US3746591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a semi-permeable membrane tube
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1970-07-14
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Granted: 1973-07-17
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Expires: 1990-07-14
Abstract
Abstract IN THE PRODUCTION OF SEMI-PERMEABLE MEMBRANE ASSEMBLIES ONE OR MORE POROUS FIBROUS TAPES ARE SPIRALLY WOUND INTO A TUBE AND THE MEMBRANE IS PROVIDED AS THE INNER OR OUTER PLY DURING OR AFTER WINDING. DURING WINDING AT LEAST ONE TAPE IS OVERLAPPED ON ITSELF BY UP TO 25% OF ITS WIDTH AND THE OVERLAPPED PORTIONS ARE SEALED.
Inventors
- 👤 D Banfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:35
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/04; B01D63/00; B01D63/06; B01D63/061; B01D63/062
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |