GB2196366A

GB2196366A - Conveyor systems

Info

Publication number: GB2196366A
Application number: GB08724223A
Authority: GB
Inventors: Andrew John Walker; Mark John Dale Kingshott; Gordon Edmund Powell
Original assignee: Dowty Meco Ltd
Current assignee: Dowty Meco Ltd
Priority date: 1986-10-15
Filing date: 1987-10-15
Publication date: 1988-04-27
Also published as: GB8624667D0; GB8724223D0; ZA877443B; AU7944387A

Abstract

A rack assembly (1) for engaging a mining machine, along its path of travel along a mining conveyor (3), which consists of a plurality of conveyor pan sections comprises a plurality of elongate rack members (4) and a mounting means (9, 10, 11, 13, 14) for mounting the rack members on the conveyor pan sections. The elongate rack members are joined so as to allow articulation thereof in directions transverse to the path of travel, and the number thereof may be greater than the number conveyor pan sections. Each rack member has along it's length a plurality of engagement elements spaced at a pitch which corresponds to the pitch of engagement elements of a drive means. The mounting means is such that it allows sliding of the rack members relative to the conveyor pan sections during the advance of the conveyor 3 pan sections. <IMAGE>

Description

SPECIFICATION Conveyor systems This invention relates to conveyor systems, and in particular, to rack assemblies of the type used for engaging a mining machine along its path of travel along a mining conveyor.

It is common practice for a mining machine, such as a drum cutting machine, to be engaged along a path parallel to the cutting face by a rack or chain assembly extending along the front of the mining conveyor for clearing the cut mineral from the face.

Furthermore, drive for propulsion of the mining machine along its path of travel is imparted by meshing of a driven sprocket, pinion, chain or the like on the mining machine with engagement elements spaced along the rack assembly.

Clearly it is important that the spacing pitch of the engagement elements should be maintained substantially constant along the length of the rack assembly in order to ensure correct meshing engagement between these elements and the sprocket teeth or the like on the mining machine.

A known rack assembly comprises a plurality of elongate rack members each of which is attached to a respective conveyor pan section such that the propelling force imparted by the mining machine is transmitted to the conveyor pan section in the immediate vicinity of the machine. These rack members are joined together by further rack members bridging the joints between adjacent conveyor pan sections, and the arrangement is such as to allow for snaking of the conveyor as the conveyor pan sections are advanced successively and one at a time towards the cutting face on movement of the conveyor to a new position ahead of, and parallel to, the original position.

However, considerable difficulties are experienced with such arrangements in ensuring that the spacing pitch of the engagement elements is maintained within allowable tolerances at the joints between adjacent rack members when the joints are at maximum articulation during conveyor advance. This is because the rack members are fixed to the conveyor pan sections with only very limited allowance, if any, for longitudinal movement relative to the conveyor pan sections, so that the snaking movement of the conveyor will substantially affect the spacing at the joints between the rack members.

This invention is concerned with providing an improved rack assembly for a mining machine which substantially avoids the aforementioned difficulties.

According to the present invention a rack assembly for engaging a mining machine along its path of travel along a mining conveyor which consists of a plurality of conveyor pan sections joined in end-to-end relationship, comprises a plurality of elongate rack members joined in end-to-end relationship so as to allow articulation, in directions transverse to the path of travel, between the adjacent rack members, and a mounting means for mounting the rack members on the conveyor pan sections so as to allow sliding of the rack members relative to the conveyor pan sections along the path of travel to compensate for variations in the spacing at the joints between adjacent conveyor pan sections during advance of the conveyor pan sections one at a time towards the cutting face, wherein, each rack member has a plurality of engagement elements spaced at a constant pitch along its length which correspond to the pitch of engagement elements of a drive means for drivingly engaging the rack members, pitch which is maintained between adjacent rack members.

It should be noted that by use of the term "constant pitch" it is implied that the spacing pitch is maintained within the tolerances allowed for meshing engagement between the drive means and the rack assembly.

As the rack members are capable of sliding relative to the conveyor pan sections along the path of travel, the effect of snaking movement of the conveyor during conveyor advance towards the cutting face can be taken up along the complete length of the rack assembly. This means the pitch variation at the joints of two adjacent rack members can be kept to a minimum and easily maintained within the allowable tolerances.

In a preferred embodiment of the invention the assembly comprises a number of rack members greater than the number of conveyor pan sections. The rack assembly, preferably, has at least two rack members to each conveyor pan section.

This is made possible by the sliding engagement of the rack members with the conveyor so that there is no longer the constraint that each rack member has to be uniquely associated with a single conveyor pan section. It is advantageous to provide a larger number of rack members to conveyor pan sections as this enables the effect of snaking movement of the conveyor to be taken up at a greater number of joints between rack members, and thereby reduced.

The mounting means for the rack members may comprise a respective rail for extending continuously or discontinuously along each conveyor pan section in the direction of the path of travel. Each rail may consist of one or more sections having two parallel guide members for holding a saddle member connected to each rack member therebetween in such a manner as to allow the saddle member to slide along the rail. The guide members may include in turned retaining flanges for preventing the saddle members from lifting off the rails. Advantageously at least one of the guide members is detachable to enable the rack members fo be lifted off the rails.

In one form of the invention each rack member is integrally formed with a respective saddle member having a base portion adapted to be engaged by the mounting means. The saddle member may extend either over the complete length of the rack member or over only part of the length, for example at one or both ends of the rack member.

In an alternative form of the invention adjacent rack members are jointed together at their ends by being pivotally connected to a common saddle member having a base portion adapted to be engaged by the mounting means.

In a further alternative form of the invention, every alternate rack member is integrally formed with at least one saddle member, preferably with a respective saddle member at eachend, each saddle member having a base portion adapted to be engaged by the mounting means, and the intermediate rack members are formed without saddle members but are adapted to be pivotally coupled at their ends to the saddle members of the adjacent rack members.

In order that the invention may be more fully understood, two embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of part of a rack assembly of a first embodiment, Figure 2 is a section along the line ll-ll of the assembly of Figure 1, Figure 3 is a side view of part of a rack assembly of a second embodiment, Figure 4 is a section along the line IV-IV through the assembly of Figure 3, and Figure 5 is a simplified side view of an extended length of the rack assembly of Figure 3, on a smaller scale.

Referring to Figures 1 and 2, the rack assembly 1 shown comprises a mounting rail 2 welded to forward portion 3 of each conveyor pan section of a scraper chain conveyor.

The assembly also comprises a plurality of rack members 4, of greater number than conveyor pan sections, which are joined together at their ends and slidably engaged with the rails in a manner which will be described in detail below.

It should be noted that the rail 2 and conveyor portion 3 have been omitted from Figure 1 in order to render the figure easier to read.

Each rack member 4 comprises two parallel elongate side members 5 and 6 having six holes 7 spaced regularly along their lengths.

The side members 5 and 6 are connected together by six engagement elements 8 of circular cross-section which extend into the holes 7 in the side members 5 and 6. The side member 5 is integrally formed with a saddle member 9 having a foot 10 for sliding engagement with the rail 2.

Each rail 2 comprises a base plate 11, an upright plate 12 welded to the front of the base plate 11, and two parallel guide members 13 and 14. Each of the guide members 13 and 14 has a respective in-turned retaining flange 15 or 16 overlying opposite side edges of the foot 10 of the saddle member 9 in such a manner as to prevent the saddle member 9 lifting off the rail 2 whilst permitting unrestricted sliding of the saddle member 9 along the rail 2. The guide member 14 is attached to the upright plate 12 by a bolt 17 and nut 18 in such a manner as to enable the guide member 14 to be easily detached for the purposes of assembly or disassembly.

The cutting machine 20, part of which is indicated diagrammatically and in broken lines in Figure 2, is supported on the conveyor in conventional manner and drivingly engages the rack member 4 by means of a sprocket (not shown) which meshes with the engagement elements 8 intermediate the side members 5 and 6.

To this end the spacing of the engagement elements 8 along the length of the rack member 4 corresponds to the pitch of the sprocket teeth.

Adjacent rack members 4 are joined together by a half-dumbbell connector 21 projecting from an end of the saddle member 9 of one of the rack members 4 and engaging within a correspondingly shaped recess 22 in the adjacent end of the saddle member 9 of the other rack member 4. The connection is such as to allow limited articulation between the rack members 4 in both horizontal and vertical directions transverse to the length of the rack assembly.

There is illustrated in Figure 1 the extent to which the connection permits articulation in the vertical direction.

Figures 3 and 4 show an alternative embodiment of rack assembly 1, like parts being given the same reference numerals as in Figures 1 and 2. This embodiment differs primarily from that of Figures 1 and 2 in the form of the saddle member, indicated generally by the reference numeral 30 in Figures 3 and 4, and the fact that the saddle member is not integrally formed with the rack member 4. Instead the saddle member 30 is a separate unit having a foot 31 which is slidably engaged with the rail 2 in a similar manner as described with reference to Figures 1 and 2, and having two side members 32 and 33 for receiving a downwardly extending portion 34 of the rack member 4 therebetween.

Each rack member 4 has a respective downwardly extending portion 34 at each end forming an extension of the side member 5 and provided for pivotal connection of the rack member 4 to a respective saddle member 30. Furthermore each saddle member 30 is adapted for pivotal connection with the ends of two adjacent rack members 4, and thus serve the additional function of joining together adjacent rack members 4. To this end the downwardly extending portion 34 has a hole 35 therethrough for alignment with holes 36 and 37 in the side members 32 and 33 of the saddle member 30, and a pivot pin 38 extends through the aligned holes 35, 36 and 37 and is held therein by a retaining pin 38A engaged between the side member 32 and retaining posts 39 and 40 on the saddle member 30.

