Evans Deakin Engineering Pty Ltd v the ANI Corporation Ltd

[2001] APO 66

OFFICIAL NOTICE

DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS

Application  :          No.695779 in the name of Evans Deakin Engineering Pty Ltd

Title:          Lifter Bar

Action: Opposition under s59 of the Patents Act 1990 by The ANI Corporation Ltd

Decision:          Issued            .

Abstract

The invention relates to a lifter bar for a grinding mill in which the studs that secure the lifter bar to the inside of the mill are inserted and removed from a position outside of the shell and in which the lifter bars do not have conventional bolt through-holes.

The opponent alleged that the claims are not entitled to have a priority date of either the date of filing of the provisional specification or the complete specification as filed.  The opponent further asserted that as a result of the amendments, the specification claimed matter not in substance disclosed.  Consequently, the opponent argued that the claims were not novel in view of the disclosures in either the provisional or complete specification as filed.  This submission was rejected as it is difficult to understand how a claim lacking in fair basis on its own provisional or claiming matter not in substance disclosed in the specification as filed can at the same time be rendered not novel on the basis of the disclosures in those documents.

While there was a product that was produced between the OPI date and date of the amendment, there was insufficient evidence on the public availability of the product for a review of the priority dates of the claims of the opposed application to be conducted.

With the exception of claim 10, the claims lacked fair basis as they excluded an essential feature of the invention, such essentiality being derived from the only stated object of the invention and from the preferred embodiments.

Independent claims 1, 11, and 12 required that the studs are releasable through rotation of the studs themselves, and that insertion and removal occur externally of the shell of the mill.  This is an essential feature of the current invention that was not disclosed in the prior art cited.  Hence the claims were found to be novel.  In relation to inventive step, no piece of the relevant prior art was found to be common general knowledge in Australia.

The applicant was given an opportunity to amend.

PATENTS ACT 1990

DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS

Re:Patent Application No. 695779 by Evans Deakin Engineering Pty Ltd and an opposition thereto by The ANI Corporation Ltd under section 59 of the Patents Act 1990.

BACKGROUND

The present application was filed on 5 January 1996 as 40859/96.  It claims priority from provisional application PN0393 that was filed on 5 January 1995.  The application was advertised accepted on 20 August 1998 and allocated number 695779. 

The ANI Corporation Ltd (ANI) filed opposition to the present application on 20 November 1998.  All evidentiary stages were completed by 22 November 2000.  The matter was heard on 9 April 2001 in Melbourne.  The applicant, Evans Deakin Engineering Pty Ltd (Evans Deakin) was represented by Mr Paul Savage, patent attorney of the firm Freehills Carter Smith Beadle, Sydney, and the opponent was represented by Mr Claude Anese, patent attorney of the firm Cullen & Co, Brisbane.

THE SPECIFICATION

The invention relates to a lifter bar for a grinding mill used for grinding ore.

The specification explains that grinding mills are used for grinding mineral bearing ores into relatively small particles that can be subsequently processed for mineral extraction. 

The grinding mill typically comprises a cylindrical shell that is lined on its inner surface with a plurality of metallic or rubber liners.  These liners protect the inner surface of the shell from being worn away by the ore being ground and are held in place by lifter bars which are bolted to the cylindrical shell and which clamp opposite longitudinal edges of the liner to the inner surface of the cylindrical shell (or drum). 

The lifter bars of a typical grinding mill are elongated members that extend substantially the length of the shell and are circumferentially spaced about the inner surface of the shell.  In order to fix the bars to the shell, each lifter bar is provided with a plurality of counter-sunk holes (through bolt-holes) which extend wholly through the bar in the radial direction of the shell.  Bolts are then passed through the holes from the inside of the shell and extend through holes provided in the shell.  Each bolt is provided with a head shaped so as to mate with the counter-sunk holes in the lifter bar.  A nut is then screwed onto the opposite end of each bolt in order to fix the lifter bar and liners to the shell.  When the grinding mill is in use the shell is rotated and the lifter bars lift the ore and any grinding ball where they fall by action of gravity, thereby producing a tumbling action that has the effect of grinding the ore.

Lifter bars are made by casting with cavities being formed during the casting process in order to provide the bolt-holes.  In use, these cavities form weak points in the casting and the corresponding bolt-holes provide a site for accelerated wear of the lifter bars.  The specification explains that it is common to strengthen the lifter bars by providing pads or bulges in the area of the bolt-holes.  However, this increases the cost of the lifter bars and in any event cannot prevent accelerated wear in the vicinity of the bolt-holes.  The object of the invention is to provide a lifter bar that can be fastened to a grinding mill without the use of conventional bolt through-holes.

The specification ends with 18 claims of which 3 are independent.  Claim 1 is directed to a lifter bar assembly while claims 11 and 12 are respectively directed to a method of attaching a lifter bar assembly to the rotatable shell of a grinding mill and to a method of detaching a lifter bar assembly attached to the internal surface of the rotatable shell of a grinding mill. 

The independent claims read as follows:

"1  A lifter bar assembly adapted to be mounted to the inner surface of a rotatable shell of a grinding mill, the lifter bar assembly comprising:

an elongate member having an upper portion which is in use exposed to material to be ground by said mill when said lifter bar is mounted to the inner surface of the shell, and a lower portion adapted to lie adjacent the inner surface of the shell;

a plurality of elongate fastening studs releasably secured to said elongate member and spaced apart from each other, along the length of said elongate member, and projecting in a direction away from said upper portion, said studs being adapted to pass through mounting holes formed in the shell;

the studs each having screw threads formed on or adjacent the distal end thereof adapted to receive a securing nut for releasably securing the respective studs and the elongate member to the shell;

the studs being releasable from the elongate member by rotating the studs relative to the elongate member from a position exterior of the shell."

"11  A method of attaching a lifter bar assembly to the rotatable shell of a grinding mill, the lifter bar assembly including an elongate member having a plurality of threaded bores spaced apart along its length, the shell having a plurality of mounting holes thereon spaced apart in registry with the threaded bores in the elongate member, the method including the steps of:

aligning the threaded bores of the elongate member with the mounting holes in the shell;

inserting threaded studs through the holes in the shell into the threaded bores in the elongate members and rotating the studs to screw them into the respective threaded bores, the studs having sufficient length to project out of the holes in the shell and stand proud of the shell; and

securing the elongate member and studs in position on the shell by screwing securing nuts onto the ends of the studs projecting out of the holes in the shell.

12  A method of detaching a lifter bar assembly attached to the internal surface of the rotatable shell of a grinding mill, the lifter bar assembly including an elongate member having removable fastening studs securing the lifter bar to the shell, said fastening studs being releasably engaged with the elongate member and having securing nuts screwed onto the outer ends thereof and tightened against the outer surface of the shell, the method including the steps:

disengaging the studs from the elongate member from a position exterior of the shell; and

withdrawing the studs from the elongate member from said exterior position."

Amendments to the specification were filed on 19 March 1998.  Included with the proposed amendments were changes to the description of the invention and the inclusion of an additional drawing.  No further amendments were filed and after an adverse report which issued on 21 April 1998 and rebuttal thereto the application was accepted.

Grounds of Opposition

ANI opposed the application on the grounds of lack of novelty, inventive step, and fair basis.  It also submitted that the application was not entitled to the priority date of the provisional application that was filed on 5 January 1995 and that as a result of the amendments, the accepted specification claimed matter not in substance disclosed in the specification as filed.  As a consequence, the opponent alleged that the claims lacked novelty in view of the disclosures in the provisional and complete specifications.

THE EVIDENCE

Evidence-in-support
Claude Paul Anese, patent attorney for the opponent filed a statutory declaration with accompanying exhibits CPA1-CPA17.  These exhibits consisted of patent documents.

Robert Alexander Eaton filed a statutory declaration with accompanying exhibits with RAE1-RAE6.  The details of these exhibits are as follows.

• RAE1 is a copy of drawing number M3191-1-1 of a pulplifter installed at Mount Isa Mine prior to 1995,

• RAE2 is a copy of an extract from a mining products catalogue distributed by Deks Industries Pty Ltd,

• RAE3 is a copy of brochure illustrating JAQUES double toggle jaw crusher,

• RAE4 is a brochure illustrating ANI RUWOLT Jaw double toggle jaw crusher,

• RAE5 is a copy of brochure illustrating ALLIS-CHAMBERS A-1 double toggle jaw crusher, and

• RAE6 is an extract from SME Mineral Processing Handbook published by the Society of Mining engineers in 1985.

Gary David Everson filed a statutory declaration with accompanying exhibits GDE1-GDE2.
Exhibit GDE1 is a copy of drawings of part of a 48"X36" DT jaw crusher manufactured and sold in Australia by Vickers Ruwolt Pty Ltd.  Exhibit GDE2 is a copy of drawings of a stud (also known as a jaw bolt) and nut from a 48"X42" rock crusher manufactured and sold in Australia by Vickers Ruwolt Pty Ltd.

Evidence-in-answer
Peter Paterson filed a statutory declaration.  Mr Paterson is managing director of Pacific Relines (Aust) Pty Ltd. 

Ian James Christie filed a statutory declaration.  Mr Christie is an employee of Vaughan Castings, a division of Evans Deakin Engineering Pty Ltd.  He had previously worked for ANI. 

Evidence-in-reply
Robert Alexander Eaton filed a second declaration.

DECISION

Priority date issues

As part of its submission, the opponent alleged that the claims are not entitled to have as their priority date, the date of filing of the provisional specification.  Mr Anese further submitted that the complete specification as amended was not entitled to the priority date of the complete specification as filed since the amendments proposed on 19 March 1998 and ultimately allowed were claiming matter not in substance disclosed in the specification as filed.  Consequently, Mr Anese argued that the provisional document and the specification as filed that were published on 18 July 1996 rendered the claims not novel as the claimed invention could only have an earliest priority date of 19 March 1998. 

Mr Anese made a number of submissions on this point including pointing out the fact that the tests for novelty and for "in substance disclosed" differ.  I have some difficulty with this argument.  This difficulty is well expressed in previous decisions of the Commissioner.

"Although the tests for novelty and fair basis are not the same I cannot agree with …[the] argument.  The disclosure in the specification which is sought to be used of the purpose of novelty,…, also serves to support for the claims in so far as fair basis is concerned.  Thus, whatever is fairly based cannot be held not novel and whatever is not fairly based cannot be used as an anticipation."  The Regents of the University of California The Dow Chemical Company [2001] APO 34 (26 July 2001)

In Orenco Systems, Inc v Everhard Industries Pty Ltd [1999] APO 68 (26 October 1999), the delegate stated;

"The opponent's argument in effect is that the amended claims are disclosed in the originally filed specification for the purposes of assessing novelty, but are not disclosed for the purposes of fair basis as they have been broadened beyond what was described.  Although the tests for fair basis and novelty are not the same, I have difficulty with the logic of this argument."

"A similar argument was put to me in Firebelt Pty Limited v MacDonald Johnston Engineering P/L [1994] APO 67 (25 November 1994) in considering the fair basis of a petty patent on a provisional application. In that case, I said that either the claims were fairly based on the earlier application, in which case the claims were entitled to the earlier priority date, or if there was such a discernible shift away from the provisional application such that the claims were defining a different invention, there would be no lack of novelty."

I am in agreement with these decisions and hence I need not consider the argument any further.

While there is no document that has a publication date between the earliest priority date and the date of the proposed amendment, there is some suggestion that there was a product publicly available that would render the claimed invention as lacking novelty.  This information was contained in the declaration filed by Mr Everson for ANI.

In his declaration, Mr Everson referred to a product that was made publicly available in late 1996.  This date is after the publication date of the current specification but before the specification was proposed to be amended.  Mr Everson stated.

"Around late 1996, ANI Braken publicly released a lifter bar assembly for sale.  The lifter bar assembly used studs which were inserted through the shell of the grinding mill and onto nuts held captive in respective bores in the lifter bar.  These bores were through-holes which extended to the top of the lifter bar, i.e. the surface of the lifter bar exposed to wear.  The bores were filled with inserts."

Mr Christie for Evans Deakin commented in his declaration that "the date of release of the ANI lifter bar assembly was after the publication date of the patent application". 

Given Mr Anese's comments on priority dates, if the claims under opposition were to have a later priority date as set by patents regulations 3.14 (b), then the evidence of the publication of this material would have been relevant to this opposition.  However, there is in my view insufficient evidence on the publicly availability of the product for me to need to review the priority dates of the claims of the opposed application.

As no other documents have been raised that depend upon an assessment of priority dates, I need not consider the issue any further.  However, the issue of fair basis of the claims is an issue in this opposition, which I will now consider.

Fair Basis

The opponent points out that while the object of the invention is to provide "a lifter bar which can be fastened to a grinding mill without the use of conventional bolt through-holes", claims 1-9 and 11-15 are broad enough to include within their scope a lifter bar having conventional bolt through holes.  Mr Anese submitted that only in claim 10 was this construction denied.  Claim 10 stated.

"A lifter bar assembly according to any preceding claim wherein the elongate member has a continuous upper surface which is exposed to material to be ground by the mill when the lifter bar assembly is fixed to the inner surface of the shell."

[italics my emphasis]

By defining the elongate member as having a continuous surface, a construction in which there is a through bolt-hole is denied.  Hence, Mr Anese concluded that the stated claims lack fair basis as they exclude an essential feature of the invention, such essentiality being derived from the only stated object of the invention and from the preferred embodiments where the through bolt-holes extend transversely through the lifter bar.

To answer this allegation, it is necessary to review the specification as filed and as amended.  This review will reveal that there is a significant difference between "conventional bolt through-holes" and "through holes" as used in the current specification.  Conventional bolt through-holes of the admitted prior art were radial in direction.

In the specification as amended, a new figure 7 was introduced.  The specification states that it relates to a "lifter bar having a through slot."  The amended text states.

"Further, although the slots 28 areas shown as not extending wholly through the lower part 22, (that is they are in they may be in the form of blind holes), they could be as is illustrated in figure 7, that is the slots 28 pass all the way through the lifter bar holes 10."  [Italics new text, underline deleted text]

Figure 5, a second embodiment, which remained unamended refers to a slot 28' that extends only partially rather than wholly through the lower portion 22' of the lifter bar.  It is this slot that becomes extended as in figure 7 to becoming a through hole.

The description refers to the lifter bar as being provided with "three recesses in the form of slots 28 that extend transversely through lower portion 22.  A separate hole 30 extends through the lower portion 22 to each slot 28." 

"Significantly, the present embodiment does not require bolt-holes which extend wholly through the elongate member 16 in the radial direction in order to allow fastening to the shell 14.  Therefore the inherent weaknesses of the prior art lifter bars are avoided by the present embodiment.  Further, as the upper surface 20 is continuous and free of bolt-holes has much improved wear characteristics."

From these embodiments, I conclude that the invention relates, inter alia, to the provision of slots/bolt-holes that are provided transversely through the lower portion of the lifter bar.  This avoids the problems of the prior art and satisfies the stated object of the invention.

However the language of the claims is somewhat different to that of the description of the preferred embodiment and the word "slots" is not used.  Claim 1, in fact, makes no reference to any mechanism of "releasably fastening" the studs to the elongate member.  Claim 1 merely states that the studs are releasable through rotation and leaves unspecified how it is held in place.  Therefore, the claims are clearly not restricted to the use of the transverse slots and can thus include a hole passing through the lifter bar (i.e. the "conventional bolt through-holes"). 

In my view there is clearly no support for the construction in which the bolt-holes pass through the lifter bar in a radial direction.  The applicant echoes this in the declarations that were provided-in-answer to the opposition.  Specifically, Mr Christie referred to the product manufactured by Vaughan Castings, a division of the applicant Evans Deakin, which he stated is identical to the lifter bar described in the current application.  Interestingly, Mr Christie described that the lifter bars "do not have openings in their wear sides".  Mr Paterson, a declarant for the applicant who was also familiar with Vaughan castings clearly stated that "stud fixing does not pass through the full thickness of the lifter bar and thus there are no bolt-holes cavities on the wear side of the lifter bar".  The specification and the evidence provided by the applicant support the proposition proffered by the opponent that a construction in which the bolt-hole passes through the lifter bar in radial direction has no support from the description.  Thus there is no "real and reasonably clear disclosure" of this feature in the specification.  Apart from claim 10, the claims lack fair basis as they include within their scope a construction in which the through bolt-hole passes through the lifter bar in a radial direction.  Alternatively, this could be expressed in similar terms to the words in claim 10, namely that there is an essential feature of the invention, whereby the elongate member has a continuous upper surface that is exposed to material to be ground by the mill when the lifter bar assembly is fixed to the inner surface of the shell, that has been omitted from the stated claims.

Further argument on fair basis related to the lack on any limitation in the claims that the securing studs are threaded into the lower portion of the lifter bar.  Mr Anese argued that there was no express disclosure or any implied suggestion in the body of the specification that the securing studs are screwed into the lifter bars at any location other than at the lower portion thereof.  Hence, Mr Anese argued that claims 1-15 lacked fair basis.  Given my finding on fair basis in relation to the continuous upper surface, it seems to me to be implied that the stud will need to be located at a position "lower" than the continuous surface.

In summary, I have found that claims 1-9, 11-15 lack fair basis, as they do not define that the elongate member has a continuous upper surface as per the construction of claim 10. 

There is one further matter.  Claim 11 holds that the stud is inserted into the lifter bar from a position outside of the shell.  The preferred embodiment specifically refers to the attachment of the stud to the lifter bar prior to insertion. 

"The elongate member 16 [the lifter bar] with attached fastening means 26 [the stud] is then placed inside the shell and disposed adjacent shell liners 46."

Mr Paterson confirms this method of attachment when he stated.

"…liner components are installed with the studs in already in place, once the liner component is aligned with the holes in the shell the liner component can be pressed into position against the shell wall and the studs will all simultaneously pass through the bolt holes in the wall of the shell."

However, there is support for the construction of claim 11 in the specification when it is stated in the last paragraph of the description that "..the stud 36 can be screwed onto nut 32 from outside of shell 14."  There is on the whole a "real and reasonably clear disclosure" of this feature.

Novelty

The test for determining whether an invention lacks novelty is the " reverse infringement test" as set out in Meyers Taylor Pty Ltd v Vicarr Industries Ltd, (1977) CLR 228 at page 235 (see also 13 ALR 605 at page 611), where Aickin J stated:

"The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent were valid, constitute an infringement."

Infringement of a claim occurs where "each and every one of the essential integers" of that claim have been taken.  See e.g. Rodi and Wienenberger AG v Henry Showell Ltd, (1969) RPC 367 at page 391.

The argument on novelty revolved around the use of the studs in the Trellex pulplifters (as evidenced in the Eaton declaration) and on the following patent specifications.

• Australian provisional PN0393

• Australian patent application 40859/96

• Australian patent application 78038/95

• Australian patent application 32970/95

Trellex pulplifters
Mr Eaton, who worked at Mount Isa Mines for 37 years, attested to the knowledge of the design and construction of crushers and grinding mills in Australia prior to 1995.  Specifically, Mr Eaton refers to the Trellex pulplifter, the drawing of which formed exhibit RAE1.  The drawing is dated 1990 and illustrates a pulplifter.

Pulplifters are found in grate discharge mills such as semi-autogenous mills and are installed between the grates and the discharge ends of the mills.  Mr Eaton, a declarant for the opponent, stated the following.

"Pulplifters and lifter bars have somewhat similar shapes, and can be bolted to the mills in the same way.  However, they serve different purposes.  …lifter bars are used to move the grinding media in the mill, whereas pulplifters are used to lift the slurry (or "pulp") which has passed through the grates up to the discharge port of the mill."

Mr Eaton further described the Trellex pulplifter as having studs that hold the lining material against the inner surface of the shell of the mill, the inner end of which was threaded onto a nut welded to the metal backing plate of the rubber lining.  The studs were screwed into the pulplifter from outside of the mill and a tensioning nut was fitted to the outer ends of the studs and tightened.  Removal was the reverse process involving loosening of the tensioning nuts and unscrewing of the studs from outside of the mill.

In answer to these submissions, Mr Savage submitted that the written text on the drawing indicates that the studs are simply for "holding pulplifters loosely in place while assembling headplates & grateplates with 042 bolts".  He submitted that this means that the studs were not the primary holding system.  Mr Christie, whom I consider to be a man skilled in the art, makes the same points. 

However, the matter of novelty can readily be resolved by referring to the following quote from Mr Eaton.  It is clear form this quote that lifter bars were not attached in a manner similar to pulplifters.  The quote is as follows.

"In the mill of exhibit 'RAE1', both pulplifters and lifter bars were used.  In that particular mill, the lifter bars were formed integrally with the liner.  I say that, prior to 1995, it would have been obvious to a person involved in the design of grinding mills to fasten lifter bars or the liner to the grinding mill with studs in a similar manner to that shown in exhibit 'RAE1'".

In other words, the drawing of the Trellex pulplifter does not disclose, for the purposes of novelty, the features of the claimed invention.

Australian provisional PN0393 and Australian patent application 40859/96
Australian provisional PN0393 is the priority document for the current specification and was filed on 5 January 1995 and Australian patent specification 40895/96 is the OPI specification of the opposed application, both of which were published on 18 July 1996.  I have already discussed this issue and concluded that neither of these documents are relevant.

Australian patent application 78038/95 (Trelleborgs Gummifabriks Aktiebolag)
Mr Anese submitted that claims 1, 2, 7, 10-13 and 15 lacked novelty in view of this citation.

The citation relates to the releasable attachment of a lining material to a surface subject to wear.  The invention of this application is applicable to "rotatable shell or drum" mills and thus is applicable to the field of the invention under opposition. 

While Mr Savage submitted that the field of the inventions is different and that the liner of the citation would not be capable of sustaining the shear forces that occur in lifting bar assemblies, the specification makes it very clear that a grinding mill is included.  The citation states the following.

"Wear-resistant linings of resilient material such as natural or artificial rubber are commonly employed to protect surfaces which otherwise are exposed to wear during use.  For example, rotary mill, rotary ball, tube and rod mills are provided with such linings to protect the inner surface of the rotatable shell or drum of the mill from abrasion by material being pulverized or mixed and from the effects of impact of the balls, tubes, rods or other grinding media placed in the drum during operation thereof."

The citation also refers to the use of "T-slots" in which a threaded fastener is received and supported.  The shank of the bolt is threaded and fits through the corresponding opening in the shell for retention by a threaded nut.

The invention as disclosed in figures 1 to 3 of the citation uses a self tapping threaded fastener that is screwed into the lining material.  In one embodiment the "fastener can be inserted through the opening and screwed into the liner segment to initiate the embedding operation".  Once the fastener has being screwed into the liner segment, a nut can be threaded onto the outer end of the shank of the fastener to draw the liner segment onto tight engagement with the liner surface of the support member.  Figure 4 illustrates a lining structure for a mill drum.  Mr Anese suggested that as the fastener was capable of engagement it was inherently capable of being releasable and therefore the invention as defined by claims 1 and 12 was disclosed. 

However, Mr Christie commented in his declaration that the stud of this citation,

"is hollow and is more like a self tapping hollow cylinder than a stud.  It is screwed into position after the liner has been fitted into position, and clearly would not carry the loads to which a typical lifter bar would be subjected."

In my view, once the fastener of the citation is embedded into the liner material it is not releasable in the sense used in the specification.  Hence this citation does not deprive the claims 1 and 12 and appended claims of novelty.

In relation to claim 11, it is clear that the fastener of the claim need not be releasable.  However, as the bore of the elongate member is threaded in this claim and the citation does not disclose such a threaded bore, this claim is also novel.  

Hence the claims of the application are novel in view of this citation.

Australian patent application 32970/95 (Svedala Industries)
Mr Anese submitted that claims 1, 2, 10-12, and 15 lacked novelty in view of this citation.  This citation has a priority date of 3 October 1994 and was published on 18 April 1996.  As such this citation falls to be considered under paragraph (b)(ii) of the definition of prior art base.

In the prior art described in the citation the liner segments for primary grinding autogenous or semi-autogenous mills are held in place by bolts.

"The liner segments are held within the cylindrical shell of the mill by bolts having heads received in tapered sockets which extend completely through the liner segments.  Threaded shanks of the bolts pass through the holes within the liner segments and the shell to threadably engage washers and nuts at the outer surface of the mill.  Because the holes extend completely through the liner segments, the holes are a point of weakness within the liner segment where the segments typically crack or break due to wear or stress."

The specification refers to the typical mounting of rubber or composite liners in secondary grinding applications as follows.

"…T bolts having flat, elongated heads which are positioned in T-shaped grooves formed centrally within the rubber portion of the liner."

The purpose of the invention of this citation is to extend the life of a worn liner by mounting it to a different grinding mill and in particular to mount the liners from a primary grinding mill to a secondary grinding mill.  The liners include lifter bars for lifting the material. 

The specification further discloses that a liner having a longitudinally extending slot, which does not extend through the liner, avoids the problem associated with holes that extend through the liner.  This echoes the problem addressed by the current specification.

The citation discloses the use of an adapter to couple the worn liner to the different mill.  The liner is attached to the adapter via a bolt that in use also will extend through the external shell of the grinding mill.  The liner and adapter function as a single unit that is then attached to the inner surface of the grinding mill.  Three different means of attachment are contemplated: through bolts, a blind bores, and longitudinally slotted holes are used. 

Mr Savage submitted that the citation was silent on the studs being releasable.  While there is no reference to the liner/adapter assembly being releasable from the grinding mill, the specification states that the liner and adapter are releasably connected.  From this and the structure presented in the citation, I can see no reason why the liner/adapter are not considered to be releasably connected to the inner wall of the grinding mill.  The citation specifically requires that the liner from the primary grinding mill be removed.  The structures of the liners in two of the embodiments illustrated in figure 6 appear to be the same as that described in the current application.  However, independent claims 1, 11, and 12 require that the studs are releasable through rotation of the studs themselves and that insertion and removal occur externally of the shell of the mill.  This is an essential feature of the current invention. 

Mr Paterson for the applicant stated the following in his declaration

"Removal of the worn components is facilitated by the fact that the stud can be removed from the liner component from outside the mill shell."

The citation does not show this. 

In relation to claim 11, the citation discloses a method in which the stud is already mounted on the liner before it is attached to the shell.  The method of the invention resides in attaching the stud externally of the shell. 

Hence, independent claims 1, 11, and 12 are novel.

Inventive step

Mr Anese submitted that the pulplifter alone rendered the invention as lacking in inventive merit.

In a quote previously referred to Mr Eaton asserted that it would be obvious to use the attachment means described in relation to pulplifters in a grinding mill.  The point is well answered by the declarant for Evans Deakin, Mr Christie who made the following points.

• The purpose of the studs in the pulplifter are completely different to the studs employed in the current invention,

• The studs simply hold the pulplifter in position, and

• There is no suggestion or evidence that a person skilled in the art of grinding mills would look to pulplifters for a solution as the stress involved in these application differ markedly.

In the evidence-in-reply, Mr Eaton responded to the statements of Mr Christie.  In particular, Mr Eaton agreed that the studs used in the Trellex pulplifter are not identical to the manner in which the studs are used in the lifter bar assembly but that the principle is the same.  He acknowledged that in the Trellex pulplifter the studs are not the only items holding the installed lifters in place, whereas in the opposed application it is intended that the studs be the sole means of attachment.

Given these admissions I am not convinced that the invention is obvious in light of the disclosures in the pulplifter.

Mr Anese further submitted that either patent documents 78038/75 and 32970/95 when combined with common general knowledge renders claims 1-6, 7-15 as lacking an inventive step.  Mr Anese also submitted that the individual pieces of common general knowledge render the claimed invention as lacking an inventive step. 

Before considering these issues, common general knowledge in Australia will need to be identified and established.

In Minnesota Mining & Manufacturing Co v Beiersdorf (Australia) Limited, (1980) 144 CLR 253 at page 292, Aickin J. stated:

"The notion of common general knowledge itself involves the use of that which is known or used by those in the relevant trade.  It forms the background knowledge and experience which is available to all in the trade in considering the making of new products, or the making of improvements in old, and it must be treated as being used by an individual as a general body of knowledge."

Mr Anese submitted that the common general knowledge in the art consisted of the following:

(i) lifter bar assemblies fixed by bolts in through holes with nuts on the exterior of the shell,
(ii) threaded studs generally as evidenced in Christie declaration,
(iii) double threaded studs as use in jaw crushers as evidenced in Christie declaration,
(iv) SME mineral processing handbook (exhibit RAE6),
(v) DEKS mining products catalogue (exhibit RAE2), and
(vi) treaded studs with drive formulations on one end as evidence in the Everson declaration.

(i) Lifter bar assemblies fixed by bolts in through holes with nuts on the exterior of the shell
Mr Savage conceded that items (i) forms part of the prior art.  This concession, (i) in relation to the lifter bar being fixed to bolts in through bore-holes is not enough to deprive claim 1 of novelty as it does not specify how the studs are released from the lifter bar.  Indeed, the implication is that the bolts are inserted from inside of the grinding mill.

(ii) Threaded nuts as evidenced in the Christie declaration
Mr Anese submitted that the Christie declaration attested to the fact that threaded nuts were known in the industry.  While the mere existence of threaded nuts per se would be insufficient for lack of inventive step per se, it does suggest that threaded nuts were common general knowledge.  In my view, this is all Mr Christie was alluding to in his declaration.  Hence, while I accept that that threaded nuts are well known and Mr Savage concedes this point, there is no evidence that a person skilled in the art would make the necessary improvements in arriving at the claimed invention.

(iii) Jaw Crushers (exhibits RAE3, RAE4 and RAE5)
In the jaw crushers as illustrated in the brochures, studs are used to hold the wear plates to the jaws.  The studs are screwed into the head nuts in recesses in the wear plates from outside the jaws.  The recesses in the jaw plates hold the head nuts, the nuts being shaped to prevent the nuts from rotating when the studs were screwed into them.  Securing nuts are screwed into the outer ends of the studs.  The Eaton declaration describes various methods for attaching and detaching the studs from the jaw plates.  Mr Eaton attested that the use of these studs was common knowledge in the industry prior to 1995.  The evidence of Mr Christie supports this.  However, this knowledge alone is insufficient to deprive the application of an inventive step.  What I consider that the evidence establishes is that the two fields are disparate; i.e. a person skilled in the art of grinding mills would not necessarily look to the field of jaw crushers for a solution to a problem in grinding mills.

(iv) SME mineral processing handbook (exhibit RAE6)
Extracts of chapters dealing with jaw crushers and grinding were annexed in this exhibit.  Mr Eaton specifically referred to the Allis-Chalmers jaw crusher and stated that "the wear plates are fixed to the jaws by studs passing through the jaws and threaded into nuts captively held in recesses in the wear plates" with tensioning nuts being screwed onto the outer ends of the studs. 

While, the document attests to the knowledge of design of studs as used in the technology of jaw crushers, it is not obvious to me that a person skilled in the art would have recourse to this technology for a solution to a problem with grinding mills.

(v) DEKS mining catalogue (exhibit RAE2)
According to Mr Eaton the one page copy of the extract from the catalogue illustrated rubber lifter bars.  But, according to Mr Christie the extract merely illustrated rubber liners.  Mr Eaton further declared that there is no inventive difference between the mounting of rubber liners and the mounting of lifter bars. 

Mr Anese supported the views expressed by Mr Eaton in his declaration.  It is obvious that mountings using "T" bolts and cap head screws are illustrated.  And while there are obvious similarities between the mounting of rubber liners and lifter bars, the evidence does not establish that a person skilled in the art of grinding mills would have recourse to the art of mounting rubber liners.  Thus, while I agree that this extracts goes to the point that mountings of rubber liners with "T" bolts and cap head screws are known, I am not in agreement that this establishes the point that the application lacks an inventive step.

(vi) Threaded nuts (exhibits GDE1 and GDE2)
Mr Everson is an employee of the opponent ANI.  In his declaration, he referred to the studs that held wear plates in a jaw crusher.  The exhibits attached to the declaration are design drawings that have a date ranging from 1966 to 1975.  These drawings show studs that have an inner end that is threaded into a square nut held in the wear plate.  The outer end of the stud is threaded and has a tensioning nut screwed onto it.  The outer end also has a square section on it so that it can be screwed into and out of the nut held in the wear plate.  Mr Anese submitted that the structure and function of the studs as used to secure the wear plate in a jaw crusher is the same as the structure and function of the studs that secure the lifter bars to the shell of a grinding mill.  Mr Savage for Evans Deakin submitted that as the forces that occur in jaw crushers differ from the forces that occur in grinding mills, it is not clear that the same studs are being used.  While Mr Christie for Evans Deakin suggested that double headed studs were used in an analogous manner to that described in the specification, he submitted that the long lapse of time between the disclose of the studs in jaw crushers (approximately 30 years before the invention) and the current invention is suggestive of the presence an inventive step rather than the lack thereof.  I agree with the applicant's view on the matter.  It seems to me that the evidence is not conclusive on this point.

Mr Anese further submitted that as it is common to find jaw crushers and ball mills in the same plant, it would be obvious to use the threaded nut that secures the wear plate in a jaw crusher to secure the lifter bar to the shell of a grinding mill.  Mr Christie attested that the technology fields of jaw crushers and grinding mill differ to such an extent that a skilled person in the art of designing grinding mills would not look to the art of jaw crushers for a solution to the problems being faced by a designer of a grinding mill.  While Mr Everson's declaration suggested the contrary, there is no evidence to suggest that a skilled person in the art would make that connection between the jaw crusher and grinding mill.

In summary, I am not convinced that these documents are indicative of the common general knowledge of the art of grinding mills in Australia, and that what common general knowledge that is conceded or established is not relevant.

Australian patent application 78038/95 (Trelleborgs Gummifabriks Aktiebolag) combined with CGK
Mr Anese submitted that this specification combined with common general knowledge rendered claims 1-5, 7-15 as lacking an inventive step.  However, as it is not obvious to replace the stud disclosed in the citation with the stud as used in jaw crushers, the claims possesse an inventive step.

Australian patent application 32970/95 (Svedala Industries) combined with CGK
I have already found that claims 1, 2, 10-12, and 15 are novel.  As no common general knowledge in the art has been established, these claims possess an inventive step.  Mr Anese made a further submission that claims 3-5, 7-9, 13, and 14 lack an inventive step when combined with common general knowledge.  While in my view there is nothing in these claims that could be said to involve an inventive step, although there is no evidence of this, that result does not materially affect the inventive step of the independent claims to which these claims are appended.

Conclusion

I have found that the opposition succeeds in part.  I have found that claims 1-9, 11-15 lack fair basis.  However, I am satisfied that there is patentable subject matter and therefore I allow the applicant 60 days from the date of this decision in which to propose suitable amendments.

Costs

The usual practice is that costs should follow the event.  As I have found the opposition successful on the grounds of fair basis, the opponent, The ANI Corporation Ltd is entitled to an award of costs.  Hence, I award costs against the applicant, Evans Deakin Engineering Pty Ltd.

G.M.Cox
Delegate of the Commissioner of Patents

Patent attorneys for the applicant:  Freehills Carter Smith Beadle, Sydney

Patent attorneys for the opponent:  Cullen & Co, Brisbane