GB2081661A

GB2081661A - Scraper-chain conveyors

Info

Publication number: GB2081661A
Application number: GB8024353A
Authority: GB
Original assignee: DOWTY MINING DEV Ltd
Current assignee: DOWTY MINING DEV Ltd
Priority date: 1980-07-25
Filing date: 1980-07-25
Publication date: 1982-02-24
Also published as: ZA814583B; AU7280181A; GB2081661B

Abstract

A scraper-chain conveyor 1 having an endless chain 2 or chains passing lengthwise and substantially centrally of its pan structure 3 in upper and lower runs and carrying a number of members 6 disposed at predetermined intervals therealong, has a section 7 of its pan structure shaped to turn through a bend. An element 8 is mounted with freedom to rotate about an axis 9 which is vertical, or substantially so, and which is so disposed adjacent the wall 10 of the pan structure on the inside of the bend that the element overlies the pan structure sufficiently far as to be engaged by abutment surfaces 12 provided on the members as, successively, the members negotiate the bend. The members 6 can be part of the scraper flights or be similar to the central portion of the scraper flights without the flights attached. <IMAGE>

Description

SPECIFICATION Scraper-chain conveyors This invention relates to scraper-chain conveyors suitable for use in mineral-mining operations.

Hitherto in order to provide during operation of a scraper-chain conveyor for smooth change in direction of the chain or chains of the conveyor, together with flight bars carried thereby, as they negotiate a bend in the conveyor pan structure, disc-like elements have in some cases been provided which are rotatable about a vertical axis and which are so disposed on the inside of the bend that the tips of the flight bars on that side of the conveyor are guided in their movement around the bend by a respective disc-like element.

However, since the disc-like elements are engaged by the tips of the flight bars, the said vertical axis is so offset from that wall of the pan structure on the inside of the bend that valuable space has been occupied in this zone by support structur-e for such elements, and in certain cases this has placed limitations on the disposition of other components associated with the conveyor, for example of mine roof-supporting equipment and/or mineral cutting machines intended to travel along the conveyors, as well as the means used for propelling the machines.

The invention is intended to provide a remedy.

It solves the problem of how to design a scraperchairs conveyor in which such limitations are avoided.

The advantages offered by the invention are that less of the valuable space on the inside of the bend is needed to support the means for guiding the chain or chains and flight bars as they negotiate the bend, the flight bars are more stable in their movement, and smoother movement of the flight bars around the bend is afforded.

According to the invention a scraper-chain conveyor having an endless chain or chains passing lengthwise and substantially centrally of its pan structure in upper and lower runs and carrying a plurality of members disposed at predetermined intervals therealong, and also having a section of its pan structure shaped to turn through a bend, includes an element mounted with freedom to rotate about an axis which is vertical, or substantially so, and which is so disposed adjacent the wall of the pan structure on the inside of the bend that the element overlies the pan structure sufficiently far as to be engaged by abutment surfaces provided on said members as, successively, the members negotiate the bend.

The element is preferably of disc-like shape, its peripheral edge being engageable by said abutment surfaces.

The members may all comprise flight bars which are intended to have a scraping action along the deck of the pan structure. Each such flight bar may comprise a central portion, adapted for attachment to the chain or chains, and a pair of wing portions extending therefrom, a said abutment surface being provided on that part of each central portion remote from said deck.

Alternatively, only certain of said members may comprise flight bars while each of the remaining members comprises a portion similar to said central portion but have no wing portions, a said abutment surface being provided on that part thereof remote from said deck.

One way of carrying out the invention is described in detail below with reference to drawings which illustrate only one specific embodiment, in which: Figure 1 is a plan view of part of a scraperchain conveyor in accordance with the invention, and, Figure 2 is a cross-section taken along the line Il-Il on Figure 1.

