GB2153326A - Scraper device for belt conveyor - Google Patents

Abstract

A scraper device for a belt conveyor includes a scraper element held in contact with the belt as it passes around a drum. So that the device can be of very simple form and be unlikely to cause wear and damage to the belt, the scraper element is in the form of a resilient element (10) adapted to at least partly conform to the cylindrical shape of the drum, and has a part extending helically of the drum with tensioning means (16,18) at its opposite ends. <IMAGE>

Description

SPECIFICATION Scraper device for belt conveyor The invention relates to a scraper device for a belt conveyor.

Endless belt conveyor mechanisms of the kind widely used for example in quarries and in coal mines usually require the fitment of some kind of scraper device for the removal of the residue of the substance being conveyed.

This is now particularly so in coal mines where the increasing use of water spray apparatus for the suppression of dust results in a considerable build up of slurry which is a mixture of coal dust and water.

Various designs of scraper devices are presently in use. Most of these include a rigid scraper bar held in engagement with the conveyor belt, at or in the region of a rotatable drum around which the endless belt passes, usually by means of resilient mounting apparatus. However, such known devices have a number of disadvantages. For example, they are relatively costly and the connection of the required mounting apparatus can sometimes be a problem, especially if space is limited. In addition, the engagement of the rigid scraper bar with the endless belt of the conveyor can sometimes be a major cause of belt wear and damage.

The object of the invention is to provide a scraper device which will be of relatively simple form, and therefore relatively cheap to produce, and which will be less likely to cause wear and damage to the endless belt of the conveyor.

According to the invention, there is provided a scraper device for a belt conveyor, the device including a resilient scraper element adapted to at least partly conform to the cylindrical shape of a drum around which the endless belt extends, said scraper element having at least one part extending helically of the drum and being provided with tensioning means at the opposite ends of said helically extending part for holding the scraper element in engagement with a part of the belt as it passes around the drum. The resilient scraper element will preferably be of substantially Vshape in developed form, that is to say if laid flat before use. The cross sectional shape of the or each part which extends helically of the drum may be such that two spaced scraper edges are held in contact with the conveyor belt when the device is in use.Alternatively, the or each part may be notched at intervals along its length, such notching having the effect of providing a series of scraper edges for removing the dirt or other substance from the belt conveyor and having been found also to facilitate the manner in which the or each scraper part can conform to the cylindrical shape of the drum around which the endless belt extends. When the scraper element is of substantially V-shape in developed form, the means for holding the element in engagement with the conveyor belt may comprise a pair of tensioning members at the outer extremities of the arms of the 'V', said tensioning members conveniently taking the form of screwthreaded rods, and a single tensioning means at the base of the 'V'.The single tensioning means at the base of the 'V' may be constituted by a length of screwthreaded rod or by a spring connected to an anchorage point.

The resilient scraper element may be provided with metal or synthetic plastics reinforcement extending along the or each part adapted to conform to the cylindrical shape of the drum around which the endless belt extends, such reinforcement conveniently taking the form of wire rope or metal strip or braided material.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a scraper device embodying the invention shown fitted partly around the head drum of a belt conveyor mechanism, Figure 2 is a sectional view on the line 2-2 in Figure 1, Figure 3 is a sectional view on the line 3-3 in Figure 1, Figure 4 is a view of a modified form of scraper device, drawn to a slightly larger scale than Figures 1 to 3 and being illustrated in developed (that is laid flat) condition, and Figure 5 is a sectional view on the line 5-5 in Figure 4.

Referring now to Figure 1 of the drawings.

the scraper device there illustrated is shown to comprise a resilient scraper element 10 which conforms to the cylindrical shape of a drum 1 2 around which the endless belt 1 4 extends.

The resilient scraper element is of substantially V-shape in developed form, that is to say if laid flat before use. Tensioning means which are provided for holding the scraper element in engagement with a part of the belt as it passes around the drum comprise a pair of screwthreaded rods 1 6 at the outer extremities of the arms of the 'V' and a single tensioning means, indicated 18, at the base of the 'V'. The resilient scraper element 10 is shown to have been moulded with a central aperture 20 for the connection of the single tensioning means 18, which may be either a rod, or wire rope or a tensioning spring connected to an anchorage point (not shown).

