Patent US2989987A successfully refreshed from Google Patents.
US2989987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
2-stage hydraulic servo valve
Assignee: Lockheed Martin Corp
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Filing: 1956-05-07
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Granted: 1961-06-27
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Expires: 1976-05-07
Abstract
No abstract record available.
Inventors
- 👤 Paul F Hayner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:43
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/043; F15B13/0438; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86582; Y10T137/8659
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1718673A
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FR874370A
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US2615466A
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US2599159A
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US2625136A
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US2884940A
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US2767689A
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US2738772A
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US2813519A
Cited
US2838028A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-26 | 1964-12-26 | 1965-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-26 | 1968-12-26 | 1969-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-26 | 1972-12-26 | 1973-06-27 | $7700.00 | Window Closed / Lapsed |