Patent US2639478A successfully refreshed from Google Patents.
US2639478A
Expired / Lapsed
US
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Process of preparing patterns
Assignee: United States Gypsum Co
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Filing: 1949-12-16
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Granted: 1953-05-26
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Expires: 1969-12-16
Abstract
No abstract record available.
Inventors
- 👤 Brainard W Nies
- 👤 Edward W Duffy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:37
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/14; B; B22; B22C; B22C7/00; B22C7/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
108 words
THE PROCESS OF CASTING A SUBSTANTIALLY DIMENSIONALLY ACCURATE REPRODUCTION OF AN OBJECT FROM A HARDENABLE FLUID MATERIAL WHICH SHRINKS UPON HARDENING, COMPRISING FORMING A MOLD HAVING A CASTING CAVITY CONFORMING TO THE SHAPE OF THE OBJECT TO BE REPRODUCED, POURING AN AQUEOUS SLURRY OF A CALCINED GYPSUM PLASTER HAVINGG A SETTING EXPANSION OF AT LEAST ABOUT 0.65% INTO SAID CAVITY, PREMITTING SAID PLASTER HAVING TO EXPAND UPON SETTING TO FORM A PATTERN, FORMING A MOLD FROM SAID PATTERN, AND CASTING A HARDENABLE FLUID IN SAID MOLD, THE INCREASE IN SIZE OF SAID PATTERN OVER SAID OBJECT BEING SUBSTANTIALLY THE SAME AS THE SHRINKAGE OF SAID FLUID DURING HARDENING.
Claim 2
Dependent Claim
108 words
THE PROCESS OF CASTING A SUBSTANTIALLY DIMENSIONALLY ACCURATE REPRODUCTION OF AN OBJECT FROM A HARDENABLE FLUID MATERIAL WHICH SHRINKS UPON HARDENING, COMPRISING FORMING A MOLD HAVING A CASTING CAVITY CONFORMING TO THE SHAPE OF THE OBJECT TO BE REPRODUCED, POURING AN AQUEOUS SLURRY OF A CALCINED GYPSUM PLASTER HAVINGG A SETTING EXPANSION OF AT LEAST ABOUT 0.65% INTO SAID CAVITY, PREMITTING SAID PLASTER HAVING TO EXPAND UPON SETTING TO FORM A PATTERN, FORMING A MOLD FROM SAID PATTERN, AND CASTING A HARDENABLE FLUID IN SAID MOLD, THE INCREASE IN SIZE OF SAID PATTERN OVER SAID OBJECT BEING SUBSTANTIALLY THE SAME AS THE SHRINKAGE OF SAID FLUID DURING HARDENING.
References Cited (Backward Citations)
CA198973A
Cited
US1508800A
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US910166A
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US980888A
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US1901054A
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US2118468A
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US2078199A
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US2078200A
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US2391855A
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US2396195A
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US2494403A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-25 | 1956-11-24 | 1957-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-25 | 1960-11-24 | 1961-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-25 | 1964-11-24 | 1965-05-26 | $7700.00 | Window Closed / Lapsed |