Referring now to Figure 2, it will be seen that the resilient scraper element is of moulded form and that it is provided with metal reinforcement (in the form of wire rope 32) extending along each part which is adapted to conform, as shown, to the cylindrical shape of the drum. The opposite ends of the lengths of wire rope 22 encircle the central aperture 20 and provide loops 24 at the extremities of the arms of the 'V' for connection to the screwthreaded rods 16.

Each of the two parts of the 'V' are such that, as shown in Figure 2, two spaced scraper edges 26 are held in contact with the conveyor belt when the device is in use. The outer corners of the two parts are bevelled at 28 and the arrangement is such that the amount of side wall remaining beneath the bevelled surfaces gives an indication of how worn down the two scraper edges are becoming.

Referring to Figure 3, it will be seen that the screwthreaded rods 1 6 extend at an angle through side plates of the conveyor mechanism and through wedge shaped washers 30.

Nuts 32 which engage the screwthreaded rods can be tightened to draw the resilient scraper element into appropriate engagement with the belt. As the scraper edges of the scraper element wear away, slack will require to be taken up from time to time.

It will be seen that the scraper device just described is particularly simple. It is inexpensive to make and very easily and quickly mounted in position. The mounting means are so very simple and compact that it is very unlikely indeed that any conveyor installation, through lack of available space, would be unable to be fitted with a scraper device embodying the invention.Removal of a worn scraper element for replacement by a new one is particularly simple, requiring only the disconnection of the single tensioning means 1 8 to enable the outer ends of the arms of the 'V' to be unhooked from the hooked ends of the screwthreaded rods 1 6. The mounting of the new scraper element in position can be effected almost equally quickly, although of course this may require the re-extension of the screwthreaded rods if slack in the previously used scraper element has been taken up by shortening their effective length from time to time. On the other hand, it will be understood that if the single tensioning means 18 is constituted by a tension spring, the latter may be capable of taking up any slack in the scraper element throughout its life so that the screwthreaded rods do not require adjustment.A further advantage of the preferred embodiment, that is to say of a scraper element of substantially V-shape in developed form, is that the material scraped from the belt will tend to fall from the belt in a stream falling substantially midway of the width of the belt.

Various modifications may be made, both to the resilient scraper element and the manner in which it is located in position. For example, the scraper element could be moulded in such a way that although similar in cross section to that of Figure 2, the or each of its lengths which contact the conveyor belt is provided with three or more spaced scraper edges. The metal reinforcement need not necessarily be in the form of lengths of wire rope. It could be of flat metal strip or even of lengths of chain moulded into the or each longitudinal length of scraper element. Indeed, the reinforcement need not necessarily be of metal. It could, for example, be carbon fibre or of some other braided material.

The resilient scraper element need not necessarily be of substantially V-shape in developed form. It could possibly be a single straight length extending diagonally across the belt, and of course conforming to the cylindrical shape of a drum. In this way, as in the preferred embodiment, the tensioning means which hold the scraper element in position are abie to constitute the means whereby the element is urged into contact with the surface of the belt. By virtue of the fact that the or each part of the scraper element which contacts the belt extends across the latter diagonally, it is thought that the belt will be prevented from being damaged by the scraper because the usual belt fasteners which extend directly across the belt will come into contact with the scraper element in succession rather than collectively together.

Referring to Figures 4 and 5, there is there illustrated a form of scraper basically the same as that illustrated in Figures 1 to 3 but incorporating some small modifications. For example, it will be seen that the cross sectional shape of each part capable of extending helically of a drum is rectangular and that the reinforcement through each part is a braided material in the form of a single relatively wide band 32. Inner ends of the lengths of reinforcement are connected to a metal shackle member 34 of triangular shape as shown. The synthetic plastics material which has been moulded around the reinforcement and around the metal shackle has formed an excellent key on and in fact into the reinforcement material.

