Patent GB-897591-A (GB)
Title: Method and apparatus for cold forming a disk
IPC: B21H1/02
Filed: 1960-01-15
Abstract: 897,591. Rolling discs. KELSEY-HAYES CO. Jan. 15, 1960 [Jan. 16, 1959], No. 1517/60. Class 83 (4). In a method of radially-tapering a disc, a blank of uniform thickness is rolled simultaneously by two pairs of rolls while a radial component of force acts axially of the rolls, the rolls are withdrawn radially outwards at equal rates, the distance between the rolls of each pair is varied and either the rolls are withdrawn at a constant rate while their speed of rotation is varied or the speed is maintained constant while the rate of withdrawal is varied. One or more blanks are fed into a mill by a loading device 176, Fig. 1 (not shown), to be located on a resilient spindle 114 and held in position by a fluidoperated hold-down 126. Prior to each rolling pass the spindle 114 is accelerated so that the work attains the speed of the rolls. The roll-pass is varied by wedges 24b actuated by a motor through a gear 97b, and a threaded shaft 93b. The final pass is indicated by dials 104a and 104b. The initial pass is set up by another motor which through gearing rotates splined gears 92b so adjusting the position of stop-nuts 95b on the wedge-rods to permit movement of the wedges to increase the roll-gap for the initial pass. An indicator 109 shows the reduction to be made on the second pass. Each pair of rolls 71a, 72a and 71b, 72b are mounted in chocks such as the chocks 42b, 43b which are pivotally mounted on a stand 59b mounted on a movable platform 73b. The platforms 73a, 73b for the respective pairs of rolls are interconnected for equal movement by a rod 81 and the platform 73a is moved outwardly from the roll-stand by a double-acting cylinder 77 attached to a sub-frame 75a while the platform 73b is also moved outwardly from the stand but indirectly through a pair of racks 82 and 85, both of which engage a pinion 84, the rack 82 being attached to the rod 81 while the rack 85 is attached to the platform 73b. The rolls are driven at constant or at variable speed by motors 62a, 62b, through gears 70a, 70b and shafting accommodated in the stands 59a and 59b. When the rolls operate at variable speed, that is, when the rolls are retracted radially at a constant rate, the speed of the motors is controlled by a cam 152, Fig. 9, attached to the moving platform 73b. The cam moves a plunger 154 in a saturable-core reactor 158 to vary the speed of the motors. The radial point at which the rolls engage and disengage from the work is controlled by adjustable cam blocks 146a and 146c carried by a support 143 attached to the movable platform 73b. During movement of the platforms towards and away from the roll stand the cam blocks 146a and 146c operate limit switches 142a and 142c respectively which according to whether the rolling pass is about to commence or to end operate cylinders 33b, 34b to insert or withdraw wedges such as 31b, 32b, causing the rolls of each pair to move together or apart. The radius at which the rolls engage or disengage from the blank or blanks is determined by the setting of the camblocks. When it is required that the rolls operate at constant speed the platforms 73a and 73b are withdrawn at a variable rate decreasing with increase of radius, the variation being controlled by valves 159a, 159b, 159c, operated by a cam attached to the platform 73a. The degree of taper imparted to the work is controlled by exchangeable cams 37b, 38b, and shims 41 which are fixed relative to the rollhousing and on which following rollers 54b and 55b move during the outward movement of the rolls on the platforms 73b. The roll-chocks may be mounted centrally in the roll-housing windows 15, Fig. 4, but by suitable positioning of shims 46 the rolls may be adjusted to positions in which each pair is on an opposite side of the central longitudinal plane through the rollstand. This roll-positioning induces a slight axial force on the rolls which may assist or oppose the withdrawing action of the platforms 73a and 73b. During roll-changing the chocks are supported on slides 87a and 87b and the platforms 73a and 73b retract fully to tilt safety platforms 86a and 86b into a vertical position.