US4440864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemically bondable foundry sand
Assignee: Cosworth Research and Development Ltd
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Filing: 1982-03-19
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Granted: 1984-04-03
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Expires: 2002-03-19
Abstract
Abstract A chemically bondable foundry sand comprising a mixture of sand, binder and a plurality of fibres intimately mixed and dispersed throughout the mixture. Cores and moulds made from such sand have improved fracture resistance. The mixture may comprise from 0.01 to 1.0 wt. % of fibres, the length/diameter ratio of each fibre may be at least 10 and the fibres may have a length of from 1 to 20 mm. The fibres may be glass fibres, organic fibres or natural fibres. The binder may comprise a silicate binder or an organic binder such as a phenolic binder or a furane binder.
Inventors
- 👤 John Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:31
CPC Classifications
B; B22; B22C; B22C1/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
94 words
A chemically bondable reclaimable foundry sand mixture for fabricating cores or moulds used in metal castings consisting essentially of a granular mixture of sand, organic resin binder and a plurality of organic fibres intimately mixed and dispersed throughout the mixture and which fibres increase resistance to fracture and breakage of cores or moulds used in metal castings, whereby a core or mould prepared from said sand mixture is physically strong and handleable and relatively unbreakable during metal casting but which core or mould is easily reclaimed from said sand mixture by resin burn-off procedures.
Claim 2
Dependent Claim
18 words
A sand mixture according to claim 1 wherein the mixture comprises from 0.01 to 1.0 wt.% of fibers.
Claim 3
Dependent Claim
18 words
A sand mixture according to claim 1 wherein the length/diameter ratio of each fiber is at least 10.
Claim 4
Dependent Claim
19 words
A sand mixture according to claim 1 wherein the fibers have a length of from 1 to 20 mm.
Claim 5
Dependent Claim
24 words
A sand mixture according to claim 1 wherein the fibers are selected from the group comprising polypropylene fiber, polyvinyl alcohol fiber and polyester fiber.
Claim 6
Dependent Claim
13 words
A sand mixture according to claim 1 wherein the fibers comprise natural fibers.
Claim 7
Dependent Claim
25 words
A sand mixture according to claim 1 wherein the organic resin binder is selected from the group comprising a phenolic binder or a furane binder.
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) | 1987-04-03 | 1987-10-03 | 1988-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-03 | 1991-10-03 | 1992-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-03 | 1995-10-03 | 1996-04-03 | $7700.00 | Window Closed / Lapsed |