US3763746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic actuator controls
Assignee: Vickers Inc
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Filing: 1971-09-13
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Granted: 1973-10-09
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Expires: 1991-09-13
Abstract
Abstract A device for controlling the pressure of fluid applied to or the flow of fluid to a hydraulic actuator comprises a pilot valve for controlling a pressure operated main valve. A transducer converts an electrical input signal into a force which is applied to the pilot valve spool. A feedback pressure is applied to piston means on or associated with the spool to apply a force thereto in opposition to the first-mentioned force. For pressure control a pressure sensing means produces a pressure difference equal to the pressure difference between the higher and lower operating pressures of the actuator. For flow control a flow sensor produces a feedback pressure differential dependent on the flow of fluid to the actuator. Pressure and flow control can be optionally obtained by providing two pilot valves in series, one responsive to the pressure sensing means and the other responsive to the flow sensor. One of the pilot valves is set to override the feedback signal thereto, whereby the other pilot valve becomes effective as desired.
Inventors
- 👤 R Walters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:20
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/02; F15B5/00; F15B5/003; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/2053; F15B2211/20538; F15B2211/20546; F15B2211/20553; F15B2211/30; F15B2211/305; F15B2211/3052; F15B2211/30525; F15B2211/32; F15B2211/329; F15B2211/60; F15B2211/605; F15B2211/6051; F15B2211/6054; F15B2211/635; F15B2211/6355; F15B2211/67; F15B2211/70; F15B2211/705; F15B2211/7051; F15B2211/7053; F15B2211/76
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
174 words
A device for controlling the pressUre of fluid applied to a double acting hydraulic actuator responsively to an electrical input signal comprising double-acting hydraulic actuator having opposed chambers, fluid pressure operated main control valve means for regulating the fluid flow to and from the actuator, pilot valve means for controlling the main control valve means, said pilot valve means including spool means for regulating the fluid pressure for operating the main control valve means, electrical input signal means, transducer means for producing a first force dependent upon said electrical input signal means and for applying said force to said spool means, piston means associated with said spool means and comprising substantially equal piston areas effective in opposite directions, and feedback means including shuttle valve means connected by conduit means to the opposed chambers of said actuator for applying to said opposed piston areas a pressure differential dependent upon the magnitude of the fluid pressure difference operating on the actuator to apply to said spool means a second net force opposed to said first force.
Claim 2
Independent Claim
174 words
A device for controlling the pressUre of fluid applied to a double acting hydraulic actuator responsively to an electrical input signal comprising double-acting hydraulic actuator having opposed chambers, fluid pressure operated main control valve means for regulating the fluid flow to and from the actuator, pilot valve means for controlling the main control valve means, said pilot valve means including spool means for regulating the fluid pressure for operating the main control valve means, electrical input signal means, transducer means for producing a first force dependent upon said electrical input signal means and for applying said force to said spool means, piston means associated with said spool means and comprising substantially equal piston areas effective in opposite directions, and feedback means including shuttle valve means connected by conduit means to the opposed chambers of said actuator for applying to said opposed piston areas a pressure differential dependent upon the magnitude of the fluid pressure difference operating on the actuator to apply to said spool means a second net force opposed to said first force.
Claim 3
Dependent Claim
121 words
A device according to claim 1 in which said shuttle valve means comprises a housing at whose opposite ends are inlet ports connected to said hydraulic actuator, at least during operation thereof, said housing having two outlet ports, and a valve member including valve passages movable in said housing responsively to the pressures at said inlet ports to connect said inlet ports alternately to said outlet ports such that one of said outlet ports is always subjected to the higher of the operating pressures in the double acting actuator and the other of said outlet ports is always subjected to the lower of said operating pressures, said feedback means including means connecting said outlet ports respectively to said opposed piston areas.
