Patent US3862644A successfully refreshed from Google Patents.
US3862644A
Expired / Lapsed
US
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Flow control
Assignee: RTX Corp
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Filing: 1973-07-12
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Granted: 1975-01-28
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Expires: 1993-07-12
Abstract
Abstract The accuracy of a flow control for a compressible fluid, where the static and throat pressures of a venturi are sensed, is improved upon by judiciously locating the point at which the force generated by the sensed pressure is applied and/or selecting the respective forces generated by the sensing mechanisms for a given sensed pressure. When diaphragms are utilized the area of the diaphragms or the moment arm are judiciously selected for applying the forces to a fulcrum lever or just the area may be judiciously selected in an in-line arrangement in order to obtain a substantially constant flow schedule over a given pressure range.
Inventors
- 👤 Floyd R Emmons
- 👤 George C Rannenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:16
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/03; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7759
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
171 words
A flow control for a compressible fluid having a restriction disposed in a flow line and a metering valve also disposed in said flow line for adjusting the flow therein in response to said flow control, said flow control including sensing means for measuring the pressure in proximity to said restriction, control means responding to said sensing means operatively connected to said metering valve, said sensing means comprised of a pair of force producing elements arranged to produce a differential force signal in accordance with the following equation: where: W square root T square root P1C1 - P1(P1 - Pa)C2 W weight flow of controlled fluid T absolute temperature in degrees Rankine P1 pressure in pounds per square inch absolute (psia) of fluid upstream of flow restriction or Pa total pressure absolute (psia) surrounding the flow control C1 constant indicative of fluid properties and mechanical arrangement C2 constant indicative of mechanical arrangement whereby said control means positions said metering valve for maintaining a substantially constant weight flow of the compressible fluid.
Claim 2
Dependent Claim
171 words
A flow control for a compressible fluid having a restriction disposed in a flow line and a metering valve also disposed in said flow line for adjusting the flow therein in response to said flow control, said flow control including sensing means for measuring the pressure in proximity to said restriction, control means responding to said sensing means operatively connected to said metering valve, said sensing means comprised of a pair of force producing elements arranged to produce a differential force signal in accordance with the following equation: where: W square root T square root P1C1 - P1(P1 - Pa)C2 W weight flow of controlled fluid T absolute temperature in degrees Rankine P1 pressure in pounds per square inch absolute (psia) of fluid upstream of flow restriction or Pa total pressure absolute (psia) surrounding the flow control C1 constant indicative of fluid properties and mechanical arrangement C2 constant indicative of mechanical arrangement whereby said control means positions said metering valve for maintaining a substantially constant weight flow of the compressible fluid.
Claim 3
Dependent Claim
14 words
A flow control as claimed in claim 1 wherein said restriction is a venturi.
Claim 4
Dependent Claim
17 words
A flow control as claimed in claim 1 wherein said restriction is downstream of said metering valve.
Claim 5
Dependent Claim
15 words
A flow control as claimed in claim 1 wherein said force producing elements include diaphragms.
Claim 6
Dependent Claim
143 words
A flow control for compressible fluid for maintaining a substantially constant weight flow over a given pressure range including a venturi disposed in a duct and a metering valve disposed in said duct upstream of said venturi, a servo system including an actuator for positioning said metering valve and a forced balanced lever, a pair of disphragms one communicating with static pressure at the throat of said venturi and the other communicating with the static pressure immediately upstream of said venturi, said forced balanced lever being subjected to the forces generated by said diaphragms to control said actuator and position said metering valve as a function of the sensed pressures and said diaphragms being in opposed relation relative to the fulcrumed lever, and the area of said diaphragm in communication with said throat pressure being smaller than the area of the other diaphragm.
Claim 7
Dependent Claim
143 words
A flow control for compressible fluid for maintaining a substantially constant weight flow over a given pressure range including a venturi disposed in a duct and a metering valve disposed in said duct upstream of said venturi, a servo system including an actuator for positioning said metering valve and a forced balanced lever, a pair of disphragms one communicating with static pressure at the throat of said venturi and the other communicating with the static pressure immediately upstream of said venturi, said forced balanced lever being subjected to the forces generated by said diaphragms to control said actuator and position said metering valve as a function of the sensed pressures and said diaphragms being in opposed relation relative to the fulcrumed lever, and the area of said diaphragm in communication with said throat pressure being smaller than the area of the other diaphragm.
Claim 8
Dependent Claim
37 words
A flow control as claimed in claim 5 wherein said diaphragms are substantially equal area but the diaphragm subjected to throat pressure being spaced closer to the fulcrum point of said fulcrumed lever than the other diaphragm.
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) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |