Patent US2661121A successfully refreshed from Google Patents.
US2661121A
Expired / Lapsed
US
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Safety pressure device
Assignee: Black Sivalls and Bryson Inc
•
Filing: 1950-08-23
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Granted: 1953-12-01
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Expires: 1970-08-23
Abstract
No abstract record available.
Inventors
- 👤 Robert S Coffman
- 👤 Howard N Simms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:17
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/02; F16K17/14; F16K17/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US568680A
Cited
US2536321A
Cited
US1584523A
Cited
US2526794A
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US2571961A
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US2576431A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-30 | 1957-06-01 | 1957-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-30 | 1961-06-01 | 1961-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-30 | 1965-06-01 | 1965-12-01 | $7700.00 | Window Closed / Lapsed |