Patent ID: 8235090

Claim:
A method of casting a piston comprising: moving a pair of first mandrels along a converging linear path oblique to a central axis into an engaged position; moving a pair of mold halves into an engaged position to provide at least a portion of a mold cavity with said first mandrels being received in said mold cavity while in their engaged position; moving a lower mold projection in a vertical direction along said central axis to an engaged position spaced from and between at least a portion of said pair of first mandrels in their engaged position; introducing a quantity of fluid piston material into said mold cavity; curing the fluid piston material to form a solid piston having an upper crown formed by said mold halves and a cooling gallery formed by said first mandrels and a pair of pin bosses formed by said lower mold projection and said mold halves, said cooling gallery being undercut radially inwardly from a ring belt of said upper crown, and said pin bosses flaring outwardly at an angle with respect to said central axis; moving said first mandrels along a diverging linear path oblique to said central axis to a disengaged position substantially removed from said mold cavity; moving said mold halves to a disengaged position; and thereafter moving said lower mold projection in a vertical direction along said central axis to a disengaged position substantially removed from said mold cavity; and removing the cured piston from said mold cavity.