US2819901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Knockdown backstop
Assignee: United States Steel Corp
•
Filing: 1955-02-23
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Granted: 1958-01-14
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Expires: 1975-02-23
Abstract
No abstract record available.
Inventors
- 👤 Joseph S Mateja
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:55
CPC Classifications
A; A63; A63B; A63B71/00; A63B71/02; A63B71/022
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) | 1961-01-13 | 1961-07-15 | 1962-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-13 | 1965-07-15 | 1966-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-13 | 1969-07-15 | 1970-01-14 | $7700.00 | Window Closed / Lapsed |