US2975857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extensible ladder constructions
Assignee: Individual
•
Filing: 1955-11-17
•
Granted: 1961-03-21
•
Expires: 1975-11-17
Abstract
No abstract record available.
Inventors
- 👤 Suroff Hyman
- 👤 Suroff Leonard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:13
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/42; E06C7/44; E06C1/00; E06C1/02; E06C1/14; E06C1/16; E06C1/20; E06C1/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US359716A
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US409711A
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US623540A
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US722409A
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US1169700A
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US1371125A
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US1513854A
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US1579574A
Cited
US1731611A
Cited
US2588959A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-03-20 | 1964-09-19 | 1965-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-03-20 | 1968-09-19 | 1969-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-03-20 | 1972-09-19 | 1973-03-21 | $7700.00 | Window Closed / Lapsed |