US2997853A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for driving tunnels
Assignee: Individual
•
Filing: 1958-07-14
•
Granted: 1961-08-29
•
Expires: 1978-07-14
Abstract
No abstract record available.
Inventors
- 👤 Maxwell F Kemper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:14
CPC Classifications
E; E21; E21D; E21D9/00; E21D9/06; E21D9/0642; E21D9/065
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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DE567122C
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US1275910A
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US1478163A
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US1751147A
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US2196100A
Cited
DE911961C
Cited
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Cited
US2757515A
Cited
GB773407A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-08-28 | 1965-02-27 | 1965-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-28 | 1969-02-27 | 1969-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-28 | 1973-02-27 | 1973-08-29 | $7700.00 | Window Closed / Lapsed |