US3383172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing silica in the form of hollow spheres
Assignee: Evonik Operations GmbH
•
Filing: 1964-02-04
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Granted: 1968-05-14
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Expires: 1984-02-04
Abstract
No abstract record available.
Inventors
- 👤 Biegler Hanns
- 👤 Kallrath Gottfried
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:48
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01B33/181; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/34; C01P2004/51; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/11; C01P2006/12; C01P2006/80; C01P2006/82
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US3094384A
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US3120495A
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US3105052A
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US3243262A
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US3273962A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-05-14 | 1971-11-13 | 1972-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-05-14 | 1975-11-13 | 1976-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-05-14 | 1979-11-13 | 1980-05-14 | $7700.00 | Window Closed / Lapsed |