A further modifications which has been incorporated in this construction of scraper is the forming of the belt contacting surface of each part capable of extending helically of the conveyor or drum with a plurality of notches 36. It has been found that these have the effect of providing a series of scraper edges for removing the dirt or other substance from the belt which the scraper is to clean. The notches have also been found to facilitate the manner in which the or each scraper part can conform to the cylindrical shape of the drum around which the endless belt extends.

It will also be seen that the attachment means at the opposite ends of the arms of the 'V' have been modified and now take the form of a pair of angle brackets~38 provided with respective bolt holes for the reception of respective clamping bolts.

Various other modifications may be made, particularly to the cross sectional shape of the two parts of the 'V' element. It will also be understood that if the V-shaped element is located so that the single tensioning means at the base of the 'V' can extend vertically downwards, the single tensioning means may be constituted by a suitable weight instead of by a spring or by a physical force imposed by means of a length of screwthreaded rod connected to an anchorage point.

Claims (3)

1. A scraper device for a belt conveyor, the device including a resilient scraper element adapted to at least partly conform to the cylindrical shape of a drum around which the endless belt extends said scraper element having at least one part extending helically of the drum and being provided with tensioning means at the opposite ends of said helically extending part for holding the scraper element in engagement with a part of the belt as it passes'around the drum.

2. A scraper device accordng to claim 1, in which the resilient scraper element is of substantially V-shape in developed form, that is to say if laid flat before use.

3. A scraper device according to either one of the preceding claims, in which the or each part capable of extending helically of the drum is notched at intervals along its length, this providing a series of scraper edges for removing the dirt or other substance from the belt conveyor and also facilitating the manner in which the or each scraper part can conform to the cylindrical shape of the drum around which the endless belt extends.

3. A scraper device according to claim 2, in which the cross sectional shape of the or each part which extends helically of the drum is such that two spaced scraper edges are held in contact with the conveyor belt when the device is in use.

4. A scraper device according to any one of the preceding claims, in which the or each part capable of extending helically of the drum is notched at intervals along its length, this providing a series of scraper edges for removing the dirt or other substance from the belt conveyor and also facilitating the manner in which the or each scraper part can conform to the cylindrical shape of the drum around which the endless belt extends.

5. A scraper device according to any one of claims 2 to 4, in which the means for holding the element in engagement with the conveyor belt comprises a pair of tensioning members at the outer extremities of the arms of the 'V' and a single tensioning means at the base of the 'V'

6. A scraper device according to claim 5, in which the tensioning members are constituted by screwthreaded rods.

7. A scraper device according to either one of claims 5 and 6, in which the single tensioning means at the base of the 'V' are constituted by a length of screwthreaded rod or by a spring connected to an anchorage point.

8. A scraper device according to any one of the preceding claims, in which the resilient scraper element is provided with metal or synthetic plastics or fibre reinforcement extending along the or each part adapted to conform to the cylindrical shape of the drum around which the endless belt extends.

9. A scraper device constructed, arranged and adapted to be used substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.

CLAIMS Amendments to the claims have been filed, and have the following effect: (a) Claims 1 to 4 above have been deleted or textually amended.

(b) New or textually amended claims have been filed as follows: Claims 1 to 3 (c) Claims 5 to 9 have been renumbered as 4 to 8 and their appendancies corrected.

1. A scraper device for a belt conveyor, the device including a resilient scraper element adapted to at least partly conform to the cylindrical shape of a drum around which the endless belt extends, said scraper element having at least one part extending helically of the drum and being provided with tensioning means at the opposite ends of said helically extending part for holding thy scraper element in engagement with a part of the belt as it passes around the drum, the cross sectional shape of the or each part which extends helically of the drum being such that two spaced scraper edges are held in contact with the conveyor belt when the device is in use.

2. A scraper device according to claim 1, in which the resilient scraper element is of substantially V-shape in developed form, that is to say if laid flat before use.