US2531496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of forming a plaster mold or core for casting metals
Assignee: Antioch College
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Filing: 1949-11-04
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Granted: 1950-11-28
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Expires: 1969-11-04
Abstract
No abstract record available.
Inventors
- 👤 Xarifa L Bean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:38
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
131 words
THE METHOD OF FORMING A PLASTER MOLD WHICH INCLUDES FORMING A DESIRED SHAPE FROM A MIXTURE COMPRISING PLASTER OF PARIS, AN INERT FILLER, A WATER-SOLUBLE ALKALI METAL SILICATE SELECTED FROM THE CLASS CONSISTING OF SODIUM SILICATE AND POTASSIUM SILICATE AS THE ESSENTIAL EXPANSION CONTROL AGENT IN AN AMOUNT BETWEEN 0.1% AND 1.0% OF THE DRY WEIGHT OF THE PLASTER; DEHYDRATING THE SET PLASTER TO CONVERT CALCIUM SULFATE DI-HYDRATE TO CALCIUM SULFATE HEMI-HYDRATE AND TO LEAVE FREE WATER DISTRIBUTED THROUGHOUT THE MOLD; THEREAFTER REHYDRATING THE HEMI-HYDRATE TO THE DIHYDRATE; AND THEN DRYING THE MOLD TO REMOVE PRACTICALLY ALL OF THE REMAINING FREE WATER FROM THE PLASTER, THE TEMPERATURE TO WHICH THE PLASTER IS SUBJECTED THROUGHOUT THE ENTIRE PLASTER CONDITIONING TREATMENT AND PRIOR TO CASTING MOLTEN METAL INTO THE MOLD NOT EXCEEDING 500*F.
Claim 2
Independent Claim
131 words
THE METHOD OF FORMING A PLASTER MOLD WHICH INCLUDES FORMING A DESIRED SHAPE FROM A MIXTURE COMPRISING PLASTER OF PARIS, AN INERT FILLER, A WATER-SOLUBLE ALKALI METAL SILICATE SELECTED FROM THE CLASS CONSISTING OF SODIUM SILICATE AND POTASSIUM SILICATE AS THE ESSENTIAL EXPANSION CONTROL AGENT IN AN AMOUNT BETWEEN 0.1% AND 1.0% OF THE DRY WEIGHT OF THE PLASTER; DEHYDRATING THE SET PLASTER TO CONVERT CALCIUM SULFATE DI-HYDRATE TO CALCIUM SULFATE HEMI-HYDRATE AND TO LEAVE FREE WATER DISTRIBUTED THROUGHOUT THE MOLD; THEREAFTER REHYDRATING THE HEMI-HYDRATE TO THE DIHYDRATE; AND THEN DRYING THE MOLD TO REMOVE PRACTICALLY ALL OF THE REMAINING FREE WATER FROM THE PLASTER, THE TEMPERATURE TO WHICH THE PLASTER IS SUBJECTED THROUGHOUT THE ENTIRE PLASTER CONDITIONING TREATMENT AND PRIOR TO CASTING MOLTEN METAL INTO THE MOLD NOT EXCEEDING 500*F.
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) | 1953-11-27 | 1954-05-29 | 1954-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-27 | 1958-05-29 | 1958-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-27 | 1962-05-29 | 1962-11-28 | $7700.00 | Window Closed / Lapsed |