AU2018250397B2

AU2018250397B2 - Apparatus for Measuring Cover Thickness of Conveyor Belting

Info

Publication number: AU2018250397B2
Application number: AU2018250397A
Authority: AU
Inventors: Barry Charles Brown; Robert JANEVESKI
Original assignee: Bemo Pty Ltd
Current assignee: Bemo Pty Ltd
Priority date: 2017-11-01
Filing date: 2018-10-17
Publication date: 2024-03-07
Anticipated expiration: 2038-10-17
Also published as: AU2018250397A1

Abstract

P-AU ABSTRACT Apparatus to measure the thickness of the carry cover (2) of a conveyor belt (3) is 5 disclosed. An inductive probe (4) and an ultrasonic probe (1), are located within a sensor (1). Such a sensor is located at each of a number of known or anticipated belt wear locations above the conveyor belt. The sensors are located on a spine (25).which extends across the belt (3). The number of sensors (1) can be varied to match a known transverse belt wear profile. Each sensor (1) generates a longitudinal belt wear profile 10 corresponding to its position on the belt. Measurements can be taken with the belt running and the apparatus can be moved from belt to belt. 13 1(5d

Description

1(5d

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"Apparatus for Measuring Cover Thickness of Conveyor Belting"

Field of the Invention The present invention relates to conveyor belts, and, in particular, to apparatus and methods for measuring the carry cover thickness of conveyor belts.

Background Art Steel cord belting is commonly used in the bulk materials handling industry, and the nature and construction of steel cord belting is well known. Such belts have a tension-bearing carcass, made from steel-cord tension members, which is disposed between top (carry) and bottom (pulley) elastomeric covers, typically made from rubber.

A mechanism that commonly determines the end-of-life of steel cord belting is the loss of carry cover material. This problem can be managed by replacing the belt when the thickness of the original carry cover is worn down to a minimum desired value at which the belt carcass is approaching exposure. The prediction of when carcass exposure will occur (or relatedly when the minimum desired value is reached) is an important task for conveyor owners, as it enables planning for the purchase and installation of new belting.

These predictions usually rely upon periodical measurements of the amount or thickness of the cover material remaining. A number of apparatus and methods have been described for performing these measurements.

Belt owners often desire the cover thickness to be measured and known across the entire belt width. For example, thickness may be measured at a significant number of transverse locations across the belt and at a number of longitudinal locations along the belt, in order to form a representative 'carry cover wear profile'.

The use of hand-held measurement devices is common, however these devices require the conveyor to be stopped and electrically isolated at the drivehead to ensure safe access. This is problematic, because the time windows available for conveyor

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stoppages are often short and hence not amenable to a large number of manual measurements. Furthermore, scheduled plant 'shuts' are commonly months apart.

Mechanised or automated approaches to the measurement of carry cover thickness have been described that involve the use of non-contact 'sensors'. Such sensors can enable the taking of measurements while the belt is running, and there can be multiple such opportunities between plant shuts. There are, however, some applications where a mechanised apparatus is unnecessarily complicated.

A non-contact sensor is described in Australian Patent Application No 2012 216 769 that can measure remaining cover thickness using an ultrasonic probe in concert with an inductive probe. The pair of probes can be positioned approximately 20mm above a running belt surface. The signal outputs from the probes can be analysed by a processor which converts voltage or current into a dimension in millimetres, and the remaining cover thickness can be mathematically deduced from the two signals.

A method of cover thickness measurement that uses the aforesaid two-probe sensor is described in Australian Patent Application No 2016 202 263. The method involves performing a series of diagonal 'scans' across a steel cord belt, by moving the sensor transversely across the running belt at an unloaded position. The thickness estimations from the individual scans can be recombined to form a representative cover wear profile for the belt.

Carry covers typically wear unevenly across the width of the belt. In fact, a given belt will tend to establish its own characteristic wear pattern or wear profile in the carry cover. This can be revealed from the historical cover thickness measurements. The general shape of the wear profile tends to remain constant for the life of the belt, unless modifications are made to the geometry of the 'load point'.

An exception to the above 'fixed wear profile' concept can arise at either of the two 'skirt wear' locations. Rubber 'skirts' are commonly used at load points to reduce the amount of mineral product (and dust) escaping from the belt edges during loading. The skirts consist of rubber flaps which contact the carry cover surface at positions

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typically about 150mm inward from each edge of the belt. The contact between the skirt and the belt surface can lead to lumps of product becoming trapped there between, causing high rates-of-wear. Accelerated skirt wear due to trapped product is a substantially random event and does not occur in all cases.

Genesis of the Invention The genesis of the present invention is a desire to provide simplified apparatus and methods for the measurement of remaining carry cover thickness, or otherwise overcoming or at least ameliorating some of the deficiencies of the prior art.

Summary of the Invention In accordance with a first aspect of the present invention there is disclosed a sensor assembly for measuring cover thickness of a conveyor belt having a steel cord carcass with an elastomeric cover on each side of the carcass, said assembly comprising an elongate spine carrying at least one sensor and being engageable with a support means extending transversely across said belt from at least one belt edge to at least the other belt edge, said spine extending transversely across said belt without said spine contacting the belt, whereby said spine can be engaged and dis-engaged with said support means by an operator positioned beyond said belt edges to thereby permit said sensor(s) to interact with said belt with the belt running.

In accordance with a second aspect of the present invention there is disclosed a method of relocating the spine and sensor(s) of the sensor assembly as defined above for measuring the thickness of a cover of at least two distinct said conveyor belts each having a corresponding said support means, said method comprising the steps of: following completion of the thickness measurement on a first of said distinct conveyor belts, relocating the spine and sensor(s) to the support means of the second of said distinct conveyor belts, and carrying out a thickness measurement on said second belt.

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The above aspects can be modified by measuring the thickness of the pulley cover of the belt instead of the thickness of the carry cover of the belt.

Brief Description of the Drawings Some embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a longitudinal sectional view of a sensor for measuring carry cover thickness and an adjoining mount of a first embodiment; Fig. 2 is a longitudinal sectional view of the sensor of Fig. 1 when mounted adjacent a tail pulley of the conveyor belt and further illustrating a tachometer and lateral position indicator for determining a relative position of readings taken with the sensor; Fig. 3 is a top view of the sensor configuration of Fig. 2 further illustrating a channel that supports three sensors for measuring cover thickness at each of three transverse belt locations; Fig. 4 is an underside view of a spine that couples the three sensors of Fig. 3 and that can be internally accommodated within the supporting channel; and Fig. 5 is a schematic diagram of communication and processing circuits for the analysis of signals output from the sensors of Fig. 3.

Detailed Description According to a first embodiment of the invention there is provided an apparatus and method of measuring remaining carry cover thickness at pre-determined locations on a running belt.

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As illustrated in Fig. 1, there is provided a sensor 1 for measuring a thickness of carry cover 2 remaining on a conveyor belt 3. The sensor 1 consists of an inductive probe 4 and an ultrasonic probe 5. The sensor 1 can be substantially as described in Australian Patent No 2012 216 769, the contents of which are incorporated herein in their entirety by cross-reference.

Each of the probes 4,5 is potted in a hard resin potting material 6, and has a flexible signal cable 7 that exits the potting material 6 through a cable entry 10. The potting material 6 is rounded in shape at a leading end of the sensor 1.

The sensor 1 is attached to a compliant vertical leg 11. The leg 11 is preferably fabricated from fibreglass by a process similar to that used to make fishing poles and sail battens. The compliance in the leg 11 allows for movement of the probes 4,5 when they come in contact with protruding anomalies on the carry cover 2 such as patches, repairs, and the like (not illustrated). The rounded shape of the potting material 6 also aids in deflecting the sensor 1. The leg 11 can return to its original position after the anomaly passes.

The leg 11 is attached to a solid anchor block 12 that has a coupling tab 14 on at least one end of the block 12. The anchor block 12 is sized to be internally accommodated within a C-shaped channel 13. The anchor block 12 can slidably engage with the C shaped channel 13, and the coupling tab 14 enables multiple anchor blocks 12 to be coupled together and accommodated inside the C-channel 13.

Turning now to Fig. 2, the C-channel 13 is mounted on the conventional conveyor structure (not illustrated) near a tail pulley 15. At this location the belt 3 is substantially planar, under substantially uniform tension, and substantially flap-free. The C-channel 13 spans the conveyor belt 3 in a direction transverse to the direction of travel 16 of the belt 3.

