Such conveyor belts are often laterally steel reinforced and supported at opposite edges by ropes. Such conveyors are expensive and it has been known for the reinforcement to break and collapse between the supporting ropes. Belts composed of steel cord are also used, but these are highly expensive and can be punctured by sharp material. They have been.known to split longitudinally.

It is also known, for example, from GB-1591461, to provide an arrangement in which the belt has longitudinal formations at opposite faces near the edges of the belt, for supporting the belt on continuous ropes. The formations on one face engage the upper run of the ropes and the formations on the other face engage the lower run _o£ the ropes. The ropes follow a tortuous path and are consequently subjected to damaging forces and the face of the belt, which carries bulk material, carries formations which are liable to damage. The present invention is concerned with providing a belt conveyor arrangement which uses a standard conveyor belting which is cheaper and more reliable.

The present invention provides a beit conveyor arrangement comprising an elongate frame having a roller at each end and a continuous belt passing around the rollers, at least one of the rollers being driven, a multiplicity of rotatable members carried at spaced intervals along the frame and including upper members to support an upper run of the belt and lower members to support a lower run of the belt, a plurality of laterally spaced continuous ropes running around the members, the belt being supported by the ropes, and first means for diverting the path of the lower run of the belt with twisting of the belt as it leaves one of the rollers and for leading the belt back onto the ropes, so that the bottom run is supported on the ropes, and second means for diverting said path again with twisting of the belt and

returning the belt below the lower runs of the ropes before the belt reaches the other roller.

In one embodiment, each of the first and second means diverts the path of the lower run of the belt laterally

5 beyond said members and ropes, whilst twisting the belt, before returning the belt back onto the ropes, or back below the lower runs of the ropes, respectively.

In another embodiment, third and fourth means are provided for diverting the paths of the ropes upwardly and 10 downwardly beneath the upper run of the belt to provide space for twisting of the belt beneath said upper run of the belt. This embodiment is preferred, since broadening of the conveyor arrangement near each end is avoided and the whole arrangement is maintained within the confines of the upper τ_5 run of the belt.

It is preferred tnat the rotatabie memoers are arranged in transverse rows, eacn row including more than two members, the members of each row engaging respective ropes.

The belt may comprise longitudinally extending 2o reinforcement and guide strips on one face of the belt, the strips engaging the ropes, and advantageously the strips are shaped to conform to cne shape of the ropes.

Magnetic means may be provided to establish attraction forces between the belt and the rotatacle memcers or the 25 ropes to inhibit lateral displacement of the belt.

Reference is now made to the accompanying drawings, wherein:

Figure 1 is a diagrammatic perspective view of a first embodiment of a conveyor arrangement according to the 30 invention;

Figure 2 is a detail view of the arrangement; Figure 3 is a side elevation of a part of the second embodiment of a conveyor arrangement according to the invention; and 35 Figure 4 is a plan view of the second embodiment.

Arrangement of Figures 1 and 2 comprises an elongate frame 11, only the uprights 11a of which are illustrated for

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clarity. The uprights are interconnected by horizontal members, cross-pieces and diagonal braces (not shown) in conventional manner, e.g. as disclosed in GB-A-1591461. At each end of the frame is mounted a roller 12, 13, at least one of which is driven, and a continuous woven belt 14 passes over the rollers. The rollers 12, 13 and the drive means therefor, may also be conventional.

Between the rollers at spaced intervals, the frame is provided with upper rows 20 of wheels 21 and lower rows 22 of such wheels. The wheels are freely rotatable. Each row 20,

22, which extends laterally of the frame, comprises a plurality of spaced wheels 21. Each wheel has a peripheral channel for receiving and guiding a rope 23.

A plurality of continuous steel ropes 23 are provided for supporting the beit 14. Each rope corresponds to one of the wheels 2i in eacr. row 20, 22, ana has an upper run 23a_ supported on the wneels 21 of the upper rows 20 and a lower run 23b_ supported on the wheels 21 of the lower rows 22.

The belt 14 is provided with longitudinally extending strips, 15, which reinforce the belt. Each strip has a concave recess 16 conforming the strip to the shape of a rope

23, and each strip engages a corresponding rope to locate and guide tne belt. Each strip may be composed ot hard rubber or plastics material secured to the beit. As the lower run of the belt 14 ieaves the roller 12, it is diverted laterally by rollers 30 from its normal path to one side of the upper run of the belt and then inverted and rediverted back to its normal path, but inverted with the strips 15 engaged on top of the lower run of the ropes 23. Before the belt reaches the other roller 13, rollers 31 again laterally divert and re-invert the belt 14 and then return it to a position below the ropes 23. The long lower run of the belt is, therefore supported throughout its run on the ropes, except where the diversion and twisting is effected. This arrangement permits use of cheap material for construction of the belt, which will be strong in use, due to the substantial support provided by the ropes. No lateral

reiπforcement of the belt is required. Further there is no twisting of the ropes, so that the ropes last much longer. The strips 15 are provided on only one face of the belt and do not cause any obstruction, nor are they exposed to likely damage.

The embodiment of Figures 3 and 4 is similar to that of Figures 1 and 2, but the belt is not diverted laterally of the upper run of the belt. The path of the belt is diverted angularly through 180 as in the first embodiment, but the path remains beneath the upper run of the belt 114 within the normal width of the conveyor arrangement.

The lower run of the belt is twisted adjacent one main roller 112 by means of deflecting rollers 130. To permit such twisting within the confines of the upper run of the belt, deflecting wheels 131, 132 are provided to lift the ropes 123 above tne twisting beit, without twisting the ropes. Further wneels 133,134 deflect the rope back below the lower run of the belt where the latter is twisted substantially 90° from its normal path, and return the ropes to their normal path substantially where the belt regains its normal path.

A similar assembly is provided near the other mam roller (not shown) at the opposite end of the conveyor arrangement, for deflecting the belt: back below the lower run of the ropes.

This arrangement has all the advantages of the first embodiment with the additional advantage that the arrangement near each end of the conveyor is very compact.

OMPI