Patent ID: 7251976
Filing Date: 2007-08-07
Classification: B21C

Abstract:
1. An apparatus adapted for the noncircular bending of a tube, said apparatus comprising: a holding element engaging a first section of the tube; and a bending element including a bending die having a tube engaging surface, wherein the surface presents a longitudinal cross section having a noncircular circumferential profile, a rotatable member including a gear having a radius equal to R, fixedly connected to the die and configured to cooperatively bend a second section of the tube by rotating the bending die an angular distance, and an actuator including a driven gear rack presenting a lead incline edge defining an angle Φ with respect to horizontal, and communicatively coupled to the member, so as to cause the rotation of the member and die, and the rack and gear are interconnected and cooperatively configured to cause the angular and linear displacement of the gear relative to the rack, said bending and holding elements being cooperatively configured to retain the first section in a fixed position relative to the bending and holding elements, and to bend the second section into a final condition, wherein the second section presents a noncircular bend having a gradually increasing radius of curvature, said bending element being configured to compress the second section of the tube against the surface, so as to conform the second section to the noncircular profile of the surface, said profile defining an involute of a circle concentrically aligned with the gear and having a radius equal to R sinΦ, so that the die engages the tube at a fixed point during bending.