WO2006060862A1

WO2006060862A1 - Roller support frame

Info

Publication number: WO2006060862A1
Application number: PCT/AU2005/001850
Authority: WO
Inventors: Gary Shields
Original assignee: Bhp Billiton Innovation Pty Ltd
Priority date: 2004-12-07
Filing date: 2005-12-07
Publication date: 2006-06-15

Abstract

A roller assembly for a conveyor belt assembly is disclosed. The roller assembly simplifies roll changeover. The roller assembly includes at least one roller (7) and a carriage (9) that supports the roller and is movable between an operative position in which the roller engages an undersurface of a conveyor belt (5) and an inoperative position in which the roller is positioned at least partly to one side of the conveyor belt and is accessible from a walkway running along the side of the conveyor belt.

Description

ROLLER SUPPORT FRAME

The present invention relates to a support frame for a conveyor belt assembly.

The present invention is concerned particularly with the issue of carrying out maintenance work, including roller replacement, on sections of conveyor belt assemblies that are at considerable heights above a ground surface.

A standard conveyor belt assembly, for example of the type used in the mining industry for transporting mined material, such as coal at a mine site and at a coal loading facility, includes (a) a conveyor belt, (b) a support frame for the conveyor belt, and (c) a plurality of rollers that are supported by the support frame to extend transversely to the direction of movement of the conveyor belt and contact the undersurface of the conveyor belt and thereby support the conveyor belt at spaced intervals along the length of the conveyor belt. The rollers are supported to rotate freely on their shafts.

The current procedure for carrying out roller replacements on elevated sections of conveyor belts at mine sites and coal loading facilities involves maintenance workers carrying out a first step of positioning a work platform below a given roller or rollers that requires replacement.

Typically, the work platform is a narrow rectangular tray that is manhandled by the workmen from a permanent walkway on one side of the conveyor belt to a position below the roller or rollers to be replaced and secured in that position.

Thereafter, the workers move out onto the work platform and carry out the necessary overhead work to remove one or more heavy rollers from roller mounts at opposite ends of roller shafts and position new rollers on the mounts. This is extremely hazardous work and requires extreme caution. The work is also very difficult in that the work has to be performed overhead in cramped conditions on a relatively unstable work platform (compared to the walkway) and involves dislodging, often by hammering, rollers from the roller mounts, thereafter lifting the rollers clear of the mounts and onto the walkway, and thereafter lifting replacement rollers overhead and positioning the rollers in the mounts.

In view of the work conditions, the workmen are required to wear safety harnesses. Whilst entirely appropriate for safety reasons, the harnesses tend to restrict freedom of movement and add to the difficulties in carrying out the necessary work.

At the completion of the roller replacement at a given position along the length of the conveyor belt, the workers have to move off the work platform onto the walkway and then release the platform from the position below the replaced roller or rollers before moving to the next roller position requiring roller replacement (or other maintenance work) and repeating the above procedure.

In overall terms, the above procedure is time consuming in that a substantial amount of the time required to replace a roller or rollers is involved in set-up of the work platform and movement onto and off the platform and removing the work platform from below the replaced roller or rollers.

The present invention makes it possible to use a more efficient and safer procedure to the above-described procedure for carrying out roller replacements on elevated sections of conveyor belt assemblies. According to the present invention there is provided a roller assembly for a conveyor belt assembly, which roller assembly includes at least one roller and a carriage that supports the roller and is movable between an operative position in which the roller engages an undersurface of a conveyor belt and an inoperative position in which the roller is positioned at least partly to one side of the conveyor belt and is accessible from a walkway running along the side of the conveyor belt.

The above-described movable carriage makes it possible to gain access to the roller assembly to carry out roller maintenance, including roller replacement, from the walkway, which is usually a permanent part of the conveyor belt assembly. This is a far more convenient and less cramped and safer position for carrying out maintenance work than the above-described work platform that has to be positioned below a roller or rollers requiring maintenance work. In addition, in overall terms roller replacement can be carried out in a far shorter time period and in much safer conditions than the above-described current practice.

Preferably the carriage is movable (a) between the operative position and a lowered position in which the roller is positioned below and no longer engages the conveyor belt and (b) between the lowered position and the inoperative position.

Preferably the roller assembly includes a frame for supporting the carriage in each of the operative, lowered and inoperative positions and for movement between these positions .

Preferably the carriage support frame supports one end of the carriage so that the carriage can be moved from the operative position to the inoperative position (via the lowered position) by pivoting the carriage downwardly about an inner end of the carriage from the operative position to the lowered position and thereafter sliding the carriage outwardly to the side of the conveyor belt to the inoperative position.

Preferably the carriage support frame includes a guide for supporting the carriage for sliding movement outwardly to the side of the conveyor belt to the inoperative position.

Preferably the carriage includes a complementary member to the guide that can locate the carriage on the guide for sliding movement.

Preferably the guide on the carriage support frame and the complementary member on the carriage are elongate channel members that have the same transverse profile.

The channel members may have any suitable profiles.

For example, the profiles may be V-shaped or C- shaped.

Preferably the channel members have downwardly inclined sides. This feature makes it difficult for material to build up on the members. This is an important feature in terms of preventing or at least minimising sticking of the members.

The above-described roller assembly may extend across the whole width or part way only across the width of the conveyor belt.

Preferably the roller assembly extends substantially across one half of the width of the conveyor belt and the roller is inclined upwardly from an inner end thereof that is proximate a centre-line of the conveyor belt when the carriage is in the operative position.

Preferably there are two such roller assemblies, with one roller assembly on each side of the centreline of the conveyor belt, and the rollers of the roller assemblies defining a V-shaped cradle for a conveyor belt.

The roller assembly may include one or more than one roller.

According to the present invention there is also provided a conveyor belt assembly of the type described above that includes

(a) a conveyor belt,

(b) a main support frame for the conveyor belt, and

(c) a plurality of the above-described roller assembly supported by the main support frame to extend transversely to the direction of movement of the conveyor belt and support the conveyor belt at spaced intervals along the length of the conveyor belt.

Preferably each conveyor belt assembly includes pairs of the roller assembly at spaced intervals along the length of the conveyor belt, with the roller assemblies of each pair being positioned in end-to-end relationship across the width of the conveyor belt and defining a generally V-shaped cradle for the conveyor belt.

The present invention is described further by way of example with reference to the accompanying drawings, of which:

Figure 1 is a perspective view of one embodiment of a roller assembly in accordance with the present invention in an operative position as part of a conveyor belt assembly in accordance with the present invention; and

Figures 2 to 10 illustrate the roller assembly shown in Figure 1 in more detail and a sequence of steps to replace the rollers of the roller assembly.

The conveyor belt assembly partially shown in the Figures is of a standard form and includes:

(a) a conveyor belt 5;

(b) a main support frame that supports the conveyor belt 5;

(c) roller assemblies that include rollers 7 and are supported by the main frame transversely to the direction of the conveyor belt 5 so that the rollers 7 contact the undersurface of the belt and thereby support the belt at spaced intervals along the length of the belt.

The conveyor belt assembly also includes a walkway 11 running along each side of the conveyor belt 5 for the length of the belt 5.

The conveyor belt assembly shown in Figure 1 includes two roller assemblies positioned in end-to-end relationship across the width of the conveyor belt 5, i.e. transverse to the direction of the belt, at the location shown in the Figure and defining a generally V-shaped arrangement.

One such roller assembly is completely shown in Figure 1 and the second roller assembly is only partly shown in Figure 1 - see the left hand side of the Figure.

Figure 1 shows the roller assemblies as viewed from under the conveyor belt 5 looking upwardly towards the conveyor belt 5 at an angle of approximately 45° .

In addition, Figure 1 shows the roller assemblies positioned with the rollers 7 supported to contact the undersurface of the conveyor belt 5, i.e. in operative positions.

The conveyor belt 5 may be any suitable conveyor belt.

The main support frame includes an assembly of beams in the form of elongate angle members 17 welded or bolted together as required. Only one such member 17 is shown in the Figures.

In the operative positions shown in Figure 1 the roller assemblies are positioned so that the rollers 7 define a relatively shallow V-shape that defines a cradle for the conveyor belt 5, with each roller assembly forming one arm of the V and being inclined upwardly from an inner end of the roller assembly at the centre-line of the belt 5 to one side of the belt 5.

