GB666200A - Apparatus for reducing the particle size of materials - Google Patents

Abstract

666,200. Colloid mills. MESSINGER, W. Dec. 7, 1949. [March 14, 1949] No. 31449/49. Class 59. Grinding apparatus for preparing dispersions of paint pigments in liquid vehicles such as varnishes, oils and resins, includes an inner grinding shell 16 enclosing a plurality of conical rollers 31 secured in a cage comprising top and bottom members 35 and 36 respectively, said rollers co-acting with a conical grinding head 32 formed on an arbor 33 driven through a coupling 41 by an electric motor 43. The top of the grinding head is formed with a vertical chamber 48 having radial openings 49 whereby charge material from a hopper 18 is distributed over the grinding surfaces and discharge tubes 26 receive ground material from a discharge cavity 30. The included angle of taper of the rollers 31 is one half that of the grinding head 32 enabling the assembly to fit into the cylindrical bore of the shell 16, and since the taper of the rollers and grinding head are oppositely inclined the motion between them is largely a combination of rolling and sliding or shearing. The lower cage member 36 is supported on a thrust bearing 38 having its inner race seated on a spider 28 secured between outer casing members, and a flange 40 on a collar 39 prevents ground material from collecting round the arbor 33.