Aluminum Company of America

Alcoa Inc.

Blair T Allison

William A Graham

Daniel Bergstrom

Lawrence W Cisko

Jeffrey M Shoup

Daniel E Hunter

Robert P Evert

Walter R Reichelt

Paul E Ringbloom

Thomas J VanSumeren

Peter J Coppola

John S Schultz

Larry W Cisko

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.

Forming of hollow extrusions with double plane bends and twists

A method of gripping a metal tubular member during a forming operation to resist damage to the gripped ends and reduce scrap, includes providing an outer tool having a recess structured to receive an end of the tubular member, inserting a resilient mandrel into the end of the tubular member and inserting the tubular member end into the recess. A compressive force is applied to the resilient member in a direction aligned generally axially of the tubular member to establish transverse expansion of the resilient member in order to clamp the tubular member end between the mandrel and the outer tool recess. The tube may be stretched beyond the yield point and formed while so clamped, after which the compressive force is removed so as to facilitate withdrawal of the formed tube. In one embodiment, the mandrel may consist of a composite which may have a lower durometer hardness inner portion and higher durometer hardness outer portions. In another embodiment, a substantially rigid mandrel is received within the tube end and an annular resilient sleeve is positioned on the outside of the tube end. The method may be used for a wide variety of purposes including forming structural vehicular members. Associated apparatus is provided.

Method of gripping tubular members during forming operations and

Apparatus and a method for forming an elongated workpiece are provided. In a first embodiment, a press has a ram and movable upper platen to which is secured a first die. Upper guide members are provided on the upper platen for movement of slide members on each responsive to movement of the platen. Lower guide elements, which cooperate in a telescoping manner with upper guide members, are secured to a lower platen. The first die cooperates with a pair of rotatable second die members which are provided with each being rotatable responsive to movement of a slide member. In a preferred embodiment, the upper guide members secured to the platens are in relative sliding contact and links connect the slide members with the rotatable second dies. In a preferred embodiment, the elongated metal workpiece may be formed by bending under the influence of the forces applied to the first die and second die members through the upper platen by the press ram. In a second embodiment, the press first die and associated guide members are not employed and forming is effected by the second die members. Associated methods are provided.

Apparatus for forming elongated metal articles and related method

A process for stretch forming hollow metal bodies, such as aluminum alloy extrusions. The extrusions are stretched longitudinally, bent transversely of the pulling direction, and then subjected to pressure from an incompressible fluid in a hollow interior. In a preferred embodiment, the incompressible fluid is water at a pressure sufficient to deform at least part of the extrusion outwardly of its hollow interior. The incompressible fluid reduces dimensional distortions in the shaped product.

Process for stretch forming hollow metal bodies

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Cheswick, PA, United States of America

Blair T Allison