US3027969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic locking self-leveling ladder
Assignee: Individual
•
Filing: 1959-08-19
•
Granted: 1962-04-03
•
Expires: 1979-08-19
Abstract
No abstract record available.
Inventors
- 👤 Leonard R Erickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:47
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/42; E06C7/44
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US368199A
Cited
US2109787A
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US2113282A
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US2139479A
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US2444384A
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US2451113A
Cited
GB636896A
Cited
US2476650A
Cited
US2894670A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-04-02 | 1965-10-02 | 1966-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-04-02 | 1969-10-02 | 1970-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-04-02 | 1973-10-02 | 1974-04-03 | $7700.00 | Window Closed / Lapsed |