Patent US2723100A successfully refreshed from Google Patents.
US2723100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Releasable supports for roofs in underground mines
Assignee: Individual
•
Filing: 1951-07-03
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Granted: 1955-11-08
•
Expires: 1971-07-03
Abstract
No abstract record available.
Inventors
- 👤 Muschamp Norman James
- 👤 Cowlishaw Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:26
CPC Classifications
E; E21; E21D; E21D15/00; E21D15/60
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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GB191020472A
Cited
US1046517A
Cited
US1450329A
Cited
GB419939A
Cited
GB425120A
Cited
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Cited
GB455942A
Cited
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Cited
US2256620A
Cited
FR923079A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-11-07 | 1959-05-09 | 1959-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-11-07 | 1963-05-09 | 1963-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-11-07 | 1967-05-09 | 1967-11-08 | $7700.00 | Window Closed / Lapsed |