In the drawings the scraper-chain conveyor is indicated generally at 1 and has an endless chain, part of which is shown at 2, passing lengthwise and substantially centrally of its pan structure 3 in upper and lower runs 4, 5. The chain carries a plurality of members 6 disposed at predetermined intervals therealong. A section 7 of the pan structure 3 is shaped to turn through a benci, in this embodiment of 90 degrees.This section is provided with an element 8 mounted with freedom to rotate about an axis 9 which ts substantially vertical and which is so disposed adjacent the wall 10 of the pan structure on the inside of the bend that the element overlies the upper channel 11 of the pan structure sufficiently far as to be engaged by abutment surfaces 1 2 provided on the members as, successively, the members negotiate the bend in the upper channel.

A further element 13 is mounted with freedom to rotate about the axis 9 and is so disposed as to underlie the lower channel 14 of the pan structure 3 sufficiently far as to be engaged by the abutment surfaces 12 as, successively, with the chain passing on its return run along the lower channel, the members 6 negotiate the bend.

Each of the elements 8, 13 is of disc-like shape and both of the same diameter, being mounted for independent free rotation in suitable and respective anti-friction bearing stacks 15, 1 6. The peripheral edge 17, 1 8 of each element is engageable by the abutment surfaces 12.

The members 6 form flight bars which are intended to engage and to have a scraping action upon the deck 1 9 of the conveyor when mineral material, for example coal, is being conveyed along the upper channel 11 by the moving chain 2 and its flight bars.

Each flight bar comprises a central portion 20, which is held fast with respect to the chain 2 by suitable securing means, and a pair of wing portions 21, 22 extending therefrom.

As shown, the abutment surface 12 of each member 6 is formed by one flank of an upstanding part 23 of the central portion 20.

A spill plate 24 is provided in association with the wall 10 of the pan structure, this plate following the curvature of the conveyor through 90 degrees.

The major potion of each of the elements 8, 1 3 together with the bearing stacks 1 5, 1 6 and associated vertically-disposed spindle 25, are housed within a chamber 26. This chamber is defined by a portion 27 of the base 28 which is apertured to receive the spindle 25, a curved outer wall 29, that part of the wall 10 on the inside of the bend, the part 30 of the spill plate 24, and a part-circular cover member 31 which is suitably adapted to support the spindle 25.

In this embodiment the wall 10 and also the wall 32 on the other side of the conveyor pan structure are of sigma-shaped cross-section.

A gap 33 is provided between The part 30 of the spill plate 24 and the wall 10 through which the remaining portion of the element 8 extends in the direction towards the chain 2. A cut-away portion 34 is provided in the lower part of the wall 10 and adjacent the base 28 through which the element 13 extends in the direction towards the chain 2.

At the bend a plate member 35 is provided on the upper portion of the wall 32 to accommodate any tendency of the flight bars 6 to "aeroplane" during operation of the conveyor.

A spill plate, as at 36, is provided in association with the wall 32. Further, deflectors 37 and 38 are provided respectively immediately ahead of and immediately beyond the element 8 in the upper channel 11 to provide for smooth deflection of mineral material being conveyed.

In operation of the conveyor in the direction indicated by the arrow in Figure 1, mineral is conveyed around the bend, and the abutment surfaces 12 of the flight bars 6, upon successively engaging the periphery of the element 8, cause the element to rotate freely in the clockwise direction about the axis 9 as viewed in Figure 1. In consequence the generation of undue friction between the flight bars and pan structure, as the flight bars negotiate the bend, is avoided and such engagement withstands the high radial forces arising from the increasing tension in the chain as it changes its direction.

The spill-plate 24 is a close fit with respect to the element 8 at the gap 33 to prevent mineral material from being carried by the element to the exterior of the upper channel 11.

As the flight bars 6 negotiate the bend, the tips of their wing portions 22 are, due to the engagement of the abutment surfaces 12 with the element 8, lifted from contact with the wall 10. As a result a smooth transition around the bend is achieved.

As the chain 2 and the flight bars pass on the return run along the lower channel 14 and negotiate the bend in the opposite direction, the abutment surfaces 12 come into engagement with the element 13 which rotates freely in the anti-clockwise direction about the axis 9 as viewed in Figure 1, again avoiding the generation of undue friction and withstanding the high radial forces arising from the increasing tension in the chain as it changes its direction.

Due to the fact that in the construction above described each flight bar engages each element 8, 13 at a position nearer to the chain 2 than to the tip of the flight bar on the inside of the bend, the flight bar is more stable in its movement around the bend.

Although in the embodiment above described with reference to the drawings the abutment surfaces are provided only on flight bars, in alternative embodiments greater spacing between flight bars is provided, and here, for adequate guidance around the bend, not only are such abutment surfaces provided on the flight bars but are also provided on guide members or pads. Such members or pads, which are similar in shape to the central portions of the flight bars but do not have wing portions, are attached at desired positions on the chain between successive flight bars. In this way unnecessarily close pitching of flight bars is avoided.

The guide members or pads may be adapted for the fitment of wing portions so that at any time any of them can be so fitted to form a flight bar. In some installations the chains may only carry such guide members or pads so fitted with wing portions to form flight bars. In other installations flight bars so formed are carried at certain positions on the chains, while in positions on those chains where flight bars are not required the wing portions are simply omitted.

By the invention since the upper element overlies the upper channel of the conveyor there is no need to break into the wall of the pan structure to provide an aperture for accommodating the means for guiding the flight bars as they negotiate the bend in the upper channel. Such apertures have hitherto been employed in certain conveyors, but have been susceptible to the ingress of material being conveyed with the likelihood of jamming of the guiding means disposed therein.

Although in the embodiment above described with reference to the drawings a single chain is provided, in other embodiments a double chain, also passing substantially centrally of the pan structure, may be provided. Further the associated flight bars may be of less-conventional form, for example of the catamaran type. In yet further embodiments the chain may have more than two strands arranged to pass substantially centrally of the pan structure, and carry flight bars appropriate to the chain configuration and to the crosssectional shape of the pan structure.

Claims

1. A scraper-chain conveyor having an endless chain or chains passing lengthwise and substantially centrally of its pan structure in upper and lower runs and carrying a plurality of members disposed at predetermined intervals therealong, and also having a section of its pan structure shaped to turn through a bend, including an element mounted with freedom to rotate about an axis which is vertical, or substantially so, and which is so disposed adjacent the wall of the pan structure on the inside of the bend that the element overlies the pan structure sufficiently far as to be engaged by abutment surfaces provided on said members as, successively, the members negotiate the bend.

2. A conveyor as claimed in Claim 1, wherein said element is of disc-like shape and its peripheral edge is engageable by said abutment surfaces.

3. A conveyor as claimed in either Claim 1 or Claim 2, wherein said members all comprise flight bars which are intended to have a scraping action along the deck of said pan structure.

4. A conveyor as claimed in Claim 3, wherein each flight bar comprises a central portion, adapted for attachment to said chain or chains, and a pair of wing portions extending from said central portion.

5. A conveyor as claimed in Claim 4, wherein one of said abutment surfaces is provided on that part of each said central portion remote from said deck.

6. A conveyor as claimed in either Claim 1 or Claim 2, wherein only certain of said members comprise flight bars which are intended to have a scraping action along the deck of said pan structure.

7. A conveyor as claimed in Claim 6, wherein each flight bar comprises a central portion, adapted for attachment to said chain or chains, and a pair of wing portions extending from said centra! portion, each of the remaining said members comprising a portion similar to said central portion but having no wing portions.

8. A conveyor as claimed in Claim 7, wherein a said abutment surface is provided on that part of each said central portion remote from said deck and on that part of each said portion similar to said central portion remote from said deck.

9. A conveyor as claimed in any one of the preceding claims, wherein a further element is mounted with freedom to rotate about said axis and underlies said pan structure sufficiently far as to be engage by said abutment surfaces as said members, when moving with the lower run of said chain or chains, successively negotiate said bend.

10. A conveyor as claimed in Claim 9, wherein said further element is of disc-like shape and of the same diameter as the first said element.

.

11. A scraper-chain conveyor substantially as hereinbefore described with reference to the accompanying drawings.