Abstract: A method and apparatus for forming hollow extrusions. Specifically, a method and apparatus for imparting one or more bends and/or twists in a hollow extrusion under stretch. The apparatus may perform all of these formation and stretch functions as the result of one single physical or mechanical force imparted on the apparatus from either an internal or an external source. The forming apparatus and method may provide an easy way to mount and/or dismount the hollow extrusion form the machine by way of separate or integral gripper mounts. The single-force stretch-bend-twist apparatus may be used in a mass production manufacturing environment where the machine and method can perform complex formation steps and may automatically reset itself back to a starting position after formation.
Type:
Grant
Filed:
February 11, 2000
Date of Patent:
July 17, 2001
Assignee:
Alcoa Inc.
Inventors:
Larry W. Cisko, Blair T. Allison, William A. Graham, Paul E. Ringbloom