In this configuration, at least one sensor 1 can be fitted to the C-channel 13 using an anchor block 12, and aligned to take a measurement at a pre-determined position on the belt 3.

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The tail pulley 15 is provided with a tachometer 20 for measuring the speed of the belt 3, which includes a small permanent magnet 21 and an inductive probe or tachometer probe 22. The magnet 21 is fitted to the shell of the tail pulley 15, and the tachometer probe 22 is fitted to the conveyor structure. The tachometer probe 22 generates an output signal in the form of a voltage spike with each pass of the magnet 21 as the tail pulley 15 rotates.

The waveform-like output signal of the tachometer probe 22 is amplified and shaped to produce a pulse train. The pulse train has a frequency which is proportional to the speed of the belt 3, and in combination with the circumference of the tail pulley 15 is used to deduce the actual speed of the belt 3.

The actual speed of the belt 3 can be used to derive the relative positions of the measurements taken with the sensor 1, along the 'endless' loop of belting in its circuit around the conveyor path. In this manner, longitudinal position information can be assigned to the measurements made with the sensor 1.

A Lateral Position Indicator (LPI) 23 having an ultrasonic probe 24 (Fig. 2) is fixed to the conveyor structure, and provides information relating to the lateral position of the belt 3 (or transverse position along an axis perpendicular to the direction of travel 16), as the belt 3 can wander relative to the conveyor structure.

As illustrated in Fig. 3, there is provided a telescopic spine 25 that can be disposed within the C-channel 13 and can couple together multiple sensors 1 including a sensor 26 for a first location 30 of skirt wear on the belt, a sensor 31 for a second location 32 of skirt wear on the belt, and also a sensor 33 for a third location 34 that is known or expected to have the highest rate of belt wear, whether from historical cover thickness measurements or otherwise.

The tail pulley 11 and surrounding conveyor structure are enclosed by guards 35 that are configured to ensure personnel safety. Personnel can work adjacent a running conveyor belt 3 provided that they remain outside the guards 35. Accordingly, the

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spine 25 is dimensioned in length to exceed the width of the belt 3, and to further extend beyond the conveyor structure (not illustrated) and guarding 35 when fully inserted into the C-channel 13. The C-channel 13 is also dimensioned to extend beyond the guarding 13 on at least one side of the conveyor 3.

Prior to insertion of the apparatus 36 into the C-channel 13, the set of sensors 26, 31, 33 are attached to the spine 25 with pre-determined spacings therebetween that correspond to the distances between the corresponding known or anticipated locations 30,32,34 of belt wear when measured along the axis of the C-channel 13. After the insertion, each the sensors 26, 31, 33 is positioned above a corresponding known or anticipated location 30, 32, 34 of belt wear.

Accordingly, personnel can prepare the set of sensors 26, 31, 33 on the spine 25 and both insert, and remove, the assembled apparatus 36 into the C-channel 13 while the belt 3 is running.

As illustrated in Fig. 4, the spine 25 is formed of two telescopic elements 40 each disposed between a pair of anchor blocks 12 such that the pre-determined spacings between the sensors 26, 31, 33 can be varied as desired. The telescopic elements 40 are fastened to the corresponding anchor blocks 12 at fixing points 41. This configuration renders the apparatus 36 both portable and versatile, in that the apparatus 36 can be moved between conveyor belts and the pre-determined spacings adjusted to correspond to the differently spaced locations 30, 32, 34 of belt wear on different belts.

Prior to installation of the assembly 36, each inductive probe 4 in the sensor 1 can be calibrated and linearized using a small sample of the target belt 3 to be measured, from which the cover material 2 has been removed. The characteristic linearization profile for each type of belt 3 is stored in non-volatile memory for future use.

As illustrated in Figure 5, the output signals from the probes 4, 5 and the tachometer probe 22 are returned to a processing unit 42 of an industrial computer 43. The processing unit 42 can be fixed or portable. In the case of afixed processing unit 42,

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the sensors 1 are permanently emplaced for the life of the belt. In the case of a portable processing unit 42, for example a laptop computer 43, the sensors 1 can be moved from conveyor to conveyor and accessed from the laptop computer 43. Communication between the computer 43 and the sensors 1 can be via a Universal Serial Bus (USB), Ethernet, or wireless broadband connection using a modem 44 and external antenna 45. Data is stored by the computer 43 and processed in the processing unit 42 and is then made available for analysis using a suitable waveform rendering software platform. The computer 43 is able to be accessible remotely via a network connection 46.

