GB1341983A - Production of foundry cores - Google Patents

Abstract

1341983 Foundry moulding machines and sand preparing apparatus BRITISH LEYLAND (AUSTIN-MORRIS) Ltd and BORDEN CHEMICAL CO (UK) Ltd 17 Jan 1972 [16 Jan 1971] 2237/71 Heading B3F [Also in Division B1] Foundry cores are prepared by forming a sand/resin mix and a sand/catalyst mix separately, mixing the two mixes in a final mixing chamber to form a cold-setting moulding composition and blowing the final mixture from the final mixing chamber into a core-box. The final mixing chamber is then purged of moulding composition by applying a gas blast thereto. As shown in Fig. 3 sand from a hopper 1 is separately mixed with resin and catalyst in horizontal mixers 4, 5. A tilting hopper 22 measures the two mixes into a final mixing chamber 8. Valves 25, 26 close the openings to the chamber 8 and a blast of gas through a pipe 31 forces moulding composition from the chamber 8 along a flexible tube 12 to a blowhead 10 and from thence into a core-box 11. The mixing chamber 8 is then purged by supplying compressed gas and either moving the corebox 11 away, to blow excess moulding composition into a shoot (not shown) or by moving the blow head 10 on rails (not shown) to a position clear of the core box 11 and above a shoot (Fig. 5, not shown) to blow excess moulding composition away. In Fig. 4 the two mixes from mixers 4, 5 are conveyed by tubes 34, 25 to the final mixing chamber 8. After mix delivery, the tubes 34, 35 are tilted away from the chamber 8 and their openings are sealed by lids 36, 37 operated by fluid motors 38, 39. The final moulding composition is blown from chamber 8 through a funnel extension 8a to a blowhead 10 and thence to a core-box 11. After core-blowing, the core-box 11 is moved away from the blowhead 10 and replaced by a movable shoot (30, Fig. 8, not shown) or a movable manifold (43, Fig. 9, not shown) co-operating with a fixed shoot (30), so that excess moulding composition may be blown away from the chamber 8.