Method of producing molds
US5558148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1995 |
| Grant date | Sep 24, 1996 |
| Priority date | — |
| Expiry date | May 5, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22C15/28
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Molding sand (5) is fed into a space defined by a pattern plate (2) and a flask (3) mounted on the pattern plate (2), and the space is enclosed at the upper part of the flask (3) by a cover (6). The air in the enclosed space is evacuated to reduce the air pressure between the grains of the molding sand in the enclosed space to 1 Torr to 150 Torr, and then air is introduced into the enclosed space from the upper part of the space so that the pressure in the space can increase at the rate of 15 atm/s to compress the molding sand (5). The method eliminates the need for vent holes and enables the mold to be crack-free since the air flow is not reflected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.