Patent US2284883A successfully refreshed from Google Patents.
Patent US2220441A successfully refreshed from Google Patents.
US3497451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permeation separation with type-8 nylon membranes
Assignee: EIDP Inc
•
Filing: 1967-10-11
•
Granted: 1970-02-24
•
Expires: 1987-10-11
Abstract
No abstract record available.
Inventors
- 👤 Harvey H Hoehn
- 👤 Donald G Pye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:50
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/56
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2783894A
Cited
US3140256A
Cited
US3228877A
Cited
US3220960A
Cited
US3170867A
Cited
US3276996A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-02-23 | 1973-08-25 | 1974-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-23 | 1977-08-25 | 1978-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-23 | 1981-08-25 | 1982-02-24 | $7700.00 | Window Closed / Lapsed |