Patent US2578523A successfully refreshed from Google Patents.
US2578523A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polytetrafluoroethylene packing material and process for making same
Assignee: EIDP Inc
•
Filing: 1950-06-30
•
Granted: 1951-12-11
•
Expires: 1970-06-30
Abstract
No abstract record available.
Inventors
- 👤 Walter E Llewellyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:18
CPC Classifications
B; B29; B29B; B29B9/00; B29B9/12; F; F16; F16J; F16J15/00; F16J15/16; F16J15/18; F16J15/20; Y; Y10; Y10S; Y10S277/00; Y10S277/935; Y10S277/944; Y10S277/945; Y10S277/946
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
73 words
A PROCESS FOR THE MANUFACTURE OF A PACKING AND GASKET MATERIAL WHICH COMPRISES PASSING PARTICLES OF UNSINTERED POLYTETRAFLUOROETHYLENE BETWEEN MILLING ROLLS A PLURALITY OF TIMES, AND REPEATEDLY REROLLING THE RESULTANT COMPACTED MASS UNTIL THE POLYTETRAFLUOROETHYLENE CHANGES ITS PHYSICAL APPEARANCE AND ASSUMES THE FORM OF MATTED SHREDS, FLAKES, OR STRANDS OF THE POLYMER, SAID MAT BEING MADE UP OF UNSINTERED POLYTETRAFLUOROETHYLENE WHICH IS TOUGH AND RESILIENT AND SUITABLE FOR USE AS A GASKET MATERIAL.
Claim 2
Dependent Claim
73 words
A PROCESS FOR THE MANUFACTURE OF A PACKING AND GASKET MATERIAL WHICH COMPRISES PASSING PARTICLES OF UNSINTERED POLYTETRAFLUOROETHYLENE BETWEEN MILLING ROLLS A PLURALITY OF TIMES, AND REPEATEDLY REROLLING THE RESULTANT COMPACTED MASS UNTIL THE POLYTETRAFLUOROETHYLENE CHANGES ITS PHYSICAL APPEARANCE AND ASSUMES THE FORM OF MATTED SHREDS, FLAKES, OR STRANDS OF THE POLYMER, SAID MAT BEING MADE UP OF UNSINTERED POLYTETRAFLUOROETHYLENE WHICH IS TOUGH AND RESILIENT AND SUITABLE FOR USE AS A GASKET MATERIAL.
References Cited (Backward Citations)
US2185789A
Cited
US2400099A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-10 | 1955-06-11 | 1955-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-10 | 1959-06-11 | 1959-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-10 | 1963-06-11 | 1963-12-11 | $7700.00 | Window Closed / Lapsed |