US4050500A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a shell mold
Assignee: Grede Foundries Inc
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Filing: 1976-03-15
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Granted: 1977-09-27
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Expires: 1996-03-15
Abstract
Abstract A stronger, thinner shell mold suitable for making cast metal parts comprises a base member of resin bonded sand and a second surfacing layer of a cured thermosetting binder material. Also disclosed is a method for forming the new shell mold.
Inventors
- 👤 Jack T. Steinbacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:04
CPC Classifications
B; B22; B22C; B22C1/00; B22C1/16; B22C1/165
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
122 words
A method of making a thin reinforced shell mold from a resin-coated sand comprising the steps of: A. investing a heated pattern with a mixture of sand and thermal setting resin to coat the heated pattern; B. heating the coated pattern to cure the resin forming a base layer for the shell mold, the interior surfaces of the base layer being adapted to receive molten metal for forming a cast article; C. applying a thin coating of a solution of inorganic silicate and a wetting agent to the external surfaces of the base layer opposite the internal surfaces, the material penetrating at least a portion of the base layer; and D. curing the inorganic silicate to form a reinforced thin shell mold.
Claim 2
Independent Claim
122 words
A method of making a thin reinforced shell mold from a resin-coated sand comprising the steps of: A. investing a heated pattern with a mixture of sand and thermal setting resin to coat the heated pattern; B. heating the coated pattern to cure the resin forming a base layer for the shell mold, the interior surfaces of the base layer being adapted to receive molten metal for forming a cast article; C. applying a thin coating of a solution of inorganic silicate and a wetting agent to the external surfaces of the base layer opposite the internal surfaces, the material penetrating at least a portion of the base layer; and D. curing the inorganic silicate to form a reinforced thin shell mold.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the heat for curing the inorganic silicate is residual heat provided by the base layer of resin bonded sand.
Claim 4
Dependent Claim
32 words
The method of claim 1 wherein the silicate is sodium silicate and the silicate is applied so as to penetrate no more than about 50% of the thickness of the base layer.
Claim 5
Dependent Claim
33 words
The method of claim 1 where the sodium silicate binder is exposed to an acidic insolubilizing agent chosen from the class consisting of: carbon dioxide, or a weak solution of an inorganic acid.
References Cited (Backward Citations)
CA619560A
Cited
US2748435A
Cited
US2837798A
Cited
GB819391A
Cited
GB823970A
Cited
GB1031587A
Cited
US3511302A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-26 | 1981-03-28 | 1981-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-26 | 1985-03-28 | 1985-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-26 | 1989-03-28 | 1989-09-27 | $7700.00 | Window Closed / Lapsed |