US3475331A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permeability separatory apparatus and process of making and using same
Assignee: Dow Chemical Co
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Filing: 1968-02-23
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Granted: 1969-10-28
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Expires: 1988-02-23
Abstract
No abstract record available.
Inventors
- 👤 Earl A Mclain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:55
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/02; B01D63/021; B01D63/022; B01D63/0221; B01D63/0233; Y; Y02; Y02A; Y02A20/00; Y02A20/124; Y02A20/131; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/496; Y10T29/49604
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) | 1972-10-27 | 1973-04-28 | 1973-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-27 | 1977-04-28 | 1977-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-27 | 1981-04-28 | 1981-10-28 | $7700.00 | Window Closed / Lapsed |