US4986333A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of supporting a core in a mold
Assignee: Rolls Royce PLC
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Filing: 1989-01-10
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Granted: 1991-01-22
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Expires: 2009-01-10
Abstract
Abstract The ceramic core is located within the ceramic mold by the insertion of recrystallized alumina pins through the wax encasing the core prior to encasing the whole in a ceramic slurry; on the subsequent removal of the wax, the molten metal, i.e. superalloy, is injected into the resulting space; the recrystallized alumina pins remain intact during the casting process hence substantially increasing the success rate of achieving accurate core locating during casting solidification.
Inventors
- 👤 Frederick H. Gartland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:42
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/02; B22C9/04; B22C21/00; B22C21/12; B22C21/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
A method of locating and maintaining a core in fixed space relationship with the interior of a ceramic shell mold in the investment casting process for making a cast component, comprising the steps of: encasing the core in wax, inserting a plurality of recrystallized alumina pins through the wax encasing the core until said pins abut the core, encasing the wax encased core in a ceramic slurry and hardening the slurry to form a ceramic shell mold and to fix the recrystallized alumina pins, the fixed recrystallized alumina pins remaining intact during subsequent casting and solidification processes, thereby maintaining the core in an accurate location within the ceramic shell mold during the casting and solidification processes.
Claim 2
Independent Claim
116 words
A method of locating and maintaining a core in fixed space relationship with the interior of a ceramic shell mold in the investment casting process for making a cast component, comprising the steps of: encasing the core in wax, inserting a plurality of recrystallized alumina pins through the wax encasing the core until said pins abut the core, encasing the wax encased core in a ceramic slurry and hardening the slurry to form a ceramic shell mold and to fix the recrystallized alumina pins, the fixed recrystallized alumina pins remaining intact during subsequent casting and solidification processes, thereby maintaining the core in an accurate location within the ceramic shell mold during the casting and solidification processes.
Claim 3
Dependent Claim
22 words
The method as claimed in claim 1 in which the cast component is a superalloy turbine blade which has a passageway therein.
Claim 4
Dependent Claim
23 words
The method as claimed in claim 1 in which the cast component is a superalloy nozzle guide vane which has a passageway therein.
Claim 5
Dependent Claim
15 words
The method as claimed in claim 2 in which the superalloy is a nickel/chrome alloy.
Claim 6
Dependent Claim
15 words
The method as claimed in claim 4 in which the superalloy is a nickel/chrome alloy.
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) | 1994-01-21 | 1994-07-23 | 1995-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-21 | 1998-07-23 | 1999-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-21 | 2002-07-23 | 2003-01-22 | $7700.00 | Window Closed / Lapsed |