Patent GB-1503621-A (GB)
Title: Method and apparatus for forming wheel rim blanks
IPC: B21C37/08
Filed: 1976-01-14
Abstract: 1503621 Making wheel rim blanks; shearing; curving sheets GROTNES MACHINE WORKS Inc 14 Jan 1976 [14 Feb 1975] 01315/76 Headings B3A B3E B3L and B3W A method of forming cylindrical wheel rim blanks 11 from blanks of strip material 10 comprises coiling blank 10 to form a cylinder 11a with the longitudinal edges of the strip forming a gap, pressing the longitudinal edges to prepare the blank 11b for welding, buttwelding the seam to form a cylinder 11c and trimming the welded seam to remove welding flash. Blank 10 is fed into the coiler, Fig. 2, which forms station A of a machine for carrying out the method, blank 10 being curved by outer rollers 20, 21 and adjustable inner rollers 22, 23 so that the end 13 of blank 10 comes against a stop 12a. The blank 10 is already cut to the size necessary to form the cylinder and the diameter of the cylinder can be varied by adjusting the position of rollers 22, 23. The coiled blank 11a is then transferred to pressing station B via a double sided cam (53, 54). Fig. 4 (not shown), to ensure the correct width of gap and locate the gap in the correct circumferential position for the pressing tools. At station B, Fig. 3, dies 43, 44, in co-operation with dies 41, 42 flatten the edges of the gap, the edges being initially pressed beyond their desired position to allow for them to return to this under their own resilience. Coiled blank 11b is then transferred to station C where it is welded by any known method to form a welded cylinder 11c and transferred from this station to the finishing stations. The blanks are automatically transferred between stations A, B and C by a transfer mechanism which moves the blanks simultaneously between the stations as a blank is fed into station A. The blanks are supported throughout by supports inside the blanks at the top and the transfer mechanism is beneath the blanks and comprises three pairs of pivoted levers (60a), 60b, (61a), 61b, (62a), 62b, Figs. 5-8 (not shown), which grip the blanks at both ends and which are pivoted in beams 73, 76 on plate 63, and which are pivoted by the movement of beams (74, 77) to grip the blanks When plate 63 is moved forward the levers grip the blanks and move them forward and when they are in the next station, the levers are pivoted flat and plate 63 is retracted, leaving the blanks behind. The forward position of the transfer mechanism is shown in dotted lines in Fig. 1 and the withdrawn position in solid lines. From the welding station C, the blank 11c is transferred to station D where it is supported on an internal horn 120 and engaged at the top by a shuttle mechanism 122 which presses the top of the welded cylinder against internal supports on either side of the welded seam and moves the cylinder through a station E where tools 133, 134 cut off the flash both inside and outside the cylinder, to station F where planishing rollers 140, 141 finish the seams and to station G, where tools 151, 152 cut off the flash at either end of the cylinder, the internal supporting horn 180 pivoting away to allow the finished cylinder 11 to fall down a ramp 181. The finishing operations are given in detail in Figs. 9-12 (not shown).