Patent ID: 8371014

Claim:
A method of forming a metallic container comprising: providing a pre-formed body portion being open at one end, the open end having an angled flange extending circumferentially therearound, and supporting the pre-formed body portion on a support assembly; providing a pre-formed lid portion having a shape sized to close the open end of the body portion, said lid portion including an angled flange extending circumferentially therearound; contacting the lid portion with a sonitrode that is movable with respect to the support assembly, moving the sonitrode with the lid portion into an initial engagement with the open end of the body portion so that an inner surface of the flange of the lid portion contacts an inner surface of the flange of the body portion and applying a first downward force to keep the flange inner surfaces of the lid portion and the body portion held in contact with one another; and reciprocally rotating the lid portion with respect to the body portion at a first rate for a predetermined amount of time; increasing the downward force to a second downward force, larger than the first downward force, and continuing the rate of reciprocal rotation of the sonitrode to a rate that is at least as large as the first rate after the predetermined amount of time has passed; and holding the sonitrode in the engaged position at the second downward force and maintaining the reciprocal rotation of the sonitrode for a second predetermined amount of time, thereby generating frictional heat between the inner surface of the flange of the lid portion and the inner surface of the flange of the body portion such that a metallic friction weld is formed therebetween.