US2456537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic door check
Assignee: SEAMAN
•
Filing: 1944-08-07
•
Granted: 1948-12-14
•
Expires: 1964-08-07
Abstract
No abstract record available.
Inventors
- 👤 David J Seaman
- 👤 Albert E Wood
- 👤 Clarence A Hathaway
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:05
CPC Classifications
E; E05; E05F; E05F3/00; E05F3/04; E05F3/10; E05Y; E05Y2900/00; E05Y2900/10; E05Y2900/13; E05Y2900/132
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1951-12-14 | 1952-06-14 | 1952-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-12-14 | 1956-06-14 | 1956-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-12-14 | 1960-06-14 | 1960-12-14 | $7700.00 | Window Closed / Lapsed |