AU2012216578B2

AU2012216578B2 - Sealing device and method

Info

Publication number: AU2012216578B2
Application number: AU2012216578A
Authority: AU
Inventors: Stewart Fernandez
Original assignee: Trelleborg Engineered Systems Australia Pty Ltd; Trelleborg Engineered Products Australia Pty Ltd
Current assignee: Trelleborg Engineered Systems Australia Pty Ltd
Priority date: 2012-08-31
Filing date: 2012-08-31
Publication date: 2014-12-11
Anticipated expiration: 2032-08-31
Also published as: AU2012216578A1

Abstract

-32 A sealing device for sealing an aperture in a wall through which a fixing member extends for attaching a liner to the wall, the sealing device comprising: a backing portion with an aperture 5 for said fixing member to extend therethrough; and a sealing portion with an aperture for said fixing member to extend therethrough; wherein the backing portion is adapted to force the sealing portion against the wall; and wherein the sealing portion comprises a sealing face, for contact with the wall, the 10 sealing face having at least one sealing ridge extending around, and spaced apart from, the aperture of the sealing portion. 3481990_1 (GHMatters) P90185.AU '2-0 S - - b-- -o - --- 4Fig. 1A 4- 4+0 Fg.

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant (s): Trelleborg Engineered Systems Australia Pty Ltd Invention Title: SEALING DEVICE AND METHOD The following statement is a full description of this invention, including the best method for performing it known to me/us: -2 SEALING DEVICE AND METHOD FIELD The present invention relates to a sealing device and 5 especially, but not exclusively to a sealing device for use in attaching mill linings to mill shells in a grinding mills, including ball, rod, autogenous (AG) and semi-autogenous (SAG) grinding mills. 10 BACKGROUND A grinding mill may comprise a cylindrical or conical drum which rotates about an axis. The drum may be provided with an internal liner to protect against wear. Liners in grinding mills are often held in place by locking mechanisms which may be 15 in the form of bolts or other fixing members which pass through the liners and extend through suitably positioned apertures in the wall or surface which is lined by the liner. It is desirable to ensure that the apertures in are adequately sealed to prevent egress of liquid from the mill interior through the 20 apertures. The bolts or other fixing members may be subject to substantial forces during grinding, which may result in wear and deformation of the apertures. The wear and deformation of the apertures may be caused by movement of the bolts or other fixing members. 25 The inventor has discerned that there is a need for improvement in sealing apertures. It would be desirable for at least some embodiments in accordance with the present disclosure to provide an improved sealing device, or at least to provide a useful alternative to currently available sealing arrangements. 30 5633519_1 (GHMatters) P90185.AU D ENI SET -3 SUMMARY According to a first aspect of the disclosure there is provided a sealing device for attaching a liner to the inside wall of a grinding mill, the sealing device comprising: 5 a backing portion with an aperture for a fixing member to extend therethrough, wherein the backing portion comprises a back wall portion having a side wall portion depending therefrom; and a sealing portion with an aperture for said fixing 10 member to extend therethrough, wherein the sealing portion comprises a sealing face, for contact with the wall of the grinding mill, the sealing face having at least one sealing ridge extending around, and spaced apart from, the aperture of the sealing portion; 15 wherein the backing portion is adapted to force the sealing portion against the wall when a fixing member is extended through the apertures, the fixing member engagable with the back wall portion of the backing portion; wherein the sealing face comprises an elastomer 20 adapted to deform when the sealing portion is forced against the wall; and wherein the side wall portion extends along almost the entire thickness of the sealing portion to assist in preventing undesirable spreading of the elastomer in use. 25 According to a another aspect of the present disclosure there is provided a sealing device for sealing an aperture in a wall through which a fixing member extends for attaching a liner to the wall, the sealing device comprising: a backing portion with an aperture for said fixing 30 member to extend therethrough; and a sealing portion with an aperture for said fixing 5633519_1 (GHMatters) P90185.AU D ENI SET -4 member to extend therethrough; wherein the backing portion is adapted to force the sealing portion against the wall; and wherein the sealing portion comprises a sealing face, 5 for contact with the wall, the sealing face having at least one sealing ridge extending around, and spaced apart from, the aperture of the sealing portion. Embodiments of the invention and other embodiments, are described below. 10 In an embodiment at least one sealing ridge is substantially annular. In an embodiment the or each sealing ridge is substantially annular. In an embodiment the sealing face has a plurality of 15 sealing ridges each extending around the aperture of the sealing portion. In an embodiment the at least one sealing ridge is made of a deformable material. In an embodiment the at least one substantially ridge 20 is made of a resiliently deformable material. In an embodiment the at least one sealing ridge is made of an elastomer. The elastomer may be a heat-resistant elastomer. In an embodiment the at least one sealing ridge is 25 made of rubber, polyurethane-based elastomer, thermoplastic elastomer, and/or silicone-based elastomer. In an embodiment the sealing portion is made of a deformable material. 5633519_1 (GHMatters) P90185.AU DENISET -5 In an embodiment the sealing portion is made of a resiliently deformable material. In an embodiment the sealing portion is made of an elastomer. 5 The elastomer may be a heat-resistant elastomer. In an embodiment the sealing portion is made of elastomeric rubber, polyurethane-based elastomer, thermoplastic elastomer, and/or silicone-based elastomer. In an embodiment the sealing portion comprises a 10 single sealing member. In an embodiment the at least one sealing ridge is formed as an integral part of the sealing portion. In an embodiment the sealing device further comprises a sleeve portion. 15 In an embodiment the sleeve portion projects away from the sealing face, and is arranged to extend into an aperture in the wall through which said fixing member extends, in use. In an embodiment the sleeve portion provides a 20 channel for accommodating part of said fixing member. In an embodiment the sleeve portion is part of the sealing portion. In an embodiment the sleeve portion is formed as integral part of the sealing portion. 25 In an embodiment the sealing portion comprises at least two sealing ridges. In an embodiment with a plurality of sealing ridges at least one of the annular sealing ridges may project further from the rest of the sealing face than does at least one other 5633519_1 (GHMatters) P90185.AU D ENI SET -6 of the annular sealing ridges. In an embodiment the sealing portion comprises at least three said sealing ridges. In an embodiment each sealing ridge has a diameter, 5 and the substantially annular sealing ridge which has the second smallest diameter projects further from the rest of the sealing face than does a substantially annular sealing ridge with greater diameter. In an embodiment each substantially annular sealing 10 ridge has a diameter, and the substantially annular sealing ridge which has the second smallest diameter projects further from the rest of the sealing face than does a substantially annular sealing ridge with smaller diameter. In an embodiment each substantially annular sealing 15 ridge has a diameter, and the substantially annular sealing ridge which has the second largest diameter projects further from the rest of the sealing face than does a substantially annular sealing ridge with greater diameter. In an embodiment each substantially annular sealing 20 ridge has a diameter, and the substantially annular sealing ridge which has the second largest diameter projects further from the rest of the sealing face than does a substantially annular sealing ridge with smaller diameter. In an embodiment each substantially annular sealing 25 ridge has a diameter, and the sealing face provides a largest diameter substantially annular sealing ridge, a smallest diameter substantially annular sealing ridge, and at least one intermediate diameter substantially annular sealing ridge. At least one intermediate diameter substantially 30 annular sealing ridge may project further from the rest of the sealing face than do the largest diameter substantially annular sealing ridge and the smallest diameter substantially annular 5633519_1 (GHMatters) P90185.AU D ENI SET -7 sealing ridge. In an embodiment the cross sectional shape of at least one sealing ridge is such that the substantially annular sealing ridge narrows with distance away from the rest of the 5 sealing face. In an embodiment the cross sectional shape of the or each sealing ridge is such that the substantially annular sealing ridge narrows with distance away from the rest of the sealing face. 10 In an embodiment the cross sectional shape of at least a sealing ridge which projects furthest from the rest of the sealing face is such that the substantially annular sealing ridge narrows with distance away from the rest of the sealing face. 15 In an embodiment the cross sectional shape of at least one sealing ridge is substantially semi-circular. In an embodiment the cross sectional shape of at least a sealing ridge which projects furthest from the rest of the sealing face is substantially semi-circular. 20 In an embodiment the sealing portion comprises at least two spaced apart sealing ridges, wherein a void area is provided between the spaced apart sealing ridges, the void area adapted to provide a sealed space when the sealing face is forced against a wall. 25 In an embodiment the sealing face is configured so that, in use, a partial vacuum is created in the sealing space if the force which is applied to force the sealing portion against the wall is reduced. Creating a partial vacuum in the sealing space can 30 result in the device providing a suction effect against the wall, which assists in maintaining the position of the sealing 5633519_1 (GHMatters) P90185.AU D ENI SET -8 device relative to the wall. In an embodiment the sealing face is configured so that in use, when the sealing portion is forced against the wall, the sealing ridges provide a biasing force which tends to 5 force the device away from the wall. This will result in the sealed space tending to increase in size if the force which is applied to force the sealing portion against the wall is reduced, thereby creating the partial vacuum in the sealed space. 10 In an embodiment the backing portion comprises a back wall portion. In an embodiment the back wall portion engages a back of the sealing portion, the back of the sealing portion being on a side of the sealing portion substantially opposite to the 15 sealing face. In an embodiment the back wall portion is substantially annular in form. In an embodiment the backing portion comprises at least one side wall portion. 20 In an embodiment the at least one side wall portion extends about at least part of the sealing portion. In an embodiment the at least one side wall portion engages the sealing portion and restrains deformation of the sealing portion in a direction parallel to the sealing face. 25 In an embodiment the at least one side wall portion extends closer to the sealing face than does the back wall portion. In an embodiment the backing portion is formed as a backing member. 30 In an embodiment the backing portion is attached to 5633519_1 (GHMatters) P90185.AU D ENI SET -9 the sealing portion. This can facilitate use of the device, as the device may be provided as an intergral unit, unlike some known sealing arrangements in which a metal washer and a sealing part such as 5 a rubber washer are provided separately. In an embodiment the backing portion is bonded to the sealing portion. The backing portion may be bonded to the sealing portion by use of an adhesive. 10 In an embodiment the backing portion is made of metal. In an embodiment the backing portion is made of steel. In an embodiment the backing portion is formed as a 15 single unitary backing member. In an embodiment the backing member comprises the back wall portion and the at least one side wall portion. In an embodiment the backing member is generally dish shaped. 20 In an embodiment the backing member is generally hemispherical. In an embodiment in which the backing member is generally hemispherical, a part of the backing member closer to the aperture of the backing member may be regarded as at least 25 part of the back wall portion, and a part of the backing member further from the aperture of the backing member may be regarded as at least part of the side wall portion. In an embodiment the backing member is made of metal. In an embodiment the backing member is made of steel. 5633519_1 (GHMatters) P90185.AU D ENI SET -10 In an embodiment the width of the sealing face is at least twice the width of the aperture of the sealing face. In an embodiment the width of the sealing face is at least 2.5 times the width of the aperture of the sealing face. 5 In an embodiment the width of the sealing face is approximately three times the width of the aperture of the sealing face. According to a second aspect of the present disclosure there is provided a sealing device for sealing 10 apertures in a wall through which a fixing member extends for attaching a liner to the wall, the sealing device comprising: a backing portion with an aperture for said fixing member to extend therethrough; and a sealing portion with an aperture for said fixing 15 member to extend therethrough; wherein the backing portion is adapted to force the sealing portion against a wall; and wherein the sealing portion comprises a sealing face, for contact with the wall, and wherein the width of the sealing 20 face is at least twice the width of the aperture of the sealing face. In an embodiment the width of the sealing face is at least 2.5 times the width of the aperture of the sealing face. In an embodiment the width of the sealing face is 25 approximately three times the width of the aperture of the sealing face. Providing a sealing face which is substantially greater in width than the aperture of the sealing face (which will generally be approximately the same width as the aperture 30 in the wall provided the aperture in the wall is not deformed by 5633519_1 (GHMatters) P90185.AU D ENI SET - 11 wear, corrosion or the like) can assist in providing effective sealing around deformed wall apertures. In an embodiment the aperture in the sealing face is generally circular. 5 In an embodiment the sealing face is generally circular. In an embodiment the diameter of the sealing face is at least twice the diameter of the aperture of the sealing face. In an embodiment the diameter of the sealing face is 10 at least 2.5 times the diameter of the aperture of the sealing face. In an embodiment the diameter of the sealing face is at approximately three times the diameter of the aperture of the sealing face. 15 In an embodiment the sealing face provides at least one substantially annular sealing ridge extending around, and spaced apart from, the aperture of the sealing portion. In an embodiment the sealing face provides a plurality of substantially annular sealing ridges each extending 20 around, and spaced apart from, the aperture of the sealing portion. It will be appreciated that features set out above in relation to embodiments of the first aspect may also apply to embodiments in accordance with the second aspect. 25 According to a third aspect of the present disclosure there is provided a sealing device for sealing apertures in a wall through which a fixing member extends for attaching a liner to the wall, the sealing device comprising: a backing portion with an aperture for said fixing 30 member to extend therethrough; and 5633519_1 (GHMatters) P90185.AU D ENI SET -12 a sealing portion with an aperture for said fixing member to extend therethrough; wherein the backing portion is adapted to force the sealing portion against a wall; and 5 wherein the sealing portion comprises a sealing face, for contact with the wall, and wherein the sealing face comprises an elastomer adapted to deform when the sealing portion is forced against the wall to provide a seal. In an embodiment the sealing face comprises 10 elastomeric rubber, polyurethane-based elastomer, thermoplastic elastomer, and/or silicone-based elastomer. Use of an elastomer provides a greater degree of resilience (rebound) than at least some previously known deformable sealing elements, which can assist in maintaining an 15 effective seal. It will be appreciated that features set out above in relation to embodiments of the first and second aspects may also apply to embodiments in accordance with the third aspect. According to a fourth aspect of the present disclosure 20 there is provided a sealing device for sealing apertures in a wall through which a fixing member extends for attaching a liner to the wall, the sealing device comprising: a backing portion with an aperture for said fixing member to extend therethrough; and 25 a sealing portion with an aperture for said fixing member to extend therethrough; wherein the backing portion is adapted to force the sealing portion against a wall; and wherein the sealing portion comprises a sealing face, 30 for contact with the wall, the sealing face comprising at least 5633519_1 (GHMatters) P90185.AU D ENI SET -13 two spaced apart resilient sealing regions, each extending around the aperture of the sealing portion, wherein a void area is provided between the spaced apart sealing regions, the void area adapted to provide a sealed space when the sealing face is 5 forced against a wall. In an embodiment the sealing face is configured so that, in use, a partial vacuum is created in the sealing space if the force which is applied to force the sealing portion against the wall is reduced. 10 Creating a partial vacuum in the sealing space can result in the device providing a suction effect against the wall, which assists in maintaining the position of the sealing device relative to the wall. In an embodiment the sealing face is configured so 15 that in use, when the sealing portion is forced against the wall, the resilient sealing regions provide a biasing force which tends to force the device away from the wall. This will result in the sealed space tending to increase in size if the force which is applied to force the sealing portion against the 20 wall is reduced, thereby creating the partial vacuum in the sealed space. The spaced apart resilient sealing regions may comprise sealing ridges provided on the sealing face. It will be appreciated that features set out above in 25 relation to embodiments of the first to third aspects may also apply to embodiments in accordance with the fourth aspect. According to a fifth aspect of the present disclosure there is provided a method of sealing an aperture in a wall, comprising use of a sealing device in accordance with the first 30 second, third and/or fourth aspects. The wall may be a wall of a grinding mill. 5633519_1 (GHMatters) P90185.AU D ENI SET -14 In an embodiment the wall is a wall of a ball, rod, autogenous (AG) or semi-autogenous (SAG) grinding mill. The method may comprise sealing the aperture in a grinding mill wall as part of attachment of a liner to the wall. 5 The method may comprise sealing the aperture in a grinding mill wall as part of attachment of a liner to an interior surface of the wall. The method may comprise passing a fixing member through the liner, the aperture in the wall, the aperture of the 10 backing portion and the aperture of the sealing portion, and then tightening the fixing member to force the sealing portion against an exterior surface of the wall. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention and other embodiments 15 will now be described by way of example only, with reference to the accompanying drawings in which: Fig. 1A is a cross sectional view of a first embodiment of a sealing device in accordance with the present disclosure; 20 Fig. 1B is an isometric view of the sealing device of Fig. 1A; Fig. 2A is a cross sectional view of a second embodiment of a sealing device in accordance with the present disclosure; 25 Fig. 2B is an isometric view of the sealing device of Fig. 2A; Fig. 3 is a cross sectional view of a third embodiment of a sealing device, being similar to the embodiment of Fig.s 1A and 1B, but having different dimensions; 5633519_1 (GHMatters) P90185.AU D ENI SET -15 Fig. 4 is a cross sectional view of a fourth embodiment of a sealing device, being similar to the embodiment of Fig.s 2A and 2B, but having different dimensions; Fig. 5 is a cross sectional view of a further 5 embodiment of a sealing device, being similar to the embodiment of Fig.s 1A and 1B, but being different in certain dimensions; Fig. 6 is a cross sectional view of a further embodiment of a sealing device, being similar to the embodiment of Fig.s 2A and 2B, but having different dimensions; 10 Fig. 7 is a cross sectional view of a further embodiment of a sealing device, being similar to the embodiment of Fig.s 1A and 1B, but being different in certain dimensions; Fig. 8 is a cross sectional view of a further embodiment of a sealing device, being similar to the embodiment 15 of Fig.s 2A and 2B, but having different dimensions; Fig. 9 is a cross sectional view of a further embodiment of a sealing device, being similar to the embodiment of Fig.s 1A and 1B, but being different in certain dimensions; Fig. 10 is a cross sectional view of a further 20 embodiment of a sealing device, being similar to the embodiment of Fig.s 2A and 2B, but having different dimensions; Fig. 11 is a schematic cross sectional view of the embodiment of Fig.s 1A and 1B in use, with an aperture in a mill shell wall which is not worn; and 25 Fig. 12 Fig. 11 is a schematic cross sectional view of the embodiment of Fig.s 2A and 2B in use, with an aperture in a mill shell wall which is worn and enlarged. Description of Embodiments 5633519_1 (GHMatters) P90185.AU D ENI SET -16 Referring to Fig.s 1A and 1B, an embodiment of a sealing device, in the form of a sealing washer is designated generally by the reference numeral 10 and is adapted to seal an aperture in a grinding mill wall through which a member extends 5 for attaching a liner to the grinding mill wall. In this embodiment the sealing washer 10 is generally circular. The sealing washer 10 comprises a backing member 20 and a sealing member 40. The sealing washer 10 may be provided 10 with the backing member 20 and sealing member 40 mutually attached, to provide a single unit. The backing member 20 and sealing member 40 may be substantially permanently attached, for example by bonding using a suitable adhesive (not shown). The backing member 20 is provided with a central 15 aperture 22, adapted to receive a fixing member (such as a bolt) therethrough. The backing member 20 comprises a back wall portion 24 and a short peripheral side wall portion 26, which in this embodiment is substantially perpendicular to the back wall portion 24. The side wall portion 26 is connected to the back 20 wall portion 24 at a rounded shoulder portion 28. The side wall portion 26 and the back wall portion 24 may be formed from a single piece of metal, for example by a pressing operation. The sealing member 40 is provided with a central aperture 42, adapted to receive a fixing member (such as a bolt) 25 therethrough. The aperture 42 of the sealing member is coaxial with the aperture 22 of the backing member 20. The aperture 42 of the sealing member may be slightly smaller than the aperture 22 of the backing member 20. The aperture 42 of the sealing member and the aperture 22 of the backing member 20 may be 30 circular, although (other shapes of aperture could be used in conjunction with suitable fixing members). The sealing member 40 is provided with a sealing face 44. The sealing face 44 is provided with a plurality of 5633519_1 (GHMatters) P90185.AU D ENI SET -17 projecting sealing ridges. In this embodiment there are three sealing ridges, although it will be appreciated that more or fewer sealing ridges could be provided if desired. In this embodiment the sealing ridges comprise a least wide sealing 5 ridge 46, a middle sealing ridge 48, and a widest sealing ridge 50. The sealing face may, in this embodiment be regarded as being generally planar, except for the sealing ridges 48, 46, 50. Further, in this embodiment, the sealing member is bevelled at its outer periphery, having a peripheral bevel 52 which 10 extends between the sealing face 44 and the side wall portion 26 of the backing member 20. In this embodiment the side wall portion 26 of the backing member 20 terminates in a bevelled edge 30. The bevelled parts 52, 30 assist in providing a sealing washer in which the sealing face 44, at least when the 15 sealing member 20 is in a non-deformed state, is further from the back wall portion 24 than is any part of the side wall portion 26. This assists in avoiding undesirable engagement of the side wall portion 26 (or any other part of the backing member 20) with a surface against which the sealing face 44 is 20 intended to provide a seal, which could adversely affect contact and sealing by the sealing member. It will be appreciated that the provision of of a side wall portion which extends almost the entire thickness of the sealing member assist in preventing undesirable lateral spreading of the sealing member in use. 25 In this embodiment the sealing ridges 46, 48, 50 are generally annular. In this embodiment the middle sealing ridge 48 projects further from the rest of the sealing face 44 than does the least wide sealing ridge 46, and the widest sealing ridge 50 projects less far from the rest of the sealing face 44 30 than does the least wide sealing ridge 46. The sealing member 40 is made of a deformable material, such as a suitable elastomer, so that the sealing ridges can deform when forced against a wall of a grinding mill shell. This can assist in providing a good seal. Suitable 5633519_1 (GHMatters) P90185.AU D ENI SET -18 elastomers include, but are by no means limited to, elastomeric rubber, polyurethane-based elastomer, thermoplastic elastomer, and/or silicone-based elastomer. The elastomer may be a durable and heat-resistant elastomer (for example a silicone-based 5 elastomer) which can increase the service life of the sealing member, and the washer as a whole, in the harsh conditions often encountered. Use of an elastomer, as against a less resilient (or lower rebound) deformable material also assists in prolonging service life, and reduces the likelihood of cracking 10 or irreversible deformation of the sealing member. In one example of the sealing washer 10 of Fig,s 1A and 1B, the dimensions of various features are as follows. The diameter of the sealing washer 10 as a whole D 5 w is 105mm. 15 The diameter of the aperture in the backing member Dbm is 26mm. The diameter of the aperture in the sealing member Dsm is 24mm. The thickness of the backing member material Tm is 20 8mm. (Thus the diameter of the sealing member, which is equal to the diameter of the sealing washer 10 as a whole, minus twice the thickness of the backing member material, is approximately 89mm.) The (uncompressed) thickness of the sealing washer 10 25 as a whole T., is 27.25mm. The widest sealing ridge projects approximately 1mm from the base part of the sealing face. The least wide sealing ridge projects approximately 2mm from the base part of the sealing face. 30 The middle sealing ridge projects approximately 4mm from the base part of the sealing face. 5633519_1 (GHMatters) P90185.AU D ENI SET -19 Thus the difference in projection between the middle sealing ridge and the least wide sealing ridge P. is 2mm, and the difference in projection between the middle sealing ridge and the widest sealing ridge Pw is 3mm. 5 It should be understood that the dimensions provided above are by way of example, and are not intended to be limiting. Further, additional embodiments having at least some different dimensions are illustrated in Fig.s 3 to 10, and the labels which include subscripts, as introduced above, are for 10 convenience used to designate corresponding (but not necessarily identical) dimensions in the alternative embodiments. Fig.s 2A and 2B illustrate an alternative embodiment of a sealing device, in the form of a sealing washer designated generally by the reference numeral 110. In this embodiment the 15 sealing washer 110 is identical to the sealing washer 10 (and corresponding identical parts will not be described again) except that the sealing washer 110 further comprises a sleeve portion 154 which defines a channel 156 continuous with a central aperture 142 of sealing member 120. The sleeve portion 20 154 is thus adapted to accommodate a part of a fixing member (such as a bolt) which, in use passes through the mill shell wall. The sleeve portion 154 may serve to avoid or reduce damage to the mill shell wall by the fixing member. The sleeve portion 154 may serve to provide a degree of sealing between the 25 fixing member and an edge provided by the mill shell wall which defines an aperture through which the fixing member passes, in use. In this embodiment the length of the sleeve portion is approximately equal to the thickness of the rest of the sealing member, although it should be appreciated that the sleeve 30 portion could be longer or shorter than this if desired. In this embodiment the sleeve portion 154 is formed as an single piece with the rest of the sealing member 140, although it should be appreciated that the sleeve portion could be formed as a separate part if desired. 5633519_1 (GHMatters) P90185.AU D ENI SET -20 Fig.s 3 and 4 illustrate alternative embodiments. It will be appreciated that sealing washer 210 of Fig. 3 is similar in many respects to the sealing washer 10 of Fig.s 1A and 1B, except that it is different in at least some dimensions. 5 Similarly, sealing washer 310 of Fig. 4 is similar in many respects to the sealing washer 110 of Fig.s 2A and 2B, except that it is different in at least some dimensions. Sealing washer 310 is similar in dimensions to sealing washer 210 except that sealing washer 310 includes a sleeve portion which is not 10 provided in sealing washer 210. In an example the dimensions of various features of sealing washers 210 and 310 are the same as for sealing washer 10 of Fig.s 1A and 1B, and sealing washer 110 of Fig.s 2A and 2B except that in sealing washers 210 and 310, the diameter of the 15 aperture in the backing member Dlm is 32mm, and the diameter of the aperture in the sealing member D.m is 30mm. It should be understood that the dimensions provided above are by way of example, and are not intended to be limiting. 20 Fig.s 5 and 6 illustrate further alternative embodiments. It will be appreciated that sealing washer 410 of Fig. 5 is similar in many respects to the sealing washer 10 of Fig.s 1A and 1B, except that it is different in at least some dimensions. Similarly, sealing washer 510 of Fig. 6 is similar 25 in many respects to the sealing washer 110 of Fig.s 2A and 2B, except that it is different in at least some dimensions. Sealing washer 510 is similar in dimensions to sealing washer 410 except that sealing washer 510 includes a sleeve portion which is not provided in sealing washer 410. 30 In an example the dimensions of various features of sealing washers 410 and 510 are the same as for sealing washer 10 of Fig.s 1A and 1B, except that in sealing washers 410, 510, the diameter of the aperture in the backing member Dam is 45mm, 5633519_1 (GHMatters) P90185.AU D ENI SET -21 and the diameter of the aperture in the sealing member D.m is 38mm. It should be understood that the dimensions provided above are by way of example, and are not intended to be 5 limiting. Fig.s 7 and 8 illustrate further alternative embodiments. In an example, sealing washer 610 of Fig. 7 is similar to the sealing washers 10, 210 and 410 (of Fig.s 1A and 1B, Fig. 3 and Fig. 5, respectively) except that the diameter of 10 the aperture in the backing member Dlm is 45mm, and the diameter of the aperture in the sealing member D.m is 42mm. Similarly, in the illustrated embodiment sealing washer 710 of Fig. 8 is similar to the sealing washers 110, 310 and 510 (of Fig.s 2A and 2B, Fig. 4 and Fig. 6, respectively) except that the diameter of 15 the aperture in the backing member Dlm is 45mm, and the diameter of the aperture in the sealing member D.m is 42mm. Fig.s 9 and 10 illustrate further alternative embodiments. It will be appreciated that sealing washer 810 of Fig. 9 is similar in many respects to the sealing washers 10, 20 210, 410 and 610 (of Fig.s 1A and 1B, Fig. 3, Fig.5 and Fig. 7, respectively) except that it is different in various dimensions. Similarly, sealing washer 910 of Fig. 10, having a sleeve portion, is similar in many respects to the sealing washers 110, 310, 510 and 710 (of Fig.s 2A and 2B, Fig. 4, Fig. 6 and Fig. 8, 25 respectively) except for differences in dimensions. Sealing washer 910 has dimensions corresponding to those of sealing washer 810 except that sealing washer 910 includes a sleeve portion. In an example the dimensions of various features of 30 sealing washers 810 and 910 are as follows (where the labelling set out in relation to Fig. 1 is used to designate corresponding features). The diameter of the sealing washers 810, 910 as a 5633519_1 (GHMatters) P90185.AU D ENI SET -22 whole Dsw is 150mm. The diameter of the aperture in the backing member Dbm is 50mm. The diameter of the aperture in the sealing member Dsm 5 is 48mm. The thickness of the backing member material Tsm is 10mm. (Thus the diameter of the sealing member is approximately 130mm.) The (uncompressed) thickness of the sealing washer 10 810 as a whole Tsw is 29.25mm. It should be understood that the dimensions provided above are by way of example, and are not intended to be limiting. Further, it will be appreciated that many other 15 variations in dimensions and form are possible, within the scope of the present disclosure, since Fig.s 1 to 10 are provided only by way of example. Fig.s 11 and 12 illustrate schematically use of a sealing washer in accordance with the present disclosure. Fig. 20 11 illustrates use with an aperture in a sealing mill wall which has not been deformed, and Fig. 12 illustrates use of the sealing washer with an aperture in a sealing mill wall which has been deformed and enlarged, for example by forces imparted by a fixing member, and/or as a result of corrosion of one or more 25 parts of the grinding mill wall which define the aperture. Fig. 11 illustrates a sealing washer, for example sealing washer 10, used in conjunction with a fixing member in the form of a bolt 1010 and an associated nut 1020 which fix a mill liner 1030 to a grinding mill wall 1040. The nut 1020 may 30 be a locking nut, for example of the type which includes a nylon insert (examples of which are sold under the Trade Mark NYLOC). 5633519_1 (GHMatters) P90185.AU DENISET -23 The sealing washer 10 engages an exterior surface 1042 of the grinding mill wall 1040. The bolt 1010 has a bolt head 1012 which is retained against an interior surface 1032 of the mill liner 1030. The bolt 1010 further has threaded shaft 1014 which 5 passes through an aperture 1034 of the mill liner, through an aperture 1044 of the grinding mill wall, through the aperture 42 of the sealing member 40 of the sealing washer 10, and through the aperture 22 of the backing member 20 of the sealing washer 10. The nut 1020 is tightened onto the threaded shaft 1014 to 10 clamp the part of the mill liner 1030 adjacent the mill liner aperture 1034 to the grinding mill wall 1040, and to force the sealing washer 10 against the exterior surface 1042 of the grinding mill wall 1040. More specifically, the sealing face 44 of the sealing washer 10 is forced against the exterior surface 15 1042 of the grinding mill wall 1040. This causes deformation of at least one of the sealing ridges, and as illustrated, least wide sealing ridge 46 and middle sealing ridge 48, so that at least the deformed sealing ridge provides a continuous seal against the grinding mill wall 1040, surrounding the aperture 20 1044 of the grinding mill wall 1040, thus effectively sealing the aperture 1044. Further, it will be appreciated than when two or more sealing ridges form respective continuous seals against a surface of a wall, such as the exterior surface 1042, a sealed 25 space 60 is created between two adjacent sealing ridges. The sealed space 60 is defined by the two adjacent sealing ridges (e.g. least wide sealing ridge 46 and middle sealing ridge 48), the part of the sealing face 44 between the sealing ridges, and the part of the surface (e.g. exterior surface 1042) between the 30 sealing ridges. When the sealing face 44 is forced against the surface of the wall, for example by tightening a nut and bolt arrangement (providing as a fixing member) the sealing ridges deform, and the space 60 reduces in volume until the force applied reaches a maximum. Air is forced out of the space 60 as 35 its volume decreases. The resilient sealing ridges are 5633519_1 (GHMatters) P90185.AU DENISET -24 elastically compressed and provide a force which tends to push the sealing washer as a whole away from the wall, but the force applied by the fixing member retains the washer in position. If the applied force is reduced at some point (for example due to 5 loosening of the nut/bolt over time) the washer will move slightly away from the wall increasing the volume of the space 60. As the space 60 is sealed this results in a partial vacuum in the space 60 which resists further movement of the washer away from the wall in a manner that may be regarded as similar 10 to a suction cup arrangement. Thus the space 60 and associated partial vacuum or suction enhances locking of the washer in position. Fig. 12 illustrates a sealing washer 110, as described above with reference to Fig. being used in a manner 15 corresponding to that illustrated in Fig. 11 except that that the aperture 1044 of the grinding mill wall 1040 is considerably somewhat worn or damaged, for example by forces imparted by a fixing member, and/or as a result of corrosion of one or more parts of the grinding mill wall which define the aperture 1044. 20 It will be appreciated that the sealing washer 110 effectively seals even the enlarged deformed aperture since it provides a middle sealing ridge 148 (corresponding generally to the middle sealing ridge 48 of sealing washer 10) has a greater diameter than the enlarged aperture 1044. It will be appreciated that 25 embodiments which include sleeve portions (such as, for example, sleeve portion 154) are particularly appropriate for use with worn or damaged apertures. The sleeve portion, being made of a material which is soft compared to the bolt, protects the part of the wall defining the aperture from further damage from the 30 bolt or other fixing. Further, the thickness of the sleeve portion may partially (or even completely) bridge the gap between the bolt or other fixing member and the part of the wall defining the aperture, which may enable it to provide at least a partial seal (in addition to the seal provided by one or more 35 sealing ridges of the device. 5633519_1 (GHMatters) P90185.AU DENISET -25 It is preferred that the fixing member used is a threaded fastener such as a bolt, although other types of faster. In a practical embodiment the fixing member is a threaded faster of the type sold under the Trade Mark HUCK by 5 Alcoa Fastening Systems, and known as a HUCK bolt or HUCK LockBolt. One such bolt is sold under the Trade Mark BOBTAIL. The bolt may include a bolt head and a threaded shaft for engagement with a collar (which acts as a nut) and may further include an engagement part, distal from the bolt head, which can 10 be engaged by a setting tool (such as, for example, the Alcoa BTT20SF). The setting tool can grip the engagement part and apply a force in an axial direction of the threaded shaft to allow increased tightening of the collar, may also push the collar against the joint, and may also swage the collar against 15 the joint. This is considered to provide a tight and secure fixing which can be rapidly applied. It will be appreciated that at least embodiments disclosed herein provide a washer which is convenient to use and which may be regarded as a specialised sealing device which can 20 be used to seal, lock and provide a firm base for fixing nuts in, for example, mineral ore, cement and quarrying applications to hold liners in place in relation to a wall. Embodiments are particularly suitable for use on grinding mills. The describe washer may be provided as a single unit, which can enhance ease 25 of use compared to some known sealing arrangements in which a metal washer and a sealing part such as a rubber washer are provided separately. In the claims which follow and in the preceding description, except where the context requires otherwise due to 30 express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is 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. 5633519_1 (GHMatters) P90185.AU DENISET -26 It is to be understood that, if any prior publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or in any other 5 country. Modifications and improvements may be incorporated without departing from the scope of the present invention. 5633519_1 (GHMatters) P90185.AU DENISET

Claims

1. A sealing device for attaching a liner to the inside wall of a grinding mill, the sealing device comprising: a backing portion with an aperture for a fixing 5 member to extend therethrough, wherein the backing portion comprises a back wall portion having a side wall portion depending therefrom; and a sealing portion with an aperture for said fixing member to extend therethrough, wherein the sealing portion 10 comprises a sealing face, for contact with the wall of the grinding mill, the sealing face having at least one sealing ridge extending around, and spaced apart from, the aperture of the sealing portion; wherein the backing portion is adapted to force the 15 sealing portion against the wall when a fixing member is extended through the apertures, the fixing member engagable with the back wall portion of the backing portion; wherein the sealing face comprises an elastomer adapted to deform when the sealing portion is forced against the 20 wall; and wherein the side wall portion extends along almost the entire thickness of the sealing portion to assist in preventing undesirable spreading of the elastomer in use.

2. A sealing device as claimed in claim 1 wherein the or each 25 sealing ridge is substantially annular.

3. A sealing device as claimed in claim 1 or 2 wherein the sealing face has a plurality of sealing ridges each extending around the aperture of the sealing portion.

4. A sealing device as claimed in any preceding claim wherein 30 the at least one sealing ridge is made of rubber, polyurethane based elastomer, thermoplastic elastomer, and/or silicone-based 5633519_1 (GHMatters) P90185.AU DENISET -28 elastomer.

5. A sealing device as claimed in any preceding claim wherein the sealing device further comprises a sleeve portion which projects away from the sealing face, and is adapted to extend 5 into an aperture in the wall through which said fixing member extends, in use, and wherein the sleeve portion provides a channel for accommodating part of said fixing member.

6. A sealing device as claimed in claim 5 wherein the sleeve portion is formed as integral part of the sealing portion. 10

7. A sealing device as claimed in any preceding claim wherein the sealing portion comprises at least two spaced apart sealing ridges, wherein a void area is provided between the spaced apart sealing ridges, the void area adapted to provide a sealed space when the sealing face is forced against a wall. 15

8. A sealing device as claimed in claim 7 wherein the sealing face is configured so that, in use, a partial vacuum is created in the sealing space if the force which is applied to force the sealing portion against the wall is reduced.

9. A sealing device as claimed in any preceding claim wherein 20 the at least one side wall portion extends about at least part of the sealing portion, engages the sealing portion and restrains deformation of the sealing portion in a direction parallel to the sealing face.

10. A sealing device as claimed in any preceding claim wherein 25 the backing portion is bonded to the sealing portion.

11. A sealing device as claimed in any preceding claim wherein the backing portion is made of metal.

12. A sealing device as claimed in any preceding claim wherein the width of the sealing face is at least twice the width of the 30 aperture of the sealing face.

13. A sealing device as claimed in claim 12 wherein the width of 5633519_1 (GHMatters) P90185.AU DENISET -29 the sealing face is approximately three times the width of the aperture of the sealing face.

14. A sealing device substantially as hereinbefore described with reference to the drawings. 5

15. A method of sealing an aperture in a wall, comprising use of a sealing device in accordance with any one of claims 1 to 14

16. A method as claimed in claim 15 wherein the wall is a wall of a grinding mill.

17. A method as claimed in either of claims 15 or 16 wherein the 10 method comprises sealing the aperture in a wall as part of attachment of a liner to the wall.

18. A method as claimed in any one of claims 15 to 17 comprising passing a fixing member through the liner, the aperture in the wall, the aperture of the backing portion and the aperture of 15 the sealing portion, and then tightening the fixing member to cause the backing portion to force the sealing portion against an exterior surface of the wall.

19. A sealing device substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

20 5633519_1 (GHMatters) P90185.AU DENISET