GB295434A - Improvements in abrading drums for grinding or comminuting rubber and other materials - Google Patents

Abstract

295,434. Gardner, C. E. May 12, 1927. Rasping -apparatus.-In an abrading drum for grinding or comminuting rubber &c., provided with an open end or ends to admit a cooling medium, such as air, and with a number of abrading devices or cutters distributed around the peripheral surface of the drum between which are apertures for the passage of air, a fan or blower is adapted to discharge air under pressure into the interior and out through the shell of the drum. The fan may be placed at each end of the drum and may be separate from the drum or the blades may be integral with or partly or wholly form the end or ends of the drum. The drum may also be provided with impelling vanes projecting inwardly from the shell of the drum. The drum in Fig. 1, is cast in one piece, and comprises cutting teeth 2 integral with the shell and slots 1 on each side of the teeth, internal curved tangential impeller blades 4 projecting inwardly from the shell, and ends having spokes 6 in the form of fan blades which are parts of right-handed helices at one end and left-handed helices at the other. The shell is strengthened by inwardly projecting, radial ribs 9 intersecting the impeller vanes 4. The root of each tooth is tapered to present a large air cooling surface; the teeth may be straight or they may be like the teeth of a saw and may be rough cast or machined or sharpened. The teeth are in axial rows or in the form of a helix with part helical slots or series of isolated apertures, or they may be of ring or other form as described in Specification 272,572. In modifications the tangential impeller vanes are helical and taper in the axial direction or are of uniform depth and helical instead of straight and. the drum is provided with a central annular diaphragm nearly dividing it -into two compartments each of which is supplied with air by a separate fan. The fan blades may extend entirely across the end of the drum or across an annular ring formed in the end thereof. The drum may be formed separate from the ends or as shown in Figs. 13 and 14 may comprise six segments 73 each provided with a sector-like flange 730 at each of its ends and furnished with a central web 740 forming the outer part of an impeller vane. Each end is cast with fan blades 76 and has an outwardly projecting flange 777 by which the ends are connected to the angular impeller vanes 74. When assembled, the central longitudinal ribs 740 abut the impeller vanes 74 to form a continuous surface. In a further modification one end of the drum is closed.