Claim 4
Independent Claim
188 words
A device for controlling the pressure of fluid applied to a double acting hydraulic actuator responsively to an electrical input signal comprising a double-acting hydraulic actuator having opposed chambers, fluid pressure operated main control valve means for regulating the fluid flow to the actuator, pilot valve means for controlling the main control valve means, said pilot valve means including spool means for regulating the fluid pressure for operating the main control valve means, a directional control valve between said pilot valve means and said main control valve means for determining the direction of operation of said actuator, electrical input signal means, transducer means for producing a first force dependent upon an electrical input signal means and for applying said force to said spool means, piston means associated with said spool means including valve means connected by conduit means to said opposed chambers of said actuator, and pressure responsive feedback means for applying in a given direction to said piston means a pressure dependent upon the magnitude of the fluid pressure operating on the actuator to apply to said spool means a second force opposed to said first force.
Claim 5
Independent Claim
188 words
A device for controlling the pressure of fluid applied to a double acting hydraulic actuator responsively to an electrical input signal comprising a double-acting hydraulic actuator having opposed chambers, fluid pressure operated main control valve means for regulating the fluid flow to the actuator, pilot valve means for controlling the main control valve means, said pilot valve means including spool means for regulating the fluid pressure for operating the main control valve means, a directional control valve between said pilot valve means and said main control valve means for determining the direction of operation of said actuator, electrical input signal means, transducer means for producing a first force dependent upon an electrical input signal means and for applying said force to said spool means, piston means associated with said spool means including valve means connected by conduit means to said opposed chambers of said actuator, and pressure responsive feedback means for applying in a given direction to said piston means a pressure dependent upon the magnitude of the fluid pressure operating on the actuator to apply to said spool means a second force opposed to said first force.
Claim 6
Dependent Claim
17 words
A device according to claim 3 in which said pilot valve means comprises a three port valve.
Claim 7
Independent Claim
187 words
A device for controlling the pressure of fluid applied to a double acting hydraulic actuator responsively to an electrical input signal comprising a double-acting hydraulic actuator having opposed chambers, fluid pressure operated main control valve means for regulating the fluid flow to and from the actuator, pilot valve means for controlling the main control valve means, said pilot valve means including spool means for regulating the fluid pressure for operating the main control valve means, electrical input means, transducer means to producing a first force dependent upon said electrical input signal means and for applying said force to said spool means, piston means associated with said spool means and comprising substantially equal piston areas effective in opposite directions, directional control valve means connected in series with said pilot valve meanS, and pressure responsive feedback means including valve means connected by conduit means to said opposed chambers of said actuator for applying to said opposed piston areas a pressure differential dependent upon the mangitude of the fluid pressure difference operating on the actuator to apply to said spool means a second net force opposed to said first force.
Claim 8
Independent Claim
187 words
A device for controlling the pressure of fluid applied to a double acting hydraulic actuator responsively to an electrical input signal comprising a double-acting hydraulic actuator having opposed chambers, fluid pressure operated main control valve means for regulating the fluid flow to and from the actuator, pilot valve means for controlling the main control valve means, said pilot valve means including spool means for regulating the fluid pressure for operating the main control valve means, electrical input means, transducer means to producing a first force dependent upon said electrical input signal means and for applying said force to said spool means, piston means associated with said spool means and comprising substantially equal piston areas effective in opposite directions, directional control valve means connected in series with said pilot valve meanS, and pressure responsive feedback means including valve means connected by conduit means to said opposed chambers of said actuator for applying to said opposed piston areas a pressure differential dependent upon the mangitude of the fluid pressure difference operating on the actuator to apply to said spool means a second net force opposed to said first force.
Claim 9
Dependent Claim
19 words
A device according to claim 5 further comprising second electrical transducer means for operating said directional control valve means.
Claim 10
Dependent Claim
26 words
A device according to claim 5 in which said directional control valve means is connected between said pilot valve means and said main control valve means.
Claim 11
Dependent Claim
17 words
A device according to claim 7 in which said pilot valve means comprises a three port valve.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |