Patent ID: 7082796
Filing Date: 2006-08-01
Classification: B21D,F16L,F24F,Y10T

Abstract:
1. A method of spin-forming flanged rings from thin gauge metal, said flange rings used for interconnecting adjacent sectional ends of thin gauge ducting for heating, ventilating and air conditioning systems, the ducting having an inner diameter, the method comprising: (a) placing a cylindrical, collar-shaped workpiece composed of 10-gauge or higher gauge metallic material into a spin die, the spin die having an end edge portion, the workpiece being substantially devoid of any deformations along its circumference and having a first end portion extending outwardly of the spin die beyond the end edge portion of the spin die when the workpiece is placed in the spin die; (b) locking the workpiece to the spin die; (c) spinning the cylindrical, collar-shaped workpiece about its central axis substantially corresponding to the concentric center of the workpiece by spinning a spin die; (d) forming the first end portion of the collar-shaped workpiece as the workpiece is spinning to expand the first end portion of the workpiece against the end edge portion of the spin die to define a generally annularly-shaped mating flange extending substantially transversely to the central axis of the remainder of the collar-shaped workpiece, the remainder of the workpiece retaining its original cylindrical, collar-shaped configuration for serving as an insertion flange for insertion within the sectional end of the ducting to be connected; and (e) forming the workpiece as the workpiece is spinning to force the outward marginal portion of the transverse mating flange over, to form a hem section disposed substantially concentrically to the insertion flange and extending outwardly from the mating flange substantially concentrically to the insertion flange.