Patent US2447922A successfully refreshed from Google Patents.
US2447922A
Expired / Lapsed
US
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Explosion-proof lighting equipment
Assignee: Holophane Corp
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Filing: 1944-07-12
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Granted: 1948-08-24
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Expires: 1964-07-12
Abstract
No abstract record available.
Inventors
- 👤 Davis H Tuck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:21
CPC Classifications
F; F21; F21V; F21V25/00; F21V25/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-08-24 | 1952-02-23 | 1952-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-08-24 | 1956-02-23 | 1956-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-08-24 | 1960-02-23 | 1960-08-24 | $7700.00 | Window Closed / Lapsed |