IE49545B1 - Improvements in belt conveyors - Google Patents

Abstract

The gravel or sand conveyor comprises an upper transport run and a return run below it forming an endless belt. It has a portion (4) forming a passage in which the top run (2) travels over one or more idler wheels (10) rotating on transverse shafts (11). The wheels extend through an oblong opening (6) in the bottom of the passage. The lower return run(3) travels over one or more free supports (14), e.g. a set of garland rollers, keeping its edges higher than its centre, thus retaining any material which drops through the opening.

Description

This invention concerns improvements in belt conveyors, particularly for use in transporting particulate materials such as sand, grit, powders, grains, flour or the like.

Belt conveyors are conventionally used to transport materials of the foregoing kinds, and various problems arise from the nature of the material and the design of the belt conveyor and ancillary equipment. For instance, the commonest problem is spillage of the material which is disadvantageous because of waste, cleaning required and contamination. Usually such spillage arises because of uneven or surge loading, and when the belt does not run true and runs out of alignment to cause displacement of the material over the edge(s) of the conveyor belt. Other problems arise at transfer positions where the material is diverted, either wholly or partly to other positions, for example to another conveyor.

It is also known that with belt conveyors for such 20 particulate materials, hazards arise from the fine particles., e.g. dust, and special steps are required for extraction and control of dust as well as spillage.

It is an object of this invention to provide a belt conveyor which overcomes the foregoing problems, and which provides other advantages as will be explained herein.

According to this invention, there is provided a belt conveyor apparatus comprising a continuous belt arranged to provide a transport strand for loading and transporting material and a return strand arranged to run underneath said transport strand, characterised in that the conveyor further comprises a transport section including an elongate trough through which the transport strand advances in supporting engagement on at least one idler wheel mounted for rotation on a spindle extending transversely of the trough with the trough having an elongate opening in the bottom portion through which said idler wheel extends, a return section underlying said transport section and comprising an idler assembly for supporting the return strand of the belt which is arranged to extend so that the opposed edges are higher than the centre and any material leaking through the bottom trough opening is caught thereon.

The belt conveyor apparatus of this invention prevents spillage by the confinement of the transport strand within the trough, and any leakage is caught on the 9 5 4 5 return strand for return to a suitable catchment.

The idler assembly may comprise a flexible, linked or jointed member which hangs from the transport section in bowed configuration. Alternatively, the idler assembly may comprise a rigid support of generally channel shape with idler rollers or wheels in the bottom section or extending across an open bottom section.

Preferably, the trough comprises two opposed side walls between which the transport section extends. These side walls confine the material from spilling over the edge of the transport strand. If desired, the trough may be provided with a top cover or other enclosure, this being preferable for conveying certain materials, or in some locations.

Preferably, the bottom of the trough comprises two opposed inclined support flanges having faces which converge towards the elongate opening. These faces ensure that any material leaking between the side walls and the edges of the transport strand tends to fall down through said opening.

To prevent further spillage, the flanges mount a respective strip of material which extends lengthwise of the trough and engages the underside of the transport strand to provide a seal. The strip is preferably made of a low-friction material such as plastics so as to avoid drag.

The elongate opening at the bottom of the trough may be defined by opposed dependent lips which extend from the inclined flanges. This provision of the lips serves to strengthen and Increase rigidity of the trough and the opposed lips provide spaced supports for the opposed ends of the spindle carrying the aforesaid at least one idler wheel. Conveniently, a plurality of idler wheels may be mounted on a spindle, and a series of spindles may be spaced along the length of the transport section of the conveyor according to this invention.

The idler wheels may be of special disc form and arranged or grouped on respective spindles depending on the loading requirements, angle of the conveyor or speed and other typical requirements.

Preferably, the trough is mounted at spaced apart positions along its length by supports or hangers for securing to appropriate structural members or a base framework in known manner. These supports are channelshaped into which the trough is received, and the supports may be used to join modular lengths of trough together.

The trough may comprise two elongate elements which are of similar configuration and which are connected together by the trough supports. The two elements are opposed and spaced apart to leave a gap therebetween at the bottom of the trough, which gap constitutes said opening.

The trough supports are also used for supporting the opposed ends of the idler assembly so that no separate mounting is required and the return strand of the conveyor belt is aligned with and adjacent to the •^5 opening in the trough.

Preferably, the idler assembly comprises a flexible support that is jointed or curved and has guide surfaces or rollers on which the return strand rests with the edges of the belt being raised to form a bow-section. 2o Each end of the flexible support is provided with a hook or hanger tongue to be received in the hanger bracket. As will be appreciated, under any load comprising leaked material, or in the unloaded condition, the return strand is advanced in the opposed direction to the transport strand, and is self-centering on the idler assembly.

It is envisaged that the idler assembly could comprise a secondary trough with elongate sealing strips and idler wheels or roller. This secondary trough could be suspended from the trough or mountings of the transport section of the conveyor.

In case there should be any spilt or leaked material on the return strand, a cleaning plough, scraper blade or diverter may be provided at the end of the return strand adjacent to or forming part of the tail unit where the return roller for the conveyor is located.

Such cleaning devices permit the removal of spilt or leaked material into a bin, container, hopper or the like, and can return material to the original source where this can be done without risk of contamination.

As will be understood, the conveyor as previously described merely comprises a single length of conveyor 2o which would usually be linear. However, the charactistics and design of the conveyor apparatus according to this invention enable it to be arranged as a conveyor system with transfer and change-over stations that also 495 45 avoid spillage and pollution by confining the material during transfer.

Furthermore, it has been appreciated that in many existing installations, the conversion or modification of existing conveyors of the belt or similar type is desirable for health and safety reasons. Accordingly, in the modular concept of the invention where the trough is made to a standard length and lengths are joined by supports, it is considered that the conversion of existing conveyor systems can be achieved at low cost as many parts, for example, drive motors, belts and other original fixings can be retained.

Other features of this invention will be apparent from the exemplary embodiment of this invention which will now be described with reference to the accompanying drawings wherein:FIGURE 1 is a cross-sectional view of a belt conveyor according to this invention and depicting the support or mounting for the trough; and FIGURE 2 is a schematic perspective view of a conveyor system incorporating the belt conveyor of Figure 1.

With reference to the view of Figure 1, the conveyor comprises a continuous belt (generally referenced 1) having a transport strand 2 and a return strand 3. The material of the belt 1 is of any suitable kind which is resilient and flexible, for example, rubber or elastomeric material with textile and/or steel reinforcments.

The transport strand 2 extends through a trough formed by two similar elongate elements 4 providing opposed side walls, each having a flange 5 extending therefrom and inclined downwardly towards the bottom of the trough. A dependent lip 6 extends along and from the edge of each flange 5. The lips 6 define an elongate opening extending lengthwise of the trough.

The side walls of the elements 4 forming the trough extend upwardly to a level above the edges of the transport strand 2 of the belt, and the walls confine the material thereon. The upper edge of each element 4 has an outwardly extending rim flange 7 to which a cover 8 Is secured to enclose the transport section of 20 the conveyor. This cover 8 is optional and can be of any suitable design.

Welded or otherwise secured to the inside face of each 45 element 4 is a reinforcement angle 9 which assists in strengthening the trough. The angle 9 may extend along the whole length of the respective element 4, or it may comprise short spaced apart sections. The angle can also assist in guiding and keeping the material level in the trough even should there be a surge load or sideways off-load of material. The angle may be especially designed for this purpose by having fins, ribs or having a special shape.

The underside of the transport strand 2 is arranged to be supported for movement by idler wheels 10 which are mounted for rotation on a spindle 11 mounted on, and extending between the lips 6 of the trough 3. The transport strand 2 is also supported by two sealing strips 12, each of which is secured and located by suitable studs or fasteners 13 to a respective one of the two inclined flanges 5 of the trough bottom.

The sealing strips 12 are made of a low-friction material and the marginal edge portions of the belt ride thereon in sliding sealing engagement to obviate the egress of material from the trough. The sealing strips 12 may have planar surfaces or be provided with grooves or ribs. To accommodate expansion/contraction of the strip relative to the elements 4, expansion gaps may be provided as desired. However, should any material leak from the transport strand 2 behind and underneath the sealing strips 12, such material will pass down the respective inclined flanges 5 through the elongate opening between the lips 6 and fall onto the return strand 3.

The return strand 3 of the conveyor belt is supported on a transverse jointed or linked idler assembly 14 which is hung by hooks 15 engaging on brackets 16. The idler assembly 14 is flexible in use so that it hangs in the bowed configuration depicted in Figure 1, and it supports the return strand 3 so that it has a bowedsection with the marginal edges higher than the centre. This ensures that any material leaked from the transport strand 2 is contained within the dip of the return strand 3.

The elements 4 forming the trough are supported on a channel-shaped mounting plate 17 which carries the brackets 16 at each side, and serves to join two 2o adjacent trough sections together. The mounting plate 17 has suitable flanges with bolt holes or the like for connecting and securing the trough sections thereto. The mounting plate 17 also serves to connect the conveyor to a fixed structure or frame as desired depending on the particular installation. Preferably, the cross-section of the mounting plate is T-shaped to provide locating ledges or flanges for supporting and locating the elements 4 during assembly.

Although the mounting plate 17 is shown as a single piece, it may comprise an assembly of two opposed and similar side members with a lower stringer or crossmember connecting them together. Such an assembly permits variations in belt widths to be accommodated 1° easily.

With reference to the arrangement of a conveyor system as depicted in Figure 2, there is shown a principal conveyor 20 according to this invention which overlies a transverse conveyor 21 to which material is to be supplied. The transverse conveyor 21 is also in accordance with this invention, and only brief outlines of the principal and transverse conveyors are shown having regard to the detailed description given previously with reference to the sectional view of Figure 1.

