BACKGROUND ART Various different configurations of flat decking are employed in vibratory machines in many applications such as coal washing, bore treatment and separation of salt, potash, sand and gravel etc. One particular known construction comprises a plurality of deck panels, each being a rigid fully welded assembly of a plurality of side by side wedge-section wires supported on a plurality of transversely extending spaced frame members. A deck panel of this type is normally constructed of stainless steel and fitted with rigid metal side angles so as to form a strong and stable integral unit which has a relatively high strength. In use the decking panels are clamped along their opposite marginal side edges to the machine. However, unevenness which often occurs in the machine beds tends to reduce the life of the deck. This occurs because the deck panels, when tightened down on an uneven bed, are subject to stresses and therefore are liable to break up in use. A further disadvantage of the above construction is that the material being screened tends to gather about the side angle members and cause clogging up of portion of the screen.

The above types of screen are normally formed of stainless steel material. However, other screens in use are moulded of plastics material such as polyurethane. Whilst this type of screen can cope with uneven mountings, the capacity of such screens is less than the capacity of the above type of metal

screen and thus is less efficient in use.

OUTLINE OF THE INVENTION The present invention aims to overcome or alleviate at least some of the above disadvantages by providing an improved decking particularly suited to vibratory screening applications which has substantially the same capacity of metal decking assemblies but which overcomes or reduces the disadvantages associated with the use thereof. Other objects and advantages of the invention will be hereinafter apparent.

With the foregoing and other objects in view, the invention resides broadly in a screening deck panel including a screen assembly defined by a plurality of screening wires arranged in fixed spaced relationship on spaced support members, at least part of the periphery of said screen assembly being embedded in encapsulating edge members of resilient material, said edge members constituting resilient mounting means for said deck panel.

In one embodiment, the invention resides broadly in a screening deck panel including a screen assembly defined by a plurality of parallel coplanar screening wires arranged in fixed spaced relationship ; on spaced parallel support members disposed transversely therebeneath, said support members having their end extremities constituting opposite sides of said screen assembly, said screening wires extending to the end extremities of said support members, both said end extremities and said screening wires at said end extremities being embedded in encapsulating edge members of resilient material, said edge members constituting resilient mounting means for said deck panel. Preferably each resilient edge member has opposite securing faces disposed uppermost and

lowermost in operative dispositions, said faces constituting upper and lower extremities of the screening deck panel.

Preferably the encapsulating edge members are formed by a moulding process, and the resilient material for the encapsulating edge members may suitably be polyurethane. Other features of the invention will be clear from the following description. BRIEF DESCRIPTION OF DRAWINGS

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate the apparatus of the invention and wherein:-

Fig. 1 is a perspective view of a screening deck panel according to the present invention;

Fig. 2 is a sectional view along line A-A of Fig. 1, and

Fig. 3 is a cut-away partial side view of the deck according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings there is illustrated a screening deck panel 10 according to the present invention which as is conventional includes a plurality of transversely extending frame or support members 11 which support a plurality of longitudinally extending screening wires 12 which in this embodiment are of a wedge shape cross-section and which are spaced apart to define therebetween a plurality of screening apertures 13. Preferably the wires 12 and support frame members 11 are formed of stainless steel and each wire 12 is secured to each support member 11 at its cross-over point by means of welding.

Disposed at the opposite sides of the deck 10 are respective edge members 14 which extend longitudinally of the deck panel 10 and which are formed of a flexible and resilient non-metallic material such as a rubber or plastics material, preferably polyurethane. The edge mearibers 14 as illustrated encapsulate the opposite side marginal portions of the deck panel 10 so as to support the deck panel 10 against collapse. Furthermore the edge members 14 extend above the wedge wires 12 and below the support members 11 so as to define a support for the deck when arranged on a machine bed and to permit clamping of the deck 10 by means of the edge members 14 to the machine bed, these uppermost and lowermost securing faces 15 and 16, respectively, constituting the upper and lower extremities of the deck panel 10.

In this embodiment, the edge members 14 are rectangular in cross-section and extend inwardly of the side portions of the deck panel a sufficient distance to support and encapsulate both the wedge wires 12 and the end extremities 17 of the support frame members 11 and thus prevent collapsing movement of the frame members 11 in a longitudinal direction.

Preferably the opposite edge members 14 of the deck panel 10 are formed in a moulding operation. For this purpose the respective wires 12 and frame support members 11 are assembled and supported in a substantially vertical plane so that one side marginal portion thereof extends into a heated mould. Polyurethane or any other suitable material is then poured into the mould and allowed to cure so as to form a solid edge member 14 which encapsulates both the end portions of the support members 11 and the wedge wires 12 at the marginal portions of the deck.

A deck panel 10 formed in the above manner is, unlike the rigid wholly metal decks, somewhat flexible so that it may easily conform to irregularities in the machine bed without importing stresses into the operative screening members. This will result in a deck which not only has a high treatment capacity but which also has a long working life.

Whilst the above has been given by way of illustrative example of the invention, it will of course be realised that many modifications and variations may be made to the above described embodiment by persons skilled in the art without departing from the broad scope and ambit of the invention as defined by the appended claims.