US4529653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible, asbestos-free gasket material
Assignee: T&N Materials Research Ltd
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Filing: 1983-11-07
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Granted: 1985-07-16
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Expires: 2003-11-07
Abstract
Abstract Non-asbestos flexible sheet material suitable for use in gaskets for the exhaust manifold 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% non-fibrous layer silicate: 25-40% graphite: 10-30% cellulose fibres: 3-15% synthetic rubber: 1-10% starch: 1-5%.
Inventors
- 👤 Brian Hargreaves
- 👤 Robert A. Lancaster
- 👤 Noel C. McKenzie
- 👤 John D. Crabtree
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 05:47
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/68; F; F16; F16J; F16J15/00; F16J15/02; F16J15/06; F16J15/10; F16J15/12; F16J15/121; F16J15/122; Y; Y10; Y10S; Y10S106/00; Y10S106/03; Y10S277/00; Y10S277/935; Y10S277/936; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31692; Y10T428/31699; Y10T428/31703
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
59 words
Non-asbestos flexible sheet material made by dewatering on a water-permeable conveyor a layer of aqueous slurry and compressing and drying the dewatering layer, the aqueous slurry employed being one that contains the following ingredients in the following proportions by dry weight: ball clay: 25-44% mica or chlorite: 25-40% graphite: 10-30% cellulose fibers: 3-15% synthetic nitrile rubber: 1-10% starch: 1-5%.
Claim 2
Dependent Claim
59 words
Non-asbestos flexible sheet material made by dewatering on a water-permeable conveyor a layer of aqueous slurry and compressing and drying the dewatering layer, the aqueous slurry employed being one that contains the following ingredients in the following proportions by dry weight: ball clay: 25-44% mica or chlorite: 25-40% graphite: 10-30% cellulose fibers: 3-15% synthetic nitrile rubber: 1-10% starch: 1-5%.
Claim 3
Dependent Claim
27 words
Non-asbestos flexible sheet material according to claim 1, in which the slurry also contains rayon fibers, in an amount forming 1-10% by dry weight of the slurry.
Claim 4
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 |