Patent US2469712A successfully refreshed from Google Patents.
US2469712A
Expired / Lapsed
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Control for spill ports in free-piston units
Assignee: RTX Corp
•
Filing: 1944-08-23
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Granted: 1949-05-10
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Expires: 1964-08-23
Abstract
No abstract record available.
Inventors
- 👤 Richard S Buck
- 👤 Walter A Ledwith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:25
CPC Classifications
F; F02; F02B; F02B71/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1579782A
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US2016613A
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US2038442A
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US2064976A
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US2090709A
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US2139425A
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US2147935A
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US2108890A
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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) | 1952-05-09 | 1952-11-08 | 1953-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-05-09 | 1956-11-08 | 1957-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-05-09 | 1960-11-08 | 1961-05-10 | $7700.00 | Window Closed / Lapsed |