Each roller assembly includes :

(a) a pair of the rollers 7;

(b) a carriage, generally identified by the numeral 9, that supports the rollers 7 in end-to-end relationship as shown and is moveable between the operative position shown in Figure 1 in which the rollers 7 engage the υndersurface of the conveyor belt 5 and an inoperative, i.e. maintenance, position in which the rollers 7 are positioned at least partly to one side of the conveyor belt 5 and are accessible from a permanent walkway 11 running the along the side of the conveyor belt 5 - as shown for example in Figure 5;

(c) a sub-frame generally identified by the numeral 13 that supports the carriage 9 in the operative position and for movement between the operative and inoperative positions.

The carriage sub-frame 13 is an assembly of elongate angle members that are welded together.

The carriage sub-frame 13 includes :

(a) an upright U-shaped section 15 that has a base 41 (Figure 2) and two upstanding arms

43 and is bolted at upper ends of the arms 43 to a lengthwise extending beam 17 that forms part of the main support frame of the conveyor belt assembly; and

(b) a generally horizontal elongate inverted V- shaped guide member 21 that is connected at one end to the base 41 of the U-shaped section and extends across the width of the conveyor belt 5 from one side to the other side of the belt 5. The guide member 21 includes an upstanding stop 35 mid-way along the length of the member 21. As is described further below, in use, the stop 35 limits the sliding movement of the carriage 9 on the guide member 21.

The carriage 9 includes:

(a) an elongate base member 23,

(b) four upstanding roller mounts 25 welded to the base member 23, and

(c) a bracket 31 welded to the outer end of the base member 23, as viewed in Figure 1.

The roller mounts 25 have upwardly opening notches that receive shafts of the rollers 7, whereby the rollers 7 are supported to rotate freely about the axes of the shafts.

The base member 23 of the carriage 9 has a complimentary transverse inverted V-shaped profile to that of the guide member 21 of the sub-frame 13 so that the base member 23 can be positioned to overlie and slide on the guide member 21.

The inner end of the base member 23, as viewed in Figure 1, rests on the guide member 21 when the carriage is in the operative position shown in the Figure. The arrangement is such that the base member 23 can be pivoted about the inner end in a vertical plane between the operative position shown in Figure 1, which is a raised position of the carriage 9, and a lowered position of the carriage 9 shown, for example, in Figure 4 in which the base member 23 overlies the guide member 21.

The bracket 31 and the arms 43 of the sub-frame 13 have drilled holes that are positioned so that when the holes are aligned and bolts are positioned to extend through the holes and nuts are positioned on the bolts, the carriage 9 is releasably connected to the sub-frame 13 and holds the carriage 9 in the raised operative position shown in Figure 1.

The bracket 31 includes an outwardly facing handle 37 (Figure 2) that can be gripped conveniently by a workman on the walkway 11.

With reference to Figures 2 to 10 the rollers 7 of the roller assembly shown on the right hand side of Figure 1 can be replaced by workmen on the walkway 11 carrying out the following procedure.

The first step in the procedure involves removing the nuts from the bolts holding the bracket 31 to the arms 43 of the sub-frame 13 - see Figure 2.

The carriage 9 is then moved outwardly and downwardly from the raised operative position to the lowered position with the base member 23 of the carriage 9 positioned on and overlying the guide member 21 of the sub- frame 13 - see Figures 3 and 4.

Thereafter, as is shown in Figures 4 and 5, the carriage 9 is slid outwardly over the guide member 21 to a first inoperative position shown in Figure 5 in which the outer roller 7, as viewed in Figure 1, extends above the walkway 11. In this position, the roller 7 can be lifted conveniently from the roller mounts 25.

The guide member 21 includes a lug 61 (Figures 1 and 6) mid-way along the length of the guide member and the base 41 of the U-shape section 15 of the sub-frame 13 includes an aligned opening 53 (Figure 5) . The position of - li ¬

the lug 61 along the length of the guide member 21 is selected so that the lug extends into the opening 53 in the base 41 when the carriage 9 is in the first inoperative position and thereby stabilises the assembly in this position.

Thereafter, the carriage 9 is slid initially inwardly to release the lug 61 from the opening 53 and then further outwardly over the guide member 21 to a second inoperative position shown in Figure 7 in which the inner roller 7, as viewed in Figure 1, extends above the walkway 11. In this position, the roller 7 can be lifted conveniently from the roller mounts 25. The guide member 21 includes a lug (not shown) at the inner end of the guide member. The position of the lug is selected so that the lug extends into the opening 53 in the cross-member 51 when the carriage 9 is in the second inoperative position and thereby stabilises the assembly in this position.

