| 摘要 |
PURPOSE:To prevent the deformation of a rubber pattern for a product and to obtain a gypsum casting mold having high accuracy by embedding a core material in a lower rubber pattern for the product, and receiving the weight of a rubber pattern for a sprue on the upper side with said core material. CONSTITUTION:A rubber pattern 1 for a sprue is assembled on the top side of a rubber pattern 2 for a product, and the assembly is contained in a metallic flask 3, and is placed on the base plate 4 in the bottom part thereof. A core material 6 penetrating vertically the pattern 2 is embedded in said pattern. A core material 7 for removal is beforehand embedded in the pattern 1. The projection 6b at the top end of the material 6 and the recessed hole 7a at the bottom end of the material 7 are fitted to each other to support the pattern 1 on the shoulder part 6c of the material 6 and the weight thereof is received with the support part 6a. Then, even if the pattern 2 is formed of soft rubber for the purpose of easy removal, the deformation is prevented as far as possible, and the gypsum casting mold having high accuracy is obtd. |
