Patent GB-518803-A (GB)
Title: Improvements in abrasive throwing centrifugal apparatus
IPC: B24C5/06
Filed: 1938-10-15
Abstract: 518,803. Sand - blast. ST. GEORGE'S ENGINEERS, Ltd., and WILSON, F. W. Oct. 15, 1938, No. 29896. [Class 60] In an abrasive throwing centrifugal apparatus for sand-blasting or the like of the type in which the shot or other abrasive is fed to the centre of a revolving disc or wheel with radial delivery blades, the abrasive being drawn into a passage along which a current of air is induced by the rotation of the wheel and the passage being arranged with its orifice at the centre of the wheel in the upper part of its inner end adjacent the inner ends of the blades and being angularly adjustable to vary the position of the orifice to alter the position at which abrasive is delivered to the blades and thus the position and direction of discharge, the abrasive is fed to a tube or duct along which the air induced by rotation of the wheel travels from a hopper arranged on the upper side of the tube, said hopper having at its bottom a regulating valve or damper to vary the effective area of the outlet from the hopper. Curved or straight blades A may be fixed to discs A', A<2> rotated in an openended casing B<1>. The abrasive is supplied from a hopper D with contact plate d' carried by an inclined tube C at the hollow centre of the wheel, through which the current of air is induced. The tube is mounted on a bolt b coaxial with the axis of the wheel so that its angular position may be adjusted to vary the position of the outlet orifice c and thus the position and direction of discharge from the outer ends of the blades. The tube may be divided into several passages. The abrasive may be discharged into a tumbling barrel described in Specification 432,377. In Fig. 4, the tube C may be provided with an inclined front end c<1> and arranged in a horizontal axis coaxial with the wheel and is angularly adjustable in a casing B' and secured in adjusted position by an annular disc b'. The forward end is divided into two compartments l, a longitudinal and transverse partition; the outlet c extending right through the tube and the second compartment having slots in upper ends thereof and a slot c<5> in the lower end so that any abrasive not thrown through the blades falls back into this compartment and away from the wheel through the slot c<5>. The front and back of the casing may be provided with shouldered liner plates fitting in guides on the casing so that they may be received when worn by any abrasive impinging thereon. The blades may be adjustable or renewable when worn. In one form the wheel may consist of radial, rectangular, circular or hexagonal tubes A<5>, Fig. 7, secured to a hollow hub A<4>, the tubes being adjustable on their axes so as to present a new surface to the abrasive. In another form blades A, Fig. 10, may be placed radially between discs A<1>, A<2>, secured together and bolts a through distance pieces a<1>, the disc A<1> being secured to the shaft B. The blades have projections a<3> fitting in slots in the discs, and one of the projections may have a hole a<4> to receive a split pin. In a further form, Fig. 13, channel members a<5> with slots a<6> at the ends of the web may be placed between the discs, the slots receiving shaped side members a<8> for clamping the blades a<11> which is effected by screws a<12> which engage the channels to force the members a<8> against inclined stops a<14> secured to the discs. The members a<8> may be formed integral with the blades. In another form, Fig. 17, channel members a<23> secured to the discs are provided with apertures a<24> to receive projections a<15> on the blades A. The channels have stepped ends between which and the stepped front edges of the blades are received wedges a<16>. The wedges are secured in position by transverse pins a<17> surrounded by distance pieces a<16>, a<19> with inclined faces adjusted by the conical ends of bolts a<20> forced through holes in the pins a<17>. Specification 9085/05, [Class 51], also is referred to.