US2385251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tunneling method
Assignee: Individual
•
Filing: 1944-11-22
•
Granted: 1945-09-18
•
Expires: 1964-11-22
Abstract
No abstract record available.
Inventors
- 👤 Ayers Frederick Percival
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:43
CPC Classifications
E; E21; E21D; E21D11/00; E21D11/40; E21D11/403; E21D11/04; E21D11/06; E21D11/08; E21D11/14; E21D11/18; E21D9/00; E21D9/06; E21D9/08; E21D9/0875; E21D9/0879
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1948-09-17 | 1949-03-19 | 1949-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1952-09-17 | 1953-03-19 | 1953-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1956-09-17 | 1957-03-19 | 1957-09-18 | $7700.00 | Window Closed / Lapsed |