Patent US2857125A successfully refreshed from Google Patents.
US2857125A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mine roof supports
Assignee: Dowty Hydraulic Units Ltd
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Filing: 1954-02-24
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Granted: 1958-10-21
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Expires: 1974-02-24
Abstract
No abstract record available.
Inventors
- 👤 Joseph A W Mills
- 👤 Hugh L Holt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:25
CPC Classifications
E; E21; E21D; E21D15/00; E21D15/14; E21D15/44; E21D15/50; E21D15/51; E21D15/517; E21D23/00; E21D23/04; E21D23/06
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) | 1961-10-20 | 1962-04-21 | 1962-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-20 | 1966-04-21 | 1966-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-20 | 1970-04-21 | 1970-10-21 | $7700.00 | Window Closed / Lapsed |