim 2
Dependent Claim
147 words
An electro-hydraulic flow control valve comprising a body having an inlet and an outlet for pressure fluid, means forming a main flow passageway for fluid flow from the inlet to the outlet, an adjustable orifice valve and a pressure compensating valve effective to maintain a constant but adjustable rate of flow through the main passageway, means forming an auxiliary passageway from the inlet to the outlet, a pressure reducing valve near the upstream end of the auxiliary passageway effective to maintain a constant reduced pressure in the auxiliary passageway, a fixed restriction in the auxiliary passageway, an electrically controlled flapper valve downstream of the fixed restriction, means responsive to the pressure between the fixed restriction and the flapper valve for urging the orifice valve in one direction, means biasing the orifice valve in the opposite direction, and feedback means between the orifice valve and the flapper valve.
Claim 3
Dependent Claim
25 words
A valve as defined in claim 1 wherein the feedback means includes a resilient mechanical force transmitting member between the orifice valve and the flapper.
Claim 4
Dependent Claim
28 words
A valve as defined in claim 1 wherein the biasing means for the orifice valve includes an expansible chamber connected to the outlet of the pressure reducing valve.
Claim 5
Dependent Claim
111 words
A remotely adjustable flow control valve comprising a pilot operated adjustable throttle valve, a valve responsive to the pressure drop across the throttle valve for maintaining a constant flow rate through the throttle, and a pilot control system for remotely positioning the throttle valve and including an electrohydraulic transducer having a nozzle and a flapper valve opposing the nozzle, means forming a source of control fluid at a constant pressure, a fixed restriction connected between the source and the nozzle, and means for hydraulically shifting the throttle valve including a small area servomotor connected to the source and an opposing large area servomotor connected between the fixed restriction and the nozzle.
Claim 6
Dependent Claim
111 words
A remotely adjustable flow control valve comprising a pilot operated adjustable throttle valve, a valve responsive to the pressure drop across the throttle valve for maintaining a constant flow rate through the throttle, and a pilot control system for remotely positioning the throttle valve and including an electrohydraulic transducer having a nozzle and a flapper valve opposing the nozzle, means forming a source of control fluid at a constant pressure, a fixed restriction connected between the source and the nozzle, and means for hydraulically shifting the throttle valve including a small area servomotor connected to the source and an opposing large area servomotor connected between the fixed restriction and the nozzle.
Claim 7
Dependent Claim
31 words
A valve as defined in claim 4 wherein the source of control fluid includes a pressure reducing valve connected to receive pressure fluid from the stream entering the flow control valve.
Claim 8
Dependent Claim
29 words
A valve as defined in claim 4 wherein the transducer includes a solenoid having a central core, and the nozzle is formed on one end of the central core.
Claim 9
Dependent Claim
24 words
A valve as defined in claim 4 wherein the flapper valve is biased toward open position by a spring connected with the throttle valve.
References Cited (Backward Citations)
US3302531A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |