| 摘要 |
<p>971,133. Making moulds. PRECISION METALSMITHS Inc. Oct. 1, 1962 [Oct. 17, 1961], No. 37132/62. Drawings to Specification. Heading B5A. In a method of making a mould by dipping a wax pattern into a slurry, draining off excess slurry and stuccoing the slurry with further refractory material, the slurry is subjected to vacuum to remove air from the pattern and slurry and then restored to atmospheric pressure to drive the slurry into interstices in the pattern or in previous coatings. The stuccoing may be carried out by sieving, rotating under a vibrating screen or by immersion in a " fluid bed." Specification 971,134 is referred to.</p> |
