EP1937905A1

EP1937905A1 - Tyne replacement indicator

Info

Publication number: EP1937905A1
Application number: EP06741184A
Authority: EP
Inventors: Brian Davies
Original assignee: Brian Investments Pty Ltd
Current assignee: Brian Investments Pty Ltd
Priority date: 2005-06-02
Filing date: 2006-06-02
Publication date: 2008-07-02
Also published as: WO2006128258A1

Abstract

A system (10) for detecting the required replacement of tynes/teeth (14,16) of an earth digger comprising a capsule (32) of fluid (38) which changes to a gas form when released. Wear or breakage causes the embedded capsule, supported by resin (42) and holder (44) to break, releasing the fluid to be detected by a nearby gas analyser, which raises an alarm.

Description

TYNE REPLACEMENT INDICATOR

FIELD OF THE INVENTION

The present invention relates to a system and a method for detecting a physical change in a component.

BACKGROUND TO THE INVENTION

Failure of equipment in materials handling and mine machines results in equipment down time and, ultimately, loss of income. Specific components of machines are known to fail during the operational life of the machine. For example, the tines of a bucket of an excavator are subjected to high loads. When the tip of the tine is loaded, the tine can fail due to excessive shear forces and/or bending moments. For this and other reasons, such components are designed to be replaced.

Continued use of the machine after failure of such a component is usually at reduced performance. In the worst case, continued use can result in more serious damage to the machine. Accordingly, operators need to be vigilant for damage to their equipment. To assist the operator, it is known to provide the machine with a small closed- circuit television system, which, for example, monitors the bucket. This arrangement relies on the operator to be checking the monitor frequently whilst controlling the machine .

The lost tine must often be discovered quickly. If it is removed from the scene it can become mixed up with material being handled. In these situations a lost tine can find its way into processing equipment, such as a rock crusher. This equipment cannot handle a tine and will fail, causing major delays and costs in repair. SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a system for detecting a physical change in a component, the system comprising: a capsule containing a compound that has a fluid form when released from the capsule, the capsule being supported by the component; and a fluid analyzer for monitoring for the presence of the fluid compound; wherein the physical change of the component causes the capsule to release the compound, on detection of the compound the analyzer produces a signal indicating the presence of compound.

In one embodiment the physical change is fracture of the component. In another embodiment the physical change is movement or removal of the component. In another embodiment the physical change is wear of the component beyond a certain amount.

In one embodiment the fluid compound is gaseous in atmospheric conditioners. Thus in this embodiment the fluid analyzer is a gas analyzer. In another embodiment the fluid compound is a liquid.

Accordingly, a signal indicating the presence of the gaseous compound is indicative of the physical change of the component .

Preferably, the compound is predominantly a liquid when inside the capsule and forms a vapour in atmospheric conditions. That is, the liquid is volatile when exposed to the atmosphere. Preferably, the capsule is located adjacent a common fracture location in the component and across the fracture location. Alternatively, the capsule is located within the component such that capsule intersects a common fracture location.

Preferably, fracture of the component at the common fracture location causes the capsule to rupture.

The signal produced by the analyzer may be transmitted to a controller.

In one embodiment, the location of the analyzer is fixed relative to the component. Alternatively or additionally, the analyzer is remote from the component. The analyzer may be portable or provided in a fixed location.

In one embodiment, the analyzer can be one of a plurality of analyzers which are provided in spaced apart locations.

According to a second aspect of the present invention, there is provided a capsule when used in a system for detecting physical change in a component, the capsule comprising: a hollow body containing a compound that has a fluid form in atmospheric conditions, the body being made of a frangible material and the hollow inside of the body being sealed from the external atmosphere .

Preferably, the compound is predominantly a liquid when inside the capsule and forms a vapour in atmospheric conditions. Preferably, the liquid comprises an organic or inorganic liquid. Preferably, the liquid is volatile in atmospheric conditions such that detectable vapour is produced when the liquid is released from the capsule. Preferably, the capsule further comprises one or more wicks within the body. Preferably each wick is attached to an internal surface of the body.

Preferably, the capsule is elongate, such that the body has two spaced apart ends . Each wick can be attached to the one of the spaced apart ends. More preferably, the capsule is generally cylindrical.

Preferably, the body is a thin walled vessel. Preferably, the frangible material is glass. Alternatively, the frangible material is a glassy polymer.

According to a third aspect of the present invention, there is provided a mechanical assembly comprising a first portion having a passage for receiving a capsule according to the second aspect, the passage extending through at least part of the first portion, wherein physical change of the first portion causes the capsule release a fluid compound into the atmosphere.

Preferably, the first portion is further provided with a cavity, wherein a first end of the passage opens into the cavity. The capsule may be adhered in place using a settable compound provided within the cavity. A portion of the capsule is positioned in the cavity prior to the settable compound setting. Preferably, the settable compound is an epoxy resin.

Preferably, a second end of the passage opens onto an external surface of the first portion.

Preferably, the mechanical assembly further comprises a second portion and a fastening means for fastening the second portion to the first portion, such that the second end of the passage is covered by the second portion. Preferably, the first portion is a tine holder that can be attached to a support, such as a bucket of an excavator, for example by welding the tine holder to the support. More preferably, the second portion is a tine tip. Even more preferably, the first portion has a protruding tongue and the second portion has a recess for receiving the tongue .

Preferably, the mechanical assembly further comprises a plate member that is independently attached to the support such that the plate member is positioned within the cavity. The plate member is provided with a hole through which a part of the capsule extends. Accordingly, if the attachment of the tine holder to the support fractures, the plate member remains attached to the support causing the capsule to rupture during separation of the tine holder from the support.

According to a fourth aspect of the present invention there is provided a method for detecting a physical change to a component, the method comprising the steps of: releasing a compound into the atmosphere when the component physical change occurs the compound having a gaseous form in atmospheric conditions; and, monitoring the atmosphere for the presence of the gaseous compound.

BRIEF DESCRIPTION OF THE DRAWINGS

In order the that the present invention may be more easily understood, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a partial cross section view of a tine assembly provided with a fracture detection system according to a first embodiment of the present invention; Figure 2 is a cross section view of a capsule for use in the fracture detection system of Figure 1;

Figure 3 is an exploded cross section view of the tine assembly of Figure 1; Figure 4 is a cross section view of the tine holder shown in Figure 1 ;

Figure 5 is a cross-section view of the tine holder, as viewed along the line A-A in Figure 4;

Figure 6 is a top view of the tine holder of Figure 4;

Figure 7 is a partial cross section view of the tine assembly shown in Figure 1, showing a first failure mode of the tine assembly;

Figure 8 is a partial cross section view of the tine assembly shown in Figure 1, showing a second failure mode of the tine assembly;

Figure 9 is a perspective view of a hydraulic excavator provided with a system for detecting a fracture in a component according to a second embodiment of the present invention;

Figure 10 is a schematic view of a system for detecting a fracture in a component according to a third embodiment of the present invention;

Figure 11 is a schematic side elevation of a rotor of a crushing mill having a system for detecting a physical change in a component according to a third embodiment of the present invention;

Figure 12 is a schematic side elevation of a blade of the rotor of Figure 11 from the point of view of the arrow AA; and,

Figure 13 shows an alternative form of the assembly as provided in Figure 1 with another embodiment of the system of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figures 1 and 3 show a tine assembly 10 attached to a bucket 12 of an excavator (not shown) . The tine assembly 10 comprises a tine holder 14 and a slip-on tine tip 16.

The tine holder 14 has a tongue 18 that extends from a main body 20. The main body 20 is welded to the under side of the bucket 12 adjacent the leading edge 22. A hole 24 extends transversely through the tongue 18 is provided for receiving a fastener, such as a bolt or rivet

(not shown in the figures) .

The tine tip 16 has a first pointed end 26 and, at the opposing end, a recessed portion 28 for receiving the tongue 18. A pair of holes 30 extend transversely through the tine tip 16, each opening into the recessed portion

28. When the tine tip 16 is located on the tine holder

14, the pair of holes 30 line up with the hole 24 such that a bolt (not shown) can fasten the tine tip 16 onto the tine holder 14.

As shown in Figures 4 and 6, a passage 32 extends through the tine holder 16, generally in the direction of the tip 26. One end of the passage 32 opens onto the tongue 18 at an opening 34. The other end of the passage opens into a cavity 36. An elongate capsule 38 (which is shown in detail in Figure 2) comprising a sealed, hollow body is provided within the passage 32. The capsule 38 is a thin walled glass vessel, which contains a liquid (not shown) . Two wicks 40 are contained within capsule 38, each being attached to a respective end of the capsule 38. The wicks 40 draw at least part of the liquid into the wick material.

The liquid is selected to be readily vapourised in atmospheric conditions. Furthermore, the vapour produced by the liquid is distinct from other vapours and gases in the atmosphere such that the possibility of false indication of failure of the tine assembly 10 is reduced. Suitable liquids may comprise a organic liquid having a hydrocarbon backbone. The liquid may also have a particular odour such that presence of the vapourised liquid in the atmosphere can be observed by an operator of the excavator .

Attaching the tine 18 to the tine holder 14 closes the opening 34, thus retaining the capsule 38 within the passage 32. To further secure the capsule 38 in the passage 32, the cavity 36 can be at least partially filled with an epoxy resin 42. The capsule 38 is inserted into the passage 32 as the epoxy resin 42 is setting, such that one end of the capsule 38 is within the epoxy resin 42.

Prior to welding the tine holder 14 onto the bucket 12, a plate 44 can be welded onto the bucket 12. The plate 44 (which is shown in Figure 5) is sized such that it can be received within the cavity 36. A hole 46 is provided within the plate 44 such that a portion of the capsule 38 can protrude therethrough. The plate 44 extends generally transverse to the passage 32. The epoxy resin 42 adheres onto the plate 44.

Figures 7 and 8 illustrate two failure modes of the tine assembly 10. In Figure 7 the weld between the bucket 12 and the tine holder 14 has fractured, resulting in separation. During the failure the capsule 38 is broken, with the end of the capsule 38 within the cavity remaining attached to the bucket 12. The liquid is released from the capsule 38. Once exposed to atmospheric conditions, the liquid rapidly vapourises, allowing the vapour to propagate from the bucket 12 and the broken tine holder 14. The epoxy resin 42 and the plate 44 assist the retention of at least part of the capsule 38 on the bucket 12. Accordingly, the capsule is unlikely to remain intact after failure.

In Figure 8, the tine holder 14 has sheared adjacent the tongue 18. The shear surface extends through the passage 32 causing the capsule 38 to break, releasing the liquid.

A gas analyzer (not shown) with a sensor located nearby the machine is continuously monitoring the air for presence of the vapour from the capsule 38. Upon detection of the vapour, an alarm is triggered which indicates that one of the tine assemblies is damaged. The operator is automatically notified of damage to the machine. The gas analyzer can further comprise a sampling pump and a conduit for directing gas from a selected location to the gas analyzer. A suitable gas analyzer is available from Drager Safety AG & Co. KgaA, such as the Drager Polytron 7000.

The wicks 40 retain liquid for a short period of time. This extends the time in which the liquid is released into the atmosphere, which increases the likelihood of the sensor detecting the presence of the vapour in the atmosphere .

The plate 44 increases the surface area connecting the epoxy resin 42 to the bucket 12. In the case of the failure illustrated in Figure 7, the likelihood of the capsule 38 being retained within the tine assembly 10 in an unbroken state is reduced.

The tine assembly 10 shown in Figures 1 and 3 is also known to fail by a pin or bolt inserted through holes 30 shearing or failing in some other manner. In this case the tine tip 16 may simply fall off the tongue 18. To detect this type of failure an additional or an alternate system may be incorporated as shown in Figure 13. This system includes a passage 32' extending through the tongue 18 and into the tine tip 16. An elongate capsule 38' is positioned in the passage 32'. The passage 32' includes a passage portion 90 which is within the tine tip 16. An end portion 92 of the capsule 38' extends into the passage portion 90 and is secured in place, such as by use of epoxy resin. The capsule 38' includes a portion 94 which may be flexible but is also sufficiently frangible or tearable or the like, so that upon removal of the tine tip 16, the portion 94 releases liquid within the capsule 38'. Thus once the tine tip 16 comes off the tongue 18 the portion 94 fails and releases the liquid in capsule 38 '.

Figure 9 shows a hydraulic excavator 50 provided with a system for detecting a physical change, such as a fracture or removal of a time in the tine assemblies 10 that are attached to the bucket 12. A gas analyzer 52 is provided on the excavator 50. In Figure 9, the gas analyzer 52 is represented schematically. When one of the tine assemblies 10 fails (as shown in Figures 8 and 9) the gas analyzer 52 will detect the presence of vapourised liquid from the capsule of the respective tine assembly 10. The gas analyzer 52 provides a signal to the operator of the excavator 50, notifying the operator of the fracture.

Figure 10 illustrates schematically a system 54 for detecting a physical change, such as a fracture or wear in a component or removal of the component, such as a tine assembly 10. The tine assembly 10 is attached to the leading edge of a bucket 12 of an excavator. The system comprises a capsule 38 within the tine assembly 10. A first gas analyzer 56 is provided on a tripod stand 58, and thus is portable such that it can be placed at any desired location. A second gas analyzer 60 is provided on a mining truck 62. The gas analyzers 56, 60 are depicted schematically.

In Figure 10, the tine assembly 10 may have sustained a fracture similar to that shown in Figure 8. Accordingly, the liquid within the capsule 38 has been released and vapourised in the atmosphere. Arrows W indicate the vapour drifting in the atmosphere away from the tine assembly 10.

One or both of the gas analyzers 56, 60 detects the presence of vapourised liquid in the atmosphere. A signal 64 is transmitted, via radio waves as indicated by arrows T, to a controller 66 at a central location. Upon receipt of a signal 64 from either of the gas analyzers 56, 60 the controller 66 notifies an operator of damage to the tine assembly 10. The signal may be relayed to the operator of the excavator, as indicated by arrow R.

A gas analyzer 56 on a portable stand, such as tripod 58, can be of benefit where a prevailing wind is present that will carry the vapour in a particular direction. The gas analyzer 56 can be positioned in a region where the vapourised liquid is most likely to drift.

As shown in Figure 9, a gas analyzer can be installed on the machine itself. Alternatively or additionally, the gas analyzer can be installed at other suitable locations, including on trucks for hauling the material removed by the machine, on a portable stand or at a permanent location. A signal indicating the detection of the vapour can be transmitted from the respective sensor to a central location by any suitable means, including electrical wires.

In Figure 11 a rotor 100 of a rotary impact crusher is shown. The rotor 100 has a number, in this case four, blow bars 102 which strike material 104 being crushed as the rotor 100 rotates as indicated by arrow R. The rotary- impact crusher operates a known matter, such that the material struck impacts on impact bars within a vessel surrounding the rotor 100. The blow bars are subject to wear as indicated by the section 104 of one of the blow bars 102 being worn away. When the wear reaches a certain level the blow bars 102 must be replaced or inverted so that a fresh side is exposed.

In order to detect the extent of wear of the blow bars 102, the system of detecting a physical change in the blow bars can be employed. In this embodiment the system has one or more passages 108 extending through the blow bar 102 as seen in Figure 12. Recessed within each passage 108 is located a capsule 110. The capsule 110 contains a liquid that may be vapourised upon exposure to the atmosphere. The gas detector can then be used to detect release of vapour from the capsule when the capsule ruptures or otherwise releases the vapour. Thus the capsule must be sufficiently recessed within the channel 108 so that the capsule will only rupture when the wear to the blow bar 102 is to the extent that it requires replacement. Alternatively the capsule may be segmented to provide staged release of distinctive vapours, so that the degree of the wear can be monitored, due to the detection of the various types of vapour that are progressively released due to wear of the blow bar 102.

It will be appreciated that the present system can be adapted to other applications aside from a tine assembly and a rotor impact crusher / mill. In particular, the capsule system of the present invention may be used in many applications where upon a physical condition being met, a capsule releases a fluid such as a gas or a volatile liquid or some other liquid, which can be detected by an analyzer, such as a gas analyzer. It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention. For example, it will be appreciated that embodiments can also be provided other machines, such as a face shovels and loaders, a bucket wheel excavator, a drag line excavator, the rippers of a tractor, and boom excavators.

The system can also be applied to other components which commonly fail by physical change such as fracture, wear, movement or removal of the component at a known location within the component . The capsule can be provided either within the component or provided in a holder and attached to an external surface of the component at the known location. The capsule should be positioned such that, in use, failure by fracture at the known location causes the capsule to rupture, which releases the liquid.

It will be appreciated that the capsule can be formed of frangible materials other than glass, such as, for example, glassy polymers. Sufficient stress on the capsule caμses the capsule to rupture .

It will also be appreciated that the capsule can be arranged to detect a fracture in the form of a crack in the component . Accordingly, a fracture prior to complete failure of the component can be detected.

In one variation not illustrated, the tine tip 16 is provided with a passage which aligns with the passage 32 when the tine tip 16 is fastened to the tine holder 14. The capsule 38 is arranged to extend into both the tine holder 14 and the tine tip 16. Accordingly, if the tine connection of the tine holder 14 to the tine tip 16 fails, for example by the fastener shearing, the capsule 38 will be ruptured. This fracture of the tine assembly 10 can also be detected.

Alternative compounds may be provided within the capsule, including a gas or a solid which sublimes in atmospheric conditions. The amount of gas/vapour produced by the compound should allow detection of the presence of the gas/vapour. In addition, the gas/vapour should be uncommon in the atmosphere the component is to be used.

In the claims of this application and in the description of the invention, except where the context requires otherwise due to express language or necessary implication, the words "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

1. A system for detecting a physical change in a component, the system comprising: a capsule containing a compound that has a fluid form when released from the capsule, the capsule being supported by the component; and a fluid analyzer for monitoring for the presence of the fluid compound; wherein the physical change of the component causes the capsule to release the compound, on detection of the compound the analyzer produces a signal indicating the presence of compound.

2. A system as claimed in Claim 1, wherein the physical change is fracture of the component.

3. A system as claimed in Claim 1, wherein the physical change is movement or removal of the component.

4. A system as claimed in Claim 1, wherein the physical change is wear of the component beyond a certain amount .

5. A system as claimed in Claim 1, wherein any one of claims 1 to 4 wherein the fluid compound is gaseous in atmospheric conditioners .

6. A system as claimed in Claims 1 to 5, wherein the fluid compound is a liquid.

7. A system as claimed in Claims 1 to 6, wherein the signal indicates the physical change of the component.

8. A system as claimed in Claims 1 to 7, wherein the compound is predominantly a liquid when inside the capsule and forms a vapour in atmospheric conditions.

9. A system as claimed in Claim 8, wherein the liquid is volatile when exposed to the atmosphere.

10. A system as claimed in Claims l to 9, wherein the capsule is located adjacent a common fracture location in the component and across the fracture location.

11. A system as claimed in Claims 1 to 9, wherein the capsule is located within the component such that capsule intersects a common fracture location.

12. A system as claimed in Claims 1 to 11, wherein Preferably, fracture of the component at the common fracture location causes the capsule to rupture.

13. A system as claimed in Claims 1 to 12, wherein the signal produced by the analyzer may be transmitted to a controller.

14. A system as claimed in Claims 1 to 13, wherein the location of the analyzer is fixed relative to the component .

15. A system as claimed in Claims 1 to 14, wherein the analyzer is remote from the component.

16. A system as claimed in Claims 1 to 15, wherein the analyzer may be portable or provided in a fixed location.

17. A system as claimed in Claims 1 to 16, wherein the analyzer can be one of a plurality of analyzers which are provided in spaced apart locations.

18. A capsule for detecting physical change in a component, the capsule comprising: a hollow body containing a compound that has a fluid form in atmospheric conditions, the body being made of a frangible material and the hollow inside of the body being sealed from the external atmosphere .

19. A capsule as claimed in Claim 18, wherein the compound is predominantly a liquid when inside the capsule and forms a vapour in atmospheric conditions .

20. A capsule as claimed in Claim 19, wherein the liquid comprises an organic or inorganic liquid.

21. A capsule as claimed in Claim 20, wherein the liquid is volatile in atmospheric conditions such that detectable vapour is produced when the liquid is released from the capsule .

22. A capsule as claimed in Claims 18 to 21, wherein the capsule further comprises one or more wicks within the body.

23. A capsule as claimed in Claim 22, wherein each wick is attached to an internal surface of the body.

24. A capsule as claimed in Claim 23, wherein the capsule is elongate, such that the body has two spaced apart ends.

25. A capsule as claimed in Claim 24, wherein each wick can be attached to the one of the spaced apart ends.

26. A capsule as claimed in Claims 18 to 25, wherein the body is a thin walled vessel.

27. A capsule as claimed in Claims 18 to 26, wherein the frangible material is glass .

28. A capsule as claimed in Claims 18 to 26, wherein the frangible material is a glassy polymer.

29. A mechanical assembly comprising a first portion having a passage for receiving a capsule, the passage extending through at least part of the first portion, wherein physical change of the first portion causes the capsule release a fluid compound into the atmosphere.

30. An assembly as claimed in Claim 29, wherein the first portion is further provided with a cavity, wherein a first end of the passage opens into the cavity.

31. An assembly as claimed in Claims 29 or 30, wherein the capsule may be adhered in place using a settable compound provided within the cavity.

32. An assembly as claimed in Claim 31, wherein a portion of the capsule is positioned in the cavity prior to the settable compound setting.

33. An assembly as claimed in Claim 32, wherein the settable compound is an epoxy resin.

34. An assembly as claimed in Claims 30 to 33, wherein a second end of the passage opens onto an external surface of the first portion.

35. An assembly as claimed in Claims 29 to 34, wherein the mechanical assembly further comprises a second portion and a fastening means for fastening the second portion to the first portion, such that the second end of the passage is covered by the second portion.

36. An assembly as claimed in Claims 29 to 35, wherein the first portion is a tine holder that can be attached to a support, such as a bucket of an excavator, for example by welding the tine holder to the support.

37. An assembly as claimed in Claims 29 to 36, wherein the second portion is a tine tip.

38. An assembly as claimed in Claims 29 to 37, wherein the first portion has a protruding tongue and the second portion has a recess for receiving the tongue.

39. As assembly as claimed in Claims 29 to 38, wherein the mechanical assembly further comprises a plate member that is independently attached to the support such that the plate member is positioned within the cavity.

40. An assembly as claimed in Claims 29 to 39, wherein the plate member is provided with a hole through which a part of the capsule extends.

41. An assembly as claimed in Claims 29 to 40, wherein if the attachment of the tine holder to the support fractures, the plate member remains attached to the support causing the capsule to rupture during separation of the tine holder from the support.

42. A method for detecting a physical change in a component, the method comprising the steps of: releasing a compound into the atmosphere when the component has a physical change, the compound having a gaseous form in atmospheric conditions; and, monitoring the atmosphere for the presence of the gaseous compound.