GB221447A - Improvements in or relating to machinery for granulating, crushing and screening stone, ore and like materials - Google Patents

Abstract

221,447. Baxter, Ltd., W. H., and Baxter, W. H. April 16, 1924. Roller mills. - Relates to apparatus for granulating, crushing, and screening stone, ore, &c., and of the type described in Specifications 5909/98 and 19586/09, in which a revolving " Raff wheel " screen is combined with a pair of crushing or granulating rollers whereby any insufficiently-reduced material may be returned to the crusher. The rollers are provided with corrugated peripheries so arranged that the material to be crushed and granulated forms a cushioning medium and aids in rotating one of the rollers of the crusher. The rollers 27, 28, Figs. 2 and 5, are mounted on shafts 18, 11 respectively, the shaft 18 being carried in adjustable sliding bearings 19 and the shaft 11 being driven through spur gearing 10, 29 from the driving-shaft 7. The corrugations 44, 45 of the rollers may be parallel to the axes of the rollers, or they may be arranged at one or more angles thereto, the teeth that form the. corrugations being of less width than the spaces between the teeth, so that spaces are left for the stone &c. to pass between the teeth and act as a cushioning- medium when in a meshed position for crushing purposes. The bearings 19, Fig. 4, are acted upon by two sets of springs 20, 21 of different strengths, mounted upon rods 22 which pass through the bearings and are provided with locknuts 24. The position of the bearings is determined by a set-screw 24 mounted in a lug 25 and bearing against a projection 26. A pinion 13 on the reduced inner end 12 of the shaft 11 gears with a wheel 14 on the shaft 15 of the Raff wheel, which consists of two circular screens 30, 31, Fig. 1, of different diameters and widths. Elevator buckets 34 are secured to the smaller and wider screen 31, and the end-piece 32 is connected by arms to the central boss 37. The material is fed by a hopper 39 and a cone 38 on the end-piece 32 into the screen 31 and is raised by the buckets 34 and delivered to a shoot 40 which conveys it to the crushing-rollers 27, 28. The crushed material is conveyed by a shoot 41 to the screen 31 through which the small material passes to be screened by the outer screen 30, the large particles being again elevated and returned to the rollers. A hinged piece 42 allows the supply to the rollers from the shoot 40 to be regulated.