The present invention relates to conveyors.

A typical example of a conveyor in use is that for the filling and packing of milk or fruit juices on a production line. Empty containers, such as bottles or cartons, are supplied to the production line and conveyed to a filling station, sealed and then packed into crates or cartons. As each piece of production machinery is not usually positioned co-linearly with the other pieces of machinery, various lengths and configurations of conveyor modules are required to be joined to interconnect the machinery. Modules comprising straight and curved conveyor sections are the most common shapes commercially available.

A conveyor section usually comprises a support structure which is adapted to carry a conveyor belt on its top face. The conveyor belt being driven longitudinally along the axis of the structure by a drive means such as, for example, an electric motor and sprocket arrangement mounted, usually, at a discharge end of the conveyor module. In one common form, the belt comprises a plurality of flat-topped slat members which are interconnected by a connecting arrangement to thereby provide an articulated continuous belt which, when fitted to the support structure, forms a conventional slat conveyor section or module.

Conveyor sections are abutted to each other in end to end relationship and then fixed to one another by, for example, bolting rectangular connecting plates to both an inner and outer vertical face of the support structures to be joined, the connecting plates overlying a portion where the modules abut.

The legs on which the support structure is carried are usually fixed to the outer, vertical face of the connecting plates by welding. In addition, upright pedestals are often mounted to the outer, vertical face of the outside plates to carry guide rails above the top surface of the conveyor belt to prevent articles falling from the belt, particularly on curved conveyor sections, or where articles bank up, for example, on a surge conveyor.

Conventional slat conveyor sections, however, have certain disadvantages. They are particularly difficult to clean due to the enclosed nature of their support structures and the complex bracing used to give these support structures structural rigidity. Waste or spilt product flows down through the gaps between the slats and

builds up on the top surfaces of the bracing and other components contained within the structure. The spilt product builds up over time and can, ultimately, result in significant sanitation problems.

Further, change-overs to the production line to facilitate carrying articles of a different size and alterations to the configuration of the production line layout are time consuming and labour intensive due to the difficulties faced in aligning and abutting the conveyor modules when they are to be joined due to the considerable weight of each conveyor module and the method by which they are fixed to each other. Another problem encountered with change-overs is that the guide rails fitted to curved conveyor modules must either be fabricated specifically for each article size, as the guide rails are required to be moved inwardly or outwardly to accommodate larger or smaller articles, or a number of short guide rails are mounted in end to end relationship thereby approximating a generally curved, though irregular, guide rail. Similarly, when a straight conveyor module is joined to a curved conveyor module, the guide rail in the portion where the conveyors join is discontinuous and irregular.

According to one aspect of the present invention there is provided a conveyor module including a support structure having means for supporting opposed elongate side walls lying on opposite sides of a conveyor belt loop, the side walls being connected in spaced apart relationship by a plurality of transverse connecting rods which have a convex profile at least on their upper surface and each end of the side walls is profiled to provide a support surface adapted to engage a complementary support surface of a like module joined in end to end relationship whereby part of the weight of one of the modules is

transferred to the other module through the engaging support surfaces.

Conveniently, the conveyor module is curved and the support structure has guides for guiding the conveyor belt loop on its unladen, return path.

According to another aspect of the present invention there is provided a guide rail arrangement for conveyor modules joined in end to end relationship, the guide rail arrangement including a plurality of guide rails which are inter-connected in end to end relationship to thereby provide guide rail pairs, at least one of the guide rails of the guide rail pair having a slot formed in an arcuate end portion of the guide rail into which slot the other guide rail of the guide rail pair is adapted to slidably engage to allow relative movement of the engaging guide rails to provide a movable, continuous guide rail along a length of the guide rail pair.

Embodiments of the present invention will now be further described by way of example only with reference to the accompanying drawings in which:-

Figure 1 is a perspective view of a straight module of slat conveyor;

Figure 2 is a schematic view of an articulated flat- topped slat conveyor;

Figure 3 is a sectional view of a curved module of slat conveyor;

Figure 4 is a sectional view of another embodiment of the curved module of Figure 3;

Figure 5 is a perspective view of a side transfer conveyor module;

Figure 6 is a plan view of a guide rail arrangement for the curved module of conveyor of Figures 3 and 4;

Figure 7 is a plan view of a guide rail pair; and

Figure 8 is an elevational view of the guide rail pair of Figure 7.

Referring to Figure 1, a straight section of conveyor 2 comprises a support structure 4 fabricated from stainless steel sheet, or some other sheet material, by bending the sheet into a first elongate L-shaped member 6 and then inverting it so that one side of the member provides a substantially horizontal top face 8 and the other side of the member provides a dependent skirt 10. A second inverted L-shaped member 12, being a mirror-image of the first member 6, is placed in spaced apart relationship to the first member 6 and transverse brace members 14, as shown in Figure 3, in the form of rods having a circular cross-section, are inserted between the respective skirts 10 and releasably fixed thereto to give the support structure 4 structural rigidity. Each brace member 14 is adapted to threadingly receive a bolt 15 at each end portion 16, 18, each bolt 15 having its axis substantially co-linear with the axis of the rod member 14. A longitudinal gap 20 is provided in the top face 8 of the housing 4 in which a flat-topped slat conveyor belt 22 is disposed.

As shown in Figure 2, the conveyor belt 22 comprises a plurality of flat-topped slat members 24 which are generally T-shaped in cross-section and which are inter¬ connected by a connecting arrangement comprising hinge

me bers 26, which are integral with one longitudinal edge 25 of each slat member 24, and connecting pins 28. The slats are hingedly coupled, one to the other, by this connecting arrangement to thereby form an articulated continuous belt.

Referring again to Figure 3, the slat members 24 are generally T-shaped in cross-section having top outwardly- extending flange portions 30 and a central downwardly depending support member 31, each of the flange portions 30 having an underside portion 32. The underside portions 32 are adapted to be slidingly carried by an uppermost face 33 of a runner 34 mounted on the top face 8 of the housing 4 to provide a bearing surface for the conveyor belt 22 and the load which it carries. Transverse loads on the slats 24 are carried by the depending support members 31 bearing against an inner, vertical face 36 of the runner 34. These transverse loads increase considerably when the conveyor follows a curved path, particularly on an inner radius of the curved path. Additional runners 38 are mounted within the support structure 4 to carry the unladen conveyor belt 22 on its return path. The runners 34, 38 have a generally rectangular cross-section and are formed from a wear resistant plastics material.

In another embodiment of the curved conveyor section, as shown in Figure 4, the runners 38 are replaced by guide rollers 39 which are fitted to guide the unladen conveyor belt 22 on its return path. Each guide roller 39 is rotatably mounted on a transverse brace member 14 and is aligned by tubular spacers 39a which are also mounted on the brace member 14. The resultant structure is very open and facilitates the cleaning of spilt product.

Each conveyor 2, which may comprise straight modules, as

shown in Figure 1, or curved modules, as shown in Figures 3 and 4, is adapted at each end portion 40, 42 to be abutted in end to end relationship to another like conveyor. Referring again to Figure 1, the end portions 40, 42 of the support structure 4 are shaped to provide a bearing surface 43 on which a correspondingly shaped end portion 40, 42 of another conveyor (not shown) may be placed. The abutting of the respective shaped end portions 40, 42 results in a proportion of the weight of one of the conveyors being supported by the other conveyor which facilitates the joining operation, and, as only two fixing bolts 15 are required on each side of the support structure 4, change-overs are much simplified. The conveyors 2 are then releasably joined to each other by mounting a rectangular connecting plate 44 to an outer vertical face 46 of the support structure 4, the plate 44 partly overlying the end portions 40, 42. The connecting plate 44 is adapted, by way of two holes 48, 50, the rods 14 and the bolts 15 to releasably connect the plate 44 and the conveyors 2 being joined. A vertical support member 52 for the conveyor 2 and a guide rail support member 54 are also interposed between the bolts 15 and the skirt 10. This construction results in a conveyor which is simple in structure and which, by having a more open construction, is easier to clean. Furthermore, the less complex bracing arrangement, the round rods used to brace the structure and the guide rollers 39 reduces the overall amount of spilt product lying within the support structure.

Referring to Figure 5, a unitary side transfer conveyor module 56 is constructed using the same principle of construction as that described above whereby two substantially straight conveyor modules 58, 60 are joined along a longitudinal vertical face such that their longitudinal axes are substantially parallel and, in this

embodiment, their respective infeeds and outfeeds are offset to each other. It is not essential, however, that the respective infeeds and outfeeds be offset to one another. Other conveyors can be abutted and joined to the side transfer conveyor module 56 in end to end relationship by the means described above so that articles being carried by a first conveyor belt 62 are transferred laterally by guides 64, 66 to then be carried by a second conveyor belt 68.

The unitary side transfer conveyor module 56 may be mounted on wheels (not shown) to enable it to be moved into, and out of, position on the production line as and when required.

Figure 6 shows a guide rail arrangement 70 for a curved section of conveyor 72 which is joined in end to end relationship with two straight sections of conveyor 73. The guide rail arrangement includes an arcuate, continuous inner rail 74 and an outer arcuate continuous rail 76 mounted on uprights (not shown) fixed to the top face 8* of the support structure 4. As more clearly shown in Figures 7 and 8, the guide rails 74, 76 have end portions 78 to which an elongate, substantially vertical loop 80 is welded. Each loop 80 curves away from the longitudinal axis of the conveyor belt 22 and provides an elongate slot 81.

Guide rails 82, 84, 86 and 88 extend from the straight conveyor modules 73 and terminate in an upright cylindrical knob 90 which is welded to an end portion 92 of each rail 82, 84, 86 and 88. The end portions 92 of the rails 82, 84, 86 and 88 are bent outwardly, away from the longitudinal axis of the conveyor belt 22. The end portions 92 of each rail 82, 84, 86 and 88 are inserted into the slots 81 and the arcuate rails 74, 76 to provide

a guide rail pair, the guide rails 82, 84, 86, 88 are thereby able to slide transversely within the slots 81 so that when it is necessary to carry out a change-over to another size the arcuate guide rails 74, 76 and the guide rails 82, 84, 86 and 88 are released by unlocking a locking arrangement (not shown) on the uprights (not shown) mounted to the top face 8 of the support structure 4. The rails 74, 76 can then be moved axially and/or transversely inwardly or outwardly, as required, and the locking arrangement is again tightened to provide a smooth and continuous guide path for articles being carried along a curved section of conveyor or across a region where two conveyors have been joined.

Embodiments of the present invention, as hereinbefore described, provide a conveyor module which has a more open construction than conventional conveyor sections and which are, therefore, easier to clean, thereby reducing the risk of sanitation problems. These embodiments provide a simple means of connecting conveyor modules which is less labour intensive than for conventional conveyor modules. Some of the described embodiments provide a guide rail arrangement for a conveyor module in which a continuous guide rail is adjustable on each side of the conveyor module whereby a smooth and continuous guide rail for articles being carried on the conveyor module.

The embodiments have been described by way of example only and modifications are possible within the scope of the invention.