Process for forming shell molds
US4312397A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1980 |
| Grant date | Jan 26, 1982 |
| Priority date | — |
| Expiry date | Apr 14, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22C9/123
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A pattern holder 12 and a sand tank 14 are rotatably mounted on a frame 16 so that the pattern holder can be inverted over and sealably mounted atop the sand tank. A vented pattern 26 is secured to the pattern holder and forms a first chamber between one side of the pattern and the interior of the pattern holder. A second chamber 90 is formed between the other side of the pattern and the interior of the sand tank when the pattern holder adjoins the sand tank. O-ring seals 32 and 80 isolate the chambers from the atmosphere so that a partial vacuum can be formed therein. A mixture 84 of sand and a gas-curable binder is provided in the sand tank so that the mixture will fall onto the pattern upon inverting the sand tank over the pattern holder. A flexible line 42 is provided for controllably introducing a gas catalyst into the chamber 38 in order to cure a portion of the sand-binder mixture to form a shell mold 94 of a predetermined thickness on a pattern face 36 of the pattern. Flexible lines 41 and 43 are provided for evacuating and purging the chamber 38 at different stages in the process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.