US3535837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Entrance frames for door entrances
Assignee: Otis Elevator Co
•
Filing: 1968-10-14
•
Granted: 1970-10-27
•
Expires: 1988-10-14
Abstract
No abstract record available.
Inventors
- 👤 Norman Lewis Atkinson
- 👤 Ronald Alfred Bartholomew
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:03
CPC Classifications
E; E06; E06B; E06B1/00; E06B1/04; E06B1/12; E06B1/18; E06B1/20; E06B1/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1631224A
Cited
US1741940A
Cited
US1770267A
Cited
US1913716A
Cited
US3303616A
Cited
US3407553A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-10-26 | 1974-04-27 | 1974-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-26 | 1978-04-27 | 1978-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-26 | 1982-04-27 | 1982-10-27 | $7700.00 | Window Closed / Lapsed |