US4333977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wear-resistant article
Assignee: Waters Technologies Corp
•
Filing: 1980-08-27
•
Granted: 1982-06-08
•
Expires: 2000-08-27
Abstract
Abstract A wear-resistant and chemically-inert article made from a sintered mixture of polytetrafluoroethylene, graphite fibers, and fluorinated graphite.
Inventors
- 👤 Louis Abrahams
- 👤 Thomas P. J. Izod
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:57
CPC Classifications
F; F04; F04B; F04B15/00; F04B15/04; B; B29; B29C; B29C67/00; B29C67/02; B29C67/04; B29C70/00; B29C70/04; C; C08; C08K; C08K3/00; C08K3/16; C08K7/00; C08K7/02; C08K7/04; C08K7/06; B29K; B29K2307/00; Y; Y10; Y10S; Y10S417/00; Y10S417/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
45 words
A sintered, molded wear-resistant shaped article having a non-oxidized surface and having the empirically derived formula CF 1 .28 made from a molded and sintered granular mixture consisting essentially of 74-84% by weight polytetrafluoroethylene, 7-17% by weight graphite fibers, and 4-14% by weight fluorinated graphite.
Claim 2
Dependent Claim
45 words
A sintered, molded wear-resistant shaped article having a non-oxidized surface and having the empirically derived formula CF 1 .28 made from a molded and sintered granular mixture consisting essentially of 74-84% by weight polytetrafluoroethylene, 7-17% by weight graphite fibers, and 4-14% by weight fluorinated graphite.
Claim 3
Dependent Claim
19 words
The article of claim 1 wherein said mixture is about 79% polytetrafluoroethylene, 12% graphite fibers, and 9% fluorinated graphite.
Claim 4
Dependent Claim
20 words
The article of claim 1 wherein said article includes a working surface that rubs against another surface moving relative thereto.
Claim 5
Dependent Claim
23 words
The article of claim 3 wherein said working surface is a sealing surface and said article has the form of an annular seal.
Claim 6
Dependent Claim
13 words
The seal of claim 4 further comprising a flanged end for clamping installation.
Claim 7
Dependent Claim
25 words
The seal of claim 4 wherein there is a bore passing therethrough and an annular spring element embedded in the seal all around said bore.
Claim 8
Dependent Claim
14 words
The seal of claim 6 wherein said spring element is an endless helical spring.
References Cited (Backward Citations)
US3152201A
Cited
US3198188A
Cited
US3443817A
Cited
US3528955A
Cited
US3756925A
Cited
US3804217A
Cited
US3911072A
Cited
US4080233A
Cited
US4050701A
Cited
US4143110A
Cited
US4245963A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-07 | 1985-12-07 | 1986-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-07 | 1989-12-07 | 1990-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-07 | 1993-12-07 | 1994-06-08 | $7700.00 | Window Closed / Lapsed |