US3706320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure drop variation compensating and valve positioning mechanism
Assignee: ANCHOR/DARLING VALVE COMPANY 919 CONESTOGA RD ROSEMONT PA 19010 A CORP OF
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Filing: 1971-09-21
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Granted: 1972-12-19
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Expires: 1991-09-21
Abstract
Abstract A valve having a pneumatic operator and a linear port opening rate is provided with mechanism for compensating variations in the pressure drop across the valve, in order to make the flow a linear function of a control signal. A pressure sensitive device produces a rotation of a square root cam proportional to the pressure drop across the valve. The displacement produced by the cam is multiplied by the control signal and the product is added to a displacement proportional to the control signal. The resulting quantity is compared with the position of the valve stem, and the difference is used to adjust a pilot valve which controls the operator and resets it so as to compensate the variation in the pressure drop across the valve.
Inventors
- 👤 Manmohan S Kalsi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:33
CPC Classifications
G; G05; G05D; G05D16/00; G05D16/14; G05D16/16; G05D16/163; F; F16; F16K; F16K31/00; F16K31/12; F16K31/36; F16K31/365; Y; Y10; Y10T; Y10T137/00; Y10T137/7504; Y10T137/7668; Y10T137/7722; Y10T137/7758; Y10T137/7759; Y10T137/776; Y10T137/8593; Y10T137/86493; Y10T137/86718; Y10T137/86759; Y10T137/86791
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
126 words
Apparatus for compensating variations in the fluid pressure drop across a valve having an operator; comprising first means for supplying a valve control signal; second means for producing a quantity proportional to the square root of the pressure drop across the valve; third means for multiplying said quantity by a quantity proportional to the magnitude of the control signal; fourth means for adding the product of said quantities to another quantity proportional to the control signal; fifth means for producing a displacement representing the difference between the added quantities and a quantity representing the position of the valve; and means for actuating said operator in accordance with said displacement to adjust the valve to a position permitting a flow rate substantially proportional to the control signal.
Claim 2
Dependent Claim
126 words
Apparatus for compensating variations in the fluid pressure drop across a valve having an operator; comprising first means for supplying a valve control signal; second means for producing a quantity proportional to the square root of the pressure drop across the valve; third means for multiplying said quantity by a quantity proportional to the magnitude of the control signal; fourth means for adding the product of said quantities to another quantity proportional to the control signal; fifth means for producing a displacement representing the difference between the added quantities and a quantity representing the position of the valve; and means for actuating said operator in accordance with said displacement to adjust the valve to a position permitting a flow rate substantially proportional to the control signal.
Claim 3
Dependent Claim
73 words
Apparatus according to claim 1, wherein the operator is fluid pressure actuated, and the means for actuating the operator includes a pilot valve having an inlet port, a venting port, and an outlet; means for supplying a constant air pressure to the inlet port; and means for connecting the outlet to said operator, said pilot valve being responsive to said fifth means for varying the flow through at least one of said ports.
Claim 4
Dependent Claim
45 words
Apparatus According to claim 2, wherein said control signal is an adjustable, fluid pressure signal; and said fourth means includes an air motor having a diaphragm movable by the control signal; and means for moving said air motor bodily in response to said third means.
Claim 5
Dependent Claim
34 words
Apparatus according to claim 1, wherein said valve has a reciprocating valve member, and a body having port openings providing an effective flow area which varies linearly with the displacement of the valve member.
Claim 6
Dependent Claim
11 words
Apparatus according to claim 4, wherein said port openings are rectangular.
Claim 7
Dependent Claim
34 words
Apparatus according to claim 1, wherein said second means includes means for adjusting the proportionality of the square root of the pressure drop across the valve to the quantity produced by said second means.
Claim 8
Dependent Claim
118 words
Apparatus for compensating variations in the pressure drop across a valve; comprising a valve having a fluid actuated operator and a reciprocating valve member; first means for supplying a control signal; second means for producing a first displacement proportional to the square root of the pressure difference across the valve; third means for adding said displacement to a second displacement proportional to the control signal; fourth means for obtaining a third displacement representing the difference between the added displacements and a quantity representing the position of the valve member; and means for actuating said operator in accordance with the third displacement to adjust the valve to a position permitting a flow rate substantially proportional to the control signal.
Claim 9
Dependent Claim
118 words
Apparatus for compensating variations in the pressure drop across a valve; comprising a valve having a fluid actuated operator and a reciprocating valve member; first means for supplying a control signal; second means for producing a first displacement proportional to the square root of the pressure difference across the valve; third means for adding said displacement to a second displacement proportional to the control signal; fourth means for obtaining a third displacement representing the difference between the added displacements and a quantity representing the position of the valve member; and means for actuating said operator in accordance with the third displacement to adjust the valve to a position permitting a flow rate substantially proportional to the control signal.
Claim 10
Dependent Claim
135 words
Apparatus for compensating variations in the pressure drop across a valve; comprising a servo control system having a fluid pressure actuated operator; first means for supplying a control signal; second means for producing a displacement proportional to the square root of the pressure difference across the valve multiplied by a quantity proportional to the control signal to produce a second displacement; means for adding the second displacement to a third displacement proportional to the control signal; means for obtaining a fourth displacement representing the difference between the sum of the second and third displacements and a quantity representing the position of the valve; and fluid pressure supply means for actuating said operator in accordance with the fourth displacement to adjust the valve to a position permitting a flow rate substantially proportional to the control signal.
Claim 11
Dependent Claim
135 words
Apparatus for compensating variations in the pressure drop across a valve; comprising a servo control system having a fluid pressure actuated operator; first means for supplying a control signal; second means for producing a displacement proportional to the square root of the pressure difference across the valve multiplied by a quantity proportional to the control signal to produce a second displacement; means for adding the second displacement to a third displacement proportional to the control signal; means for obtaining a fourth displacement representing the difference between the sum of the second and third displacements and a quantity representing the position of the valve; and fluid pressure supply means for actuating said operator in accordance with the fourth displacement to adjust the valve to a position permitting a flow rate substantially proportional to the control signal.
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) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |