Patent US1793716A successfully refreshed from Google Patents.
US1793716A
Expired / Lapsed
US
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Electric-engine device for safety doors
Assignee: National Pneumatic Co Inc
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Filing: 1928-04-28
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Granted: 1931-02-24
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Expires: 1948-04-28
Abstract
No abstract record available.
Inventors
- 👤 Edward G Parvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:31
CPC Classifications
E; E05; E05F; E05F15/00; E05F15/60; E05F15/603
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1934-02-23 | 1934-08-25 | 1935-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-02-23 | 1938-08-25 | 1939-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-02-23 | 1942-08-25 | 1943-02-24 | $7700.00 | Window Closed / Lapsed |