US3521751A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtering method and apparatus
Assignee: Nivoba NV
•
Filing: 1967-12-15
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Granted: 1970-07-28
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Expires: 1987-12-15
Abstract
No abstract record available.
Inventors
- 👤 Theodorus H Holthuis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:04
CPC Classifications
B; B01; B01D; B01D33/00; B01D33/06; B01D33/073; B01D33/44; B01D33/46; B01D33/463; B01D33/466; B01D33/48; B01D33/50; B01D33/503; B01D2201/00; B01D2201/28; B01D2201/282
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2839194A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-27 | 1974-01-26 | 1974-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-27 | 1978-01-26 | 1978-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-27 | 1982-01-26 | 1982-07-28 | $7700.00 | Window Closed / Lapsed |