US3462959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for the controlled yielding of an underground opening
Assignee: Shell USA Inc
•
Filing: 1967-12-21
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Granted: 1969-08-26
•
Expires: 1987-12-21
Abstract
No abstract record available.
Inventors
- 👤 Richard G Mallander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:16
CPC Classifications
E; E21; E21D; E21D11/00; E21D11/14; E21D11/18; E21D11/22; Y; Y10; Y10T; Y10T24/00; Y10T24/14; Y10T24/1412; Y10T24/1433; Y10T24/1435; Y10T24/1437
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) | 1972-08-25 | 1973-02-24 | 1973-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-08-25 | 1977-02-24 | 1977-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-08-25 | 1981-02-24 | 1981-08-26 | $7700.00 | Window Closed / Lapsed |