GB1478887A - Shot-blasting machines - Google Patents

Abstract

1478887 Blasting TILGHMAN WHEELABRATOR Ltd 21 Aug 1975 [19 June 1974] 27159/74 Heading B3D A shot-blasting machine comprises a chamber 10 housing an openwork carrier 11, in the form of a tunnel with perforated walls, for holding a workpiece 13, such as a casting from which sand is to be removed, and adapted to be vibrated, and impellor means 18A, 18B, 18C for throwing shot against the workpiece. The openwork tunnel 11 protrudes from both ends of the chamber and is given a vibratory movement by an eccentric arrangement 14 rotated by an endless drive from a motor 15 to convey workpieces supplied from a feed conveyer 22 through the chamber 10 and on to a discharge conveyer 23. The tunnel is formed of steel bars 12 which are surrounded by a bridge structure 17 and arranged to orientate the workpiece in different attitudes along the tunnel length so that shot thrown upwardly by the impellor 18A, laterally by the impellor 18B and downwardly by the impellor 18C and constrained by guide plates (not shown) removes sand from the workpieces, the jolting of the tunnel also assisting in the removal of the sand. Kick bars, guide bars or ramps are provided in the tunnel adjacent its exit to turn, shake or jolt the workpieces so as to remove abrasive therefrom. In another embodiment, the tunnel is formed of two sections one above the other with overlapping portions and a turnover plate so that as the workpieces being cleaned fall from the first portion they turn over on reaching the second portion so as to present other surfaces to the shot from the impellors. Shot and debris fall to a screw conveyer and is carried to a shot removal vibrating conveyer 25 having vibrating sieves. Shot and small debris are carried by a screw conveyer 26 to a bucket elevator 27 which delivers it to a shoot 28. A screw conveyer 29 carries the shot and small debris from the shoot to a rotary sieve separator from which clean shot is fed along shoots 31 to the impellors.