Melbourne v Terry Fluid Controls Pty Ltd

Re: JOHN STANLEY MELBOURNE
And: TERRY FLUID CONTROLS PTY. LTD.
No. VG405 of 1989
FED No. 285
Number of pages - 13
Administrative Law

COURT

IN THE FEDERAL COURT OF AUSTRALIA

VICTORIA DISTRICT REGISTRY
GENERAL DIVISION
Jenkinson J(1)

CATCHWORDS

Patents - Novelty - Prior user - Secret use - Article delivered to potential purchaser for trial and evaluation - Circumstances in which that use is secret considered - Obviousness - Inutility.

Patents Act 1952 - s.100(2)

HEARING

MELBOURNE, 15-30 March 1993

#DATE 7:5:1993

Counsel for the Applicant: Mr. R.C. Macaw QC and Mr. M.T. Bevan-John

Counsel for the Respondent: Mr. G.S. Clarke

Solicitors for the Applicant: Galbally and O'Bryan

Solicitors for the Respondent: Garland Hawthorn Brahe

JUDGE1

JENKINSON J Trial of a proceeding for infringement of Australian Patent No. 584738 and a cross-claim for revocation.

The patent was granted in respect of an electrically insulated heat resisting air cylinder for use as an actuator for a fused salt electrolytic cell crust breaking implement. The smelting of aluminium in such cells is carried on in several places in this country. The cell is a large steel pot lined with a composite of aluminium, steel, carbon and tar based products which is thermally and electrically insulated from the steel pot. In operation the pot contains molten sodium aluminium fluoride. In that molten cryolite are suspended pure carbon blocks, which constitute anodes of the cell when electric current of low voltage and high amperage is passed through them and through the molten electrolyte to the cathode lining of the pot. Aluminium oxide (alumina) obtained from bauxite is fed into the cell in measured quantity every few minutes. The alumina particles are less than a millimetre in diameter and may be so small as to resemble talcum powder. The very high temperature of the molten electrolyte facilitates the reduction of the alumina to aluminium, the oxygen combining with the carbon of the anode to produce carbon dioxide. The aluminium sinks to the cathode whence it is periodically siphoned from the pot. The smelting process is continuous. About two tonnes of alumina and half a tonne of carbon are consumed in the production of a tonne of aluminium. The carbon anodes have to be replaced at intervals of about 8 days. Each pot has a few more than a score of carbon anodes suspended in the molten cryolite. Lines of pots, in number from 100 to 250, are installed, and are known as potlines. A very hard crust of irregular configuration forms during smelting on the surface of the molten electrolyte. The crust breaking implement which the patented cylinder actuates is a metal ram attached to the end of the piston rod of the air cylinder, which is suspended above the pot. The air cylinder extends the ram vertically down to cause it to break a hole in the crust, through which the measured quantity of alumina falls into the molten electrolyte, and then retracts the ram clear of the surface of the crust. Australian smelters introduce the alumina into the pot at the hole driven through the crust by the vertically descending ram. The means of delivering the alumina to the hole is called "point feeder technology", which was introduced into this country at the beginning of the ninth decade of this century. Feeders which slant in towards the hole from each side of the superstructure by which the anodes and the ram are suspended above the pot are called "central point feeders". What is called an "integral point feeder" contains the alumina in a barrel enclosing the bottom end of the air cylinder (called the head end or front end) and releases the alumina through an aperture in the barrel when the ram is extended to break the crust. A number of point feeders, whether they be "central" or "integral", is used in supplying alumina to each pot. At the head end of the air cylinder which encloses the piston rod there is need of -

(a) effective sealing between the surface of the piston rod and its housing to prevent escape of air under higher than atmospheric pressure within the cylinder to the outside of the cylinder;

(b) support and restraint of the piston rod in opposition to the lateral forces applied by the hard irregularly shaped crust to the ram which is attached to the piston rod;

(c) effective wiping or scraping from the surface of the piston rod, of matter adhering to it and likely to wear the piston rod and to abrade or distort the air seals, as the rod is retracted and before the adherent matter makes contact with an air seal.

There are two principal obstacles to the satisfaction of those needs : high temperatures and electric current flowing from the electrolytic cell up the metallic ram and the attached metallic piston rod when the ram plunges into the molten cryolite. If the current flows from any part of the piston assembly to the metallic cylinder there is, or should be, yet an insulation by which the flow of current to earth is prevented. The structure supporting the anodes and the crust breaking apparatus and any point feeder not integral with that apparatus is electrically isolated from the crust breaking apparatus by insulating material at the bolt connections between the supporting structure and those other structures. But the material wears and at times fails. Experience had shown the need for, and the specifications of aluminium smelter proprietors required, electrical isolation of the piston from the cylinder. Contact might occur between the head of the piston and the inner surface of the cylinder, and between the under side of the head of the piston and the end assembly of the cylinder through which the piston rod projects when the rod is fully extended. Against the flow of current at those points of contact electrically insulating material could be interposed. But contact between, or electrical arcing over the very small spaces separating, the piston rod and that part of the end assembly through which the piston rod was extended and retracted created difficulties which it was the patentee's object to overcome.

