US2649237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Counterbalance and support means for ceiling-mounted folding stairways
Assignee: MINNESOTA WOOD SPECIALTIES Inc
•
Filing: 1950-11-01
•
Granted: 1953-08-18
•
Expires: 1970-11-01
Abstract
No abstract record available.
Inventors
- 👤 Bjorklund Warren
- 👤 Kartarik Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 00:52
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/04; E04F11/06; E04F11/062; E04F11/064
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US301386A
Cited
US1091602A
Cited
US1934456A
Cited
US2314004A
Cited
US2506380A
Cited
US2572281A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-08-17 | 1957-02-16 | 1957-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-08-17 | 1961-02-16 | 1961-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-08-17 | 1965-02-16 | 1965-08-18 | $7700.00 | Window Closed / Lapsed |