US4620995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface coated gasket sheet
Assignee: Marusan Packing Manufacturing Co
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Filing: 1985-06-28
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Granted: 1986-11-04
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Expires: 2005-06-28
Abstract
Abstract Tough heat- and corrosion-resistant films of polytetrafluoroethylene (PTFE) are baked onto the surfaces of sheet-type gaskets in a curtain coating process. The gasket to be coated is passed through a flow of liquid PTFE-resin containing composition, the gasket inverted end-for-end, the opposite side coated, then baked, to form a tough film.
Inventors
- 👤 Nobuyuki Otomo
- 👤 Hiroaki Chiba
- 👤 Tsuneo Uno
- 👤 Toshiki Aono
- 👤 Kozo Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:13
CPC Classifications
B; B05; B05D; B05D1/00; B05D1/30; B05D1/305; F; F16; F16J; F16J15/00; F16J15/02; F16J15/06; F16J15/10; F16J15/12; F16J15/121; F16J15/122; Y; Y10; Y10S; Y10S118/00; Y10S118/04; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31678; Y10T428/31707
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
105 words
A process for providing a cylinder head gasket with a heat-resistant, corrosion-resistant, substantially uniform baked PTFE film coating layer on all of the gasket surfaces of a core, said process comprising the steps of: (a) providing as a gasket core a sheet of metal having fiber-reinforced rubber sheets bonded to two opposite faces thereof; (b) applying a film coating of a PTFE liquid resin composition to said core by passing said core at least once through a flowing curtain of the PTFE liquid resin composition; and (c) heating the thus-coated core to form a tough, adherent, baked-on film on the gasket surfaces of said core.
Claim 2
Dependent Claim
105 words
A process for providing a cylinder head gasket with a heat-resistant, corrosion-resistant, substantially uniform baked PTFE film coating layer on all of the gasket surfaces of a core, said process comprising the steps of: (a) providing as a gasket core a sheet of metal having fiber-reinforced rubber sheets bonded to two opposite faces thereof; (b) applying a film coating of a PTFE liquid resin composition to said core by passing said core at least once through a flowing curtain of the PTFE liquid resin composition; and (c) heating the thus-coated core to form a tough, adherent, baked-on film on the gasket surfaces of said core.
Claim 3
Dependent Claim
20 words
The process of claim 1 in which the coating layer is from about 5 to about 100 microns in thickness.
Claim 4
Dependent Claim
20 words
The process of claim 2 in which the coating layer is from about 25 to about 40 microns in thickness.
Claim 5
Dependent Claim
33 words
The process of claim 1 in which the PTFE liquid resin composition also contains up to about 10% by weight, based on the weight of the PTFE, of at least one ceramic powder.
Claim 6
Dependent Claim
27 words
The process of claim 4 in which the PTFE liquid resin coating composition contains from about 3 to 10% by weight of at least one ceramic powder.
Claim 7
Dependent Claim
29 words
The process of claim 1 in which the PTFE liquid resin composition also contains up to 10% by weight, based on the weight of the PTFE, of carbon powder.
Claim 8
Dependent Claim
24 words
The process of claim 6 in which the PTFE liquid resin coating composition contains from about 3 to 10% by weight of ceramic powder.
Claim 9
Dependent Claim
119 words
The process of claim 1, wherein: said gasket core has two external opposite faces corresponding to said two opposite faces of said sheet of metal; and said step of applying a film coating includes passing said core through said flowing curtain of the PTFE liquid resin composition in a first pass with said core so oriented as to cause one of said faces of said core to become flow-coated with said PTFE liquid resin composition and then passing said core through said flowing curtain of the PTFE liquid resin composition in a second pass with said core so oriented as to cause the other of said faces of said core to become flow-coated with said PTFE liquid resin composition.
Claim 10
Dependent Claim
14 words
The process of claim 8, wherein: said sheet of metal is made of steel.
Claim 11
Dependent Claim
29 words
The process of claim 9, wherein: said sheet of steel is perforated and said fiber-reinforced rubber sheets are bonded to one another through at least some of such perforations.
Claim 12
Dependent Claim
16 words
The process of claim 9, wherein: said fiber-reinforced sheets are made of asbestos fiber-reinforced EPDM rubber.
Claim 13
Dependent Claim
16 words
The process of claim 9, wherein: said fiber-reinforced sheets are made of polyamide fiber-reinforced EPDM rubber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |