US2928473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Opposed-slot spiral scrapers
Assignee: Individual
•
Filing: 1957-09-30
•
Granted: 1960-03-15
•
Expires: 1977-09-30
Abstract
No abstract record available.
Inventors
- 👤 Tripplehorn James Conrad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:02
CPC Classifications
E; E21; E21B; E21B37/00; E21B37/02; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/4987
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1633843A
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US1639660A
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US1758995A
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US1750851A
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US2436994A
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US2655113A
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US2712853A
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US2772741A
Cited
US2793917A
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GB761486A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-03-15 | 1963-09-14 | 1964-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-03-15 | 1967-09-14 | 1968-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-03-15 | 1971-09-14 | 1972-03-15 | $7700.00 | Window Closed / Lapsed |