Thereafter, a replacement roller 7 is positioned on the inner roller mounts 25, the carriage 9 is slid inwardly back to the first inoperative position, a replacement roller 7 is positioned on the outer roller mounts 25, and the carriage 9 with the replacement rollers 7 is slid inwardly until the inner end of the base member 23 contacts the stop 35 mid-way along the length of the guide member 21. This sequence of steps in the procedure is partially shown in Figure 8.

The next step in the procedure involves lifting the outer end of the carriage 9 via the handle 37, with the inner end of the base member 23 on the guide member 21 against the stop 35, until the carriage 9 and thereby the rollers 7 are in the raised operative positions - see Figure 9. In this position, the holes in the bracket 31 of the carriage 9 and the arms 41 of the U-shaped section 15 of the sub-frame 13 are aligned, and the final step in the procedure is to insert bolts through the holes and tighten nuts onto the bolts and thereby secure the carriage 9 in the operative position see Figure 10.

It can readily be appreciated from the above that the embodiment of the roller assembly shown in the Figures makes it possible to significantly simplify and speed up the procedure for replacing rollers 7 of roller assemblies and makes it possible to replace rollers 7 safety with workmen on the walkway 11 rather than on a work platform positioned below the conveyor belt 5.

Many modifications may be made to the embodiment of the roller assembly described above with reference to the Figures without departing from the spirit and scope of the invention.

For example, whilst the conveyor belt assembly shown in the Figures includes two roller assemblies positioned in end-to-end relationship across the width of the conveyor belt and defining a generally V-shaped arrangement, with each roller assembly including two rollers 7, the present invention is not so limited and extends to any suitable arrangement of roller assemblies and suitable number of rollers in each assembly.

Claims

1. A roller assembly for a conveyor belt assembly, which roller assembly includes at least one roller and a carriage that supports the roller and is movable between an operative position in which the roller engages an undersurface of a conveyor belt and an inoperative position in which the roller is positioned at least partly to one side of the conveyor belt and is accessible from a walkway running along the side of the conveyor belt.

2. The roller assembly defined in claim 1 wherein the carriage is movable (a) between the operative position and a lowered position in which the roller is positioned below and no longer engages the conveyor belt and (b) between the lowered position and the inoperative position.

3. The roller assembly defined in claim 1 or claim 2 wherein the roller assembly includes a frame for supporting the carriage in each of the operative, lowered and inoperative positions and for movement between these positions.

4. The roller assembly defined in claim 3 wherein the carriage support frame supports one end of the carriage so that the carriage can be moved from the operative position to the inoperative position (via the lowered position) by pivoting the carriage downwardly about an inner end of the carriage from the operative position to the lowered position and thereafter sliding the carriage outwardly to the side of the conveyor belt to the inoperative position.

5. The roller assembly defined in claim 4 wherein the carriage support frame includes a guide for supporting the carriage for sliding movement outwardly to the side of the conveyor belt to the inoperative position.

6. The roller assembly defined in claim 5 wherein the carriage includes a complementary member to the guide that can locate the carriage on the guide for sliding movement.

7. The roller assembly defined in claim 6 wherein the guide on the carriage support frame and the complementary member on the carriage are elongate channel members that have the same transverse profile.

8. The roller assembly defined in claim 7 wherein the profiles are V-shaped or C-shaped.

9. The roller assembly defined in claim 7 or claim 8 wherein the channel members have downwardly inclined sides.

10. The roller assembly defined in any one of the preceding claims includes more than one roller.

11. A conveyor belt assembly includes

(a) a conveyor belt,

(b) a main support frame for the conveyor belt; and

(c) a plurality of the roller assembly defined in any one of the preceding claims supported by the main support frame to extend transversely to the direction of movement of the conveyor belt at spaced intervals along the length of the conveyor belt.

12. The conveyor belt assembly defined in claim 11 includes pairs of the roller assembly at spaced intervals along the length of the conveyor belt, with the roller assemblies of each pair being positioned in end-to-end relationship across the width of the conveyor belt and defining a generally V-shaped cradle for the conveyor belt.