Patent ID: 6505674
Filing Date: 2003-01-14
Classification: B21C,B22D

Abstract:
An injector for a molten metal supply system, comprising:an injector housing configured to contain molten metal; a molten metal supply source in fluid communication with the housing; a piston reciprocally operable within the housing, with the piston movable through a return stroke allowing molten metal to be received into the housing from the molten metal supply source and a displacement stroke for displacing the molten metal from the housing to a downstream process, and with the piston having a pistonhead for displacing the molten metal from the housing; and a gas supply source in fluid communication with the housing through a gas control valve, wherein during the return stroke of the piston a space is formed between the pistonhead and the molten metal and the gas control valve is operable to fill the space with gas from the gas supply source, and wherein during the displacement stroke of the piston the gas control valve is operable to prevent venting of gas from the gas filled space such that the gas in the gas filled space is compressed between the pistonhead and molten metal received into the housing and displaces the molten metal from the housing ahead of the pistonhead.