Nippon Steel Corporation v BHP Steel (JLA) Pty Ltd
[1999] APO 70
•19 November 1999
OFFICIAL NOTICE
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Application : No. 678900 in the name of NIPPON STEEL CORPORATION
Title: Twin-Roll type continuous casting method and device
Action: Opposition under Section 59 of the Patents Act by BHP STEEL (JLA) PTY LTD
Decision: Issued .
Abstract
Since the specification is not fairly based on either of the earlier Japanese documents alleged by the opponent to be the earliest disclosure, it is entitled to it earliest claimed priority date of 4 April 1994.
The claims are all novel.
The claims are all fairly based on the description and give a best method of performance.
The applicant has only distinguished the invention from the prior art by means of "meaningless and arbitrary" parameters. [Raychem Corp's patents [1998] RPC 31 applied.] Consequently none of the claims exhibit an inventive step over what was known or used in Australia before the priority date.
There is no patentable subject matter present, application refused.
PATENTS ACT 1990
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Re Patent application no 678900 by NIPPON STEEL CORPORATION and opposition under section 59 of the patents act by BHP(JLA) PTY LTD
BACKGROUND
Nippon Steel Corporation (Nippon) filed Patent application 678900 as an international application on 3rd March 1995. It was based on two Japanese documents claiming a priority date of 4 April 1994. The application was advertised accepted on 12 June 1997. BHP (JLA) Pty Ltd (BHP) filed a notice of opposition on 11th September 1997 to the grant of a patent application. The company subsequently filed a statement of grounds and particulars on 8th December 1997. The specification was amended after acceptance the amendment finally being allowed on 30 July 1999. Following several extensions of time the filing of all the evidence was completed on 23rd March 1999
A hearing took place in Sydney on 23rd and 24th August 1999. Dr Annabelle Bennett SC of counsel and Dr Colin Bodkin of Spruson and Ferguson represented Nippon. Mr David K Catterns QC of counsel and Mr Geoff Mansfield and Mr Gennaro Simonetta of Griffith Hack , represented BHP. Mr Udo Beucher of BHP also attended the hearing.
THE SPECIFICATION
The invention relates to a twin-roll type continuous casting method and apparatus for conducting in-line rolling of a thin sheet casting during its transfer. More particularly it relates to an improved twin-roll continuous casting method which improves the conditions in in-line rolling, and to a twin-roll casting machine used in this method.
The invention is said to produce an ordinary steel sheet, which corresponds to a hot-rolled sheet by using a cast strip produced by the present method as a starting material. This is said to be a method that reduces variance of materials typified by elongation of the steel material.
The body of the specification describes the method and machine in some detail. Various diagrams are included that show the machine in more detail. The specification at acceptance ended with 16 claims. They were essentially in two independent groups 1 to 7 and 15 relating to the method and claims 8 to14 and 16 relating to the apparatus.
However following acceptance the applicant amended the claims, restricting them to 8 only directed to the method, excluding the apparatus claims altogether.
Claim 1 now reads as follows:
"A twin-roll continuous casting method including the steps of pouring a molten metal of an ordinary carbon steel having a carbon content of 0.0005 to 1 wt% between a pair of water cooling casting rolls, and rolling the resulting casting after solidification into a predetermined sheet thickness by an in-line rolling mill, characterized in that the resulting casting after solidification is rolled in one pass by said in-line rolling mill to a reduction ratio of 5 to 50% within a temperature range of from 850°C to less than 1350°C in which an austenite structure exists in the matrix thereof, in an inert gas atmosphere having an oxygen concentration of less than 3%, said casting is thereafter transferred, and is then taken up into a coil form by a coiler, the rolled sheet having a surface roughness not greater than 20mm."
Claim 2 now reads as follows:
"A twin-roll continuous casting method including the steps of pouring a molten metal of an ordinary carbon steel having a carbon content of 0.0005 to 1 wt% between a pair of water cooling casting rolls, and rolling the resulting casting after solidification into a predetermined sheet thickness by an in-line rolling mill, characterized in that the resulting casting after solidification is transferred, while being held in an inert gas atmosphere having an oxygen concentration of less than 3%, from said casting rolls to the entry side of said in-line rolling mill, is successively rolled by one pass by said rolling mill to a reduction ratio of 5 to 50% within a temperature range of from 850°C to less than 1350°C in which an austenite structure exists in the matrix thereof, is thereafter transferred, and is then taken up into a coil form by a coiler, the rolled sheet having a surface roughness not greater than 20mm."
The difference between the claims is that the claim 1 has the in-line rolling within the inert atmosphere whilst claim 2 has it occurring just outside.
STATEMENT OF GROUNDS AND PARTICULARS
The grounds of opposition identified in the statement are that the claimed invention is not novel, lacks an inventive step and is not a manner of new manufacture and that the complete specification does not comply with section 40.
EVIDENCE
BHP have served evidence consisting of statutory declarations and accompanying exhibits by Dr Assefpour, Mr Farr and Ms Pettit-Young. Mr Farr was and Dr Assefpour still is an employee of BHP.
Ms Pettit-Young's evidence consists solely of a statutory declaration indicating the publication date in Australia of a textbook relied on by BHP in this opposition
Nippon have served evidence consisting of a statutory declaration and accompanying exhibits by Mr Yamamura who is an employee of Nippon.
I will refer to the evidence and the parties' submissions where appropriate in my decision.
Additional Material
Mr Catterns sought to rely on two Japanese Patents by Nippon that were not particularised. Dr Bennett objected to the adducing of what she termed further evidence. I considered the matter and decided that the provisions of regulation 5.11 were applicable. The regulation reads as follows:
5.11 (1) The Commissioner may inform himself or herself of a fact by reference to any document available in the Patent Office.
(2) If the Commissioner proposes to refer to a document under subregulation (10, he or she must:(a) notify the parties accordingly; and
(b) give the parties a copy of or access to the document; and
(c) give the parties an opportunity to give evidence or make representations with respect to the fact or document.
(3) In subregulation(2) “document” does not include a document filed under regulation 5.4 (“filing of statement”), 5.8 (“time for giving of evidence”) or further evidence referred to in subregulation 5.10 (4)(“conduct of proceedings to which this Chapter applies”).
The documents in question were documents to which I might refer to inform myself of a fact. I therefore ensured that both parties had copies of them and allowed Mr Catterns to speak to them. I also allowed Dr Bennett the right of reply. She pointed out that although she believed that she had dealt with the matter fully at the hearing, she still needed to consult with her clients and therefore reserved the right to make written submissions on this matter. I therefore allowed the applicant four weeks from the date of this hearing to make written submissions. The applicant made such written submissions on 23 September 1999 by facsimile. They included a further statutory declaration by Mr Yamamura relating to the two additional documents.
Since I have given both parties the opportunity to speak to the material at the hearing; I have given the applicant a sufficient time after the hearing to make a reasoned response and the material is earlier patents by the same applicant [ie they can hardly be said to be surprised at their existence]; I propose to I deal with this material as though it were properly presented evidence.
DECISION
Priority Date
Mr Catterns submitted that the two earlier patents, referred to above as additional material, by Nippon Steel [Nos. JP-335706 and JP-55-16752] rather than the alleged priority documents, were in fact the first applications for this invention made in a convention country. Since they were made more than twelve months before the present application, it is not entitled to the claimed priority date of 4 April 1994. If this is the case the publication date of these documents would be before the priority date of 678900 and will render it not novel. [This date is however after the earliest claimed priority date of the application in suit.] To render the claims not novel the opponent must first demonstrate that the present application has claims fairly based on these earlier patents, and thus is not entitled to its claimed priority date.
The relevant law on Convention priority is well summarised in the Manual of Practice and Procedure.
11.4.10
A Convention application invoking sec 94(2) may only be made within twelve months from the date of the earliest of the basic applications. Note that there is no provision in sec 94 for an applicant to disown an earlier application - when an applicant makes a Convention application all applications previously made by the applicant for the same invention(s) in Convention countries become "basic applications" regardless of whether they are nominated as such or whether priority is claimed from them.
If one of the basic applications was made outside the 12 month limit, and is not validly the subject of a request under sec 96, a claim which is fairly based on that basic has its priority date determined by reg 3.12(1)(a). This remains true even if the claim is also fairly based on a basic which is within the 12 month limit. Provided that there are two or more basic applications, both made within the 12 month period, sec 94(2) has been properly invoked.
There has been no request under section 96 to disregard an earlier basic document.
I will deal with each of the earlier documents in turn.
Japanese patent Application 05-128605
This application was filed on 26 May 1993 by Nippon [more than 12 months before the present application] and published as Japanese patent publication 06-335706 on 6 December 1994
This specification is directed to a method for the manufacture of hot rolled steel sheet. The process starts with casting thin ingots of not more than 10mm and cooling these in an atmosphere having a low oxygen content [as in the opposed specification] down to a temperature for the commencement of hot rolling [said to be 900°C to 1200°C]. This part is of narrower scope than the opposed specification, which is directed to a single pass by an in-line rolling mill at 850°C to 1350°C. The reduction ratio is not less than 10% compared with the 5% to 50% of the opposed specification. There is insufficient disclosure in this earlier Japanese document to provide fair basis for the claims of the opposed specification.
Japanese Patent Application 53-89345
This application was filed on 24 July 1978 by Nippon and published as Japanese patent publication 55-16752 on 5 February 1980.
This specification teaches directly rolling thin sheet steel from molten steel. It makes no issue of the steel composition. [The opposed specification merely teaches any ordinary carbon steel having a very wide carbon content.] Japanese Patent Application 53-89345 teaches that more than one rolling pass may be employed, but certainly allows the use of a single pass as in the claimed invention. It teaches the use of a non-oxidising atmosphere without actually specifying an oxygen content less than 3%. The thickness of sheet is exemplified at 3mm to 6mm and very good surface characteristics of a surface roughness of 1.5mm [well within the scope of the claimed invention]. However there is no teaching of a reduction ratio of the rolls whilst specifying the use of only a single pass through an in-line rolling mill. The only mention of temperature is that the sheet is rolled while still "..at a high temperature..". This does not actually specify the exact temperature range of the claims of the opposed specification. There is insufficient disclosure in this earlier Japanese document to provide fair basis for the claims of the opposed specification.
Consequently I find that the claims of the opposed specification are entitled to their claimed priority date of 4 April 1994.
MANNER OF MANUFACTURE
The opponent argued that the claims of the opposed patent were not a manner of manufacture; but were "a claimed use that is nothing but a new use of an old substance which is not a proper subject of letters patent."
In Advanced Building Systems Pty Ltd v Ramset Fasteners (Aust) Pty Ltd (1998) 40 IPR 243 the High Court expressly preserved the interpretation of this ground in Commissioner of Patents v Microcell Ltd (1959) 102 CLR 232 at 5-6. It regarded NV Phillips Gloeilampenfabrieken vMirabella International Pty Ltd (1995) 183 CLR 655 as continuing authority (at least for new Act patents) for the proposition that a claimed use that is nothing but a new use of an old substance is not a proper subject of letters patent: [see p 255]
The contention is that shrouding thin cast strip with inert gas to prevent or reduce scale was known, and indeed admitted as such in the specification. It is also alleged that twin drum continuous casting was also known, as was the mechanism of scale formation. The concept of single pass rolling in an inert atmosphere was also alleged to be known. I note that for a continuous process using a single rolling mill it is clear that only one pass through the mill is possible if the whole process is to remain truly continuous.
There was evidence from Dr Assefpour, which I accept, that the specified rolling temperature of 850°C to 1350°C was known to produce an austenite structure in ordinary carbon steel. In fact he refers to a US textbook [The Making, Shaping and Treating of Steel, Tenth Edition, Published 1885 by United States Steel] which is authoritative. i.e. it is known that this temperature range is the austenite range.
The opposed specification does admit all this. However the invention is said to be a combination of steps to produce a better quality steel sheet in a continuous way, using twin roll casting to produce a thin sheet which is directly passed to an in line rolling mill through which it passes only once and then coiled. The reduction ratio of the mill is clearly [though very broadly ] specified as is the temperature range at which the steel is rolled. This temperature range is known to produce an austentic structure. The process is said to produce steel of a specified surface roughness because of the process conditions which include an inert gas atmosphere [less than 3% oxygen] for the casting and in one case the rolling as well.
Mr Catterns argued that this was a mere collocation of known integers with no new or synergistic effect.[Williams v Nye (1890)7 RPC 62] . On a fair reading it seems to me that the process steps all interrelate. It is not merely a series of previously known steps put in sequence. The steel is cast as a thin strip and held in an inert atmosphere to reduce or eliminate scale. This then enables it to be rolled directly in one pass, since it is scale free, to produce a thin sheet having a specified surface roughness, and this is conveniently coiled to ensure the process remains truly continuous. To me this is a true combination with each of the steps affecting the next one. Thus all the features of the claim are essential.
Thus the alleged invention is a true combination.
The opponent also submitted that the claimed invention merely recited desirable parameters for a known process and was not a manner of manufacture. They alleged that claims are directed to a process which is only distinguished from the prior art only by arbitrary and meaningless parameters. If indeed the claimed invention suffers from "parametritis" [see Raychem Corp's patents [1998] RPC 31] then this would render the claims non inventive and I shall deal with the matter later when I consider inventive step.
Thus the claims are directed to a manner of manufacture.
NOVELTY
The test for determining whether the invention lacks novelty is the " reverse infringement test" as set out in Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) 137 CLR 228 at page 235 where Aiken J stated:
"The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask whether the alleged anticipation would, if the patent were valid, constitute an infringement."
Infringement occurs when "each and every one of the essential features" of the claim have been disclosed in the prior document: See Rodi and Wienenberger AG v Henry Showell Ltd (1969) RPC 367 at page 391. However, the claim will still lack novelty even if the citation does not disclose all of the features of the claim provided all essential features are disclosed: See Nicaro Holdings v Martin Engineering (1990) 16 IPR 545 and Catnic Components Ltd v Hill and SmithLtd (1982) RPC 183.
In assessing the teaching or disclosure of the prior art, one has to consider what the skilled addressee is being taught and what they would have done on reading the citation, General Tireand Rubber Co v Firestone Tyre and Rubber Co Ltd, (1972) RPC 457 at 485,486:
"To anticipate the patentee's claim, the prior publication must contain clear and unmistakable directions to do what the patentees claims to have invented…a signpost, however clear, upon the road to the patentee's invention will not suffice"
Mr Catterns submitted that any earlier documents should be construed in the light of the common general knowledge at the date of publication of the earlier documents. [Acme Bedsteads vNewlands, 58 CLR 689 at 704]
Dr Assefpour makes comment on the US Textbook, referred to above in my discussion of manner of manufacture. This establishes clearly that the hot rolling temperature and the austentite structure are synonymous. Dr Assefpour says nothing specifically in either of his declarations about whether this was really common general knowledge in Australia as of the priority date of the claims. However the text has been shown to be a standard reference book, and thus well known in the art, I believe this information was part of the common general knowledge at the relevant date.
Other than this I have little direct evidence from the opponent establishing what was, or was not, part of the common general knowledge in Australia at the publication date of the respective citations. In essence all I have is some kind of suggestion from Mr Farr that BHP employees were likely to know what the common general knowledge was, plus some concession that the academic community were also likely to know as well. There is the evidence that the US Textbook was part of the common general knowledge at the priority date of the claims. However since there is no direct evidence that any of the other documents referred by the opponent were part of the common general knowledge in the art at the time, I cannot refer to them in conjunction with any of the specifications relied on for lack of novelty. [see Bausch & Lomb v Allergan Inc 24 IPR 310 ]
Despite the lack of any direct evidence that any of these other documents referred to were part of the common general knowledge in the art at the time, I find it hard to believe that the prior art documents must be read in a near total vacuum in this particular case. Steel making is after all a widespread art of great commercial significance .
I must therefore rely on the principle that if something is referred to in a number of patent specifications it may be part of the common general knowledge.
| As a general rule: "There may be some fields of endeavour in which those who work therein study and make themselves familiar with all patent specifications as they become available for inspection in one, or in many countries so that what was contained therein becomes common general knowledge in that particular trade or field of manufacture in the country in question. Examples are provided by Vidal Dyes Syndicate Ltd v Levinstein Ltd.** and British Celanese Ltd v Courtaulds Ltd.*" |
And in the same case it was also said
"These passages have often been quoted, and there has not been cited to us any case in which they have been criticised. We accept them as correctly stating in general the law on this point, though reserving for any further consideration whether the words "accepted without question" may not be putting the position rather high: for the purposes of this case we are disposed, without wishing to put forward any full definition, to substitute the words "generally regarded as a good basis for further action""
Mr Farr has made it very clear in his declaration that the opponent was in the habit of regularly referring to patent specifications, including a number of overseas patents particularly those filed by rival companies working in the art. From the fact that each of the features listed below are disclosed in a number of earlier patent specifications, it appears to me that the state of the common general knowledge in Australia that I can ascertain is the following:
Continuous twin roll strip casting of ordinary carbon steel in an inert [or at least reduced oxygen ] atmosphere to reduce oxide scale and thus improve the surface roughness of the finished steel.
That the as cast strip has a large crystal grain size which results in unsatisfactory mechanical strength
That this grain size can be reduced by immediately rolling the cast strip in the austenite range both in an inert atmosphere or in air
That rolling temperatures of 850°C to 1350°C were known to produce an austenite structure in ordinary carbon steel.
That about 50% reduction ratio on hot rolling is the practical limit before the rolls jam.
Coiling strip steel as a convenient means of storing product and ensuring the entire process from casting through rolling to finished strip remains continuous
This is reinforced by the evidence which suggests that BHP were fully aware of these earlier patents before the priority date, and indeed in their confidential project M, were themselves pursuing the same line of investigation as Nippon
I will consider each of the alleged anticipating documents in turn.
Australian Patent publication No. AU-B-24455/88 (Acceptance No. 600391) to John Lysaght (Australia) Limited published 17 April 1989.
This document discloses twin roll casting a metal strip within an inert atmosphere and rolling it to reduce its thickness. It is totally silent on the composition of the metal, the rolling temperature, but does specify a reduction ratio of 15% [within the scope of the claimed invention]. It is also totally silent on coiling the strip. The citation also includes a coating process which the claimed invention lacks. The reason for the rolling is stated at page 9 as " The thickness reduction causes or enables the brittle columnar as-cast grain structure to recrystallise to a more formable, more equiaxed structure". This seems to me, when read with the common general knowledge, to correspond to the rolling in the 850°C to 1350°C temperature range of the claims, and thus to disclose the austenite structure. However the essential feature of the surface roughness of not greater than 20mm is missing. Thus the opponent has not established that the claims lack novelty.
Japanese Utility Model Publication No. 64-5742-U to Ishikawajima-Harima Heavy Industries Co Ltd. Published 13 January 1989.
This merely teaches twin roll continuous casting and rolling in an inert atmosphere and does not even suggest the specific rolling temperatures, surface roughness or reduction ratios taught by the claimed invention. Consequently the claims are novel in the light of this disclosure..
Japanese patent Publication No. 04-2000801-A to Nippon Steel Corp. Published 21 July 1992.
This document is directed to twin roll casting of stainless steel strip rather than the ordinary carbon steel of the present invention. It only teaches hot rolling of stainless steel within the temperature range and at the reduction ratio of the present invention. It does not specify either casting or rolling of ordinary carbon steel under an inert atmosphere.[Stainless steel not having the scale problems encountered by ordinary carbon steel]. In fact it really does not in any way suggest applying this method of casting and rolling stainless steel, to ordinary carbon steel. Since it does not disclose all the essential features of the claims they are novel in the light of this disclosure.
Japanese Patent publication No. 62-050008 to Mitsubishi Heavy Industries Ltd. Published 4 March 1987
This document is directed to a specific design of roller to reduce the thickness of steel made by twin roll continuous casting. As an aside the document discloses a temperature adjustment device which prevents oxidation. There is no specific disclosure of the inert gas atmosphere having an oxygen content less than 3%. There is teaching that the strip is held at between 800°C and 1200°C and immediately hot rolled. Thus the hot rolling temperature is fairly within the range of the invention. There is teaching of a reduction ratio of 20%, which is again within the range of the claimed invention. There is no coiler disclosed. There is no disclosure of the steel composition nor of the desired surface roughness. Since all the essential features of the claims are not disclosed they are novel in the light of this document
Japanese Patent Publication No. 02-2470049-A to Nippon Steel Corp. Published 2 October 1990.
This document is directed to twin roll thin strip casting of stainless steel, rather than the ordinary carbon steel of the present invention. However it concedes that the process may be applied to other types of steel. It discloses rolling temperatures and reduction ratios within the range of the claimed invention. However the document does not even suggest scale formation as a problem. It is therefore totally silent as the use of an inert atmosphere as a means of solving that problem. It does not therefore disclose all the essential features of the claimed invention and the claims are novel in the light of this disclosure.
Japanese Patent Publication No. 62-009752-A to Mitsubishi Heavy Industries Ltd. Published 17 January 1987.
This is merely directed to a device for holding a continuously cast metal sheet between 1000°C and 1150°C in a non-oxidising atmosphere prior to in line rolling of the sheet. There is no disclosure of which metal the sheet is made from. There is no indication of what the rolling reduction is, nor that the rolled sheet has a surface roughness of not greater than 20mm. Thus the document does not have all the essential features of the claims. I therefore find that the claims are novel in the light of this disclosure.
Japanese Patent Publication No. 62-009753-A to Mitsubishi Heavy Industries Ltd. Published 17 January 1987.
This document has a broadly similar disclosure to 62-009752 above and the claims are novel in the light of it.
Japanese Patent Publication No. 62-1611442-A to Nippon Steel Corp. Published 17 July 1987
This document merely discloses a coiler for use with a thin strip twin roll continuous caster. Whilst the drawings illustrate the caster, heat treatment furnace and reduction rolls there is no specific disclosure of the precise atmosphere in the heat treatment furnace. The opponent argued that it would provide a non-oxidising atmosphere. Even if this is so I can see no evidence of it. There is no disclosure of the rolling temperature, the surface roughness nor the reduction ratio. Consequently the document does not have all the essential features of the claimed invention and the claims are novel in the light it.
International Patent Publication No. WO90/00100 to Sundwiger Eisenhutte Maschinenfabrik Grah & Co. Published 11 January 1990
This document is directed to the manufacture of thin cast strip. It does not disclose twin roll casting. It does indicate that continuous hot rolling of "as-cast strip" produces a fine grained homogeneous structure. It does not disclose coiling, nor the requirement that the surface roughness of the rolled sheet should be less than 20 mm. Since this document does not disclose all the essential features of the invention the claims are novel in the light it.
Japanese Patent Publication No.56-119607-A to Mitsubishi Heavy Industries Ltd. Published 9 September 1981.
This document discloses twin roll continuous casting of steel. It discloses an in-line reheating furnace, which does not specify whether its atmosphere has less than 3% oxygen or contains an inert gas. However it does contemplate the integration of the casting, the reheating, the rolling and the coiling as a continuous straight through operation. There is no reference to scale control, or rolling temperature or reduction ratio or steel composition or surface roughness of the cast strip. There is a disclosure that the rolling is in a single pass, albeit through perhaps more than one stand of rolls. In particular the drawing would indicate this. Nevertheless this document does not disclose all the essential features of the invention and the claims are novel in the light it.
United States Patent Publication No. 2058448 to C.W.Hazelett. Published 27 October 1936.
This document appears to be the original disclosure on twin roll continuous casting. It certainly discloses the casting rolls and the inert gas atmosphere to prevent oxidation of the cast strip. It also discloses single pass in line rolling. However it does not in any way suggest the exact parameters of the claimed invention. It is silent on the metal composition, the oxygen content of the inert gas atmosphere, the surface roughness of the strip, the reduction ratio of the rolls and the exact rolling temperature. As this document does not disclose all the essential features of the invention and the claims are novel in the light it.
The Making, Shaping and treating of Steel, Tenth edition. Published 1985 by United States Steel.
This discloses information about the thermomechanical treatment of steel and a discussion of the grain refinement that occurs during hot rolling. It has no disclosure of the essential features of the claimed invention and the claims are novel in the light it.
INVENTIVE STEP
Inventive step is determined in the light of the common general knowledge existing in the relevant field at the priority date of the application.
According to subsections 7(2) and 7(3) of the Patents Act, a claimed invention will lack an inventive step if it is obvious in the light of:
(a) common general knowledge; or
(b) common general knowledge considered together with information in a single document or through doing a single act, provided that the document or act could reasonably be expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area.
I have already found the opponent has not proved to my satisfaction what the state of the common general knowledge was, but I have found that the limited extent of the common general knowledge in Australia at the priority date of the claims was
Continuous twin roll strip casting of ordinary carbon steel in an inert [or at least reduced oxygen ] atmosphere to reduce oxide scale and thus improve the surface roughness of the finished steel.
That the "as-cast" strip has a large crystal grain size which results in unsatisfactory mechanical strength
That this grain size can be reduced by immediately rolling the cast strip in the austenite range both in an inert atmosphere or in air
That rolling temperatures of 850°C to 1350°C were known to produce an austenite structure in ordinary carbon steel.
That about 50% reduction ratio on hot rolling is the practical limit before the rolls jam.
Coiling strip steel as a convenient means of storing product and ensuring the entire process from casting through rolling to finished strip remains continuous
The opponent made submissions that the applicant had merely sought to re-patent the prior art by limiting the claims to a series of parameters which were not mentioned in the prior art . Whilst this might make the claims novel it did not make them inventive. This exercise is sometimes referred to as "parametritis". Mr Catterns referred me to Raychem Corp's patents supra where the court found:
"The selection of a group of compositions by reference to some arbitrary parameter having little technical significance did not involve any inventive step. Although it might not be obvious, in the common use of that word, to limit a claim by reference to some particular meaningless and arbitrary parameter, that had nothing to do with patentability. Patents were not given for skill in inventing technically meaningless parameters"
In the light of this assertion it seems to me that what I must determine is where the invention resides. To do this, I need to analyse the existing knowledge as it existed at the priority date and understand the technical contribution the applicant has made to this knowledge.
The common general knowledge has established that a continuous process for producing thin sheet steel was already known at the priority date of the claims. Basically it used twin roll continuous casting under an inert atmosphere to produce thin sheet having low scale and then reduced it by directly rolling to produce sheet that was both of the required thickness, surface roughness and grain structure. It was well known that reduced scale on the cast steel resulted in reduced surface roughness in the finished steel after rolling. The rolling was known to be undertaken either within the inert atmosphere associated with the casting or just out of it. The use of a coiler to take up the finished product was optionally part of the known process.
The specification describes the use of twin roll continuous casting to produce rolled sheet ordinary carbon steel having good surface properties. It explains how this is done by casting in an inert atmosphere and hot rolling to give an austenite structure in the matrix: It therefore recites the prior art with the specification of certain parameters which it states as .
The steel has a carbon content of 0.0005to 1 wt% carbon
The rolling mill reduction ratio is between 5 to 50%
The finished steel has a surface roughness of not greater than 20mm
The inert gas atmosphere has an oxygen content less than 3%
The rolling temperature is in the range 850°C to 1350°C
Coiling the finished sheet
The question I must answer is that in the light of the common general knowledge and the evidence do I consider these parameters to be meaningless and arbitrary.
Firstly the carbon content of the ordinary carbon steel is so broad as to include just about any non stainless steel requiring scale control when cast and there is no inventiveness in selecting this parameter.
Secondly the reduction ratio of the rolling mill encompasses all practical reduction ratios and exhibits no inventiveness.
Thirdly although it is generally desirable to produce smooth surfaced steels, the level of surface roughness is higher than the applicants own Japanese Patent Application 53-89345. It seems strange to me that the applicant seeks to produce a less high quality steel then the prior art. However there is no evidence of a selective advantage to the higher roughness figure. In the absence of this the value is an arbitrary parameter which adds no inventive step.
Fourthly the inert gas oxygen content is within the normal practical range. Earlier art has endeavoured to get a completely inert gas shroud to the casting process [ie 0% oxygen] and as a matter of practicality has not quite succeeded. Oxygen percentages up to 7% are common and claiming 3% is again a mere desideratum, the applicant has described no particular advantage of this figure which is higher then the most desirable oxygen content of 0% and lower than some other prior art.
Fifthly the rolling temperature range is that in which austenite will occur. It has been shown to be common general knowledge that "as-cast" the steel has a grain structure that needs modifying. This can be done by adding alloying elements to the steel, which is expensive or by rolling to mechanically alter the grain structure. If rolling is adopted the aim is to get an austenite structure in the finished product. To pick a temperature range that achieves this is not inventive.
Finally coiling the finished product is normal operating practice and is not inventive.
Thus the claimed invention is only distinguished from the prior art by so called meaningless and arbitrary parameters. Thus I am of the clear view that the invention as claimed lacks an inventive step in the light of what was part of the common general knowledge in Australia before the priority date.
SECTION 40
INVENTION IS NOT FULLY DESCRIBED
The opponent submitted that the specification does not give the best method of performing the invention.
However since I have already come to the conclusion that the process described in the specification doesn't disclose any invention, it is hard to see how a skilled addressee would have any difficulty in carrying it out.
FAIR BASIS
The Mond Nickel Rules (in Mond Nickel Company Ltd.'s Application, (1956) RPC 189 at page 194) give guidance in determining questions of fair basis. Although originally expressed in relation to fair basis with regard to provisional or basic documents (see the HC decision in Hoffman-La Roche & Co. AG. v Commissioner, (1971) AOJP 819 at page 822, and (1973) RPC 34), they may be expressed as:
a) Is the alleged invention as claimed broadly described in the specification?
b) Is there anything in the specification which is inconsistent with the alleged invention as claimed?
c) Does the claim include as a characteristic of the invention a feature as to which the specification is wholly silent?
However since I have already found that there is no invention in the specification there cannot be any special feature on which the claims are silent. The issue is not fair basis, but inventive step and I have already decided that the specification as a whole lacks one.
CONCLUSION
The claims are not fairly based on either of the earlier Japanese documents argued by the opponent, and the specification is thus entitled to its earliest claimed priority date of 4 April 1994.
The claims are all novel.
The claims are all fairly based on the description and the description gives a best method of performance.
The applicant has only distinguished the invention from the prior art by means of meaningless and arbitrary parameters. Consequently none of the claims exhibit an inventive step over what was part of the common general knowledge in Australia before the priority date.
I am of the clear view that there is no patentable subject matter present and thus I refuse the application.
COSTS
Both parties made submissions on costs. Mr Catterns asked that they should follow the event as is usual. Dr Bennett agreed that while this is normally the case in this instance if the opposition was to succeed on material admitted under regulation 5.11, then costs should not be awarded against the applicant. Mr Catterns agreed that if this additional material affected the outcome then some apportioning of costs might be appropriate.
Since none of the additional material has had any effect on the outcome of the opposition I award costs against the applicant.
R.A.Melvin
Delegate of the Commissioner of Patents
Patent attorneys for the applicant: Spruson and Ferguson Sydney
Patent attorneys for the opponent: Griffith Hack Melbourne