Trending of thickness values in the carry cover 2, for example as a function of product tonnage throughput and time, enables a prediction of when the belting 3 is approaching its end-of-life via the mechanism of wear to the carry cover 2.

The foregoing describes only one embodiment of the present invention and modifications, including modifications obvious to those skilled in the conveyor belt arts, can be made thereto without departing from the scope of the present invention.

For example, the number of sensors can be varied to suit particular wear conditions or to increase the width of belt measured at each wear location. The device can be fully portable and battery powered, or permanently installed on a conveyor with multiple load points and long skirt lengths, that cause greater rates of wear. The size of the ultrasonic probe can also be varied, for example to monitor very thin strips or widths of belt to correspond with narrow skirt wear. The apparatus can be used to measure the pulley cover thickness in belts where it is this cover which reaches end-of-life first.

The term "comprising" (and its grammatical variations) as used herein is used in the inclusive sense of "including" or "having" and not in the exclusive sense of "consisting only of'.

Claims

CLAIMS 1. A sensor assembly for measuring cover thickness of a conveyor belt having a steel cord carcass with an elastomeric cover on each side of the carcass, said assembly comprising an elongate spine carrying at least one sensor and being engageable with a support means extending transversely across said belt from at least one belt edge to at least the other belt edge, said spine extending transversely across said belt without said spine contacting the belt, whereby said spine can be engaged and dis-engaged with said support means by an operator positioned beyond said belt edges to thereby permit said sensor(s) to interact with said belt with the belt running.
2. The sensor assembly as claimed in claim 1 wherein said spine carries three sensors, a first sensor being aligned with a belt location adjacent said one belt edge, a second sensor being aligned with a belt location corresponding to a known or predicted location of maximum belt wear, and a third sensor being aligned with a belt location adjacent said other belt edge.
3. The sensor assembly as claimed in claim 2 wherein said spine is telescopic to permit the distances between said sensors to be adjusted.
4. The sensor assembly as claimed in claim 2 or 3 wherein said support means comprises a channel, and said spine is provided with three anchor blocks that can be internally accommodated within, and slidably engaged with, said channel when said spine is engaged with said support means, and each of said anchor blocks has a corresponding one of said sensors mounted thereon.
5. The sensor assembly as claimed in claim 4 wherein each of said sensors is mounted to the corresponding one of said anchor blocks by means of an elastically compliant leg which permits the sensor to deflect away from the conveyor belt if impacted by a moving object.
6. The sensor assembly as claimed in any one of claims 1-5 wherein said support means is located within guarding for personnel safety in a vicinity of the

5004P-AU 9 assembly, and said spine has a length sufficient to extend beyond said guarding when said spine is engaged with said support means.
7. The sensor assembly as claimed in any one of claims 1-6 wherein said sensor(s) and spine are removable from said support means and are re locatable to a like support means of another conveyor belt.
8. The sensor assembly as claimed in any one of claims 1-7 wherein each of said sensor(s) comprises an inductive probe and an ultrasonic probe.
9. The sensor assembly as claimed in claim 8 wherein each of the sensors is the apparatus as claimed in any one of claims 4 to 7 of Australian Patent No 2012 216769.
10. The sensor assembly as claimed in claim 1 and including a plurality of sensors.
11. The sensor assembly as claimed in claim 10 wherein said sensors are spaced apart along said spine.
12. The sensor assembly as claimed in claim 11 wherein said sensors are all located inwardly of said belt edges.
13. A method of relocating the spine and sensor(s) of the sensor assembly as claimed in any one of claims 1-12 for measuring the thickness of a cover of at least two distinct said conveyor belts each having a corresponding said support means, said method comprising the steps of: following completion of the thickness measurement on a first of said distinct conveyor belts, relocating the spine and sensor(s) to the support means of the second of said distinct conveyor belts, and carrying out a thickness measurement on said second belt.
14. The method as claimed in claim 13 including the further step of adjusting the position of said sensor(s) on said spine prior to carrying out the thickness

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15. The method as claimed in claim 13 or 14 and carried out while both conveyor belts are running.

Dated this 2 4 th day of January 2024 BEMO PTY LTD By FRASER OLD & SOHN Patent Attorneys for the Applicant

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