Moulding apparatus for making gas hardened sand mould

摘要

A hopper for providing moulding sand having an opened top and a bottom member having through holes for discharging the sand is positioned spaced apart at a suitable distance horizontally from a cover member connected to a suitable source for generating gas for hardening the moulding sand. A pattern plate provided with vacuum evacuating means is disposed to be selectively connected to either one of the hopper and the cover member for discharging and filling the moulding sands into a flask placed on a pattern plate and for introducing hardening gas and allowing said gas to penetrate and permeate through the layer of sand filled in the flask to harden the filled sand, respectively. By using vacuum evacuation of a hollow chamber in the pattern plate instead of pressurized air and hardening gas under pressure, the entire moulding apparatus can be rendered lighter in construction and smaller in size, while any leakage of poisonous hardening gas can be completely prevented from occurring.