Patent GB-272572-A (GB)
Title: Improvements in apparatus for grinding or comminuting rubber and other materials
IPC: B23Q11/10
Filed: 1926-02-19
Abstract: 272,572. Gardner, C. E. Feb. 19, 1926. Rasping and like abrading apparatus.-In apparatus for grinding or comminuting rubber, wood, cork, &c., and of the type comprising a rotary cylinder or drum furnished with abrading- devices having saw-like teeth, means for feeding the rubber &c. towards the drum, means for cooling the abrading-devices and the material being ground, and a fan for delivering the ground material to a collector, the feed is effected by two or more positively-driven upper feed-rollers and two or more positively-driven lower feed-rollers, the upper feed-rollers being elastically mounted and vertically adjustable. The upper or the lower feed-rollers, or both, may be provided with studs or spikes, or they may be corrugated, to grip the material between them. As shown, Figs. 1, 2, and 6, between the front and rear lower rollers g, l and level with the top thereof is mounted a perforated table u over which the material passes, and at the rear of the upper rollers i, k and close to the abrading-drum d is adjustably and elastically mounted a roller 23 which may be positively driven or frictionally driven by engagement with the material. The table u has curved ends v, w, and a detachable mouthpiece 64 is provided below the roller 23. The bearings of the upper rollers are carried by an horizontal H-shaped frame h mounted on the lower end of a rod 9 which passes upwards through a hollow screw 7 carried by a central vertical socket 5 on a bracket 2 carried by the bridge-piece 3. A small collar 10 at the top of the rod 9 prevents the rod from dropping through the screw, and a spring 12 surrounding the rod abuts at one end against the screw 6 and at the other end against a long collar or enlargement 11 of the rod. The frame h slides in vertical guides 4 and has vertical rods 13 engaging in holes in the bridge-piece 3. The drum d is reciprocated axially by means of a bell-crank lever 36, one arm of which engages a collar 39 on, or a groove in, the shaft c of the drum while the other arm is slotted and engaged by a crank-pin 35 on a worm-wheel 32 gearing with a worm 29 which is free to rotate with, but is prevented from moving axially with the shaft c. A worm on the lower end of the shaft 33 of the wheel 32 gears with a wheel on an horizontal shaft 42 connected by a clutch 44 to an horizontal shaft 43 provided with a hand-wheel 46. A worm on the shaft 43 gears with a wheel 47 connected by a spring slipcoupling 48 to a cross-shaft 49 carrying a wheel 50 gearing with pinions 51, 52 on the gudgeons of the lower feed-rollers g, l respectively- The rear upper feed-roller k is driven through gearing 54, 57 from the wheel 50', and the front upper-roller i is driven by sprocket gearing from the roller k. For withdrawing the rubber &c. from the drum before the machine slows down, the clutch 44 is disconnected and the feed-rollers rotated by means of the hand-wheel 46. A cleaning brush o engaging the drum d is driven by a belt 62 from the shaft c. The upper part of the casing 65 enclosing the drum d is made wholly or partly removable, and is provided with a vertically-adjustable door or gate 66 mounted between the top of the casing and the drum and about midway between the axis of the drum and the place where the grinding is effected to regulate the air currents. A hopper may be provided on the upper part of the casing as described in Specification 10015/15. The particles of rubber &e. are withdrawn from the casing 65 by a fan 67, an endless chain 73 with brushes 74 conveying the particles over the sloping bottom of the casing towards the inlet 75 of the fan. In a modification, the upper feed-rollers can be raised or lowered by means of handoperated worm and screw gearing. Figs. 10 and 11 show an abrading-drum comprising two flanged discs d bolted to a central hollow cylindrical portion 90 provided with inwardly-directed and tangentially-disposed vanes e which draw air in through holes 92 in the discs and deliver it through a number of annular series of radial holes 91. Groups of serrated hard-steel cutting-rings 93 spaced apart by radially-perforated annular distance-pieces 94 are mounted between the holes or slots 91. The rings 93 and pieces 94 are clamped in place by set-screws 97 which pass through threaded holes in the discs d and are provided with lock-nuts 98. The distance-pieces 94 are of less external diameter than the rings 93 and are recessed or grooved on their outer faces. In a modification, Figs. 12 and 13, the drum is provided with a series of groups of segmental cutters 99 spaced apart by slotted or perforated segmental distance-pieces 100. The cutters 99 and pieces 100 are axially perforated near each end to receive rods or wires 101, and each piece 100 is radially perforated at each end to receive a screw 102 which engages with the drum portion 90. Each group of cutters 99 and pieces 100 is separated from the next segmental group by a number of parallel and axially-arranged serrated blades 104 with corresponding slotted distance-pieces 105. Or the axial cutting-blades may be secured in position by means of a wedge-shaped piece 108, Fig. 14, riveted thereto and engaging in a corresponding recess 109, Fig. 15, in the adjoining side of the adjacent distance-piece 105. Fig. 16 shows a drum provided with a number of groups of elliptical distance-pieces 111. Wedge-shaped rings 112 form the terminal distance-pieces so that the rings 110 and pieces 111 are inclined to the axis of the drum.