US1744239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-locking ladder for floating roof tanks
Assignee: Union Oil Company of California
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Filing: 1929-01-09
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Granted: 1930-01-21
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Expires: 1949-01-09
Abstract
No abstract record available.
Inventors
- 👤 Charles S Morgan
- 👤 John T Howell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:37
CPC Classifications
E; E06; E06C; E06C9/00; E06C9/06; E06C9/14; B; B65; B65D; B65D88/00; B65D88/34
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) | 1933-01-20 | 1933-07-22 | 1934-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1937-01-20 | 1937-07-22 | 1938-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1941-01-20 | 1941-07-22 | 1942-01-21 | $7700.00 | Window Closed / Lapsed |