Patent US4892520A successfully refreshed from Google Patents.
US3516718A
Expired / Lapsed
US
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Lower thrust equalizer for drilling tools
Assignee: Smith International Inc
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Filing: 1967-10-12
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Granted: 1970-06-23
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Expires: 1987-10-12
Abstract
No abstract record available.
Inventors
- 👤 Erskine P Garrison
- 👤 John E Tschirky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:54
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/02; F; F16; F16C; F16C19/00; F16C19/02; F16C19/10; F16C19/54; F16C41/00; F16C41/02; F16C2352/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1424640A
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US1871630A
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US2301105A
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US2630354A
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DE1061576B
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DE1170717B
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US3326612A
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US3449030A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-06-22 | 1973-12-22 | 1974-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-22 | 1977-12-22 | 1978-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-22 | 1981-12-22 | 1982-06-23 | $7700.00 | Window Closed / Lapsed |