Patent US3580281A successfully refreshed from Google Patents.
US3580281A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control valve
Assignee: Lockheed Martin Corp
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Filing: 1969-10-07
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Granted: 1971-05-25
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Expires: 1989-10-07
Abstract
Abstract A plurality of spool-type valves are cascaded in tandem so that the spools of the valves are connected and respond to an input control force derived from a control mechanism, which is applied to one spool which acts against a bias force exerted on another spool so that the spools are positioned in unison and one spool delivers position feedback to the control mechanism so that the valves uniformly meter fluid flow at substantially the same pressure to a power actuator, whereby a signal power actuator may receive the total flow from all of the valves.
Inventors
- 👤 Rudolph S Petersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:56
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/043; F15B13/0436; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86582; Y10T137/86614; Y10T137/87169; Y10T137/87193; Y10T137/87209
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
162 words
A servo valve assembly comprising: a plurality of substantially identical spool-type control valves positioned in a line with their spools coaxially aligned and in end-to-end engagement, a source of fluid at supply pressure, means for connecting said source to each of said valves, means responsive to an input control signal for producing a control pressure varying therewith, means for applying said control pressure to the outside end of the spool of that one of said control valves which is at one end of said line, means for exerting a bias force on the outside end of the spool of that one of said control valves which is at the other end of said line, whereby said exerted force opposes said applied control pressure and all of said spools move as a unit a distance which varies with the magnitude of said control signal, and means for connecting the fluid outputs form each control valves to each other and to a common output.
Claim 2
Dependent Claim
162 words
A servo valve assembly comprising: a plurality of substantially identical spool-type control valves positioned in a line with their spools coaxially aligned and in end-to-end engagement, a source of fluid at supply pressure, means for connecting said source to each of said valves, means responsive to an input control signal for producing a control pressure varying therewith, means for applying said control pressure to the outside end of the spool of that one of said control valves which is at one end of said line, means for exerting a bias force on the outside end of the spool of that one of said control valves which is at the other end of said line, whereby said exerted force opposes said applied control pressure and all of said spools move as a unit a distance which varies with the magnitude of said control signal, and means for connecting the fluid outputs form each control valves to each other and to a common output.
Claim 3
Dependent Claim
26 words
A servo valve assembly in accordance with claim 1 in which said means for producing a control pressure includes a force motor and a pilot valve.
Claim 4
Dependent Claim
26 words
A servo valve assembly in accordance with claim 2 including means for providing position feedback from the spools of said control valves to said pilot valve.
Claim 5
Dependent Claim
47 words
A servo valve assembly in accordance with claim 3 in which said pilot valve is a spool-type valve and in which said means for providing position feedback includes a reference spring between said spool of said pilot valve and the spool of one of said control valves.
Claim 6
Dependent Claim
30 words
A servo valve assembly in accordance with claim 4 in which said pilot valve is a two-way valve and in which each of said control valves is a four-way valve.
Claim 7
Dependent Claim
156 words
A servo valve assembly comprising, first and second substantially identical spool-type control valves positioned side-by-side with their spools coaxial, means for mechanically coupling adjacent ends of said spools together, means responsive to an input control signal for producing a control force varying therewith, means for applying said control force to the end of the spool of said second control valve which is remote from said first valve, means for exerting a bias force in opposition to said control force on that end of the spool of said first control valve which is remote form said second valve whereby said spools move as a unit a distance which varies with the magnitude of said input control signal, and means for connecting the outputs of said valves together whereby the output fluid pressure and the rates of flow from said first and second control valves are substantially equal and vary with the magnitude of said input control signal.
Claim 8
Dependent Claim
156 words
A servo valve assembly comprising, first and second substantially identical spool-type control valves positioned side-by-side with their spools coaxial, means for mechanically coupling adjacent ends of said spools together, means responsive to an input control signal for producing a control force varying therewith, means for applying said control force to the end of the spool of said second control valve which is remote from said first valve, means for exerting a bias force in opposition to said control force on that end of the spool of said first control valve which is remote form said second valve whereby said spools move as a unit a distance which varies with the magnitude of said input control signal, and means for connecting the outputs of said valves together whereby the output fluid pressure and the rates of flow from said first and second control valves are substantially equal and vary with the magnitude of said input control signal.
Claim 9
Dependent Claim
25 words
A servo valve assembly in accordance with claim 6 in which said means for coupling includes a mechanism for adjusting the distance between adjacent spools.
Claim 10
Dependent Claim
42 words
A servo valve assembly in accordance with claim 6 in which said means for producing a control force includes a force motor responsive to said input control signal and a spool-type pilot valve responsive to the force exerted by said force motor.
Claim 11
Dependent Claim
33 words
A servo valve assembly in accordance with claim 8 including a reference spring between the spool of said pilot valve and the spool of one of said control valves for providing position feedback.
Claim 12
Dependent Claim
30 words
A servo valve assembly in accordance with claim 9 in which said pilot valve is a two-way valve and in which each of said control valves is a four-way valve.
Claim 13
Dependent Claim
21 words
A servo valve assembly in accordance with claim 10 in which the spools of said control valves are connected rigidly together.
References Cited (Backward Citations)
US2912007A
Cited
US2896588A
Cited
US3038449A
Cited
US3096690A
Cited
GB972080A
Cited
US3267965A
Cited
US3254675A
Cited
US3243958A
Cited
US3411411A
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 |