Die casting pump

An apparatus for die casting molten metal, comprising:

• a pump for pumping molten metal comprising:
• (a) a pump base comprised of non-metallic, heat resistant material and adapted to be submerged in a bath of molten metal, said pump base comprising a molten metal inlet opening;
• a molten metal valve chamber in communication with said inlet opening;
• a molten metal pumping chamber;
• a passageway that communicates said valve chamber and said pumping chamber, and a molten metal outlet opening that communicates with said pumping chamber;
• (b) a conduit extending from said outlet opening to a discharge location outside the bath, said conduit having an outlet located at said discharge location;
• (c) a first piston made of non-metallic, heat resistant material and adapted for reciprocal movement in said valve chamber;
• (d) a second piston made of non-metallic, heat resistant material and adapted for reciprocal movement in said pumping chamber;
• (e) at least one annular gasket comprised of refractory material disposed around said second piston in said pumping chamber;
• (f) a first connecting member that extends upwardly from said first piston;
• (g) a second connecting member that extends upwardly from said second piston;
• and
• (h) at least one actuator in communication with said first member and said second member, wherein the at least one said actuator acts upon said first member and said second member to effect said reciprocal movement of said first piston and said second piston;
• (i) a shot chamber fluidly connected with said discharge opening for receiving molten metal discharged from said conduit;
• and
• (j) a ram disposed in said chamber and adapted to direct molten metal in said chamber to a die for casting said molten metal.

A method of pumping molten metal using a pump base that is comprised of non-metallic, heat resistant material and adapted to be submerged in a bath of molten metal, said pump base comprising a molten metal inlet opening, a valve chamber in communication with said inlet opening, a molten metal pumping chamber;

• a passageway that communicates said valve chamber and said pumping chamber, and a molten metal outlet opening that communicates with said pumping chamber, said method comprising:
• a molten metal inlet stage comprising
• positioning a first piston made of non-metallic, heat resistant material at a location that enables molten metal to enter said valve chamber;
• and
• positioning a second piston made of non-metallic, heat resistant material in said pumping chamber so as to permit molten metal to enter said pumping chamber;
• sealing said pumping chamber using an annular sealing member comprised of refractory material disposed around said second piston;
• and
• a molten metal pumping stage comprising
• positioning said first piston so as to prevent molten metal from entering said valve chamber;
• moving said second piston so as to discharge molten metal from said pumping chamber and to direct molten metal through said outlet opening.

A method of die casting molten metal using a pump base that is comprised of non-metallic, heat resistant material and adapted to be submerged in a bath of molten metal, said pump base comprising a molten metal inlet opening, a valve chamber in communication with said inlet opening, a molten metal pumping chamber;

• a passageway that communicates said valve chamber and said pumping chamber, and a molten metal outlet opening that communicates with said pumping chamber, said method comprising:
• a molten metal feed stage comprising
• positioning a first piston made of non-metallic, heat resistant material at a location that enables molten metal to enter said valve chamber through said inlet opening, and
• positioning a second piston made of non-metallic, heat resistant material in said pumping chamber so as to permit molten metal to enter said pumping chamber;
• sealing said pumping chamber using an annular sealing member comprised of refractory material disposed around said second piston;
• a molten metal pumping stage comprising
• positioning said first piston so as to prevent molten metal from entering said valve chamber;
• moving said second piston so as to discharge molten metal from said pumping chamber and to direct molten metal from said outlet opening through a conduit into a shot chamber located outside said bath;
• and
• injecting said molten metal in said shot chamber into a cavity of a die.