GB877579A - Improvements in or relating to ring rolling mills - Google Patents

Abstract

877,579. Rolling annular bodies. ASHTON, N. C. March 10, 1959 [March 12, 1958], No. 7885/58. Class 83 (4). In a method of forming a ring or cylinder from a blank on a ring rolling mill in which radial pressure is applied to the blank between an inner and an outer roll one of which is driven, a control member is located to engage the periphery of the blank along an axial line lying in a plane containing a tangent to the inner roll at the point where the inner roll engages with the blank so that the control roller does not move relative to the axis of the inner roll during rolling. A preheated ring 46 is reduced in thickness and expanded in diameter between a driven support roll 44 and a pressure roll 48 slidably mounted on a plate 54 attached to framing 12. In a modification the rolls may be vertically mounted and arranged on a table. During rolling the blank is supported and guided to maintain a circular form by freely rotatable rollers 92, 122 or alternatively by rods located to engage the periphery of the blank at points which remain on the external periphery of the blank throughout the rolling operation. There are said to be two such points each spaced at a distance from the point of contact of the inner roll 44 with the blank given by where A is the constant annular cross-section of the blank. Each guide roller is adjustable horizontally by the rotation of a threaded spindle 104, Fig. 6. which engages in a slidable sleeve 96 carrying the bearing block 94 for the guide roller. After adjustment the rollers may be locked in position by a device operated by a handle 113. The guide rollers may also be adjusted vertically and/or tilted to suit various sizes of blank. The support roll 44 is driven by an electric motor 16 through a reduction box 22. a clutch 24, 26 and a driven shaft 28. The downward movement of the pressure roll 48 during rolling is effected by an hydraulic ram 56 fed by a pump 62 and a reservoir 64, the pump being operated by a motor 66. The ram is supplied through a two-way control valve 70. A trip lever 80 pivoted on the framing 12 is connected through a rod 82 of adjustable length to a release valve so that the downward movement of the roll 48 may be limited to control the reduction in radial thickness of the ring. To prevent axial expansion of the blank flanged support or pressure rolls may be used or alternatively tapered rollers may engage the annular surfaces. Rings of arcuate radial crosssection may be rolled using the rolls of Fig. 4 (not shown). Tapering rings may be made by rolling a ring of cheveron-shaped radial crosssection and then halving it. The apparatus may be used for truing up rings without reducing the thickness.