Patent US2857906A successfully refreshed from Google Patents.
US2857906A
Expired / Lapsed
US
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Space heater
Assignee: Dravo Corp
•
Filing: 1954-09-13
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Granted: 1958-10-28
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Expires: 1974-09-13
Abstract
No abstract record available.
Inventors
- 👤 Walter L Davidson
- 👤 Abraham P Loeb
- 👤 Morgan P O'laughlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:21
CPC Classifications
F; F24; F24H; F24H3/00; F24H3/02; F24H3/06; F24H3/065
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1218288A
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US1634706A
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US1991449A
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US2160269A
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US2114584A
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US2109876A
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US2430393A
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US2376140A
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US2612153A
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US2514011A
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US2555842A
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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) | 1961-10-27 | 1962-04-28 | 1962-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-27 | 1966-04-28 | 1966-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-27 | 1970-04-28 | 1970-10-28 | $7700.00 | Window Closed / Lapsed |