US3748155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making investment molds from improved pattern material
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1972-05-15
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Granted: 1973-07-24
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Expires: 1992-05-15
Abstract
Abstract METHOD OF MAKING INVESTMENT MOLDS WHEREIN AN IMPROVED PATTERN MATERIAL IS EMPLOYED, THE PATTERN MATERIAL CONTAINING A WAXY SOLID AND UP TO 50% BY WEIGHT OF ETHYL CELLULOSE, THE PATTERN MATERIAL HAVING A RELATIVELY LOW SOFTENING POINT AND VERY LOW VICOSITY IN THE FLUID STATE AT A TEMPERATURE AT WHICH IT IS INJECTED INTO THE PATTERN DIE.
Inventors
- 👤 F Speyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:07
CPC Classifications
B; B22; B22C; B22C7/00; B22C7/02
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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |