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Patent US2564954A successfully refreshed from Google Patents.
US2564954A
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US
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Retractable stairs
Assignee: Individual
•
Filing: 1948-04-26
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Granted: 1951-08-21
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Expires: 1968-04-26
Abstract
No abstract record available.
Inventors
- 👤 David E Brelsford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:12
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/04
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) | 1954-08-20 | 1955-02-19 | 1955-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-08-20 | 1959-02-19 | 1959-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-08-20 | 1963-02-19 | 1963-08-21 | $7700.00 | Window Closed / Lapsed |