Patent GB-628383-A (GB)
Title: Improvements in a rolling mill for bending a flat bimetallic article
IPC: B21D5/14
Filed: 1946-05-21
Abstract: 628,383. Rolling. BURGESS, A. F. (Wellman Co., S. K.). May 21, 1946, No. 13538/48. Divided out of 628,323. [Class 83 (iv)] A rolling-mill for bending flat bimetallic articles in the manner described in Specification 628,323 comprises a pair of opposed rolls and a piston connected to each end of one roll to urge it towards the other roll with a predetermined constant but yieldable pressure, such pressure being provided by a gas introduced into the cylinders at a pressure which is low in relation to the pressure exerted by the rolls on the article to be bent. One form of rolling-mill for carrying out the operation, shown in Figs. 2 and 4 comprises a base 31, and side frames formed by vertical members 47, 48 spanned at the top by plates 52. The vertical members form guideways 50 for upper and lower bearing blocks 54, 56 which carry the bearings for upper and lower backing rolls 8 and 9, each of which is independently driven from a single motor through a gear-box by separate shafts 37, 38. Alternatively, the lower roll 9 could be idle. Each bearing block supports a bearing holder 59 having cylindrical upper and lower faces permitting a tilting of the roll and its bearing relatively to the block. Each of the lower bearing blocks 56 is adjustable by a screw 72 passing through a nut 73 rotatable from a hand wheel 42 through bevel gears 81, 82. A scale 85 secured to the hand wheel indicates the position of adjustment of the lower roll 9. Each upper bearing block 54 is secured to the rod 63 of a piston 64 operating in a cylinder 66 bolted to the plate 52. Each cylinder may be supplied with oil under pressure by a pipe 104 from a pump 101 and with air under pressure from a pipe 109 and also has a connection 107 through which oil may be returned to the reservoir under air pressure. As shown, the two cylinders are inter-connected but could be supplied with fluid at different pressures for rolling strips to conical form. Disposed between the rolls 8 and 9 are pressure or working rolls 6 and 7 provided with necks 88 mounted in bearings 89 carried in holders 91 movable vertically within a larger block 92 which is in turn slidable in the guideways 50. Rolls 6 and 7 are urged apart by springs 94. Blocks 54 and 56 carry pointers 119 co-operating with a scale 121 to indicate the spacing of the rolls. For bending a strip 3“ inches wide having a facing thickness of <SP>3</SP>/ 16  inch, a backing thickness of <SP>1</SP>/ 16  inch and a length of 12 inches into a curve of radius 6 inches, rolls 6 and 7 were about 2 inches diameter, the cylinders 66 had an internal diameter of 4 inches and were supplied with fluid at a pressure of 700 pounds per square inch, the air serving as a cushion to maintain substantially constant pressure in spite of slight variations in thickness of the strip. In a modified form of apparatus, Fig. 5, a compressed air chamber 152 is connected by a pipe 153 to the space between a plate 142 and a flexible diaphragm 147 welded at its edges to the underside of the plate. The pressure is limited by a relief valve 167. The force exerted on the diaphragm is transmitted to one of the upper bearing blocks through a pressure plate 176 and rod 174. An adjustable collar 184 limits the downward movement of the block. The other upper block is independently operated by a similar device. Specification 595,920 also is referred to.