US3389504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elevator door construction
Assignee: WILLIAMSBURG STEEL PRODUCTS CO
•
Filing: 1966-05-04
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Granted: 1968-06-25
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Expires: 1986-05-04
Abstract
No abstract record available.
Inventors
- 👤 Halpern Ernst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:51
CPC Classifications
B; B66; B66B; B66B13/00; B66B13/30; B66B13/303
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) | 1971-06-25 | 1971-12-25 | 1972-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-06-25 | 1975-12-25 | 1976-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-06-25 | 1979-12-25 | 1980-06-25 | $7700.00 | Window Closed / Lapsed |