Patent GB-1527148-A (GB)
Title: Moulding
IPC: B29B7/00
Filed: 1975-10-03
Abstract: 1527148 Casting crayons &c. BINNEY & SMITH Inc 3 Oct 1975 [7 Oct 1974] 40622/75 Heading B5A A machine for casting wax crayons and similar elongate articles comprises a horizontal rotatable table 11 (Fig. 1) having a plurality of compartments 14, at least one tubular mould 18 vertically disposed in each compartment, means (e.g. fluid conduits (78, 79, 80) for controlling the temperature in each compartment, a transfer mechanism CR adapted to receive moulded articles and convey them away from the mould table, ejection means 21 (Fig. 9) for removing moulded products from the tubular moulds and inserting them in the transfer mechanism, and drive means (DS, Fig. 2, not shown) for moving the mould table, transfer mechanism, and ejection means. In the illustrated embodiment, molten wax is supplied from an adjustable volume pump 30 to threeway valve 31 and thence via conduit 34 to pouring shoot 33. The compartments are successively indexed clockwise to a position below the shoot, which floods the area of the table between retaining walls 40 and 41 with a quantity of molten wax at least sufficient to fill all the moulds 18. In this sector of the table, the moulds are heated by the countercurrent flow through the surrounding compartments of hot water supplied at conduit 85 and removed via conduct 86 (see Fig. 4). The compartments then pass through a sector in which they are cooled by the counter-current flow of cold water supplied at conduit 81 and removed via conduit 82. By the end of their passage through this sector, the wax has solidified, and any excess wax is scraped from the surface of the table by scraper blade 53; reciprocating plate 61 pushes this waste wax into reheat kettle 65 where it is remelted and returned to the wax supply system via conduit 66. The compartments then pass through a sector wherein they are neither heated nor cooled and in which the crayons are removed from the mould and placed in the transfer mechanism. As shown in Fig. 9, ejector pin 21 lifts the moulded crayon C into a resilient (e.g. rubber) tube 129 mounted inside a perforated metal tube 130, the whole being airtightly mounted inside a pressurizable chamber; this assembly is designated 100 in Fig. 1. When the chamber is supplied with, e.g. compressed air, the rubber tube is forced against the crayon, so resiliently, but releasably, gripping it. The ejector pin 21 is then retracted and the compartment moves on to another moulding cycle. The L-shaped member on which the transfer plate 100 is mounted is then rotated through 90 degrees (to the dotted-line position in Fig. 1) to bring an identical member 101 (illustrated in its article discharge position) into registration with the subsequent compartment. The crayons are then ejected from transfer plate 100 on to a conveyer belt (not shown) by pivoting the plate to the vertical position about axis 111, releasing the pressure inside the plate (so releasing the grip of the rubber tubes on the crayons) and pushing ejector pins 120 through the tubes (as shown for transfer plate 101 in Fig. 1). The machine may be adapted for the manufacture of candles or chalk sticks.