Moulding apparatus for glassware forming machine

Claim 1

A moulding apparatus for use in a cyclically operating glassware forming machine, comprising a mould including a bottom plate defining a bottom portion of a cavity of the mould in which molten glass is moulded in the operating of the machine, and two side portions defining side portions of the cavity, each side portion being movable in a cycle of operation of the machine to a first position thereof in which each side portion engages the bottom plate and the other side portion to cooperate in defining the mould cavity so that moulding can take place and to a second position thereof in which the side portions are separated to allow moulded glass to be removed from the mould cavity, the side portions also including cooling passages passing upwardly through the side portions through which air can pass to cool the side portions, wherein the cooling passages in each side portion each have an entrance in a bottom surface of that side portion and the moulding apparatus further comprises a single plenum chamber extending beneath each of the side portions when the side portions are in the first position and having at least one exit which opens upwardly and communicates, when the side portions are in the first position, through vertical passages in the bottom plate with the entrances of the cooling passages, the plenum chamber also having an entrance connected to air supply means for blowing air into the plenum chamber and valve means for opening and closing the entrance or the at least one exit of the plenum chamber to cause mould cooling air to leave the plenum chamber for a predetermined period while the side portions of the mould are in the first position, said plenum chamber and said at least one exit having dimensions such that while said valve means opens the entrance or the at least one exit, air will be supplied to each cooling passage at substantially the same pressure.