USRE27982E
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compact multiple effect still having stacked impervious and pervious membranes
Assignee: —
•
Filing: 1971-11-08
•
Granted: 1974-04-23
•
Expires: 1991-11-08
Abstract
Abstract THE COMPACT, MULTIPLE EFFECT STILL IS COMPOSED OF ALTERNATING LAYERS IN STACKED RELATIONSHIP OF THIN POROUS MEMBRANES THAT AREIMPERVIOUS TO LIQUIDS WHILE READILY PASSING THE VAPORS THEREOF AND CORRUGATED MEMBRANES THAT ARE IMPERVIOUS TO LIQUIDS AND VAPORS.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:20
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/36; B01D61/364; B01D1/00; B01D1/22; B01D3/00; B01D3/02; B01D63/00; B01D63/08; B01D63/082; B01D63/084; C; C02; C02F; C02F1/00; C02F1/02; C02F1/04; C02F1/16
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |