US2738754A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for indicating failure of mine roofs
Assignee: Individual
•
Filing: 1950-09-15
•
Granted: 1956-03-20
•
Expires: 1970-09-15
Abstract
No abstract record available.
Inventors
- 👤 Bierer Joseph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:22
CPC Classifications
E; E21; E21F; E21F17/00; E21F17/18; E21F17/185; E21D; E21D21/00; E21D21/0093; Y; Y10; Y10S; Y10S116/00; Y10S116/34; Y10S116/35
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1708333A
Cited
US1737514A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-03-20 | 1959-09-19 | 1960-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-03-20 | 1963-09-19 | 1964-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-03-20 | 1967-09-19 | 1968-03-20 | $7700.00 | Window Closed / Lapsed |