US2821680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for use in determining characteristics of porous material
Assignee: ExxonMobil Oil Corp
•
Filing: 1956-04-12
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Granted: 1958-01-28
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Expires: 1976-04-12
Abstract
No abstract record available.
Inventors
- 👤 Marion L Slusser
- 👤 Douglas K Mclean
- 👤 Harry A Barclay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:34
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/08; G01N15/0806
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) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |