GB650716A - Method and means of making moulds - Google Patents

Abstract

650,716. Casting moulds. RUBISSOW, G. A. May 8, 1947, No. 12500. [Class 87 (ii)] [Also in Group XXII] A mould is made by positioning a pattern within a casing, filling the. casing with the mould material, sawing the mould and embedded pattern into a number of parts, removing the separate parts of the pattern and then reassembling the mould parts to form a complete mould. The mould and pattern may be made of metals or alloys or of refractory material such as magnesium oxide, aluminium oxide, sand, bentonite, fire-clay, dolomite, talcum, graphite, cement either alone or mixed in powdered form with metals, natural or artificial rubber, mixtures of rubber with refractory materials, wood or cork, artificial plastics and resins including Lucite and materials known under the Registered Trade Marks " Bakelite " and " Cellophane," or of animal substances including shellac and solidified blood or of glass and various forms of silica. The pattern P may be supported within the casing by means of a runner pattern G and vent pattern V or by means of needle-like supports N<SP>1</SP>, N<SP>2</SP>, N<SP>3</SP>, N<SP>4</SP>, N<SP>5</SP>. Tubular members such as TM<SP>1</SP> and TM<SP>2</SP> may extend across the casing and after cutting the mould and removing the pattern they form holes for bolts B<SP>4</SP> and B<SP>9</SP> used for securing together the parts of the mould. A core such as K may be assembled with the mould parts. To compensate for the width of the saw cuts, either the pattern is made oversize or insertions such as IN<SP>1</SP>, IN<SP>2</SP> of a thickness approximating to the saw cuts are placed between the mould parts on assembly. In a modification, the mould material is first poured into the casing and the pattern is then thrust in before the material has solidified.