Abstract: An abrasive throwing wheel assembly comprises a throwing wheel having parallel annular side plates (29) joined by spacers with the facing surfaces of the side plates having angularly-spaced registering throwing blade locating slots (30) and throwing blades (20) with lateral rails or edges (22) for location in the slots. The side wheels slots are wider than is customary and contain central radially-extending projections (30c). The lateral rails or edges of the throwing blades are grooved (28) from the tips inwardly for at least part of their lengths. The throwing blades are located by interengagement between the sidewall projects and the rail or edge grooves of the blades. This reduces the surface contact between the blades and the side plates with consequent reduction in the accumulation of jamming abrasive during use. Throwing blade removal is thus facilitated.

Abstract: An abstract throwing wheel assembly comprises a throwing wheel having parallel annular side plates (29) joined by spacers with the facing surfaces of the side plates having angularly-spaced registering throwing blade locating slots (30) and throwing blades (20) with lateral rails or edges (22) for location in the slots. The side wheels slots are wider than is customary and contain central radially-extending projections (30c). The lateral rails or edges of the throwing blades are grooved (28) from the tips inwardly for at least part of their lengths. The throwing blades are located by interengagement between the sidewall projects and the rail or edge grooves of the blades. This reduces the surface contact between the blades and the side plates with consequent reduction in the accumulation of jamming abrasive during use. Throwing blade removal is thus facilitated.

Abstract: A filter comprises a pleated fabric filter bag of generally rectangular configuration within which is removably disposed an internal reinforcing cage of wire or rigid plastics material. The pleated fabric filter bag has an open end and a closed end and at its open end there is moulded integrally with the bag an apertured plastics end cap which has an internal configuration corresponding to the pleated fabric bag. The closed end of the bag is sealed either by the bag material or by an integrally moulded imperforate plastics end cap.The filter can be disposed vertically or horizontally within the casing of a filtering apparatus and if disposed horizontally it can be stacked in vertical array.The rectangular pleated fabric filter permits a substantially greater area of filter fabric within a given size of filtering apparatus, casing or housing than has been possible hitherto.

Abstract: An abrasive throwing wheel comprises a backplate, a plurality of equi-angularly spaced radially-extending, throwing or paddle blades and a central impellor, all formed as an integral unit, and with the blades configured to render the throwing wheel operationally bi-directional. The throwing wheel may be cast from "hard" metal generally a high chrome content alloy; or it may comprise a metallic core with a plastics coating (preferably an elastomeric polyurethane coating) moulded therearound; or it may be formed wholly of plastics, preferably an elastomeric polyurethane coating.

Abstract: A blade for use in a blast impellor wheel for use in cleaning castings has both faces identical and symmetrical about its longitudinal axis so that both faces can be used as abrasive throwing faces. The blast impellor wheel comprises two interconnected parallel side plates each of which has a central opening. Opposed pairs of slots are provided in the inner faces of the side plates and these slots are transversely stepped so that protruberances on the side of a blade can abut against the ledges so formed.