Mould for multiple moulding of e.g. anti-friction bearing cages - has centre core with main flow bore leading to axially successive tapered radial tunnel bores and pinpoint gates

摘要

In the mould for producing closed or open rings, tubes or bushes in plastics, and partic. for producing radial anti-friction bearing cages, in which two rings are joined by crosswebs distributed round the circumference, a cylindrical core to match the i.d. of the moulding has a flow bore and an outer tool which moves relative to the core to/from the centre line of the moulding. This latter tool has radially sliding members which can enter the spaces between the webs (with radial bearing cages) and which also have recesses to simultaneously produce a number of mouldings arranged one behind the other coaxially. The core tool, with little or no split line division, extends along the full length of the sliding members in the direction of the centre line; its main bore has at least one tapered bore for a tunnel gate for each moulding and the tunnel gate ends at a pinpoint entry; demoulding breaks off the sprue at this pinpoint. The layout is arranged so that the sprue in the main flow bore and that in the tunnel cool sufficiently to be demoulded from the core but are still not quite cold. ADVANTAGE - The design can produce a number (not merely two) of mouldings in each cycle a wit