Moulding method and apparatus

Apparatus for moulding an article, said apparatus comprising:

• a metering chamber and a displaceable member, together defining a metering cavity, the volume of said metering cavity being variable by reciprocal displacement of the displaceable member in the metering cavity and said metering cavity being connectable to a supply of mouldable material;
• a packing chamber and a packing piston, together defining a transition passage that is in flow communication with an inner cavity of a mould via a port and that is in flow communication with the metering cavity via a passage, the packing piston being reciprocally displaceable within the transition passage between a retracted position and a forward position, the packing piston closing said port between the transition passage and the mould cavity and a leading face of the packing piston forming part of the peripheral wall of the mould cavity, when the packing piston is in said forward position;
• characterised in that the displaceable member is a metering piston and the volume of the metering cavity is configured to be varied by a known, predetermined amount, during the reciprocal displacement of the metering piston, further characterised in that the packing piston is configured to start its working stroke while mouldable material is still being fed from the metering cavity, such that an uninterrupted flow of mouldable material in the transition passage is maintained.