BELT CONVEYOR ARRANGEMENT This arrangement relates to. elt conveyor arrangements for example, for transporting bulk materials over long distances. Such arrangements are used for removing coal from a mine and transporting rock from quarries. With very long belts, there is a risk that the belt will move laterally relative to the belt supports. This results in uneven loading on the supports and also in wear of the belt due to slippage.

One type of conveyor arrangement has steel ropes which support the belt, the ropes extending longitudinally of the belt. Each rope is in turn, supported by wheels. The belt has shaped longitudinal ribs for engaging the ropes. An arrangement of this type is disclosed in GB-A-159146. It is possible for the ribs co become displaced laterally from the rope and an object of this invention is to overcome this problem and to reduce slippage between the belt and the ropes so that wear is reduced. -

In accordance with this invention, there is provided a belt conveyor arrangement comprising a belt and a support assembly for carrying the belt, the support assembly in¬ cluding an elongate frame having a roller at each end, at least one of the rollers being driven, the celt being con¬ tinuous and passing around the rollers, and magnetic means providing attraction forces between the belt and the support arrangement to inhibit movement between the belt and the support arrangement.

The invention is particularly applicable to a conveyor arrangement wherein the support assembly includes a multi¬ plicity of rotatable members carried at spaced intervals along the frame and ropes engaged with the rotatable ^' members, the belt being provided with the magnetic means and the ropes being constructed to be magnetically attracted to the magnetic means. The magnetic means preferably defines recesses for mechanically locating the ropes relative to the belt.

The invention may result in a conveyor belt having

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for ations for mechanically locating the belt on support ropes extending longitudinally of the belt, each formation being defined by magnet members mounted at spaced intervals along the belt. Reference is now made to the accompanying drawings, wherein:-

Figure 1 is a perspective view of a conveyor arrange¬ ment according to the invention;

Figure 2 is a cross-sectional view of the belt of the arrangement;

Figure 3 is a perspective view of a magnetic block; and Figure 4 is an underside plan view of the top run of the belt.

The conveyor arrangement comprises an elongate frame 11, only the uprights 11a of which are illustrated for clarity. The upπgnts are interconnected by horizontal members, cross-pieces and diagonal braces (not shown) in conventional manner, e.g. as disclosed in GB-A-1591361. At each end of the frame is mounted a roller 12, 13, at least one of which is driven, and a continuous 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 wneels. The wheels are freely rocatable. Each row 20, 22, which extends laterally of the frame, comprises a plurality of spaced wheels 21, in this example four. 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 belt 14. Each rope corresponds to one of the wheels 21 in each row 20, 22, and has an upper run 23a_ supported on the wheels 21 of the upper rows 20 and a lower run 23JD supported on the wheels 21 of the lower rows 22. The upper run 14a_ of the belt 14 is supported by the upper, run 23a_ of the ropes. As the lower run 14*3 of the belt 14 leaves the roller 12, it is diverted by rollers 30

from its normal path, twisted, and inverted to return to its normal path engaged on top of the lower runs 23b_ of the ropes 23. Before the belt reaches the other roller 13, rollers 31 again divert and invert the belt 14 and return it to a position below the ropes 23. The long lower run of the belt is, therefore supported substantially throughout its run.

This arrangement permits use of cheap material for construction of the belt without any special reinforcement laterally. The belt will be strong in use due to the substantial support provided by the ropes.

Magnetic means is provided to resist movement between the belt and the ropes, so that wear due to slippage is reduced. The belt may have longitudinal strips which engage the ropes, as m GB-A-1591461 and these strips may include elements which are magnetically attracted to rope or to the wheels. Electromagnets may be provided to act through the wheels.

It is preferred, however, to avoid providing these longitudinal strips and to provide the arrangement illust¬ rated in Figures 2 to 4. A multiplicity of magnetic blocks 50 are mounted on the inner face of the belt 14. (These are not shown in Figure 1 for clarity) . The blocks are arranged in rows extending laterally of the belt, the rows being spaced longitudinally of the belt.

The blocks in each row are spaced to define recesses 51 and the ropes 23 are mechanically located in the recesses or in rebates 54 defined by the blocks at the ends of each row. Each block is bolted to a plate 55 on the upper side of the belt 14, with the bolts 53, passing through the belt, so as to secure the blocks to the belt.

As shown in Figure 3, each block has a groove 57, so that the thickness of the block varies from a maximum along two opposite edges 58, 59 to a minimum mid-way between those edges. This concentrates the magnetic flux in the region of each end 40, 41 of the block. The blocks are arranged so that these ends 40, 41 lie adjacent the ropes 23 and magnet-

ically grip the ropes, so as to prevent the belt from moving relative to the ropes, the ropes being made of steel.

This arrangement prevents damage due to the belt shift¬ ing relative to the ropes as well as wear due to relative vibration between the belt and the ropes.

Due to the inversion of the lower run 14b_ of the belt, the magnetic blocks 50 engage both the upper run 23a_ and the lower run 23b_ of the ropes and the blocks only need to be provided on the inner face of the belt.