Precision molded refractory articles
Abstract
Abstract A PRECISION MOLDED REFRACTORY ARTICLE, WHICH CAN HAVE AN INTRICATE GEOMETRY WITH FINE SURFACE DETAIL, SUCH AS AN ELECTRICAL DISCHARGE MACHINING ELECTRODE, IS MADE BY MOLDING IN A FLEXIBLE MOLD A PLACTIC MIXTURE OF MULTIMODAL REFRACTORY POWDERS AND A THERMOPLASTIC BINDER TO FORM A GREEN ARTICLE OF PERDETERMINED SHAPE AND DIMENSIONS, HEATING THE GREEN ARTICLE TO REMOVE SAID BINDER AND CONSOLIDATE THE REFRACTORY POWDERS WITH VERY MINIMUM SHRINKAGE OF !HE ARTICLE, INFILTRATING THE RESULTING POROUS ARTICLE OR SKELETON WITH A MOLTEN INFILTRANT OF A LOW MELTING POINT METAL OR ALLOY, AND COOLING THE INFILTRATED SKELETION, THEREBY FORMING A PRECISION REFRACTORY ARTICLE HAVING A UNIFORM HIGH DENSITY, A USEFUL WORKING SURFACE FREE OF MACHINED OR OTHERWISE DISTRUBED METAL, AND A SHAPE AND DIMENSNS PRECISELY CONFORMING TO SAID GREEN ARTICLE.
Inventors
- 👤 R Kirby
- 👤 S Wing
Bibliographic Details
Claims Analysis
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |