GB605801A - Improvements in and relating to the manufacture of wire and other brushes - Google Patents

Abstract

605,801. Casting composite articles. KIDD, F., and KIDD, T. D. Jan. 4, 1946, No. 423. [Class 83 (i)] [Also in Group V]. In a method of making die-cast brushes, a bundle of the pliant elements of the brush is inserted loosely into an opening between the dies and is flattened to the required shape by the pressure of the mechanism which closes the dies together, the bundle being thereby caused to fill completely the opening in which it is received. The lengths of wire bare formed into bundles and placed in a recess c in a stationary lower die d so that they extend into the space e in which the stock of the brush is to be cast. The die is provided with a sprue d<SP>3</SP> and with holes d' and dowels d2 for aligning the die with a co-operating movable upper die. At the constriction between the spaces c.and e, the wires are tightly gripped between the two die parts. Molten metal, preferably a zinc base alloy or an aluminium alloy is then forced into the dies to form a brush having a handle h, and stock f in which are embedded the ends of the wires a, Fig. 2. In modified forms, the dies may be shaped so that a number of brushes may be cast simultaneously or so that a number of bundles of wires may be cast into one elongated stack. In another form, Fig. 8, intended for making a circular brush, the lower die m has a central recess n and an inclined surface p co-operating with a central recess n<SP>1</SP> and surface p<SP>1</SP> of an upper die r. The wires are arranged radially on the surface p and gripped between the two dies as shown. A core s and spreader t are inserted through a bottom plate u. The invention may be applied to making brushes of fibres or bristles embedded in suitable thermoplastic materials.