Patent US3439508A successfully refreshed from Google Patents.
US3439508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mine roof support means
Assignee: WE&F Dobson Ltd
•
Filing: 1966-04-28
•
Granted: 1969-04-22
•
Expires: 1986-04-28
Abstract
No abstract record available.
Inventors
- 👤 William Woolley Payne
- 👤 Jack Hayter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:39
CPC Classifications
E; E21; E21F; E21F15/00; E21F15/02; E21D; E21D23/00; E21D23/006; E21D23/0073; E21D23/16
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1972-04-21 | 1972-10-21 | 1973-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-04-21 | 1976-10-21 | 1977-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-04-21 | 1980-10-21 | 1981-04-22 | $7700.00 | Window Closed / Lapsed |