| 摘要 |
1,219,527. Chaplets; core-supporting patterns; mould and core materials. T.R.W. Inc. 24 Sept., 1969 [1 Oct., 1968], No. 46994/69. Heading B3F. [Also in Divisions B5 and C3] A hollow casting is made by forming about a ceramic (fused silica) core 15, a low melting pattern 11 (of wax, polystyrene &c.) and then, to secure the core 15 against movement, pins 16, preferably heated, are inserted through the pattern 11 to engage the core surface before a ceramic shell mould 19 is formed around the pattern to anchor the pin ends while the pattern is melted out; molten metal is then poured into the cavity so created and the exposed parts of the pins 16, e.g. of the same metal, melt into the metal before it solidifies and the mould and core are removed. The shell mould 19 is formed by steps of dipping, dusting and drying (see Division B5). |
