AU724505B3 - Conveyor belt cleaning system - Google Patents

Description

AUSTRALIA

Patents Act 1990

COMPLETE

FOR A

SPECIFICATION

PETTY PATENT Name of Applicants: STEVEN PETER SMITH WAYNE KERN and DAVID Actual Inventors: Address for Service: Invention Title: STEVEN PETER SMITH and DAVID WAYNE KERN CULLEN CO., Patent Trade Mark Attorneys, 239 George Street, Brisbane, Qld. 4000, Australia.

CONVEYOR BELT CLEANING ASSEMBLY The following statement is a full description of this invention including the best method of performing it known to us: 2 A CONVEYOR BELT CLEANING ASSEMBLY The present invention relates to a conveyor belt cleaning assembly.

The present invention also relates to a mounting arm and a conveyor belt scraper blade for use in the cleaning assembly.

Conveyor belt cleaning assemblies for use with heavy duty conveyor belts are well known. Such conveyor belts are widely used in the mining industry to convey crushed ores, minerals coal and the like. They are also used for the transfer of bulk materials such as sugar. These materials can adhere to the conveyor belt and this is especially so when the materials are wet or damp, which is often the case. Scraper blades are provided to remove the adhering material so as to deposit it in a discharge area. Without scraper blades a large amount of material may build up beneath the conveyor belt.

This results in a loss of collected material and may interfere with the operation of the conveyor.

Conventional scraper blade arrangements include a blade or a series of blades having a scraping edge. The blades are typically mounted to a mounting (or torsion) arm which is biased towards the conveyor belt. The biasing force may be provided by means of a counterweight or be spring loaded. The blade or blades are biased towards the conveyor belt so as to contact the conveyor and provide a scraping action as the belt moves along.

Blades may be located such that they contact the conveyor belt as the belt moves about a rotating conveyor drum. These blades are commonly known as primary blades and have a curvilinear surface with a scraping edge at one end. The other end of the blade is typically provided with a mounting flange for mounting the blade to the mounting arm.

Further blades (referred to as secondary blades) may be located such that they contact that part of the conveyor belt which has just left the drum.

These blades are generally mounted to a secondary scraper arm which in turn has a mounting flange for mounting to the mounting arm.

Cleaning blade assemblies currently in use typically have a mounting arm which has a channel extending along the length thereof. The channel slidably receives a mounting flange located on the base of a scraper blade (or secondary scraper arm). Typically the channel is T shaped. In order to mount and remove the blades to and from the mounting arm the blades must be slid onto the end of the arm.

Blades must periodically be removed and replaced as they become worn or damaged. A disadvantage the above arrangement is that the environments in.which the conveyors are used are extremely dusty and dirty and a large amount of dust and grit can build up in and about the channels on a mounting arm. This dirt and grit can interfere with sliding the blades along the mounting arm. In some cases, the blades can be effectively locked onto the mounting arm. This often requires disassembly and cleaning. In extreme cases, a locked blade may have to be cut from the assembly.

One proposal which has been put forth to overcome this difficulty is to provide the contacting areas between the arm and blade with a non-stick plastic surface and/or a "loose fit" between the respective parts. In practice it has been observed that this may not fully address the problem. Further, it is still necessary to completely disengage and remove the mounting arm to be able slide the blades from an end thereof. Also should it be desired to replace only one blade, it is necessary to remove all blades leading up to the blade to be removed. This often considerably to the time involved with replacing blades and conveyor belt down time. This results in an overall loss in production time and adds to operating costs.

It is therefore an object of the present invention to provide a conveyor belt cleaning blade member, a mounting arm therefore and a conveyor belt cleaning assembly which may at least partially overcome the above disadvantages or provide the public with a useful choice.

According to a first broad form of the invention there is provided a conveyor belt cleaning assembly, the assembly including at least one scraper blade member having a base and a mounting arm upon which the at least one scraper blade member can be mounted, the mounting arm having an engagement member for engaging the base, whereby when the blade member and mounting arm are engaged, disengagement can be effected by pivoting the blade member in a direction which in use is towards the conveyor belt to be cleaned.

The scraper blade member may be any type of member which may be used to clean or scraper a conveyor belt the blade member can be a one piece blade as described above. Such blades are typically composed of a molded plastics material such as a rubber or polyurethane. The blade member may also include an arrangement in which a blade is mounted to, or integrally formed with, a scraper arm such as the secondary type blades as described above. In this case, the base of the blade member is typically the base of the scraper arm.

The mounting arm has an engagement member for engaging the base of the.scraper blade member. Disengagement is effect by pivoting the blade member in a direction which in use is towards the conveyor belt to be cleaned. In use during cleaning of the conveyor belt, the scraper blade members are biased towards and in contact with the conveyor belt. It will therefore be appreciated that in when in use the biasing force of the blade member against the conveyor belt resists disengagement of the blade member from the mounting arm.

Typically the engagement member includes a channel having an inwardly facing lip. The scraper blade member typically has a front toe portion sized such that it can be inserted into the channel by pivoting the blade member to insert the toe at an angle so as to slide past the lip and then pivoting the blade member back into the desired position. In order to disengage the blade member it is necessary to pivot the blade in the reverse direction.

The mounting arm may include further means for engaging the scraper blade member. For example a projection or recess on the mounting arm or blade member may engage a recess or projection on the other of the blade member or mounting arm.

As the scraper blade members are biased towards the conveyor belt, forces are generated at the point at which scraper blades are mounted to a mounting arm. As a result of the conventional methods of engagement between the blade and the mounting arm (such as the T shaped channel) these forces are not distributed evenly across the base of the blade but instead may be concentrated at the points of contact between the arm and blade. This may result in an uneven application of the pressure force onto the blade. This may be exacerbated by the "loose fit" type method of engagement as described above. Further, uneven forces can result in undue stress and ultimately wear and tear about the point of contact.

In a preferred embodiment of the present invention, mounting arm has a contact surface which in use contacts the base of the scraper blade member, the contact surface being configured such that when a biasing force is applied to bias the scraper blade member towards a conveyor belt, the forces is distributed in a substantially even manner across the contact surface.

Preferably, the scraper blade member has a bearing surface complimentary to the contact surface.

Typically the bearing surface is inclined relative to the longitudinal axis of the scraper blade member.

By way of example only, the present invention will now be described with reference to the following figures in which: Figure 1 is a schematic cross sectional view of a primary and secondary scraper blade assembly of preferred from of the invention in use with a conveyor belt; Figure 2 illustrates disengagement of the primary scraper blade member as illustrated in figure 1 and Figure 3 illustrates disengagement of the secondary scraper blade member.

Figure 1 illiterates a conveyor belt 11 moving in the direction marked by the arrow A about drum 12. A primary scraper blade assembly 13 is located such that a scraper blade 14 contacts the conveyor belt 11 at a point where the belt contacts drum 12. The scraper blade 14 has curvilinear front (closest the conveyor belt) 15 and rear 16 surfaces. The blade 14 has a base 17 which is inclined from the rear 15 to the front 16 surface.

Generally the assembly induced a series of blades 14. However the assembly may also include a single blade. In the following discussion reference to blade 14 will include reference to either one or any number of similar blades.

The assembly 13 includes a mounting or torsion arm 20. To the arm is mounted an engagement rail 21. The mounting arm 20 is typically constructed from a length of stainless steel pipe. The rail may also be constructed from stainless steel in which case it is typically stitch welded to the mounting arm The rail 21 has a front channel 22 having an inwardly facing lip 23 (see Figure The channel 22 engages a front toe portion 24 of the base 17 of the scraper blade 14. The toe portion 24 has a curved section of a curvature complimentary to that of lip 23. It can be seen that in the position illustrated on Figure 1 removal of blade 14 from rail 22 by applying an upwards force to the blade will be resisted by toe 23.

The rear section of the rail 21 is an inverted V shape 26. This inverted V shape 26 receives a corresponding groove 27 in the rear of base 17 of the scraper blade 14. The mounting arm 20 is biased towards the conveyor belt 11 by biasing means which are not illustrated, The biasing means may be a counterweight mechanism. The bias of the mounting arm 14 forces the scraping edge 25 of the scraper blade 14 into contact with the conveyor belt 11.

Extending between the toe 24 and groove 27 of the base 17 of the blade 14 is a bearing surface 29. This bearing surface 29 contacts the rail 21. It can be seen that as the blade 14 is urged towards the conveyor belt 11 by the biasing means, the forces generated between the blade and the mounting arm will be borne and supported by the bearing surface 29. It can be seen that the bearing surface has a relatively large surface area as compared with the points of contact in standard scraper blade assemblies of the type in which the blade is engaged by means of a T shaped slide rail located on the mounting arm. The provision of the bearing surface allows the force to be evenly distributed across a relatively large surface area. This can reduce fatigue and wear and tear to the blade. This can increase the service life of the blade.

A secondary scraper blade assembly 30 is located such that its scraper blade 31 contacts the conveyor belt 11 at a point at which it leaves drum 12.

The secondary assembly 30 includes a mounting arm 32 and rail 33 similar to that described above. The mounting arm is also biased towards the conveyor belt. The scraper blade 31 is fitted to a secondary scraper arm 34. The secondary scraper arm 34 has a base section 35 which engages rail 33 in a similar manner as described above with respect to scraper blade 14. The assembly typically includes a number of secondary scraper arm and blades mounted adjacent each other along mounting arm 32. However a single secondary scraper arm and blade 31 may also be present.

The secondary scraper arm 34 also has a bearing surface 36 which contacts the rail 33 in a similar manner to that described above.

Figure 2 illustrates removal of blade 14 from mounting arm 20. First the biasing means is disengaged such that the torque on the mounting arm is released. This enables an operator to move the scraping edge 25 of the blade 14 away from the conveyor belt 11. The blade 14 is then pushed upwards in the direction of arrow B. This movement allows toe 24 to be rotated away from lip 23, thereby allowing the blade 14 to be disengaged from the rail.

Figure 3 illustrates removal of the secondary scraper arm 34 from mounting arm 32. This is done in a similar manner as for the primary blade 14 by disengaging the biasing means as to relapse the torque. And pushing the blade upwards in the direction of arrow C.

It can be seen that blade 14 and secondary scraper arms 34 can be removed from the respective mounting arms without requiring disruption of any adjacent blades or scraper arms. This is not possible with the known mounting arms having T shaped channels in which the blades or secondary scraper arms slide in which not possible to selectively remove a single arm or blade (other than those located at the end of the arm). Still further it is not necessary to disengage the mounting arm to allow a blade or scraper arm to be slid therefrom.

It may be seen that this enables blades to be removed and replaced with much less conveyor belt down time than has been possible with current scraper blade assemblies. Also, disengagement of the blades may still be effected should there be a build up of grit and dust about the assembly.

Blades and secondary scraper arms may also be selectively removed and replaced without having to remove adjoining blades or arms.

Still further, provision of the contact and bearing surfaces provides a more uniform distribution of forces between the mounting arm and blade.

This can allow a more uniform application of pressure of the blade on the conveyor belt and can reduce fatigue and wear and tear on the respective components.

It will be appreciated that various changes and modifications may be made to the invention as described and claimed herein without departing from the spirit and scope thereof.

Claims (3)

1. A conveyor belt cleaning assembly, the assembly including at least one scraper blade member having a base and a mounting arm upon which the at least one scraper blade member can be mounted, the mouhting arm having an engagement member including a channel having an inwardly facing lip for engaging the base of each scraper blade member, whereby when the blade member and mounting arm are engaged, disengagement can be effected by pivoting the blade member in a direction which in use would be towards the conveyor belt to be cleaned. 1O

2. The assembly of claim 1, wherein the engagement member has a contact surface which is complimentary to a portion of the base and in use contacts the base.

3. The assembly of claim 1, substantially as hereinbefore described with reference to the Figures. DATED this 25th day of July 2000 STEVEN PETER SMITH and DAVID WAYNE KERN By their Patent Attorneys CULLEN CO.