US3717525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for production of a diffusion membrane arrangement
Assignee: Varian Mat GmbH
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Filing: 1968-05-23
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Granted: 1973-02-20
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Expires: 1988-05-23
Abstract
Abstract THE INVENTION IS CONCERNED WITH A METHOD OF MAKING GAS DIFFUUSION MEMBRANES. THE PORES ADJACENT THE SURFACE OF A POROUS PERMEABLE CARRIER MEMBER ARE FILLED WITH A MATERIAL, LATER TO BE REMOVED, A DIFFUSION MEMBER IS APPLIED TO THAT SURFACE, AND THE FILLER MATERIAL IS THEN REMOVED. IN ANOTHER EMBODIMENT A DIFFUSION MEMBER IS APPLIED TIO A GLASS CARRIER MEMBER WHICH IS PORE-FREE, AND THE GLASS IS THEN MADE POROUS BY HEAT TREATMENT AND SELECTIVE DISSOLUTION.
Inventors
- 👤 H Bueltemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:36
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/20; H; H01; H01J; H01J41/00
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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |