US3561162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Door opening apparatus
Assignee: Individual
•
Filing: 1969-06-16
•
Granted: 1971-02-09
•
Expires: 1989-06-16
Abstract
Abstract A DEVICE FOR OPENING A HATCH DOOR OR OTHER CLOSURE IN A SAFE AND POSITIVE MANNER. A PAIR OF SPRING ASSEMBLIES ARE COUPLED BETWEEN A HATCH AND ITS FRAME, ONE SPRING ASSEMBLY BEING COOPERATIVE WITH A VISCOUS DAMPING DEVICE. UPON RELEASE OF THE HATCH, THE FIRST SPRING ASSEMBLY CAUSES THE HATCH TO RAPIDLY OPEN BY A PREDE- TERMINED AMOUNT, WHILE THE DAMPED ACTION OF THE SECOND SPRING ASSEMBLY CAUSES THE HATCH TO SLOWLY AND POSITIVELY CONTINUE TO A FULL OPEN POSITION.
Inventors
- 👤 Maurice J Goldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:18
CPC Classifications
F; F24; F24F; F24F7/00; F24F7/02; F24F11/00; F24F11/30; F24F11/32; F24F11/33; F24F11/34
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |