AU671458B2 - Conveyor scraping system - Google Patents

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPEC IF ICAT ION FOR A STANDARD PATENT

ORIGINAL

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Name of Applicant: M* PIT TOP MINING PTY LTD, A.C.N. 001 989 895 s r cc r r s

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s r ra r r rr Actual Inventor: Edmund Stanley DONOHUE Address for Service: SHELSTON WATERS Clarence Street SYDNEY NSW 2000 Invention Title: "CONVEYOR SCRAPING SYSTEM" Details of Associated Provisional Application No: PL4050 dated August 1992 The following statement is a full description of this invention, including the best method of performing it known to us:- 3/3 iTT -2- The present invention relates to conveyor scraping i systems and in particular to a device for detecting the proximity of metallic clips or fasteners joining sections of a conveyor belt and for moving the belt scraper away from the belt in order to prevent damage to both the belt and the belt scraper blade.

Conveyor belts are a commonly used method for transporting bulk materials from one place to another.

Very often though, due to the nature of the material being transported, there is a build-up of particulate material on the surface of the conveyor belt. i It is known to use conveyor belt scrapers of various designs to remove this material adhering to the belt as it passes a selected point. These scrapers often have metal blades of tungsten carbide or tool steel construction. Interference between the blades and metal fasteners joining sections of the conveyor belt leads to S"wear and premature failure of both the fasteners and belt scraper. The increased maintenance and down time of the conveyor system is unsatisfactory.

For relatively low speed applications, it is known S to use a scraper belt arrangement which includes shoes at each end of the blade. The shOog ride on the belt ahead of the blade, and are mechanically connected to the blades so that the leading edge of any protruding joint i coming into contact with the shoes railoes the scraper blade over the forward portion of the seam. The blade is S then lowered onto the seam as the shoes ride over the P t -U q/ii: s t Ii 2a trailing edge of the joint. This system has a number of disadvantages. Firstly, the scraper blade is only lifted over the leading edge of the joint, and therefore still causes significant wear to the central and trailing sections of the joint. Furthermore, the device is unable to detect recessed or even flush joints, or stapled repairs to the belt. Finally, the device is unsuitable for use with general purpose bulk materials handling conveyor belts which may travel at speeds of up to metres per second, since the shoes cause the blade to "bounce" over the joint. This bouncing causes wear and may also damage the scraper blade and belt around the vicinity of the joint.

It is an ),bject of the present invention to overcome or at least ameliorate one or more of these disadvantages of the prior art.

Accordingly, there is provided a conveyor scraping system for detecting metal fasteners in a conveyor belt, said conveyor scraping system including: 20 a metal sensor adapted to be mounted in close proximity to the conveyor belt; ri in ii f ii i Si i! Ii i *440 *44* 0 0 0 0 0. 0 *r 0* 00 044* 0 0r 04 0 0 r 4 4 Is r a scraper element adapted to be moved between a ifted first operative position wherein it removes material from ill ^the conveyor belt and a second position spaced from said J Sconveyor belt; nable control means responsive to said metal sensor for generating a control signal indicative of the presence of a metal fastener; and actuating means responsive to said control signal I and operable to move said scraper element between said first and second positions. and In preferred embodiments the conveyor scraping 4 system includes resilient means for biasing said scraper element to said second position and said actuating means is adapted to urge said scraper element to said first operative position. Preferably, said actuating means includes inflatable means. Preferably also, said metal ping sensor is supported by a fixed member and said scraper element is supported by a movable element, said actuating means disposed between said fixed member and said movable j: I jI 20 member for selectively urging said movable member and said scraper element to said first operative position.

In the preferred embodiment, the actuating means f further includes valve means responsive to said control ;i -'I Ij signal for selectively connecting said inflatable means j! to a source of fluid pressure or to an exhaust outlet, |i wherein said inflatable means is connected to said source 1 j, .of fluid pressure when the control signal does not indicate the presence of a metal fastener, inflation of 4 said inflatable means causing- said movable member and said scraper element to move to sa.d first position, and wherein said inflatable means is connected to said exhaust outlet when saiC control signal indicates the presence of a metal fastener, deflation of said inflatable means through said exhaust outlet allowing said resilient means to bias said movable member and said scraper element to said second position.

Preferably also, said inflatable means is an air bag lifter and said source of fluid pressure is an air or "water supply. Preferably also, the control means includes an electronic timer which causes the control signal to indicate the presence of a metal fastener for a predetermined interval after the metal fastener has passed the metal sensor.

SAlt rnatively, the scraper element may be biased to said first operative position and said actuating means may be adapted to urge said scraper element to said second position. Alternatively agan, the actuating means may be adapted to urge the scraper element in both directions between the first and second positions.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying diagrams in which: Figure I is a schematic representation of a conveyor scraping system according to a first embodiment of the present invention; Figure 2 is a detailed side elevation of the ii w -1 !is i and said .r .r or r r c r

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r r r r :or a mechanical components of the conveyor scraping system according to a second embodiment of the invention; and Figure 3 is an end elevation corresponding to Figure 2.

Referring to the figures, and in particular Figure 1, belt scraper 1 is held against conveyor belt 2 by the inflation air bag 3 connected to an air or water supply (not shown) through solenoid 5. When metal sensor 6 detects the presence of metal fastener 7 joining two 10 sections 8,9 of conveyor belt 2, after any appropriate delay control box 10 instructs solenoid 5 to connect air bag 3 to an exhaust outlet 11 instead of the air or water supply. This deflates air bag 3 and belt scraper 1 is biased away from conveyor belt 2 by spring 12 to allow metal fastener 7 to pass unharmed.

An electronic timer ensures that belt scraper 1 is away from conveyor belt 2 for a sufficient time to allow the metal fastener 7 to pass. The electronic timer is preset to suit the conveyor belt speed and scraper 20 location so as to minimise the time that scraper 1 is away from the belt 2.

Figures 2 and 3 show the operation of the mechanical components of a second embodiment of the invention. Fixed member 15 supports metal sensor 13 on an adjustable articulated arm 14. Fixed member 15 is rigidly attached to the frame of conveyor belt (not shown) or other suitable structure and pivoting member 16 pivots about fulcrum 17 between limits defined by the d to

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SC C S S Tf i -6 compression of air bag 3 due to spring 12 and adjustable stop screw 18.

In use, inflation of the air bag causes pivoting member 16 to rotate about fulcrum 17 so that the scraper attached to one end 19 is brought into engagement with the conveyor belt. Should the air or water supply be inadvertently disconnected the scraper will be automatically removed from the belt preventing damage to both the scraper equipment and the conveyor belt. In addition to this failsafe feature, the conveyor scraping -system of the preferred embodiment can be retrofitted to adjustability and simple requirements.

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In addition, the invention solves a number of problems experienced by conveyor belt users. Where it has been common practice to utilise metal connectors o•joining sections of conveyor belt, problems of wear have been avoided by using scrapers with rubber or polyurethene blades. Unfortunately, these have very PI:" 20 short lives on many abrasive materials and if not S" replaced frequently so as to maintain high cleaning efficiency cause further problems with material carry-back and maintenance of ancillary conveyor equipment. With the present invention, high grade steel tipped scraper blades can be introduced with resultant i higher scraper efficiencies ani decreased hazard to the conveyor system. i Although reference has been made to preferred j 4, j -7 embodiments, it will be appreciated that the invention may be embodied in many other forms without departing from the scope of the invention.

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Claims (7)

1. A conveyor scraping system for detecting metal fasteners in a conveyor belt, said conveyor scraping system including: a metal sensor adapted to be mounted in close proximity to the conveyor belt; a scraper element adapted to be moved between a first operative position wherein it removes material from the conveyor belt and a second position spaced from said conveyor belt; 0 control means responsive to said metal sensor for generating a control signal indicative of the presence of a meltal fastener; and actuating means responsive to said control signal and operable to move said scraper element between said firsl-; and second ,-sitions.

2. A conveyor scraping system as defined in claiA.1, wherein the system includes resilient means for biasing said scraper element to said second position and' said actuating means is adapted to selectively urge said 5 scraper element to said first operative position.

3. A conveyor scraping system as defined in claim 2, wherein said scraper element is supported by a moveable member, said actuating means disposed between a fixed member and said movable member for selectively urging said scraper element to said first operative position.

4. 'A conveyer scraping system as defined in claim 3, ft. 9 ft ft. ft I 5 ft ft. F iI~ r I

9- wherein said moveable member is pivotably mounted with respect to said fixed member. A conveyor scraping system as defined in claim4, wherein said actuating means includes selectivelyI inflatable means. 6. A conveyor scraping system as defined in claim wherein said actuating means further includes valve means responsive to said control signal for selectively connecting said inflatable means to a source of fluid pressure or to an exhaust outlet, wherein said inflatable means is connected to said source of fluid pressure when the control signal does not indicate the presence of a metal fastener, inflation of said inflatable means urging C'aid scraper element to said first position, and wherein said inflatable means is connected to said exhaust outlet when said control signal indicates the presence of a metal fastener, deflation of said inflatable means through said exhaust outlet allowing said resilient means to bias said scraper element to said second position. 7. A conveyor scraping system as defined in claim 6, wherein said inflatable means is an air bag lifter and said source of fluid pressure is an air or water supply. A conveyor scraping system as defined in any S. 4 preceding claim, wherein the control means includes an electronic timer which causes the control signal to indicate the presence of a metal factener for a predetermined interval after the metal fastener has passed the metal sensor. Olt-2:-1: i 10 9. A conveyor scraping system as defined in claim 3, wherein the metal sensor is supported by the fixed member. A conveyor scraping system as defined in claim 1, wherein the system includes resilient means for biasing said scraper element to said first position and said actuating means is adapted to urge said scraper element to said second position.

11. A conveyor scraping system as defined in claim 1, wherein the actuating means is adapted to urge the scraper element in both directions between the first and second positions.

12. A conveyor scraping sys *em substantially as herein described with reference to the accompanying drawings. DATED this 23rd day of July 1993 PIT TOP MINING PTY LTD Attorney: PETER HEATHCOTE Fellow Institute of Patent Attorneys of Australia of SHELSTCN vATERS r o i i r ii 1~ i C.. C C C Ca,, CC i 1 ^t 11 ABSTRACT The present invention relates to a conveyor scraper system for detecting metal fasteners in a conveyor belt, the conveyor scraping system including a metal sensor (6) adapted to be mounted in close proximity to the conveyor belt a scraper element adapted to be moved between a first operative position wherein it removes material from conveyor belt and a second position spaced from conveyor belt control means responsive to metal sensor for generating a control signal indicative of the presence of a metal fastener, actuating means responsive to the control signal and operable to move scraper element between the first and second positions. at:: h I *r r V S S S. V V .J I' 1 2 .t k I 4 -h ~li -l