Patent US3580538A successfully refreshed from Google Patents.
US3580538A
Expired / Lapsed
US
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Pneumatic system for air motor control
Assignee: Chevron USA Inc
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Filing: 1968-11-20
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Granted: 1971-05-25
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Expires: 1988-11-20
Abstract
Abstract In a pneumatic amplifying and actuating circuit for a control system useful in controllably varying a stem of a valve within a process line, complementary output stages of the amplifying and actuating circuit are separately utilized (depending on the direction of deviation of a control signal with respect to a setpoint pressure level) to automatically control the repositioning of the valve stem.
Inventors
- 👤 Leon M Wyrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:20
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/16; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87169; Y10T137/87217; Y10T137/87225
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
253 words
Control system to controllably vary a stem of a valve within a process line, by establishing a first signal representing the position of the stem of said valve to be regulated, a second signal representing a predetermined setpoint of relatively low magnitude, a third signal representing the difference between said first and second signals and comprising pressurized air of a predetermined level above that of the atmosphere, comprising: means having complementary amplifying output stages operative in response to said third signal to amplify said third signal to a predetermined constant level, each of said complementary output stages singularly operative to amplify said third signal in accordance with the direction of deviation of said third signal above or below said predetermined setpoint; first and second pilot controlled valves, each of said valves having pilot diaphragm means connected to and controlled by one of said output stages of said amplifying means, an input port, a normally closed output port and a valve plunger means operatively connected to said pilot diaphragm means and responsive to said amplified signal whereby said output port is placed in fluid communication with said input port on the occurrence of said amplified signal at said pilot diaphragm means; an air motor operatively connected to said stem of said valve to be regulated, and having separate first and second input ports wherein each is connectable to one of said output ports of said pilot valves; and an air source of relatively high pressure connected to said input ports of said pilot valves.
Claim 2
Dependent Claim
253 words
Control system to controllably vary a stem of a valve within a process line, by establishing a first signal representing the position of the stem of said valve to be regulated, a second signal representing a predetermined setpoint of relatively low magnitude, a third signal representing the difference between said first and second signals and comprising pressurized air of a predetermined level above that of the atmosphere, comprising: means having complementary amplifying output stages operative in response to said third signal to amplify said third signal to a predetermined constant level, each of said complementary output stages singularly operative to amplify said third signal in accordance with the direction of deviation of said third signal above or below said predetermined setpoint; first and second pilot controlled valves, each of said valves having pilot diaphragm means connected to and controlled by one of said output stages of said amplifying means, an input port, a normally closed output port and a valve plunger means operatively connected to said pilot diaphragm means and responsive to said amplified signal whereby said output port is placed in fluid communication with said input port on the occurrence of said amplified signal at said pilot diaphragm means; an air motor operatively connected to said stem of said valve to be regulated, and having separate first and second input ports wherein each is connectable to one of said output ports of said pilot valves; and an air source of relatively high pressure connected to said input ports of said pilot valves.
Claim 3
Dependent Claim
104 words
Control system in accordance with claim 1 in which said amplifying means comprises a source of air, and first and second complementary differential relays having common input ports, each of said relays simultaneously receiving said third signal but only one of which being operated thereby depending on the direction of said third signal above or below said setpoint, common supply ports connectable to said air source, separate output ports operatively connectable to said pilot valves for control thereof, and separate plunger means, each of which being complementarily actuated by said third signal to place said output port in fluid contact with said supply port.
Claim 4
Dependent Claim
29 words
Control system of claim 2 in which said source of air includes regulating means to control the magnitude thereof to a constant level above that of said third signal.
Claim 5
Dependent Claim
23 words
Control system of claim 3 in which said magnitude of air pressure of said source is approximately twice that of said third signal.
Claim 6
Dependent Claim
36 words
Control system of claim 1 in which each of said pilot valves includes an exhaust port normally open to and in fluid communication with said input port and with the atmosphere exterior of said pilot valve.
Claim 7
Dependent Claim
252 words
In a control system to vary a stem of a valve within a process line in which said stem is operatively connected to an air motor and said air motor is selectively connected to a pneumatic source to provide a pulse of air to actuate said air motor by establishing a first signal representing the position of said stem of said valve, a second signal representing a predetermined setpoint of relatively low magnitude, and a third signal representing the difference between said first and second signals and comprising pressurized air of a predetermined leVel above that of the atmosphere, a pneumatic amplifier and actuator circuit comprising: means having complementary amplifying output stages operative in response to said third signal to amplify said third signal to a predetermined constant level, each of said complementary output stages singularly operative to amplify said third signal in accordance with the direction of deviation of said third signal above or below said predetermined setpoint; and first and second pilot controlled valves, each of said valves having pilot diaphragm means connected to and controlled by one of said output stages of said amplifying means, an input port, a normally closed output port and a valve plunger means operatively connected to said pilot diaphragm means and responsive to said amplified signal whereby said output port is placed in fluid communication with said input port on the occurrence of said amplified signal at said pilot diaphragm means to allow passage of said pulse of air to actuate said air motor.
Claim 8
Dependent Claim
252 words
In a control system to vary a stem of a valve within a process line in which said stem is operatively connected to an air motor and said air motor is selectively connected to a pneumatic source to provide a pulse of air to actuate said air motor by establishing a first signal representing the position of said stem of said valve, a second signal representing a predetermined setpoint of relatively low magnitude, and a third signal representing the difference between said first and second signals and comprising pressurized air of a predetermined leVel above that of the atmosphere, a pneumatic amplifier and actuator circuit comprising: means having complementary amplifying output stages operative in response to said third signal to amplify said third signal to a predetermined constant level, each of said complementary output stages singularly operative to amplify said third signal in accordance with the direction of deviation of said third signal above or below said predetermined setpoint; and first and second pilot controlled valves, each of said valves having pilot diaphragm means connected to and controlled by one of said output stages of said amplifying means, an input port, a normally closed output port and a valve plunger means operatively connected to said pilot diaphragm means and responsive to said amplified signal whereby said output port is placed in fluid communication with said input port on the occurrence of said amplified signal at said pilot diaphragm means to allow passage of said pulse of air to actuate said air motor.
Claim 9
Dependent Claim
104 words
The pneumatic amplifier and actuator circuit of claim 6 in which said amplifying means comprises first and second complementary differential relays having common input ports, each of said relays simultaneously receiving said third signal but only one of which being operated thereby depending on the direction of said third signal above or below said setpoint, common supply ports, separate output ports operatively connectable to said pilot valves for control thereof, and separate plunger means, each of which being complementarily actuated by said third signal to place one of said output ports of one of said relays in fluid contact with said common supply ports.
References Cited (Backward Citations)
US2880705A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |