GB2163120A - Twin-belt elevator - Google Patents

Abstract

A twin belt elevator (Figure 8) comprises co-operating conveying belts 10,12 forced into a zig-zag shaped path by spring-loaded idling rollers 73, 74. <IMAGE>

Description

SPECIFICATION Twin-belt elevator The present invention relates to elevators, and in particular to belt-type elevators providing the combination of a horizontal loading region with the facility to elevate at steep inclination to a discharge location located forwardly of the loading section.

This dual purpose combination is difficult to achieve using simple flat belts because of the problem of forming the necessary "concave" bend in the transition region of the belt from horizontal conveying to elevating in a manner which does not hinder the operation of the elevator. Thus, known proprietary dual purpose belt-type elevators, such as the Scholtz "Flexowell" elevator, Numec's "Large Capacity Belting" and the Ace Vulcanising "Hywall" elevator, each comprise two flexible side walls set in from the edges of a cleated base belt so as to leave a narrow strip of base belt along the outside of each wall. This construction enables the concave bend in the base belt to be formed by mounting two narrow rollers above the belt so that they contact the upper surface of the two edge strips.In operation, the material to be elevated will be wholly contained between the two flexible side walls. Without the side walls, the material would tend to spill into the side regions of the elevator and foul on the rollers.

It is an object of the present invention to provide a dual purpose belt-type elevator of comparable or better performance than those currently available, but by a simpler and therefore cheaper means.

According to the present invention, a twin-belt elevator comprises a load-supporting first belt having an elevating region which co-operates with the elevating region of a load-retaining second belt to convey the load to a discharge location positioned forwardly of the load-accepting region of the first belt, the operative run of the first belt being formed and divided into said elevating region and said load-accepting region by a lower support roller means of the second belt.

The term "roller means" in this context is to be broadly interpreted as including any rotary device or number of devices extending or spaced across the width of either belt to provide a roller type support for the belt.

A twin-belt elevator for conveying letters and packets over a C-shaped path has been proposed in French Patent Specification 647597. However, this earlier document neither suggests nor discloses the concept of using a twin-belt elevator for discharging to a location positioned forwardly of the load-accepting region even though this will be the desired elevator configuration in the vast majority of cases. It is significant too, that up to now, no such arrangement had been proposed during the fifty years or so since the French Patent Specification was published.

The French device is also deficient in other respects. For example, the belt-supporting roller defining the entrance to the elevating section has only a limited degree of freedom of movement.

This means that changes in the load being con veyed towards the elevating section will often re sult in a significant amount of roller displacement along the load-accepting belt away from the intended position of the roller. This in turn will lead to generally undesirable variations in the perform ance characteristics of the elevator. This general lack of precision is aggravated by the use of a slack length of the load-retaining belt to control the passage of the load towards the elevating section.

Returning now to the elevator of the present invention, according to a preferred feature, the roller means is carried on a pivotally-mounted support on which it is spring-loaded towards the adjacent region of the first belt. Providing the roller means with two degrees of freedom in this way reduces the tendency for the roller means to be displaced along the first belt in response to a changed load on the belt. Thus the division between the load-accepting and elevating regions of the first belt is maintained as constant as possible and as a result variations in the performance characteristics of the elevator with changing load are reduced.

Conveniently, the second belt is kept fairly taught around the roller means so that the entrance to the elevating section of the elevator is accurately defined by the position of the roller means. This enables the advantage of having a spring-loaded roller means to be exploited to the full.

Conveniently, the roller means comprises a relatively large diameter roller, or two or more rollers, arranged to shape the operative run of the first belt gradually in the region of directional change.

Where two or more rollers are used, these may, if desired, be mounted on a frame which is itself pivotally attached to the pivotally-mounted support. In a variation of this latter arrangement, only the frame pivots.

Conveniently, the spring loading of the roller means is adjustable, a single adjustment changing the tension of both belts.

In first embodiments of the invention, the two belts are supported on as few rollers as convenient so as to encourage the belts to self-tension and self-adjust. This enables the belts to accommodate, compact and sandwich the conveyed material. In addition, it allows the elevator to be constructed as a relatively lightweight device.

In second embodiments of the invention, the cooperating regions of the two belts are instead urged together by spring-loaded rollers or the like e.g. arranged to make these regions follow a zigzag path.

Preferably, the load-retaining run of the second belt is guided about a top support roller of the first belt so as to shape said load-retaining run into a concave delivery region which encourages good co-operation between the second belt and the elevating region of the first belt and ensures that the material being conveyed is firmly gripped.

In a preferred embodiment, the inclination of the elevating and load retaining regions of the belts is adjustable, so that the conveyor can, without modification, offer horizontal conveying plus elevating at a range of angles.

If desired, the second belt can overhang the top end of the first belt to some extent so as to predetermine the trajectory of discharge of material from the elevator. Alternatively, at the delivery end of the elevator, the run of the first belt may project further than the run of the second belt thereby to help reduce the amount of stray material emanating from the underside of the stream of material being conveyed.

It will be appreciated that the first andlor second belts may each be flat or cleated as desired. Conveniently, both belts are cleated belts having the cleating spanning different transverse regions of the two belts so that marginal speed differences between the two belts will not cause interference between the cleats at the elevating region of the elevator nor prevent a degree of troughing from being achieved.

Conveniently, the two belts are of the same or roughly the same width.

Conveniently, the elevator includes troughing means effective to impart a trough-like shape to the elevating region of the elevator.

Conveniently, the elevator includes spillage prevention means arranged to flank or surround the first and second belts at the elevating region of the elevator to discourage spillage of conveyed material from this region.

Conveniently, the elevator includes spillage prevention means arranged to flank or surround the first and second belts at the elevating region of the elevator to discourage spillage of conveyed material at this region and also to support at least in part the two belts at this region in such a way as to impart a trough-like shape to the elevating region of the elevator.

A convenient spillage-prevention means, which can also serve as the main structural member, is a tube or other hollow section surrounding or substantially surrounding the first and second belts at the elevating region. In one such case, the spillage prevention means comprises a three-section device having centre section surrounding orsubstan- tially surrounding the co-operating runs of the two belts at the elevating region of the elevator and two outer sections surrounding or substantially surrounding the return runs of the two belts at that region.

Alternatively, the spillage prevention means may comprise a single-duct shroud in which all the belt runs are accommodated. One advantage of this is that sufficient slack belt is readily obtained if the shroud is to be folded by means of a hinge parallel to the cross-sectional planes of the belts.

If desired, the belts may be supported on freewheeling rollers each arranged to keep apart the forward and return runs of an associated belt and to derived drive from contact with both said runs.

Conveniently, the elevating region of the first belt leads to an extension region provided either by the first belt or by a third belt.

Conveniently, the inclination of the extension region is adjustable.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a partially diagrammatic side view of an elevator according to the present invention; Figure 2 shows a similar view of an alternative embodiment; Figure 3 shows a cross section of a modified belt arrangement for use either in the embodiments of Figures 1 and 2 or in those of the later Figures; Figure 4 is a partially diagrammatic side view of another embodiment of the invention and Figure 5 is a section taken along line A-A in Figure 4; Figures 6, 7 and 8 are partially diagrammatic sectioned side views of further embodiments of the invention; and Figure 9 is a partially diagrammatic plan view of a conveyor assembly incorporating a twin belt elevator in accordance with the present invention.

Thus referring first to Figure 1 of the drawings, a dual purpose elevator 8 according to the present invention comprises first and second belts 10, 12 co-operating over an elevating section 14 as shown. To this end, the belt supporting roller 15 at the bottom of upper belt 12 is so positioned as to shape the topmost run of lower belt 10 so as to divide this run into a load accepting region 16 and an elevating region 18. Similarly, the load retaining run 22 of upper belt 12 is slightly deformed near the delivery region by the intrusion of the top support roller 24 for belt 10 so as to encourage a proper co-operation between the two belts over the elevating section 14 and to compact the crop stream finally immediately prior to delivery.

The belt supporting arrangement is completed by idling rollers 26, 28 for belt 10 and by a top roller 30 for belt 12. It is an advantage of this design that there is no need for a rigid member to space apart the upper and lower rollers of the load retaining belt.

In operation, the top rollers 24, 30 provide the drives for the two belts, and conveniently they comprise identical diameter rollers driven at the same speed from a common power source (not shown).

In practice, the load accepting region 16 of belt 10 may receive its load 32 in one of a number of ways e.g. from a hopper (not shown). In this latter case, to reduce the risk of losses, the hopper arrangement would preferably be such as to prevent material from being deposited right out to the edges of the belt.

In a modification (not shown), troughing means can be incorporated along the elevating region 18 of belt 10 so as further to reduce the possibility of losses. Alternatively or additionally, closely fitting vertical side plates covering the interface of belts 10 and 12 along the full length of the elevating section 14 may be provided to contribute to the prevention of spillage of conveyed material at the sides. If the side plates are inclined towards each other along their length at their lower edges, they will also serve the purpose of giving the upwardly inclined belt regions 18 and 22 a trough shape and general support.

As shown in Figure 1, the large diameter roller 15 at the lower end of belt 12 is spring loaded by a pair of compression springs 33 so as to allow the belts 10, 12 to self-tension and self-adjust. This enables the two belts to accommodate, compact and sandwich material reaching elevating section 14 from loading region 16. In more detail, each end of the roller support shaft 34 is anchored in an associated sleeve unit 36 which is urged along a respective rod 38 by the compression spring 33. At their lower ends, the rods 38 are secured to a common sleeve or pivot rings 40 allowing pivotal movement of the rods about an axle or pivot pins 42 secured relative to the elevator framework (not shown).The axle or pins 42 may be located wherever is convenient, provided that the loading by springs 33, either alone or in combination with additional springs (not shown), produces the required tensions in the belts 10, 12 and maintains the desired shape of the elevator.

If desired, the roller suspension linkage 33, 34, 36, 38 may be of alternative design so that tension springs can be used.

Preferably, roller 15 is of a width equal to or greater than the two belts 10, 12. The larger the diameter of the roller the more readily will bulky materials be accepted into the elevating region, even in circumstances of uneven feeding.

Where a more gradual change to the elevating section is desired, e.g. to accommodate specific materials, more than one roller joined together in the shape of a "bogey" may be used. One such arrangement is shown in Figure 2 where the bogey 44 replaces the single roller 15 of the earlier embodiment. As will be seen from the drawing, in the illustrated embodiment, bogey 44 comprises four relatively small diameter rollers 46 joined together by a common support means 48 in such a way as to define the desired curvature for the two belts.

Support means 48 is pivotally connected at 50 to the sleeve unit 36 of the suspension linkage 33, 34, 36, 38 already described with reference to the first embodiment of the invention. The pivoted bogey arrangement provides an additional degree of freedom at the intake region (acting on the principle of a sluice) and this assists in the acceptance of intermittent, severely fluctuating and bulky loads.

In operation of the elevators described above, as material arrives at the roller means provided by roller 15 or rollers 46, as the case may be, the roller means rides up over the material and sandwiches it between the two belts, springs 33 maintaining belt tension at all times. Thereafter, the material is trapped and elevated by the upwardly inclined regions 18, 22 of the belt, to be discharged at the top end of the elevator e.g. into a container (not shown).

As illustrated, the upper of the two drive rollers 30 can overhang the lower drive roller 24 to some extent. Not only does this allow the trajectory of material discharge to be predetermined but it also helps to maintain the sandwiching effect at the top of the elevator if and when large lumps of material cause the two belts to part at the lower end of the elevator.

For a given trajectory, the throw of the material can be altered by regulating the speed of the two belts.

In a modification, extra reach for delivering the conveyed material at relatively slow belt speeds can be achieved with the elevator 8 by incorporating additional rollers 52 and 54 and extending the lower belt run at the delivery end as shown by broken line 56 in the drawing.

If desired, optional extension 56 may also be pivoted about roller 24 to extend the vertical reach of the elevator. In a variation of this latter embodiment, roller 54 is driven instead of roller 24 and the linkage for roller means 15, 44 is modified so that when the vertical reach of the elevator has been extended as above described, the elevating section 14 can be pivoted about roller 28 (to the left in Figures 1 and 2) to enable material delivery to be achieved to points located over the feed region of the elevator.

If desired, a separate cleated or uncleated belt unit of variable inclination and speed can be incorporated in place of the integral belt extension 56 to achieve a greater range of delivery of the conveyed material.

Changes in the direction of delivery can be achieved by incorporating instead an impellerthrower, optionally rotatable about a near vertical axis.

In an alternative method of operating the illustrated embodiment, instead of driving roller 24 (or 54) and roller 30, only one of these rollers is driven, the co-operation between the two belts over their elevating regions being adequate to move that one of the two belts which is not directly in contact with the driven roller.

Referring now to Figures 4 and 5, these show an embodiment having much in common with the above described embodiments, the principal difference being that the belts 10, 12 are now enclosed by a three-section shroud assembly 62 (shown only in Figure 5).

Apart from preventing spillage of the material being conveyed, the illustrated shroud provides guides and safety protection for the return runs 64, 65 of the two belts, so that better control and compliance with safety regulations is achieved.

The side walls of shroud 62 are removably attached to the central shroud members as indicated by the flanges 67, thereby allowing endless belts to be inserted into and used in the assembly.

The broken lines at the top and bottom of the shroud cross-section shown in Figure 5 are to be interpreted as indicating that the outer sections of the shroud need not be fully closed provided that, as shown, the side panels have flanges of sufficient width to guide the return runs of the belts adequately. However, if desired, full horizontal panels may be provided, particularly at the top of the shroud, to fully or more fully enclose the belts and thereby increase weather protection.

It should be made clear that the optimum size and/or shape for the centre section of the shroud will depend on the throughputs and types of material to be used. For example, instead of the shape shown in Figure 5, the centre section might be circular or diamond-shaped or olive-shaped in crosssection if this were thought desirable better to help contain the load in the elevating sections of the belts.

Returning now to Figure 4, the various belt-engaging rollers illustrated are preferably cyclindrical or crowned, in conformity with normal practice, to assist tracking. Of the two belts present, only the lower belt 12 is driven and this from the lowermost roller 26. The upper belt 10 moves by frictional contact with the lower belt or the material being conveyed.

With this in mind, the lower roller 15 of the upper belt is arranged to be spring-loaded, as is the upper roller 30 of the lower belt. Movement of both these spring-loaded rollers is limited to the clearance existing within the centre section of the shroud assembly.

An angularly adjustable deflector 69 at the delivery end of the conveyor is desirable at high belt speeds, so that the material is guided into a compact stream and is directed positively towards the delivery target. The deflector may take many forms, including smoothly curved, or funnel shaped to guide into the stream also the crop from beneath.

Referring now to Figure 6, the elevator shown there differs from that shown in Figures 4 and 5 in that the feed-on section 16 is horizontal, both belts are driven, and at the delivery end, the lower belt run is longer than the upper belt run. This last aspect helps to reduce the amount of stray material emanating from the underside of the material stream. It also makes spring-loading of the upper end rollers 30 of the lower belt optional because now the belt 10 itself can flex to accommodate the crop bulk as it passes under the upper return roller 24.

As an alternative, the upper belt run may extend beyond the lower at the delivery end e.g. in the manner shown in Figure 1 for example.

Turning now to Figure 7r this shows a sectioned side view of a single-box shroud 71 in which the two belt runs, preferably both driven, are accommodated. Spaced apart pairs of guiding rollers 73, 74r spring-loaded towards the centre, apply intermittent pressure on to the load carrying belts 10, 12.

With this particular embodiment, although the construction of the belt housing has been simplified, very steep elevating angles up to the vertical can nevertheless be achieved because back sliding of the material being conveyed is prevented by the idling rollers 73, 74. In fact the range of materials which can be conveyed with this embodiment can be extended to include relatively free-flowing substances.

In a variation (not shown) of the Figure 7 embodiment, the return runs of the conveying belts can be taken outside the central box-section to separate ducts, in the manner shown in Figure 5 for example. In this case, the radius arms of the squeezing rollers 73, 74 can be fitted inside or outside the side plates of the shroud assembly 62. In the latter case the roller spindles will pass through arcuate slots in the side walls, and the slots can be dimensioned so that they limit roller movement towards and away from the centre line.

It should be appreciated that the spring means urging the two opposed idling rollers 73, 74 towards the conveying belts may be selected to exert even or uneven pressure. If the latter case, the conveying belts can be caused to be displaced to one side or the other. Thus if, in successive pairs of rollers, the spring means on alternate sides of the duct are stronger, or weaker, then the belts can be made to take a zig-zag path, so that in a vertically inclined elevating system the mass of the material being conveyed is alternately supported by sections of the right-hand and left-hand belts.

Figure 9 shows an alternative means of providing a zig-zag conveying path by having the co-operating regions 18, 22 of sandwich conveying belts 10, 12 forced into a zig-zag shaped path by spaced single spring-loaded idling rollers 73, 74 acting alternately from opposite sides. As indicated in broken line, on maximum deflection, the rollers are able to move through apertures in the flanged inner walls of the elevator shroud.

In a variation (not shown) of the Figure 8 embodiment, the three-section shroud assembly shown in Figure 8 is replaced by a single-duct structure of appropriate width accommodating both the elevating and the return runs of the twobelts.

It should be pointed out that in the tWD embodiments shown in Figures 7 and 8 and their-variations, the spring-loaded rollers 73, 74 may be so dimensioned or positioned that they are permanently, instead of occasionally, in contact with the returning belt runs. These latter would then operate to provide an additional force to help rotate the rollers.

In very long elevators employing zig-zag conveying paths, it will be necessary to make allowances for the shortening and lengthening of the belt runs under varying load conditions. This may be achieved, for example, by a parallelogram-type suspension of the end belt-supporting rollers so that they can readily move an appropriate distance in and against the direction of crop movement.

Referring now lastly to Figure 10, this shows a plan view of a shrouded belt elevator 8 which receives chopped material from a crop-slicing rotor 80 and conveys it sideways for delivery into a bulk trailer 82 being driven alongside. By pivoting the elevator 8 through 90 degrees about a vertical spindle beneath the feed-on section, the elevator can be usedternatively to deliver material into a trailer or bulk container 84 drawn in-line, for example behind a harvester.

If used in the stationary mode, the elevator of Figure 9 can be swung through any angle up to at least 180 degrees, for example when filling material stores. The inclined part of any of the elevators described may be folded over by pivoting, for example at the spindle of the intake roller of the upper belt, or by hinging sections about alternative pivots.

It should be made clear that features present in any particular embodiment of the invention as above described are, by and large, also available for inclusion in any other embodiment not already possessing the feature concerned. Some, but by no means all, of these possibilities have already been outlined above in discussing the illustrated embodiments. Another example is, for instance, the replacement of rollers 15 in the embodiments of Figure 4 onwards by the bogey arrangement 44 shown in the Figure 2 arrangement. Another example would be the introduction of squeezing rollers 73, 74 in the embodiments of Figures 1 and 2.

Dual purpose elevators according to the present invention are suitable for a wide range of materials, including cohesive materials. In operation, they tend to compact the conveyed material and this can be advantageous in certain cases where low density compressible material is being elevated in order to fill a container.

As already mentioned in the introductory portions of the application, the belts 10, 12 may, if desired, be provided with cleating spanning only part of the width of each belt in such a way as to prevent interference between the cleats should there be any relative movement between the two belts.

One such arrangement is depicted in the cross section of Figure 3 which shows two such belts co-operating at the elevating section of the elevator. As will be seen from this Figure, in the illustrated embodiment, belt 12 is provided with cleats 58 spaced apart along a central region of the belt whereas belt 10 is provided with cleats 60 lying on either side of cleats 58 and spaced therefrom. Other suitable arrangements are also possible, of course.

Besides the advantages already mentioned, the elevator of the present invention also enables complete longitudinal fill of the conveying space to be achieved with some materials, regardless of elevating angle, as opposed to the intermittent fill achievable with known designs of belt (or bucket) elevators which are dependent on elevating angle and the angle of repose of the material. Thus the present invention allows elevators to be constructed which will operate satisfactorily at virtually any desired angle of elevation.

In addition, the simplicity of design, together with minimal friction and slip of material, favour a low power requirement and quiet operation, while as already suggested, variable trajectory, range and direction of delivery can also be incorporated.

Moreover, unlike the flexible wall approach of existing dual purpose belt-type conveyors, where still more elaborate support means are required for wider belts, the principles incorporated in the twinbelt elevators of the present invention are suitable for any width of belt.

This invention finds particular application in the transporting and loading of powder materials, granular materials e.g. seeds or grain, aggregate materials including gravel and coal, long and chopped fibrous materials and small unit loads.

Claims (26)

1. A twin-belt elevator comprising a load-sup porting first belt having an elevating region which co-operates with the elevating region of a load-retaining second belt to convey the load to a dis charge location, the operative run of the first belt being formed and divided into said elevating re gion and said load-accepting region by a lower support roller means of the second belt and the co operating regions of the two belts being urged to gether by spring-loaded rollers or the like to con strain the co-operating regions of the two belts to follow a zig-zag path.

2. An elevator as claimed in Claim 1 in which the roller means is carried on a pivotally-mounted support on which it is spring-loaded towards the adjacent region of the first belt.

3. An elevator as claimed in Claim 1 or Claim 2 in which the second belt is kept taut around the roller means so that the entrance to the elevating section of the elevator is accurately defined by the position of the roller means.

4. An elevator as claimed in any preceding claim in which the roller means comprises a relatively large diameter roller.

5. An elevator as claimed in any of Claims 1 to 3 in which the roller means comprises two or more rollers arranged to shape the operative run of the first belt gradually in the region of directional change.

6. An elevator as claimed in Claim 5 when in cluding the limitations of Claim 2 in which the two or more rollers are mounted on a frame which is itself pivotally attached to said pivotally-mounted support.

7. An elevator as claimed in Claim 5 when in cluding the limitations of Claim 2 in which the two or more rollers are mounted on a frame which comprises said pivotally-mounted support, which frame is pivotally mounted on a non-pivoting sup port.

8. An elevator as claimed in any preceding claim when including the limitations of Claim 2 in which the spring-loading of the roller means is adjustable, a single adjustment changing the tension of both belts.

9. An elevator as claimed in any preceding claim in which the two belts are supported on as few rollers as convenient so as to encourage the belts to self-tension and self-adjust.

10. An elevator as ciaimed in any preceding claim in which the load-retaining run of the second belt is guided about a top support roller of the first belt so as to encourage said co-operation between the second belt and the elevating region of the first belt.

11. An elevator as claimed in any preceding claim in which the inclination of the elevating and load-retaining regions of the belts is adjustable to allow elevating at a range of angles.

12. An elevator as claimed in any preceding claim in which the second belt overhangs the upper end of the first belt so as to predetermine the trajectory of discharge of material from the eleva tor.

13. An elevator as claimed in any of Claims 1 to 11 in which at the delivery end of the elevator, the run of the first belt projects further than the run of the second belt.

14. An elevator as claimed in any preceding claim in which the first and/or second belts are each flat or cleated as desired and preferably of the same or roughly the same width.

15. An elevator as claimed in any of Claims 1 to 13 in which the first and second belt are cleated belts having the cleating spanning different transverse regions of the two belts so that marginal speed differences between the two belts will not cause iterference between the cleats at the elevating region of the elevator nor prevent a degree of troughing from being achieved.

16. An elevator as claimed in any preceding claim including troughing means effective to impart a trough-like shape to the elevating regions of the elevator.

17. An elevator as claimed in any preceding claim including spillage prevention means arranged to flank or surround the first and second belts at the elevating region of the elevator to discourage spillage of conveyed material from this region.

18. An elevator as claimed in any. of Claims 1 to 16 including spillage prevention means arranged to flank or surround the first and second belts at the elevating region of the elevator to discourage spillage of conveyed material at this region and also to support at least in part the two belts at this region in such a way as to impart a trough-like shape to the elevating regions of the elevator.

19. Anelevator as claimed in Claim 17 to Claim 18 in which the spillage prevention means is a tube or other hollow section surrounding or substantially surrounding the first and second belts at the elevating region.

20. An elevator as claimed in Claim 19 in which the spillage-prevention means comprises a threesection device having a centre section surrounding or substantially surrounding the co-operating runs of the two belts at the elevating region of the elevator and two outer sections surrounding the return runs of the two belts at that region.

21. An elevator as claimed in any one of Claims 1 to 16 including spillage prevention means in the form of a single-duct shroud in which all the belt runs are accommodated.

22. An elevator as claimed in Claim 21 in which the shroud is foldable about a hinge lying parallel to the cross-sectional planes of the belts.

23. An elevator as claimed in Claim 21 or Claim 22 in which the belts are supported on free-wheeling rollers each arranged to keep apart the forward and return runs of an associated belt and to derive drive from contact with both said runs.

24. An elevator as claimed in any preceding claim in which the elevating region of the first belt leads to an extension region provided either by the first belt or by a third belt.

25. An elevator as claimed in Claim 26 in which the-inclination of the extension region is adjustable.

26. An elevator substantially as hereinbefore described with reference to and/or as illustrated in the accompanying drawings.