The present invention relates to conveyor apparatus.

Conveyors are well known for lifting a variety of material. A particular problem arises, however, in the lif ing of material resting on a flat surface such as a road surface to a higher level, for example, the back of a lorry. For example, where excavations are carried out, for example, in digging a trench, whilst mechanical trenching machines are well known and can dig trenches quickly, there has not been provided a convenient conveying means for lifting the spoil produced by the trenching machine (which forms two piles on the side of the trench onto the back of a truck for removal. It is necessary to remove the material from the trench, because generally speaking the material removed from the trench should not be put back into the trench.

One of the particular problems is to pick up the material which is actually deposited on the ground alongside the trench.

The present invention provides a conveyor apparatus which may be used to pick up material sitting on a flat surface such as on the ground or road surface.

According to one aspect the invention comprises a conveyor apparatus for picking up material from a flat surface and delivering the material to a higher level, comprising a continuous conveyor, the continuous conveyor having outwardly directed portions such as paddles to engage the material, a lower plate beneath the lower run of the-continuous conveyor, and generally

parallel thereto, and means to drive the continuous conveyor in a direction whereby the lower run of the continuous conveyor passes upwardly from adjacent the flat surface to the higher point, whereby material on the flat surface may be engaged by the lower run of the continuous conveyor and fed to the higher level by the paddles on the lower run of the continuous conveyor, at least part of the lower plate being spaced from the lower edges of the paddles as they move up the lower run, whereby this space becoming filled with material which thereby provides its own wearing surface to prevent wearing of the lower plate.

Preferred aspects of the apparatus according to the invention include spacing of the lower plate from the lower edges of the paddles as they move up the lower run, this space becoming filled with material which thereby provides its own wearing surface to prevent wearing of the lower plate. In other words, the lower plate, in use, is provided with a wear-protecting layer of material which is being moved by the conveyor apparatus .

Another preferred aspect is that guide means is provided to guide material on the flat surface into engagement with the belt conveyor paddles. This guide means may comprise side plates generally vertically disposed so as to urge a wide heap of material into engagement with the conveyor and also a lower plate to guide the bottom of the pile of material.

Where the conveyor apparatus is to be used to remove the spoil left on either side of the trench by trenching machine, there may be provided a guide means which extends into the trench and thereby maintains

engagement of the conveyor apparatus with the line of the trench.

Means may also be provided for returning a proportion of the spoil back into the trench where desired.

The conveyor apparatus may be self propelled or may be pushed by the truck into which the lifted material is to be conveyed or may be attached, where a trench is being dug, to the trenching machine.

Preferred conveyer apparatuses according to the invention will now be described by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic side view, partly in section of the conveyor apparatus according to the invention,

Figure 2 is a diagrammatic plan view of the apparatus of Figure 1,

Figures 3 and 4 are diagrammatic side and plan views of the lower part of an alternative conveyor apparatus.

The conveyor apparatus illustrated in Figures 1 and 2 comprises a wheeled base 11 which may incorporate (not shown) a drive means such as a diesel or petrol engine or an electric or hydraulic motor driven from a remote supply or by a diesel or petrol engine so that the apparatus is self propelled. Alternatively, the wheel base 11 may include buffer means for engagement with the front or rear of a truck which may then push the wheeled base 11 to move the conveyor apparatus 10. In a third arrangement, the wheel and base 11 may include

means for engaging it with a trenching machine so that the conveyor apparatus can move in unison with a trenching machine.

The wheeled base 11 mounts a slewing ring 12 which in turn mounts a hopper 13 overlying a substantially standard belt conveyor 14. The belt conveyor 14 is attached to the slewing ring 12 by pivot means 16 as is generally well known so that the height of the upper end 17 is of the belt conveyor 14 may be adjusted by means of an adjustable link 18 which may be in the form of a hydraulic ram.

A conveying unit 19 is attached to the front of the wheeled base 11 by means of an attachment 21 which allows the conveying unit 19 to pivot about a horizontal axis and also to slide with respect to the wheeled base 11. The conveying unit 19 comprises a pair of belt (or chain) conveyers 22 having paddles 23, the lower run 24 of the belt conveyors being driven to move in an upward direction by motor means such as an electric or hydraulic motor (not shown). Each belt conveyor 22 comprises a belt 26 to which the paddles 23 are mounted, and the belt 26 extends between lower and upper rollers 27,28. Lower plates 29 are provided which extends from ground level adjacent the lower front end of the conveying unit 19 to the upper rear end disposed above the hopper 13, the lower plates 29 extending generally parallel to each lower run of the belts 26, but spaced from the lower edges of the paddles 23. In practice, the lower plates 29 are not exactly parallel to the lower run of the belts 26, but are spaced further from the belts 26 at the upper end than at the lower end.

There are also provided, side plates 31,32 extending adjacent either side of each belt conveyor 22, the side plates 31,32 extending upwardly from the lower plate 29, to a top plate 33 which extends parallel to and above the upper run of the belt conveyor 22, thereby forming a closed tunnel within which each belt conveyor 22 runs.

At the front end of the conveying unit 19 there are provided, extending from the lower plate 29 and side plates 31, flare plates 36,37 which extend generally vertically and form a flared entrance (see Figure 2) and if desired, there may be provided a bottom plate 38 extending between the flared plates 36,37 parallel and spaced only slightly above the ground level 39. The lower flared plates 36,37.

The various components of the conveying unit 19 are mounted on a suitable chassis (not shown) and the lower roller 27 is mounted to the chassis by spring means 41 so that the roller 27 may move upwardly with respect to its normal mounted position.

The conveying unit 19 also includes, extending downwardly below the lower plate 29 an optional adjustable plate 42 the purpose of which will be described later. A slidable or pivotable trap-door 45 is provided in the lower plate 29 above the plate 42.

As is clear from Figure 2, there are provided two conveying units 19A,19B side by side with one another. The belts 26 and 14 may be formed of conventional reinforced rubber or artificial rubber belting, and in the case of belt conveyor 22 may be continuous or may be formed of several bands. The paddles 23 may be of

metal or may be of flexible rubber, artificial rubber, or plastic material and may be releasibly attached to the belt so that they can be replaced, the paddles being rigidly attached to the belt 26 so as to extend substantially at right angles to the belt 26 and extending from edge to edge of the belt 26.

Guide means 43 is provided extending downwardly from the front edge of the conveying unit 19, the guide means 43 engaging in a trench 46 so as to guide the front end of the conveying unit 19 to maintain it in suitable disposition with respect to the trench 46. The guide means 43, may comprise a pair of plates for engaging the side of the trench 46. The distance between the plate may be adjustable to suit different trenches and they may also be sprung loaded away from one another.

The conveyor apparatus thus far described may be operated as follows.

As is clear from the drawing a trench 46 has been dug by a suitable trenching apparatus which leaves a pile 47 of spoil on each side of the trench 46.

The conveyor apparatus 10 is arranged so as to be able to pick up the ^" piles 47 of spoil and to deliver them from the upper end 17 into, for example, a truck.

As is clear from Figures 1 and 2, the front end of the conveying unit 19 can engage the piles 47 of spoil on each side of the trench 46. The pile 47 is guided into engagement with the lower front end of the conveying unit 19 by means of the flare plates 36,37 and, if provided, the bottom plate 38. Material engages with

the paddles 23 and is urged by means of the paddles upwardly by means of the lower run of each belt conveyor 22. Initially, material will be deposited upon each lower plate 29. The deposition of material on the lower plate 29 means that wear caused by material passing over the lower plate 29 is eliminated. At all times the lower plate 29 has above it a layer 50 (shown in dotted lines) of stationary material deposited thereon.After sufficient material has been deposited on that lower plate 29, any further material will be engaged by the paddles 23 between the belt conveyor 22, the paddles 23, and the top surface of the material resting on the lower plate 29 and will be conveyed upwardly to the rear upper end 17, will then be deposited into the hopper 13 and conveyed further upwardly by the belt conveyor 14 in a conventional manner to b deposited where desired, for example, in the back of a truck adjacent the upper end of the belt conveyor 14. The truck may, particularly if pushing the conveying apparatus, be mounted astride the trench 46 or, if the conveying apparatus 10 is self propelled, the belt conveyor 14 can be slewed about the slewing ring 12 so that its upper end is to one side of the trench 46 whereby a truck may be driven alongside the trench 46 to receive the spoil.

The position of the bottom plate with respect to ground level 39 is maintained by the wheel 40. In some cases it may be necessary to lift the lower end of the conveying unit 19, for example at the end of the trench or where the trench has not been fully dug because, for example, of the presence of gas, water O- electric pipes, and in such cases it may be necessary to remove all of the conveying unit 19, including the guide means 43 from the trench. This may be carried out either by

providing a hydraulic ram between the wheel 40 and the remainder of the conveying unit 19 or by providing a hydraulic ram acting between the wheeled base 11 and the conveying unit 19.

In some instances it is required to reinsert some of the spoil back into the trench (in practice it is rarely required to put all of the spoil back into the trench, because it is not suitable for consolidation. Thus, a variable amount of material may be passed back into the trench by opening the slidable or pivatable trap door 45 and allowing some of the spoil passing over the adjustable plate 42 to pass through the trap door 45 and then be guided by the adjustable plate 42 into the trench. Particularly if the trap door 45 is slidable, the amount of material passing through the trap door 45 can be adjusted by varying the degree of opening of the trap door.

If the pile 47 includes a large lump of material which might not pass easily into the conveying unit 19, then the resilient mounting of the lower roller 27 allows the lower roller 27 to lift to allow the large lump of material to pass into the conveyor. It will still be passed up the conveyor, because even if larger than the depth of the paddles 23, there is sufficient space between the lower plate 29 and the belt 26 to accommodate larger lumps.

The attachment 21, by virtue of its ability to pivot and slide allows the apparatus to follower variations in ground level 39 and in particular cambers on road surfaces. Each of the conveying units 19 is separately mounted on the chassis so as to be able to move up and down with respect to the ground level 29 independently.

The arrangement described utilises two conveying units 19, but clearly a single conveying unit can be provided which may pass along the trench twice.

We will now describe the arrangement of conveyor apparatus shown in Figures 3-4. Fundamentally the conveyor apparatus is the same as that shown in Figures 1 and 2 and similar parts carry the same reference numerals .

Detailed differences are as follows.

There are provided only two flare plates 36,37 to feed the two belts 26, and the input to the belts 26 is protected between the flare plates 37 by means of a grille 51 which prevents lumps of material larger than are acceptable by the conveying units 19A,19B passing to the conveying units.

In place of the hopper 13 there is provided a transverse conveyor 131 which collects material fro ^' m the top end of both conveying units 19A,19B, the material from which is dropped down through respective chutes 132.

In order to reduce the overall length of the apparatus for transportation, the upper horizontal part of the conveyor 14 folds vertically downwards about a pivot axis.

The invention is not restricted to the details of the foregoing example.

For example, the gap between the lower plate 29 and the

belt conveyor 22 can be made adjustable for different material.

Although described with respect to picking up a pile of spoil adjacent to trench, the apparatus is clearly useful for picking up piles of material and depositing them at a higher level. If necessary, if the pile of material to be lifted as compacted, vibrating or cutting means may be mounted to the front of the conveying unit 19 to break up the material.