GB2077215A

GB2077215A - Scraper units for mine conveyor scraper-chain assemblies

Info

Publication number: GB2077215A
Application number: GB8117515A
Authority: GB
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1980-06-11
Filing date: 1981-06-08
Publication date: 1981-12-16
Also published as: GB2077215B; DE3021922C2; DE3021922A1; ES8203773A1; FR2484375B1; AU543864B2; AU7162981A; ES502937A0; ZA813807B; FR2484375A1

Abstract

A scraper unit for a scraper-chain assembly is composed of an elongate scraper bar 10 with reduced height end regions 11 adapted to seat onto horizontal links of a pair of chains. Coupling pieces 12 lie beneath the chain links and are used to clamp the scraper bar 10 to the chain links. The scraper bar has internal pockets 16 which receive inner plate portions 22 of the coupling pieces 12 and bolts are inserted through bores 19, 23 in these portions 22 and the walls of the pockets 16. Each of the coupling pieces 12 also has a pair of upstanding lugs 27, 28, one of which projects through the associated chain link to engage in a blind bore 18 in the under-surface of the associated end region 11 of the scraper bar 10. The other lug 28 of each coupling piece 12 is threaded and engages in another bore 21 in the scraper bar which is open from the upper surface thereof to receive a nut 30. <IMAGE>

Description

SPECIFICATION Improvements in scraper units for mine conveyor scraper-chain assemblies The present invention relates in general to scraper-chain assemblies for use in scraper-chain conveyors and more particularly to scraper units therefor.

Scraper-chain assemblies of various designs are well known in the art. The present invention is mainly concerned with the so-called double chain assembly where spaced-apart scrapers are mounted between a pair of widely spaced oval link chains. In order to connect the scrapers to the chains various types of connectors have been employed. In one known construction, connectors in the form of shackles are fitted to the chains and engage inside internal pockets in the scrapers.

Nuts and bolts extend through the walls of the pockets and the shackles to detachably secure the scrapers to the chains. US patent specification 4113084 describes various scraper units of this known kind. These units are particularly advantageous when it is necessary to dismantle the scraper from the chains or to assemble the scraper to the chains. Once the nuts and bolts are released the scraper itself can be easily lifted clear from the chains. While maintaining the advantages of the known units a general object of the present invention is to provide an improved scraper unit.

A scraper unit constructed in accordance with the present invention is composed of a scraper or scraper bar and a pair of coupling pieces or locking elements designed to secure the scraper to the horizontal links of a pair of side chains as is known per se. The scraper has end regions reduced in height in relation to its main central region. These end regions are shaped at their undersides with grooves or the like to seat onto these chain links.

The scraper bar contains internal pockets adjacent these shaped undersides. The coupling pieces themselves have portions received by the pockets and secured therein with the aid of releasable screw-threaded connectors. In accordance with the invention, additional interengageable projections and recesses are formed between the coupling pieces and the scraper. At least some of these projections pass through the horizontal chain links. Conveniently, the upper surfaces of the coupling pieces have the projections which can take the form of upstanding integral lugs. A pair of such lugs can be provided on each coupling piece. One lug passes through the chain link in question to engage in an opening such as a blind bore in the scraper.Another lug is then received in an open bore in the scraper and is threaded to receive a nut used to additionally clamp the scraper to the coupling piece in the vertical sense.

These nuts engaged on the screw threaded lugs are conveniently accessible from the upperside of the scraper and accommodated in countersunk regions of the bores.

It is desirable to shape both the undersides of the scraper end regions and the uppersides of the coupling coupling pieces with grooves or the like to locate with the shanks of the chain links. Some clearance is desirable for the shanks however to provide flexibility to the resultant assembly. This can be achieved in a variety of ways. For example, a support surface is formed on the upperside of each coupling piece around the one lug and the undersides of the end regions of the scraper are provided with co-operating surfaces which engage with the support surfaces of the coupling pieces.

Appropriate shaping of grooves or recesses receiving the shanks can achieve the same result.

A preferred embodiment of the present invention provides a scraper unit composed of a scraper bar having a central region, end regions reduced in height in relation to the central region and overlapping said horizontal links from above and internal pockets adjacent the end regions, the pockets being open to the underside and from the lateral ends of the scraper bar. The associated coupling pieces or locking elements have shaped portions received in the pockets of the scraper bar and securable therein with the aid of bolts inserted through aligned bores in the portions and the walls of the pockets which bores project parallel to the direction of the chains, and end portions extending beneath the horizontal links.The upper surfaces of the end portions of the locking elements and the lower surfaces of the end regions of the scraper bar have co-operating recesses which positively locate with the shanks of the horizontal chain links. The upper surface of each locking element is then provided with upstanding lugs, one of which passes through the associated chain link to engage in an opening in the lower surface of the associated end region of the scraper bar and the other of which is disposed between the one lug and the bore in the portion received in the associated pocket, engages in a bore in the scraper bar and is threaded to receive a nut used to additionally clamp the locking element to the scraper bar. Additional shaping of the locking elements can be provided.Thus, each such element can have a plate-like end portion forming the portion receivable in the associated pocket of the scraper and a further end portion opposite thereto, the undersurface of the further end portion of each coupling piece being tapered towards the adjacent free end outwardly of the unit and having bevelled front and rear faces. Such shaping is advantageous in the transport of mineral ores along the pans of a conveyor utilizing the units. Despite the shaping of the coupling pieces or locking elements and the formation of the lugs these sturdy components are still simple to manufacture and can have a width considerably smaller than the scraper bar.

A unit constructed in accordance with the foregoing is easy to assemble or dismantle but provides enhanced rigidity and a firmer anchorage for the scraper in contrast to the prior art. This permits the unit to withstand high loading, especially shock loads which often occur in the harsh mineral mining conditions. Moreover, by virtue of the additional connections established by the nuts on the screw-threaded lugs the unit is protected should the normal bolts passing through the pockets become loosened or the aligned bores receiving these bolts become deformed.

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 drawing, wherein: Figure 1 is a front elevation of a scraper unit constructed in accordance with the invention; Figure 2 is a plan view of part of the scraper unit shown in Figure 1; and Figure 3 is an end view of the scraper unit taken in the direction of arrow Ill in Figure 1.

The single scraper unit depicted in the accompanying drawing is intended for use with double-side-chain scraper chain conveyors. A series of such units would be spaced apart along the chains to form therewith a scraper-chain assembly which is moved along the pans of the conveyor to transport material, especially mineral ores.

Referring now to the drawing, the scraper unit as represented is composed of an integral elongate scraper bar 10 and detachable locking devices or coupling pieces 12 which serve to clamp the bar 10 to the chains (not shown). The scraper bar 10 has a main central region with an inclined front face 1 5 merging with reduced end regions 11. The end regions 11 are reduced in height in relation to the central region of the scraper bar 10. The end regions 11 are designed to seat onto horizontal links of the associated chains. In Figure 2 one of the chains is shown in chain-dotted lines 14 and its horizontal link is designated 13. For convenience, the coupling pieces 1 2 are shown as detached from and fitted to, the scraper bar 10 at the left, and right, hand sides of Figure 1, respectively.

The coupling pieces 12 have a width considerably smaller than the scraper bar 10 as can be seen in Figure 3.

The upper faces of the coupling pieces 12 have curvilinear grooves or recesses 25, 26 while the lower faces of the end regions 11 of the scraper bar 10 have similar grooves or recesses 1 7. These recesses 1 7, 25, 26 co-operate as shown in Figure 1, to receive the shanks 13' 1 3" of the horizontal chain links 13 to which the unit is secured. The scraper bar 10 is provided with deep internal pockets 1 6. These pockets 1 6 are open from the lateral exteriors of the bar 10 as weil as from the underneath and serve to receive substantial rectilinear plate portions 22 of the coupling pieces. The walls of the pockets 1 6 and the portions 22 of the coupling pieces 1 2 are pierced by horizontal bores 1 9, 23 respectively.The bores 1 9, 23 are aligned when the coupling pieces 12 are fitted to the scraper bar 10 and bolts 20 with nuts 29 are inserted through the bores 1 9, 23 to secure the coupling pieces 12 to the bar 1 0.

Between the recesses 1 7 at each end region 11 of the scraper bar 10 there is a vertical opening or blind bore 1 8. In addition, there are vertical bores 21 in the bar 10 which communicate with the pockets 1 6 and are disposed generally between the horizontal through bores 1 9 and the vertical blind bores 1 8. These bores 21 have enlarged countersunk or counterbored regions opening to the upper face of the bar 1 0.

The coupling pieces 1 2 have end portions 24, opposite their plate portions 22, the upper faces of which are provided with the recesses 25, 26.

Between the recesses 25, 26 on the upper face of the end portion 24 of each coupling piece 12 there is an upstanding projection or lug 27. On the upper face of the portion 22 of each coupling piece 12 there is also another upstanding projection or lug 28 disposed generally between the lug 27 and the through bore 23. The lugs 28 are somewhat longer than the lugs 27 and are provided with screw threads. As can be appreciated from the drawing, when the coupling pieces 12 are mated with the scraper bar 10 the lugs 27 engage in the blind bores 18 while the lugs 28 engage in the bores 21. Nuts 30 are fitted to the lugs 28 and are accommodated in the countersunk regions of the bores 21 beneath the upper surface of the scraper bar 1 0. The end portions 24 of the coupling pieces 12 have lower tapered faces 33 which merge smoothly as radii with the laterally outermost ends thereof.These portions 24 also have bevelled front and rear faces 34 adjoining the lower faces 33 and also bevelled faces merging with the portions 22.

When the unit is to be fitted to the chains, the coupling pieces 12 are placed beneath the horizontal links 13 of the chains 14 with the shanks 13', 13" thereof in the recesses 25, 26.

The lugs 27 then project up through the links 13.

The scraper bar 10 is then introduced from above onto the coupling pieces 12 so that the portions 22 locate in the pockets 16, the lugs 27 fit into the bores 18 and the lugs 28 fit into the bores 21.

The bolts 20 are then inserted through the aligned bores 1 9, 23 and the nuts 29 are tightened onto the shanks of the bolts to engage on the rear of the scraper bar 10 via washers. The nuts 30 are likewise tightened onto the threaded lugs 28 to draw up the coupling pieces 12 and the chain links 1 3 to the bar 10. Washers are again fitted under the nuts 30 to bear on the inner faces of the countersunk regions of the bores 21. When the coupling pieces 12 are clamped to the bar 10, support faces 31 around the lugs 27 engage on support faces 32 on the underside of the end regions 11 of the bar around the bores 1 8. The shanks 13', 13" of the links 13 of the chains 14 are trapped between the recesses 17, 25 and 17, 26 but there is a certain degree of clearance by virtue of the engaging surfaces 31, 32 and especially at the outer shanks 13" where the recesses 25 are part circular in contrast to the; semi-circular recesses 26. This clearance provides flexibility which enables the scraper-chain assembly to cope with deviations in the normal path of motion and allows easier circulation of the assembly around the drive sprocket(s).

The overall configuration is particularly advantageous. The lugs 27 in the bores 18 ensure a positive location between the coupling pieces 12 and the scraper bar 10 within the chain links 13 while the screw connections 30, 28 and 29, 20 clamp the unit is both vertical and horizontal senses. This enables the assembly to cope with high loads and protects the units from become detached from the chains. In order to dismantle the unit 10, 12 from the chains it is necessary to loosen and remove the nuts 29, 30 and bolts 20 thereby permitting the bar 10 to be lifted clear of the coupling pieces 12.

Claims

1. A scraper unit for a scraper-chain assembly of a conveyor; said unit being composed of a scraper with end regions shaped at their undersides to seat onto horizontal links of a pair of chains of the assembly and containing internal pockets adjacent said shaped undersides and coupling pieces for detachably securing the scraper to the chain links, the coupling pieces having portions receivable within said pockets and securable therein with the aid of screw-threaded connectors; wherein interengageable projections and recesses are formed between the coupling pieces and the scraper, at least some of said projections locating through the horizontal links when the coupling pieces are secured to the scraper.

2. A scraper unit according to claim 1, wherein at least some of the projections are provided with screwthreads which receive nuts used to additionally secure the coupling pieces to the scraper.

3. A scraper unit according to claim 1, wherein the portions of the coupling pieces receivable in the pockets and the walls of the pockets have alignable bores therein which extend parallel to the lengths of the chains and receive said screwthreaded connectors.

4. A scraper unit according to claim 3, wherein the interengageable projections and recesses are laterally offset from the bores receiving the screw connectors towards the ends of the scraper.

5. A scraper unit according to any one of claims 1, 3 or 4, wherein the projections are formed on the upper surfaces of said coupling pieces.

6. A scraper unit according to claim 5, wherein each coupling pieces has two upstanding lugs constituting the projections, one of the lugs engaging in a blind bore in the associated end region of the scraper and locating through the associated horizontal chain link and the other of the lugs having a screw-thread and being received in another bore in said associated end region which is open from the upperside of the scraper to permit a nut to be engaged on the other of the lugs.

7. A scraper unit according to claim 6, wherein the other lug of each coupling piece is somewhat longer than said one lug thereof.

8. A scraper unit according to claim 6, or 7, wherein a support surface is formed on the upperside of each coupling piece around the one lug and the undersides of the end regions of the scraper are provided with co-operating surfaces which engage with the support surfaces of the coupling pieces.

9. A scraper unit according to any one of claims 1 to 8, wherein each coupling piece is shaped on its upperside to seat beneath the horizontal links.

10. A scraper unit according to any one of claims 1 to 7, wherein each coupling piece is shaped on its upperside to seat beneath the horizontal links and the shaping of the coupling pieces and the end regions of the scraper provide a slight clearance for the chain links.

11. A scraper unit according to any one of claims 1 to 10, wherein, each coupling piece has one plate-like end portion forming the portion receivable in the associated pocket of the scraper and a further end portion opposite thereto the undersurface of the further end portion of each coupling piece being tapered towards the adjacent free end outwardly of the unit.

12. A scraper unit according to claim 11, wherein the further end portions of each coupling piece has bevelled front and rear faces.

13. A scraper unit according to any one of claims 1 to 12, wherein the end regions of the scraper are reduced in height in relation to the main central region thereof and the width of the coupling pieces is smaller than that of the scraper.

14. In or for a scraper chain assembly for å double-chain scraper-chain conveyor; a scraper unit composed of an elongate scraper bar and a pair of locking elements for detachably securing the scraper bar to horizontal links of the chains, the scraper bar having a central region, end regions reduced in height in relation to the central region and overlapping said horizontal links from above and internal pockets adjacent the end regions, the pockets being open to the underside and from the lateral ends of the scraper bar, the locking elements having shaped portions received in the pockets of the scraper bar and securable therein with the aid of bolts inserted through aligned bores in the portions and the walls of the pockets, which bores project parallel to the direction of the chains, end portions extending beneath the horizontal links, the upper surfaces of the end portions of the locking elements and the lower surfaces of the end regions of the scraper bar having co-operating recesses which positively locate with the shanks of the horizontal chain links, the upper surface of each locking element being further provided with upstanding lugs, one of which passes through the associated chain link to engage in an opening in the lower surface of the associated end region of the scraper bar and the other of which is disposed between the one lug and the bore in the portion received in the associated pocket, engages in a bore in the scraper bar and is threaded to receive a nut used to additionally clamp the locking element to the scraper bar.

1 5. A scraper unit substantially as described with reference to, and as iilustrated in, the accompanying drawing.

1 6. A scraper-chain assembly or scraper-chain conveyor incorporating scraper units according to any of the preceding claims.