US4529663A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible, asbestos-free gasket material
Assignee: T&N Materials Research Ltd
•
Filing: 1984-04-19
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Granted: 1985-07-16
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Expires: 2004-04-19
Abstract
Abstract Non-asbestos flexible sheet material suitable for use in gaskets for the cylinder head of an internal combustion engine is made by dewatering on a water-permeable conveyor a layer of aqueous slurry and compressing and drying the dewatered layer, the aqueous slurry employed being one that contains the following ingredients in the following proportions by dry weight: ball clay 25-44% calcium silicate of high specific 15-40% surface area cellulose fibres 3-15% organic polymer binder 5-15% fibrillated poly (aromatic amide) 1-15% fibres
Inventors
- 👤 Robert A. Lancaster
- 👤 Noel C. McKenzie
- 👤 Brian Hargreaves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:24
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/68; C; C09; C09K; C09K3/00; C09K3/10; C09K3/1025; C09K3/1028; D21H13/00; D21H13/10; D21H13/20; D21H13/26; D21H13/36; D21H13/38; D21H13/40; F; F16; F16J; F16J15/00; F16J15/02; F16J15/06; F16J15/10; F16J15/102; C09K2003/1034; C09K2003/1046; C09K2200/00; C09K2200/02; C09K2200/0239; C09K2200/0243; C09K2200/0252; C09K2200/06; C09K2200/0607; C09K2200/0612; C09K2200/0692; C09K2200/0695; C09K2200/0697; Y; Y10; Y10S; Y10S277/00; Y10S277/935; Y10S277/936; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31692; Y10T428/31699; Y10T428/31703
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
77 words
Non-asbestos flexible sheet material made by dewatering on a water-permeable conveyor a layer of aqueous slurry and compressing and drying the dewatered layer, and calendering the dried dewatered layer, the aqueous slurry employed being one that contains the following ingredients in the following proportions by dry weight: ______________________________________
ball clay 25-44%
calcium silicate of specific
15-40%
surface area of at least 10 m.sup.2 /gram
cellulose fibres 3-15%
organic polymer binder
5-15%
fibrillated poly(aromatic amide) fibres
1-15%.
______________________________________
Claim 2
Dependent Claim
77 words
Non-asbestos flexible sheet material made by dewatering on a water-permeable conveyor a layer of aqueous slurry and compressing and drying the dewatered layer, and calendering the dried dewatered layer, the aqueous slurry employed being one that contains the following ingredients in the following proportions by dry weight: ______________________________________
ball clay 25-44%
calcium silicate of specific
15-40%
surface area of at least 10 m.sup.2 /gram
cellulose fibres 3-15%
organic polymer binder
5-15%
fibrillated poly(aromatic amide) fibres
1-15%.
______________________________________
Claim 3
Dependent Claim
21 words
Non-asbestos flexible sheet material according to claim 1, in which the slurry also contains 1-5% by dry weight of a wax.
Claim 4
Dependent Claim
22 words
Non-asbestos flexible sheet material according to claim 1, in which the slurry also contains 2-10% by dry weight of black iron oxide.
Claim 5
Dependent Claim
22 words
Non-asbestos flexible sheet material according to claim 1, in which the slurry also contains 1-8% by dry weight of a mineral wool.
Claim 6
Dependent Claim
22 words
Non-asbestos flexible sheet material according to claim 1, in which the slurry also contains 2-15% by dry weight of mica or chlorite.
Claim 7
Dependent Claim
16 words
A gasket comprising non-asbestos flexible sheet material according to claim 1, secured to a metal support.
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) | 1988-07-15 | 1989-01-14 | 1989-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-15 | 1993-01-14 | 1993-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-15 | 1997-01-14 | 1997-07-16 | $7700.00 | Window Closed / Lapsed |