GB2127372A - Apparatus for guiding scraper chain conveyors - Google Patents

Abstract

A structure forming a curved channel section of a scraper-chain conveying apparatus uses endless roller chains 15, 16 for guiding a scraper chain assembly 14, 15 around a corner. The roller chains 15, 16 run around chain wheels 18 and are deflected into curved paths by guide plates 17. Each chain 15, 16 is assembled from closely- adjacent similar elements 20 inter- connected via hinge pins 30 projecting through interengaging lugs 25,26. The pins 30 carry rollers 31 engaging in a track 33 in the associated guide plate 17. Each element 20 has an open-ended trapezoidal recess 21 and these recesses 21 combine to form a nearly continuous slot into which the end regions 5' of the scrapers 5 of the assembly 14, 15 are received and located for the guidance. <IMAGE>

Description

SPECIFICATION Improvements in conveying apparatus for use in mineral mining The present invention relates in general to conveying apparatus for use in transporting mineral ores, especially coal, in mineral workings.

It is well known to transport mineral with the aid of a scraper-chain conveyor composed of channel sections or pans joined end-to-end and a scraper-chain assembly which circulates along the pans in upper and lower runs. In some mineral mining installations a conveyor is arranged alongside a mineral, e.g. coal, face and discharges the won mineral onto another conveyor extending along a roadway generally perpendicular to the face conveyor.

In other installations a straight section of pans is installed in both the mine working and in the roadway and a special curved channel section interconnects the sections and guides the scraper-chain assembly around a corner or curved path defined by the curved channel section, Examples of known constructions are described in US patent specifications 4250989 and 4360102 and in German patent specifications 2013089, 2065424 and 2051384.

In order to guide the scraper-chain assembly around the curved path with the minimum of friction, pulley wheels or the like can be provided. In another known system endless roller chains are used instead of pulley wheels as described in German patent specification 2301348. One advantage of roller chains is that the curved section or structure can be reduced in size. Nevertheless, curved structures employing rollers chains as guide means have not been adopted in practice mainly because it is difficult to fit the end regions of the scraper accurately into the associated elements of the roller chains. Normally these elements are spaced-apart with intermediate joint plates and are provided with recesses for locating the scraper end regions. If a scraper does not correctly coincide with the reception recess problems arise and the guidance of the scraper-chain assembly suffers.In severe cases, the scrapers and/or roller chains can become damaged or jammed.

A general object of the present invention is to provide an improved curved conveyor channel section.

The invention provides a structure forming a curved channel section for use in conveying apparatus composed of interconnected channel sections or pans and a scraper-chain assembly circulated along the pans; said structure being composed of a frame provided with means for guiding the assembly therearound; said guiding means comprising a roller chain composed of shaped, similar elements each having an open-ended recess and outwardlyprojecting lugs, the elements being interconnected by hinge pins locating through aligned bores in said lugs and rollers supported on said pins with the recesses of the elements combining to form a near-continuous slot for receiving end regions of the scrapers of the assembly.

In accordance with the invention, the curvilinear structure forming a channel section for a scraper-chain conveyor may employ a pair of roller chains for guiding a scraper-chain assembly around a curved path in upper and lower runs. Each roller chain is then composed of similar elements each having the open-ended recess for receiving the end regions of a scraper of said assembly and outwardly-projecting connecting lugs. The lugs of the elements inter-engage in complementary fashion and receive the hinge pins and the rollers. Unlike previous constructions the elements of the roller chain are directly and flexibly interconnected without any intermediary components. Consequently, the elements can be positioned very close together with their recesses forming a nearly continuous slot only interrupted by small gaps between adjacent elements.The end regions of the scrapers can thus be readily engaged in the slot without the critical alignment manifest in the prior art. The recess of each element preferably has-a-trapezoidal shape with several surfaces engaging with the scraper end regions.

The elements of the roller chain may be onepiece components, preferably castings. Normally, the curved structure according to the invention would have a frame with horizontal plates and upstanding walls including an outer wall of curved shape with a crosssection matching that of adjacent straight channel sections. The scraper-chain assembly would be guided in upper and lower runs around the curved structure with the aid of upper and lower roller chains constructed as described. The recess of each element of the upper roller chain at least preferably has flank walls which tend to grip the scraper end regions and draw these into the curved path with minimal slippage. Each rollers chain can be entrained around chain wheels. Curved guide plates can be detachably mounted to the frame to guide the circulation of the roller chains.Preferably shallow depressions in the guide plates receive the rollers to the chains to restrict vertical movement. The roller chains constructed in accordance with the invention are particularly effective in guiding the scraper-chain assembly especially at the critical zone where the assembly enters the curved path. The roller chains are comparatively simple and easy to install and are highly stable.

Since the roller chains are stable they are largely resistant to compression and tension forces and provide especially smooth running.

Each element of the roller chains preferably has bifurcated joints constituting the lugs which are spaced apart at each end. The relative spacings are such that the pairs of lugs of each element mate with those of adjacent elements, locating between or outside these adjacent pairs of lugs. The hinge pins may then engage through aligned bores in the mated lugs and the rollers would be mounted on the pins between the closest spaced pairs of lugs. Each element would then have a main body from which extends the lugs and the open recess would be provided in this body. Conveniently, the body is also relieved or recessed to accept the widerspaced lugs of an adjacent element.

A tensioning device can be provided to adjust and control the tension in each roller chain. Conveniently, this device acts on the section of the roller chain remote from the scraper-chain assembly guided thereby and tends to bow this section outwardly from a rectilinear path. This bowing action permits the elements to be positioned very close together at the entry and exit zones of the scraper-chain assembly.

It is desirable to ensure the recesses of the elements of the roller chains are kept clean and for this purpose at least one spray device can be provided to spray a water jet into the recesses as the roller chains circulate.

The invention may be understood more readily, and various other features of the invention may become apparent, from consideration of the following description.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a part-sectional plan view of a structure constructed in accordance with the invention; Figure 2 is a sectional end view of part of the structure shown in Fig. 1, the view being taken on a somewhat larger scale; Figure 3 is a perspective view of one of the elements of a roller chain of the structure; and Figure 4 is a plan view of the element shown in Fig. 3, the view being taken in the direction of arrow IV in Fig. 3.

In general, structure 1 represented in the accompanying drawings is intended to interconnect straight sections of a scraper-chain conveyor in the order to guide the scraperchain assembly thereof through an angle of about 90 . During use, the structure 1 is incorporated in the conveyor which, as is known, is constructed from elongate channel sections or pans joined end-to-end and the structure 1 can be thought of a special curved channel section or pan. Normally the structure 1 would be used to interconnect separate but compatible conveyors which are installed in workings extending perpendicular to one another as, for example, a longwall mineral, e.g. coal, face working and a roadway. In Fig.

1 the end 2 of the structure 1 is intended to connect with an endmost channel section of a first conveyor, say extending along the coal face, while the end 3 is intended to connect with an endmost channel section of a second conveyor, say extending along the roadway.

Each conveyor is constructed from straight channel sections interconnected to permit some mobility in horizontal and vertical senses while resisting traction forces. A scraper-chain assembly circulates along the conveyors and takes the form of a central chain 4 and scrapers 5 spaced-apart along the chain 4.

The scraper-chain assembly 4,5 is driven by drive means common to both conveyors conveniently located on a frame at the end of one of the conveyors remote from the structure 1.

As is known the scraper-chain assembly 4,5 is moved along the channel sections of the conveyors in upper and lower runs and the assembly 4,5 passes around drums at the ends of the conveyors remote from the structure 1.

The assembly 4,5 also moves around the structure 1 and is guided as described hereinafter.

As shown in Figs. 1 and 2, the structure 1 has a frame 7 of welded components including a base plate 8, an intermediate plate 9 and an upper plate 10 forming a cover. The base plate 8 and the intermediate plate 9 extend across the structure 1 to partly define the curved path 11 for the assembly 4,5 in a vertical sense. On the outer side of the structure the plates 8,9 are interconnected by means of an upstanding curved side wall 1 2.

This wall 1 2 has a section similar to that of the side walls of the conveyors which resemble a sigma-shape or E-shape. The wall 12 defines inner guide channels for guiding the associated end regions of the scrapers 5 in similar manner to the side walls of the pans of the normal conveyors. Additional wear-resistant plates 13, 14 are welded on the upper faces of the plate 9,8 to form a floor surface for the scraper-chain assembly 4,5. As shown in Fig. 2, the scrapers 5 may contact the plates 1 3,14 as they pass around the curved path 11. As the assembly 4,5 passes around the structure 1 in the upper and lower runs separated by the plate 9, the scrapers 5 are guided on the inside of the curved path 11 with the aid of endless roller chains 15,16.

The chain 1 5 runs between the cover plate 10 and the intermediate plate 9 while the chain 1 6 runs between the intermediate plate 9 and the base plate 8. The chains 15,16 are themselves guided as described hereinafter and the individual chains 15,16 and their guides are of identical construction. The chains 1 5,1 6 are entrained around chain wheels 1 8,1 9 which are freely rotatable on upstanding shafts mounted to the frame.

Curved guide plates 1 7 are disposed between the plates 8,9 and 10,9 and lie on arcs between the chain wheels 18,1 9 to contact and guide the chains 15,16. The guide plates 1 7 can be welded to the frame or preferably mounted thereto for replacement when worn.

Each roller chain 1 5,1 6 is composed of elements 20. As shown in Figs. 3 and 4 each element 20 is conveniently a one-piece component, e.g. a casting, with a main body provided with a tapered or trapezoidal recess 21 adapted to receive the shaped end regions 5' of the scrapers 5. The recess 21 is open at both ends of the body of the element 20 and has flanks 23 which diverge outwardly from an inner base surface 24. The ends of the main body of the element 20 adjoin outwardly projecting lugs 25,26 offset from the recess 21 towards the rear. The lugs 25,26 are provided with bores 27,28 for receiving pins 30 (Fig. 2). The lugs 25,26 are curved as at 29 and recesses 32 are provided in the element 20 opposite the lugs 25 with matching curvature (29) to the lugs 25,26. The lugs 25 are spaced apart by a distance greater than the distance between the lugs 26.The overall arrangement in such that the pair of lugs 26 of an adjacent element 20 engage between the pair of lugs 25 and receive a common hinge pin 30 while the pair of lugs 26 engage between the lugs 25 of another adjacent element 20 and likewise receive a common hinge pin 30. This is depicted in Fig. 4 where the respective adjacent elements 20 are shown in chain-dotted outline. The lugs 25 of the adjacent (left-hand) element 20 engage in the recesses 32. Rollers 31 are mounted on the pins 30 to engage between the lugs 26 as shown in Fig. 2.

As also shown in Fig. 2, the guides 1 7 have depressions 33 which form guide tracks which receive and guide the rollers 31. The depressions 33 particularly restrain vertical movement of the rollers chains 1 5,1 6 and thus prevent the chains 1 5,1 6 contacting the plates 8,9 and 10.

As shown in Fig. 1, the elements 20 of each of the chains 1 5,1 6 lie closely adjacent one another over the arc between the chain wheels 1 8,1 9 and only small gaps 34 are present between the elements 20. The recesses 2 thus combine to form almost continuous slots receiving and guiding the scraper end regions 5'. The other run of the chain 1 5,1 6 between the chain wheels 1 8,1 9 is nearly rectilinear so that the claims 1 5,1 6 run along 'D' shaped paths. A chain tensioning device 35 is provided on the frame 7 for each chain 15,16. Each device 35 has a bar 36 which engages on the rollers 31 of the associated chain 15,16. An adjustable spring 37 urges the bar 36 against the rollers 31 slightly bowing the rectilinear path of the chain 15,16.The bar 36 preferably also has a shallow depression forming a track for positive engagement with the rollers 31. The action of the devices 35 causes narrow gaps 38 to become established between the elements 20 and permits close spacing therebetween especially in the zones where the scraper end regions 5' are taken up and released. As shown in Fig. 2, the recesses 21 of the elements 20 of the upper chain 1 5 are positioned so that scrapers 5 tend to be drawn into the recesses 21 by frictional contact with the flanks 23 under the tension in the chain 4. This ensures there is minimal slippage and the chain 1 5 will be reliably driven in circulation by the scrapers 5. Although the same arrangement can be adopted in the case of the lower chain 1 6 it is preferable to alter the angle of the flanks 23 of the recesses 21 of the elements 20. A greater clearance can then result as shown.

As shown in Fig. 1 in the zone of the chain wheels 18, 1 9 spray devices 39 are provided to cause jets of cleansing water or some other fluid to be directed in to the recesses 21 of the elements 20 in order to loosen any dirt adhering thereto as the chains 15, 1 6 circulate.

Claims (11)

1. A structure forming a curved channel section for use in conveying apparatus composed of interconnected channel sections or pans and a scraper-chain assembly circulated along the pans; said structure being composed of a frame provided with means for guiding the assembly therearound; said guiding means comprising a roller chain composed of shaped, similar elements each having an open-ended recess and outwardly-projecting lugs, the elements being interconnected by hinge pins locating through aligned bores in said lugs and rollers supported on said pins with the recesses of the elements combining to form a near-continuous slot for receiving end regions of the scrapers of the assembly.

2. A structure according to claim 1, wherein each element has a main body containing the open-ended recess and a pair of lugs at each end of the main body, the spacing between the lugs at one end being different from the spacing between the lugs at the other end to permit the lugs to be mated with complementary pairs of lugs of adjacent elements with the closest spaced lugs engaging between the widest spaced lugs.

3. A structure according to claim 2, wherein each element has additional recesses in the main body, said additional recesses being provided at the end with the closestspaced lugs and serving to receive the widerspaced lugs of an adjacent element.

4. A structure according to any one of claims 1 to 3, wherein the roller chain is entrained around chain wheels and there is further provided a curved guide plate for guiding the roller chain over a curved path where the scrapers are taken up thereby.

5. A structure according to claim 4, wherein the guide plate has a depression forming a track in which the rollers of the roller chain engage.

6. A structure according to claim 4 or 5, wherein a tensioning device is provided to subject the roller chain to an adjustable tensioning force over a region remote from the curved path.

7. A structure according to claim 6, wherein the tensioning device acts to bow said region of the roller chain outwardly from a rectilinear path.

8. A structure according to any one of claims 1 to 7, wherein the recess of each element of the roller chain is of trapezoidal shape.

9. A structure according to any one of claims 1 to 8, and further comprising a spraying device for providing a cleansing jet for the recesses of the elements of the roller chain as the latter circulates.

10. A structure according to any one of claims 1 to 9, wherein the frame has at least one horizontal plate and a curved outer side wall with the scraper-chain assembly moving in upper and lower runs relative to the horizontal plate and wherein the guiding means comprises a pair of said roller chains guiding the assembly in both the upper and lower runs.

11. A structure according to claim 10, wherein the recesses in the elements of the lower roller chain provide a greater clearance with respect to end regions of the scrapers engaged therein than that of the recesses of the elements of the upper roller chain.

1 2. A structure according to any one of the preceding claims and having roller chain elements substantially as described with reference to, and as illustrated in, the accompanying drawings.

1 3. A curved structure for conveying apparatus substantially as described with reference to, and as illustrated in, the accompanying drawings.