Patent ID: 8327537

Claim:
A method of constructing a piston, comprising: providing a piston body having a central axis along which said piston body reciprocates within a cylinder bore, said piston body having an upper crown portion having an upper combustion wall against which combustion forces directly act in the cylinder bore and an annular upper rib depending from the upper combustion wall to a free end, said piston body further including a lower crown portion having an annular lower rib extending to a free end arranged for engagement with said upper rib, said lower crown further including an inner gallery floor arranged radially inwardly from said lower rib and a pair of pin bosses depending generally from said inner gallery floor with a space provided between said pin bosses for receipt of a small end of a connecting rod, and at least one of said upper crown portion and/or said lower crown portion having a central support post extending along said central axis to a free end; initiating a friction weld joint between the free end of the central support post and a corresponding surface opposite the free end of the central support post; and forming a friction weld joint between the upper rib free end and the lower rib free end after initiating the friction weld joint at the free end of the central support, and completing the friction weld joint between the central support member free end and the corresponding surface opposite the central support post free end.