GB562467A - Abrasive wheels and method of making the same - Google Patents

Abstract

562,467. Grinding wheels. NORTON GRINDING WHEEL CO., Ltd. Dec. 15, 1942, No. 17834. Convention date, Dec. 1, 1941. [Class 60] [Also in Groups II and V] A metal ring 15, Fig. 2, is moulded from metal powder under low pressure, the upper face 16 thereof is roughened, the ring is placed in an annular mould 10, 11, 12, a mixture 17 of diamonds and metal bond is placed on the face 16, a mould ring 13 is placed on the mixture, and the 15-17 assembly is subjected to high pressure. The'resultant diamond-surfaced metal ring is removed, sintered, and machined to form on the metal part thereof a dovetail 20 and sloping surfaces 40, 41. The angles c, c<1> must be between 15 degrees and 45 degrees, e.g. 20 degrees. The machined ring is then placed, diamond face downwards, on the bottom plate 27, Fig. 3, of another mould, powdered A-stage resinoid or other plastic material 35 is filled into the mould to form a backing for the ring and the assembly is pressed hot. The angle b may be 90 degrees and the angle a 15 degrees. The abrasive surface 17a may be dished inwardly or outwardly, and may consist of one or more layers of diamonds. Other abrasives may be used, e.g. fusion products of carbide mixtures, boron carbide, silicon carbide, emery, corundum or fused alumina. The metal bond may be a brittle copper-tin alloy containing 18 per cent tin, or other bronzes containing manganese, aluminium, nickel or beryllium, or an alloy containing equal parts of copper, tin, nickel and iron, or copper, nickel, aluminium, aluminium-silicon, iron or steel. The metal bond may be one of those described in U.S.A. Specifications 2,238,351 and Re-issue 21,165. The plastic material used for the backing may be resin (phenol formaldehyde, aniline formaldehyde, alkyd, methyl methacrylate polymer, styrene), shellac or rubber.