Abstract: A method and apparatus for cleaning a succession of workpieces such as automobile engine blocks includes a first cleaning mechanism wherein cleaning media such as steel shot is directed against the workpieces. After being discharged from the first cleaning mechanism, the workpieces are inverted and passed through a second cleaning mechanism where cleaning media again is directed against the workpieces. In the second cleaning mechanism, the workpieces are separated so that the ends of the workpieces can be cleaned. The invention includes turning mechanisms for inverting the workpieces one-by-one, as well as devices for controlling the movement of the workpieces through the different cleaning and turning mechanisms.

Abstract: Apparatus for mounting a plurality of centrifugal throwing wheels within a blast drum contained within a blast cabinet such that the throwing wheels are carried by a set of tracks which permit the throwing wheels to be rolled into and out of the blast cabinet. A feed screw is located within the blast drum for transporting abrasive particles to the throwing wheels and cooling ducts are located within the blast drum for carrying a flow of air to the throwing wheels. The feed screw and cooling ducts are fixedly located within the blast drum and do not move when the throwing wheels are retracted therefrom.