US3686006A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractory cores and methods of making the same
Assignee: Precision Metalsmiths Inc
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Filing: 1970-12-02
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Granted: 1972-08-22
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Expires: 1990-12-02
Abstract
Abstract REFRACTORY CORES WHICH CAN BE USED IN INVESTMENT CASTING WITHOUR FIRST HAVING BEEN FIRED TO AN ELEVATED TEMPERATURE ARE MADE BY A PROCESS CHARACTERIZED BY THE STEPS OF: (1) MOLDING A CORE FROM REFRACTORY MIXTURE INCLUDING A SUBLIMABLE BINDER, (2) SUBLIMING THE BINDER FROM THE CORE TO PRODUCE A POROUS STRUCTURE, (3) IMPREGNATING THE PORE STRUCTURE WITH A HARDENING AND STRENGTHENING AGENT, AND (4) HARDENING THE MATERIAL USED FOR IMPREGNATION.
Inventors
- 👤 Robert A Horton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:41
CPC Classifications
B; B22; B22C; B22C1/00; B22C1/16; B22C1/20; B22C1/22; B22C1/2293; C; C04; C04B; C04B33/00; C04B33/02; C04B33/13
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |