Patent ID: 7275403
Filing Date: 2007-10-02
Classification: B21D

Abstract:
1. In a roll forming machine having a frame and being operative to form a rain gutter of indeterminate length from a supply coil of sheet metal, wherein the rain gutter is in the form of a trough having a back wall, a front wall and a bottom wall connecting the back and front walls, wherein the front wall has a greater number of bends in its lateral profile than the back wall, wherein the corners between the bottom wall and the back and front walls are formed at a final station of the machine immediately prior to the formed gutter exiting the machine, and wherein each corner is formed at the final station by a respective pair of corner forming rollers a first of which rotates about a substantially horizontal axis and the second of which rotates about a vertical axis, an adjustment mechanism at the final station to compensate for additional drag imparted to the front wall relative to the back wall due to the additional bends of the front wall and to provide a desired longitudinal curvature to the formed rain gutter, the adjustment mechanism comprising: a camber adjustment plate holding both first corner forming rollers for rotation about a single substantially horizontal axis; a vertical adjustment plate secured relative to the frame of the machine and having a first side adjacent to said camber adjustment plate, said vertical adjustment plate having a circular arcuate groove in said first side, said vertical adjustment plate having a first opening therethrough extending from said first side, wherein the radial center of said circular arcuate groove is in the plane of the bottom wall of the gutter as it passes through the final station; a boss extending out of said camber adjustment plate orthogonal to said single axis, said boss having a circular arcuate shape complemental to said circular arcuate groove of said vertical adjustment plate so that said boss is receivable and slidable in said groove; a rod secured to said camber adjustment plate and passing through the first opening of said vertical adjustment plate, wherein the rod is sized relative to the first opening so that it can be moved within the first opening orthogonal to its length; and means associated with said vertical adjustment plate for selectively moving said rod orthogonal to its length so that said camber adjustment plate is pivoted about the radial center of said circular arcuate groove to vary the angle of said single axis relative to a horizontal plane; whereby the relative pressures applied to the bottom wall of the gutter by the two first corner forming rollers can be controlled to lengthen the front corner relative to the back corner so as to compensate for the additional drag on the front wall.