Figure 5 illustrates an extended length of the rack assembly of Figures 3 and 4, -slidably mounted qn the front portions of three successive conveyor pan sections, shown as 3A, 38 and 3C in the figure. It will be appreciated from this figure that the rack members 4 are located longitudinally without reference to the joints between adjacent conveyor pan sections, and that a rack member 4 can be located over a pan to pan joint if necessary.

Furthermore the saddles 30 can travel from one conveyor pan section to another. The complete rack assembly is anchored only at its two ends so that all the saddles 30 can slide longitudinally to take up the effect of snaking advance of the conveyor. This means that the pitch tolerances at the connections between adjacent rack members 4 can be considered as being cumulative along the length of the rack assembly for the purposes of conveyor movement, and the opening of a pan joint as it articulates is not restricted by the opening of the connections between rack members. Furthermore the sliding support of the rack assembly is such that the complete assembly can act in compression as well as tension.

It will be appreciated that a wide number of variations of the above described rack assembly constructions is possible within the scope of this invention. More particularly the rack members may take a number of alternative forms and can be mounted vertically or horizontally, as is conventional in the art.

Furthermore the rails may be intermittent along the length of the rack assembly under certain circumstances.

Clearly other saddle member arrangements can also be envisaged, for example, the saddle member 30 of Figure 3 could be formed integrally with one of the rack members 4 with which it engages, whilst still being pivotally connected to the other rack member.

Each rack member 4 may be integrally formed with a respective one of the saddle members 30, or alternatively every alternate rack member 4 may be integrally formed with a respective saddle member 30 at each end, in which case the intermediate rack members 4 will be formed without saddle members and will be pivotally coupled to the saddle members 30 of the adjacent rack members 4.

Furthermore the rack assembly may be mounted on the gob side, as opposed to the face side, of the conveyor.

A further advantage of the above described rack assembly constructions is that longitudinal thrust is transmitted along the complete length of the assembly by virtue of direct abutment of adjacent rack members.

Claims

1. A rack assembly for engaging a mining machine along its path of travel along a mining conveyor which consists pf a plurality of conveyor pan sections joined in end-to-end relationship, comprises a plurality of elongate rack members joined in end-to-end relationship so as to allow articulation, in directions transverse to the path of travel, between the adjacent rack members, and a mounting means for mounting the rack members on the conveyor pan sections so as to allow sliding of the rack members relative to the conveyor pan sections along the path of travel to compensate for variations in the spacing at the joints between adjacent conveyor pan sections during advance of the conveyor pan sections one at a time towards the cutting face, wherein, each rack member has a plurality of engagement elements spaced at a constant pitch along its length which correspond to the pitch of engagement elements of a drive means for drivingly engaging the rack members, pitch which is maintained between adjacent rack members.

2. A rack assembly as claimed in claim 1 wherein the assembly comprises a number of rack members greater than the number of conveyor pan sections.

3. A rack assembly as claimed in either claim 1 or claim 2 wherein the rack assembly has at least two rack members to each conveyor pan section.

4. A rack assembly as claimed in any one of claims 1 to 3 wherein the rack members comprise a respective rail for extending along each conveyor pan section in the direction of the path of travel.

5. A rack assembly as claimed in any one of claims 1 to 4 wherein each rail comprises of one or more sections having two parallel guide members for holding a saddle member connected to each rack member therebetween in such a manner as to allow the saddle member to slide along the rail.

6. A rack assembly as claimed in any one of the preceding claims wherein the guide members include in-turned retaining flanges for preventing the saddle members from lifting off the rails.

7. A rack assembly as claimed in any one of the preceding claims wherein at least one of the guide members is detachable to enable the rnck members to be lifted off the rails.

8. A rack assembly as claimed in any one of the preceding claims wherein each rack member is integrally formed with a respective saddle member having a base portion adapted to be engaged by the mounting means.

9. A rack assembly as claimed in any one of the preceding claims wherein adjacent rack members are joined together at their ends by being pivotally connected to a common saddle member having a base portion adapted to be engaged by the mounting means.

10. A rack assembly as claimed in any one of the preceding claims in which every alternate rack member is integrally formed with at least one saddle member, preferably with a respective saddle member at each end, each saddle member having a base portion adapted to be engaged by the mounting means, and the intermediate rack members are formed without saddle members but are adapted to be pivotally coupled at their ends to the saddle members of the adjacent rack members.

11. A rack assembly as hereinbefore described with reference to Figures 1 and 2 of the drawings.

12. A rack assembly as hereinbefore described with reference to Figures 3 to 5 of the drawings.