GB624424A - Improvements in enclosed rolling mills - Google Patents

Abstract

624,424. Roller molding-machines. PARFITT, A. W. (Soudure Electrique Autogene). Feb. 15, 1946, No. 4801. [Class 87 (ii)] [Also in Groups XXII, XXXV and XXXVII] A rolling mill for fluid, plastic or solid materials of the kind in which three or more rolls have sealing surfaces and forming surfaces, the latter co-operating to form the pass, is characterised in that the sealing surfaces of each roll closely envelope the sealing surfaces of the adjacent rolls with high pressure contact nearest to the region where the forming surfaces join to shape the product and with progressively lighter pressure receding to close proximity instead of positive contact. The mill shown in Fig. 1 comprises three rolls with their axes in the same plane and intersecting at the points 86. Each roll has an annular forming section or surface 19, adapted to constitute two sides of the hexagonal pass a convex spherical outer portion 18 and a concave spherical middle portion 17 both constituting sealing surfaces. As shown, the portion 17 of one roll co-operates with the portion 18 of an adjacent roll to form an enclosed funnel 33, Fig. 5, into which molten metal may be poured from a melting pot or other container 35. The rate of pouring may be controlled through a photo-electric device to keep the level in the funnel constant (see Group XL). The mill may thus be used as a continuous casting-machine, the speed of the rolls being adjusted accordingiy and the undersides of the rolls and the cast rod 36 being cooled by a spray. Alternatively the coacting rolls may form an extrusion die. In order to reduce friction and consequent wear between the rolls, the outer parts of the surfaces 18 are backed off to leave a clearance of about 1/64 inch to 1/32 inch. Fig. 8 shows an arrangement of three driven rolls on shafts 61, 63 and 64 and an idle roll on a shaft 62. A rectangular pass is formed by surfaces 57 and 60 and the funnel by the coacting spherical surfaces 55, 56, 58 and 59. In the arrangement of Fig. 9, three roils are used to enclose a T- shaped pass. Roll 66 has forming surfaces 75 and outer spherical sealing surfaces 76 and 77 cooperating with the concave surfaces 78 and 80 of rolls 69 and 70 rotating about parallel axes. The third leg of the T is enclosed by a flange 82 of the rolls 70. In order to avoid sharp edges on the rolls where the forming and sealing surfaces would meet in order to form a circular pass, short sections of the circle may be replaced by plane surfaces 91-95, the forming surfaces of four coacting rolls being shown in Fig. 18. As these surfaces separate below the pass, the tangential portions move as shown by the arrows, 'thus rotating the product clock-wise and rolling it to the correct circular shape. A suitable form of mill-frame consists in a number of hinged panels, each supporting one roll, its bearings, drive and accessories. By removing one of the hinge pins, the panels may be spread open for inspection, cleaning or roll changing. Each roll is driven by a belt 137 from a shaft mounted in one of the panels and carrying a gear meshing with the gears of the other shafts to ensure uniform speed. The hinge pins 142 are eccentric and by applying uniform rotational adjustment to all the pins, the positions of all the rolls may be simultaneously adjusted for wear.