The Commonwealth Industrial Gases Limited v. Liquid Air Australia Limited

[1988] APO 34

In the Matter of the Patents Act 1952 and - In the Matter of Application No. 538414 for Letters Patent by THE COMMONWEALTH INDUSTRIAL GASES LIMITED - and - In the Matter of Opposition thereto under Section 59 by LIQUID AIR AUSTRALIA LIMITED.

 

DECISION OF A SUPERVISING EXAMINER OF PATENTS:

Background

THE COMMONWEALTH INDUSTRIAL GASES LIMITED (CIG) lodged patent application 538414 entitled "Coating with Metals" on 9 May, 1980. The application is a Convention application claiming priority from a United Kingdom application dated 9 May, 1979. Acceptance of the application and complete specification was notified in the Official Journal on 16 August, 1984. LIQUID AIR AUSTRALIA LIMITED (LIQUID AIR) lodged a notice of opposition under section 59 on 15 February, 1985, following allowance of an extension of time in which to do so.

The service of evidence was completed by 3 September, 1987 and the matter was heard in Canberra on 18 April, 1988. Mr. L. Allen, patent attorney of Shelston Waters, Sydney appeared for CIG and Mr. B. Caine of Counsel and Mr. P. Jones, patent attorney of Phillips, Ormonde & Fitzpatrick, Melbourne appeared for LIQUID AIR.

The notice of opposition specified all the available grounds under sub-section 59(1). At the hearing, the opponent relied only on the grounds concerning prior publication, not a manner of manufacture, obviousness, lack of novelty and non- compliance with section 40, i.e. the grounds specified in paragraphs (e), (f), (g), (h) and (i) of sub-section 59(1) of the Act.

The Specification

The specification commences by stating that:

"This invention relates to coating with metals.

In particular, it relates to a process and apparatus for coating with metal a member or workpiece typically of ferrous or other metal."

The specification explains that galvanising steel products by dipping them in a bath of molten zinc is a process which has been used for approximately 200 years. However one problem of this process is stated thus:

"there tends to be a loss of the valuable zinc metal through formation of oxide at the surface of the bath of molten zinc. Since commercial tanks designed for -holding molten zinc for use in the galvanising process are open-topped, there is continuous exposure of the surface to the atmosphere."

In the past, this problem has been alleviated by covering the bath surface with an inorganic flux. However, the flux tends to be disturbed when the steel products are dipped into the bath and therefore some oxidation takes place. Furthermore, the flux can be caught on the surface of the products and can give rise to subsequent spots of corrosion.

The invention proposes to overcome or at least reduce these problems by providing a blanket of gas over the molten metal surface of the bath, which gas is incapable of oxidising the molten metal. This blanket is established by directing liquefied gas at or across the surface, whereupon the liquefied gas vaporises in the vicinity of the surface. The preferred gas is nitrogen.

The specification continues by illustrating one embodiment of the invention. This shows a tank containing a volume of molten zinc which has on one side a number of spray nozzles and on the other side a hood with inlet ports which is connected to a fan. Liquid nitrogen is supplied to the tank by the spray nozzles at a level just above the molten metal surface where it vaporises and then the gaseous nitrogen is drawn across the tank to the hood by the fan, thereby maintaining a blanket of nitrogen over substantially the whole of the surface of the molten zinc.

The specification concludes with seventeen claims, of which claims I and 10 are independent; these read as follows:

"1. A process of coating with metal a member or work- piece including the step of dipping the member into a bath of molten metal over at least a major part of whose surface is a blanket of gas which protects the metal from oxidation, the blanket of gas being established by directing liquefied gas at or along the surface of the molten metal and thereby causing the liquefied gas to vaporise in the vicinity of said surface, and creating a flow of such vapour across the surface of the molten metal, the liquefied gas being incapable of oxidising the molten metal under the prevailing conditions.

10. Apparatus for coating with metal a member or work- piece, including a tank for holding molten metal, means for melting the metal in the tank and maintaining it in a molten state; a source of a liquefied gas which, in use, is incapable of oxidising the molten metal under the prevailing conditions; means for directing the liquefied gas at or across the surface of the molten metal whereby the liquefied gas vaporises in the vicinity of the said surface, and at least one fan or other means for drawing vapour formed by evaporation of the liquefied gas over substantially the whole of the area of at least a major portion of the molten metal in operation of the apparatus."

Evidence

The evidence-in-support of the opposition consists of a statutory declaration by Trevor William Harris. Mr. Harris has been employed by LIQUID AIR since 1978 and is currently the Gas Applications Manager. He exhibits with his declaration the following exhibits:

(i) TWHI - the opposed specification;

(ii) TWH2 - United Kingdom patent specification No. 1319282 in the name of Kuei Fan Yu (hereinafter called the "Kuei Fan Yu specification") available at the Patent Office on 1 April, 1974;

(iii) TWH3 - page 622 of The Condensed Chemical Dictionary 8th edition (1971) published by Van Nostrand Rheinhold Company; and

(iv) TWH4 - Australian patent specification No. 471226 in the name of L'Aire Liquide, et al, published at the Patent Office on 8 November, 1973.

The evidence-in-answer consists of a statutory declaration by Noel Irving Seggie, who is the Process Engineering Manager in CIG.

The evidence-in-reply consists of statutory declarations by David Lawrence Jitts and Ronald Barry Martin. Mr. Jitts is a consulting engineer with David L. Jitts and Associates. He exhibits with his declaration the following exhibits:

(i) DLJL - the opposed specification;

(ii) DLJ2 - a copy of Mr. Harris' declaration and associated exhibits;

(iii) DLJ3 - an extract from "Nitrogen in Industry" by Marshall Sittig, published by Van Nostrand Company, Inc.; and (

iv) DLJ4 - a copy of Mr. Seggie's declaration.

Mr. Martin is the Associate Librarian (Reader Services) of the University of Melbourne Library. He deposes that exhibit DLJ3 was received by the library on 14 March, 1966 and would have been available to the public prior to 9 May, 1979.

On reviewing all the evidence before me I consider that only the Kuei Fan Yu specification is directly relevant to the issues in these proceedings. Consequently I will not detail the other exhibits.

Kuei Fan Yu Specification

This specification discloses a process and apparatus for hot dip galvanising. The apparatus illustrated comprises a tank which contains molten zinc. On one side of the tank is a gas supply outlet and on the other side is a gas suction inlet. In use, gas is supplied from a source and pumped to the supply outlet, from where it passes in a stream across the surface of the molten zinc to be then drawn into the suction inlet to be exhausted. The type of gas described is one which is non-oxidising or substantially non-oxidising. In one particular embodiment, the gas referred to is flue gas, but at page 2 lines 21 to 23, it is stated that the ,non-oxidizing or substantially non-oxidizing gas is not limited to any specific kind".

Both parties made extensive submissions on whether the term "non-oxidising or substantially non-oxidising gas" includes nitrogen. It should be noted however that claims 1 and 10 of the opposed specification are not limited to nitrogen but only define the gas as being "incapable of oxidising the molten metal under the prevailing conditions". I consider that this latter expression is synonymous with the above term. Both expressions clearly include nitrogen - this is elementary chemistry. The Kuei Fan Yu specification in fact recognises that flue gas can be a particular case of a mixture of substantially non-oxidising gases, one gas of that mixture being nitrogen (see page 2 line 122).

Prior Publication

As discussed above, the Kuei Fan Yu specification discloses a hot dip galvanising process similar to that of the claimed invention. But it does not disclose the step of "directing liquefied gas at or along the surface of the molten metal and thereby causing the liquefied gas to vaporise in the vicinity of said surface", nor does it disclose a source of liquefied gas or "means for directing the liquefied gas at or across the surface of the molten metal". Whilst the Kuei Fan Yu specification does disclose a source of gas and means for directing the gas to the surface of the tank, there is no reference that these could be suitable for liquefied gases.

Mr. Caine submitted that the Kuei Fan Yu specification should be read in the light of common general knowledge and referred me to the judgement of Acme Bedstead Co. Ltd. v. Newlands Brothers Ltd. (1937) 58 CLR 689. Accordingly, he submitted that as nitrogen is supplied commercially in liquid form, then a person skilled in the art would read the Kuei Fan Yu specification as including liquid nitrogen being supplied to the tank. In response, Mr. Allen agreed that a specification could be read in the light of common general knowledge but argued that there has to be evidence as to the common general knowledge which is sought to be added and no such evidence had been produced in this case.

On this point, the common general knowledge in the art at the publication date of the Kuei Fan Yu specification (i.e. 1 April, 1974) must be ascertained. I agree with Mr. Allen that the evidence assists little in this respect. Mr. Harris states that his company has been a major supplier to Australian industry of nitrogen since at least 1966, and that nitrogen is supplied in the form of liquid nitrogen and gaseous nitrogen although he does not indicate whether both forms were supplied since 1966. Nevertheless I am of the view that by April 1974, the fact that nitrogen was available commercially in either gaseous or liquid form was a matter of common general knowledge - I am personally aware that both forms were available and employed in University study in the late 1960's. Exhibits TWH4 and DLJ3 indicate uses for liquid nitrogen in certain applications however, given that these exhibits in the absence of evidence to the contrary can only be considered documents of public knowledge, I have no evidence before me to indicate what matters may have constituted common knowledge in respect of liquid nitrogen as of 1 April, 1974.

Returning to consider Mr. Caine's submission, while I can accept that it was commonly known that nitrogen was available in liquid form at the publication date of the cited specification, this was not its only commercially available form at that time. Furthermore it is not readily apparent whether the liquid form is normally interchangeable with the gaseous form in applications and would have been so considered at the time - certainly there is no evidence on this point. Thus the fact that a skilled person would have known that nitrogen was available in either gaseous or liquid form does not, in my view, lead to the conclusion that a skilled person would have read the Kuei Fan Yu specification as disclosing the supplying of liquid nitrogen to the tank, or utilising liquid nitrogen or any other suitable gas in liquefied form in the process. Consequently, the invention claimed has not been prior published by the Kuei Fan Yu specification.

Novelty

On the question of novelty, Mr. Caine referred me to the well known statement of Dixon J. in Griffin (1942) AOJP 739 at p.740:

"Where variations from a device previously published consist in matters which make no substantial contribution to the working of the thing or involve no ingenuity or inventive step and the merit if any of the two things, considered as inventions, is the same, it is, I think impossible to treat the differences as giving novelty."

The so-called test for novelty as encompassed in that statement was applied by the Full Federal Court in Dennison Company v. Monarch Marking Systems Inc. 1 IPR 431, in which Fox J. at 441 commented that the statement encompasses what are commonly called "workshop improvements".

Before turning to an assessment of the novelty issue, I am mindful that the specification itself is drafted against the background of the use of an inorganic flux to prevent oxidisation, not against the use of a gas blanket. The stated object of the invention is "to reduce the surface oxidation of the zinc or other metal forming the coating in comparison with that which typically occurs in the aforementioned conventional processes".

In his submissions, Mr. Allen made reference to page 4 of the specification in which it is stated:

"Upon vaporisation liquid nitrogen will undergo a large increase in volume. One volume of liquid nitrogen produces over 700 volumes of nitrogen gas. This large increase in volume makes possible adequate protection of the surface of the molten zinc or other metal."

and further on:

"The use of a liquefied gas such as liquid nitrogen in the process according to the invention makes it possible to flush away oxygen in the air without creating turbulence."

Mr. Allen asserted that because of the large volumetric expansion which occurs upon vaporisation of the liquid nitrogen, the air above the molten metal surface in the tank is quickly displaced by the gas. Additionally, he argued, there results a dense gas coverage of the surface without creating turbulence thus reducing the chance of intermingling of the air and gas.

In paragraph (4) of his declaration, Mr. Seggie refers to the background art namely, a gas blanket being supplied over the surface of the bath. He continues at paragraph (5) by stating that:

"The subject invention is similar in concept to the prior art curtain referred to in paragraph (4). It differs therefrom mainly in that the supply of gas for the curtain is produced by spraying or depositing liquid nitrogen on to a portion of the bath's surface remote from the exhaust ports. This is a particularly simple way of supplying the requisite nitrogen and has the advantage that the nitrogen so produced is cold, and therefore dense, so that the flowing curtain more readily displaces the ambient air and is not so rapidly lost by intermingling therewith."

Basically then, it is CIG's contention that by directing a liquefied gas at the surface of the bath and allowing vaporisation of the gas to occur, there results a much more effective blanket than that achieved by simply directing gas at the surface as in the Kuei Fan Yu specification. This improved blanket is achieved, it is said, due to the very large volume increase on vaporisation and the low temperature of the resulting gas blanket.

Mr. Caine on the other hand submitted that the specification was silent on any advantages of using liquefied gas instead of its gaseous form except that it exhibited a large volume increase on vaporisation. However he argued that there was nothing remarkable in that as it was a well known property, and the proposition that the large volume expansion on vaporisation causes displacement of other gases is there by inference only. Furthermore there was nothing in the specification which teaches the advantages of the nitrogen so produced being cold and therefore dense.

Whilst the present specification is drafted against the backdrop of the use of inorganic fluxes and is therefore comparatively silent on advantages over the use of gas blankets, I consider that an addressee would recognise any advantages arising from the use of liquefied gas. However when considering the issue of novelty of the claimed invention in the light of the Kuei Fan Yu specification, the question to consider is whether the introduction of gas to the bath in liquefied form in lieu of the gaseous form makes no substantial contribution to the working of the invention - see one aspect of the test for novelty in Griffin v. Isaacs (supra). From the evidence adduced, there is nothing which leads me to conclude that no substantial contribution results. Thus, on this consideration of the novelty issue, my view is that the claimed invention does not lack novelty.

The novelty test in Griffin v. Isaacs (supra) has an alternative consideration whereby the variation can be considered from the point of view of whether it concerns matters which "involve no ingenuity or inventive step". In deciding whether in the present case the supplying of liquefied gas at or along the surface involves no ingenuity or inventive step, it is pertinent to consider whether this step is one that a competent workman in the trade might have been expected to use or introduce.

Mr. Caine argued that at the priority date of the claims a competent workman having the Kuei Fan Yu specification before him would appreciate, given practical and commercial reasons, the use of nitrogen as the blanketing gas - moreover, the competent workman would be aware nitrogen was available in liquid form and would have knowledge of its properties. Thus he submitted there would be no exercise of ingenuity or inventive faculty in making the step from the use of a non-oxidising gas in the prior specification to the use of liquid nitrogen or other non-oxidising gas in liquid form. Furthermore it was submitted that there was no inventive ingenuity in altering the apparatus of the Kuei Fan Yu specification in order to handle a liquefied gas.

Whilst I am prepared to agree with Mr. Caine that from a practical point of view nitrogen could be used in the process described in the prior art specification and that a competent workman would have appreciated that fact, and that liquid nitrogen is well known and commercially available, I am not satisfied that the conclusion drawn by Mr. Caine necessarily follows. There has been no evidence produced on whether it would have been inventive or not to substitute liquid nitrogen for gaseous nitrogen in the process of the prior specification, or on whether such a change to the process would have been one a competent workman might naturally have made. Whilst the applicant's evidence does not address this issue, neither does the evidence of Mr Harris for the opponent which constituted the evidence in support of the opposition. Mr. Jitts, in paragraphs 13 and 15, does make some reference to this issue but his conclusions appear to follow from the commercial availability of liquid nitrogen and his own understanding of the uses of nitrogen in industry, and not from the basis of how a competent workman in the particular art would have viewed the Kuei Fan Yu specification at the priority date of the claims in suit - in fact I tend to agree with Mr. Allen in that from Mr. Jitts' evidence, it is not clear whether Mr. Jitts qualifies as a competent workman in the particular art in question and is thus in a position to comment on what a competent worker may have done. It seems to me that in circumstances such as exist here where there is no cogent evidence to suggest, prima facie, that no inventiveness is involved in the process, it is not correct, as Mr Caine submitted, that the onus rests with the patent applicant to establish that invention is involved. In the view of the Courts, the onus rests with the opponent to establish its ground of opposition; if evidence is provided by an opponent which prima facie, supports the ground alleged then an applicant may well need to lodge countering evidence to defend its application. In relation to the apparatus, it is well established law that if there is invention in formulating an idea and if the means for carrying out that idea would appear to be easy, then that means is still inventive (see Hickton's Patent Syndicate v. Patents and Machine Improvements Company Ltd. (1909) 26 RPC 339). So, once the idea of producing a gas blanket by the vaporisation of a liquefied gas was formulated, it may be said that a competent workman could make modifications to the apparatus disclosed in the Kuei Fan Yu specification in order to achieve this purpose - however, that does not rob the invention of inventive merit. I am thus not satisfied that the claimed invention involves no ingenuity or inventive step.

Finally in support of his submission that the present invention lacked novelty, Mr. Caine referred me to the so-called "reverse infringement test" in Meyers Taylor Pty. Ltd. v. Vicarr Industries Ltd. 13 ALR 605, namely:

"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."

He suggested that in the light of this test, the Kuei Fan Yu specification would infringe the present claims as it "might be asked whether the spraying of flue gas introduced in a commercially available form which rendered it liquid would indeed infringe the patent (sic) in suit". I consider that this is an incorrect view of the above test. The submission appears to me made from the point of view of altering the prior specification in the light of the present specification so that it infringes the present claims. I do not consider that to be the spirit of the "reverse infringement test and consequently do not consider that it can be applied in that manner. The Kuei Fan Yu disclosure does not propose the use of liquefied gas, and thus would not constitute an infringement of claims of the application in suit.

In summary, I find that the invention defined in the present claims does not lack novelty based on the disclosure in the Kuei Fan Yu specification, UK 1319282.

Obviousness

I am concerned here with whether the process or the apparatus as claimed are obvious in the light of the evidence. The determination of obviousness is a matter dependent upon the common general knowledge in the field of the invention: see the judgment of Aicken J. in Minnesota Mining and Manufacture Co. v. Beiersdorf (Aust.) Ltd. (1980) 144 CLR 253; 29 ALR 29.

As I have previously mentioned, the evidence lodged in this matter establishes little in respect of matters of common general knowledge. The opponent, by way of submissions on its behalf at the hearing and by way of Mr. Jitts' declaration, tends to suggest that portions of Mr. Seggie's declaration where he refers to matters "familiar" to him or which were "well known" are admissions of matters of common general knowledge for both obviousness purposes and novelty considerations. I cannot agree with that view since nowhere does Mr. Seggie state, or could it be properly inferred, that his evidence expresses what were matters of common general knowledge in the particular art at or before the priority date of the present claims. Apart from the above arguments, the opponent, who ultimately bears the onus of establishing its ground of opposition, has not placed before me evidence relevant to the obviousness question. For example, there is no evidence which establishes that either of the prior patent specifications or exhibit DLJ3 left in evidence represented matters of common general knowledge, and more generally, there is no evidence to indicate what matters were known or used by all those in the relevant trade.

In the light of the above comments, I am not satisfied that this opposition ground has been proven and I therefore reject the allegation of obviousness of the claimed invention.

Manner of Manufacture

Mr. Caine for the opponent submitted that the present invention was not in respect of a manner of new manufacture as it concerned a mere new use of an old substance. As I understood it, his submission was based on several points. Firstly, it was argued that in this particular case all that has occurred has been the mere substitution of liquid nitrogen for another non-oxidising gas, the properties of liquid nitrogen being well known. Secondly, given the disclosure of Australian patent specification No. 471226 (Exhibit TWH4), it emerges that it is well known that the properties of liquid nitrogen make it suitable for the purpose of blanketing a bath of molten metal. In support of his argument, Mr. Caine referred me to the judgement in Commissioner of Patents v. Microcell Ltd. 102 CLR 232. I note the suggestion that certain matters were well known, but given my comments under the previous heading, I cannot agree that such matters were necessarily part of common general knowledge.

In considering this opposition ground, I note that at page 269 of the Microcell judgement, the High Court stated that:

"Many valid patents are for new uses of old things. But it is not an inventive idea for which a monopoly can be claimed to take a substance which is known and used for the making of various articles, and make out of it an article for which its known properties make it suitable, although it has not in fact been used to make that article before."

The Court also quoted from two other judgements which I consider of assistance here. The first was that of Sir Stanley Buckmaster S-G (as he then was) in Re A.F's Application (1913) 31 RPC 58 in which he stated:

"I can nowhere find any case that throws doubt on the proposition that where by the alleged invention no new product is obtained, no new method of manufacture suggested nor an old one improved, the discovery cannot be protected by a grant of Letters Patent."

The other judgement is that of Morton J. (as he then was) in Re L&G's Application (1940) 58 RPC 21 in which he commented on the practice of the British Patent Office concerning the use of a known material in the manufacture of known articles. He noted with approval the practice of that Office to allow applications to proceed in certain circumstances, namely:

"(l) where a change or variation in the construction of the apparatus is rendered necessary by reason of the use of a particular kind of material not previously used for that purpose;

(2) where the use for a particular apparatus of a known material not previously used for that purpose is due to a hitherto unknown or unsuspected property of the material;

(3) where the adaptation of the known material to the particular piece of apparatus leads to a new departure in the technique of the production of the apparatus."

(This is also the practice of the Australian Patent Office (see Examiner's Manual paragraph 35.91)).

On considering the above statements and submissions am of the opinion that the present invention is a manner of new manufacture. The invention clearly relates to a manner of manufacture in accordance with the law as stated in N.R.D.C.'s Application 1961 RPC 134. In addition, I consider that the manufacture is new since, as has been discussed previously, the method of manufacture departs from the prior art method by using liquefied rather than gaseous non-oxidising gas. Furthermore, this is not simply a case of merely substituting one non-oxidising gas by another known non-oxidising gas. In the present situation the gas of the prior art process is replaced by a liquefied gas, and because of this a change or variation of equipment is needed. Therefore, I consider the present situation falls within one of the variations referred to by Morton J. Hence my conclusion outlined above.

Section 40

Mr. Caine raised one minor matter at the hearing under this heading. He submitted that claim 12 was not clear in that it leads to the possibility of the nozzles being along more than one side of the area to be blanketed. However, I need only say that there is support in the description for such an arrangement and I fail to see that a lack of clarity exists.

Conclusion

I have decided that the opponent has not succeeded on the grounds relied upon. Accordingly I dismiss the opposition and subject to any appeal being lodged, I shall direct that the application proceed to sealing.

I award costs against the opponent.

(T.R. BRUHN)

Supervising Examiner of Patents

11 OCT 1988

Patent Attorneys for the applicant : Shelston Waters

Patent Attorneys for the opponent : Phillips Ormonde & Fitzpatrick