Patent US2455421A successfully refreshed from Google Patents.
US2252014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Instrument for indicating and recording the weight and viscosity of slush used in rotary drilling of wells
Assignee: Individual
•
Filing: 1936-03-25
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Granted: 1941-08-12
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Expires: 1956-03-25
Abstract
No abstract record available.
Inventors
- 👤 James A Lupfer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:54
CPC Classifications
G; G01; G01N; G01N11/00; G01N11/10; G01N11/16
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) | 1944-08-11 | 1945-02-10 | 1945-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-08-11 | 1949-02-10 | 1949-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-08-11 | 1953-02-10 | 1953-08-12 | $7700.00 | Window Closed / Lapsed |