Briefly, the conveyor 20 comprises a tall unit 22 having a return tensioning roller 23 for advancing the belt in the direction shown and to transport sand or like material in that direction along the transport strand 2 towards a V-plough 24. As can be seen, the trough is not enclosed in this system and the transport strand 2 runs over the return strand 3 which returns from a head unit 25 including belt drive rolls where sand, not diverted by the V-plough 24 is dumped into a hopper 26 underneath the head unit 25. The tail unit may include a scraper or diverter blade to clean the return strand 3 adjacent the roller 23.

At the V-plough station there is a box-section 27 on either side of the trough 3 which leads to a respective shute 28 into which sand diverted by the V-plough 24 is pushed and falls onto the lower transverse conveyor 21 between the sides of the trough thereof.

A supplementary head unit 29 having a conveyor of similar construction as described with reference to Figure 1 is also shown and is arranged to feed sand onto the transverse conveyor 21 downstream of the Vplough station and the shutes 28.

It will be understood that because each of the trough sections includes side walls and each transport strand of the belt extends therebetween, even at the discharge and feed positions, then there is little likelihood of spillage occurring over the sides of the belt. If any overload or surge occurs, this will be properly contained and smoothed out during advancement, especially having regard to the angle guides and the centering action of the dip in the middle of the transport strand which is controlled by the inclined flanges and the sealing strips upon which the belt rides. Should there be any leakage, then this will merely fall through the opening in the bottom of the trough and be returned to a suitable catchment by the return strand of the belt. if desired, enclosures and cover plates can be provided, and dust hazards can be avoided, or suitable extraction equipment can be provided to operate in conjunction with the enclosed conveyor system.

It will be noted by those skilled in this field that the belt of the conveyor comprises a conventional type of belt with overlying section which could be power driven by roller or other driving means. The trough sections including the mounting plates provide supports for the return strand, and for this reason it is considered that the conveyor apparatus according to the invention is well suited for converting existing installations as well as for installation as original equipment.

The length of the modules can be varied and intermediate sections could be designed for curved extents provided that sufficient camber and allowances are incorporated to ensure adequate load centering and to accommodate stresses and flexing of the belt.

It will also be appreciated that the installation shown in Figure 2 is only a simple example of an application of this invention, and many alternatives can be designed including the use of elevating sections, and movable plough or diverter devices with automatic weighing stations for load control. It is also considered that the invented conveyor may have applications in the food and grain handling industry where environmental conditions have to be controlled carefully.

Furthermore, in some installations the use of a flexible idler assembly for the return strand can be changed for a secondary trough section similar to that described with reference to Figure 1. Such . alternative has the advantage of virtually enclosing the return strand and providing continuous support along each marginal edge portion of the return strand of the belt.

Claims (15)

1. CLAIMS;

1. A belt conveyor apparatus comprising a continuous belt arranged to provide a transport strand for loading and transporting material and a return strand arranged 5 to run underneath said transport strand, characterised in that the conveyor further comprises a transport section including means defining an elongate trough through which the transport strand advances in supporting engagement on at least one idler wheel mounted for 10 rotation on a spindle extending transversely of the trough, and means defining an elongate opening in the bottom portion of the trough through which said idler wheel extends, a return section underlying said transport section and comprising an idler assembly for supporting 1'5 the return strand of the belt which is arranged to extend so that the opposed edges of the return strand are higher than the centre and any material leaking through the bottom trough opening is caught on the return strand. 20

2. A conveyor according to claim 1 wherein the idler assembly comprises flexible, linked or jointed elements.

3. A conveyor according to claim 1 or claim 2 wherein the trough comprises two opposed members providing two opposed side walls, two opposed inclined faces converging 25 towards said elongate opening. <9545

4. A conveyor according to claim 3 wherein the trough members each include a dependent flange that define the elongate Opening in the bottom of the trough.

5. A conveyor according to any one of the preceding 5 claims wherein the underside of each opposed edge of the transport strand engages a strip mounted on the trough to provide a seal.

6. A conveyor according to claim 5 wherein the opposed sides of the trough mount respective members 10 for guiding and levelling material on the transport strand.

7. A conveyor according to claim 6 wherein said guiding members are angles which reinforce the opposed sides of the trough. 15

8. A conveyor according to any one of the preceding claims wherein the trough comprises two elongate elements of similar configuration which are connected together by at least one trough support.

9. A conveyor according to claim 8 wherein the return 20 section of the conveyor is mounted on the trough support.

10. A conveyor according to claim 9 wherein the return section is mounted on the trough support by means of hanger hooks or the like.

11. A conveyor according to any one of the preceding 5 claims wherein the transport section of the conveyor includes a cover for enclosing material on the transport strand.

12. A conveyor according to any one of the preceding claims wherein the return section of the conveyor 10 comprises means defining a trough through which the return strand extends.

13. A conveyor system including a belt conveyor apparatus according to any one of the preceding claims.

14. A belt conveyor apparatus substantially as here15 inbefore described with reference to Figure 1 of the accompanying drawings.

15. A conveyor system substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.