Patent ID: 6491206
Filing Date: 2002-12-10
Classification: B23P,F04B,F16J

Abstract:
A method of manufacturing closed cavity pistons, comprising,taking an elongated piston body having an internal cavity, a closed end, and an open end, and an external wall extending around the cavity and terminating in a first contact surface at the open end of the piston body, providing a second contact surface within the cavity which is longitudinally spaced from the first contact surface, taking a cap element having an elongated stem and a head comprises of a third and fourth contact surfaces which register with the first and second contact surfaces, respectfully, of the piston body, and simultaneously welding the first to the third surface and the second surface to the fourth surface by inertia friction welding whereby longitudinal pressure is applied to the piston body and the cap element to maintain their respective contact surfaces in tight longitudinal engagement, and then rotating one of the other to generate sufficient heat between the engaged contact surfaces to cause them to be fused together.