Claim 1 of the complete specification, on which the other claims depend and which they limit, reads as follows:

"A cylinder device for use as an actuator for a fused salt electrolytic cell crust breaking implement, the device having a cylinder in which a piston is slidable, a rod of the piston extending through an end assembly at one end of the cylinder, and an isolating arrangement within the end assembly by which the piston is electrically isolated from the cylinder; the isolating arrangement being provided within the one end assembly and defining a bore through which the piston rod extends, the isolating arrangement including a sleeve which defines a substantial portion of the axial extent of the bore, and an annular scraper member at an end of the bore from which the piston rod extends, the scraper member having an annular body and annular scraper fin which projects radially inwardly from the body to slidably engage the surface of the piston rod, the arrangement further including an annular air seal intermediate the sleeve and scraper member; the sleeve, the air seal and at least the body of the scraper member being formed from a suitable heat resistant, electrically non-conducting material."

This proceeding commenced on 6 March 1990. The Patents Act 1990, by s.230 of which the Patents Act 1952 was repealed, commenced on 30 April 1991. Sub-sections (1) and (4) of s.233 of the Patents Act 1990 provide:

"(1) Subject to this Chapter and the Regulations, this Act applies in relation to a standard patent or a petty patent granted under the 1952 Act as if the patent had been granted under this Act.

(4) Objection cannot be taken to a patent mentioned in subsection

(1), and such a patent is not invalid, so far as the invention is claimed in any claim, on any ground that would not have been available against the patent under the 1952 Act."

Section 228(2)(za) of the Patents Act 1990 empowers the Governor-General to make regulations, not inconsistent with that Act, "making such transitional and savings provisions as are necessary or convenient as a result of the repeal of the 1952 Act and the enactment of this Act"; and s.228(7) provides:

"Despite the repeal of the 1952 Act by this Act, regulations made under paragraph (2)(za) may provide for the continued operation of specified provisions of the 1952 Act in relation to prescribed persons or matters, or in prescribed circumstances."

Sub-regulation 23.26(1) of the Patents Regulations 1991 provides:

"The 1952 Act applies to an action or proceeding made or started under that Act and not finally dealt with or determined before the commencing day:

(a) in which the validity of a patent is disputed; or

(b) concerning infringement of a patent."

Section 100(1)(h) of the Patents Act 1952, so far as presently relevant, provided:

"A standard patent may be revoked, either wholly or in so far as it relates to any claim of the complete specification .... on one or more of the following grounds, but on no other ground:

(h) that the invention, so far as claimed in any claim of the complete specification .... is not useful."

The cross-claim raised that ground in respect of each claim. The particulars of the ground read:

"The Cross-Claimant will rely upon the fact that a necessary feature of the alleged invention as stated in the complete specification is that the piston be electrically isolated from the cylinder. The claims of the alleged invention indicate no means whereby upon full extension of the piston rod, electrical isolation of the underside of the piston from the head end of the cylinder is achieved. Without such means an electrical circuit will occur upon the full extension of the piston rod and thus the alleged invention will not work as promised and as claimed."

The under side of the piston will contact the head end of the air cylinder on full extension. The language of the claim distinguishes between "piston" and "piston rod" : the latter expression denotes the cylindrical rod which depends from the larger cylindrical head of that which is actuated by pneumatic pressure within the cylindrical housing of the device. The word "piston" denotes the whole of that which is actuated, except the crust-breaking ram attached to the rod. Accordingly, Mr. Clarke of counsel for the cross-claimant submitted, the "promise", or result to be achieved by a device made in accordance with the claim is electrical isolation of that whole, which the word "piston" denotes, from the cylinder which houses it. But no means is suggested of preventing current from flowing between the underside of the piston head and the end assembly on contact at full extension of the rod. Therefore, in Mr. Clark's submission, there is lacking an essential integer, without which the promised result will not be achieved.

Mr Macaw QC, who appeared with Mr. Bevan-John for the applicant, submitted that on a fair reading of the claim the electrical isolation claimed was seen to be isolation from the end assembly of that part of the piston which is at any time within that assembly. I accept that submission. So much is to be discerned, in my opinion, upon a consideration of several circumstances. First, the claim is for a "cylinder device .... having .... an isolating arrangement within the end assembly". Those skilled in the art well know that to achieve isolation of the piston from the cylinder other points of contact, outside the end assembly, must have been separated by an insulating material. They would in my opinion understand the claim that the "isolating arrangement" is one "by which the piston is electrically isolated from the cylinder" as a claim having reference to isolation of piston from cylinder within the end assembly. Second, the ambiguity suggested by use of the word "piston", instead of the expression "piston rod", in the phrase which claims the achievement of electrical isolation is in my opinion removed by a reading of the body of the specification. There the description of the invention employs the same distinction between "piston" and "piston rod" as is found in claim 1, and also employs the very words of the claim in description of "an isolating arrangement within the end assembly by which the piston is electrically isolated from the cylinder". In explanation of a drawing (Figure 1), which is said to be a partial sectional view of the lower end of a cylinder device according to the invention, the draftsman notes and briefly describes several numbered parts of the device which are not part of, nor contiguous to, the end assembly. Part of the description reads:

"Within assembly 14 (that is, the end assembly)

there is provided an isolating arrangement 24 for electrically isolating rod 20 (that is, the piston rod) from assembly 14 and cylinder

12. Seals around the piston similarly isolate the latter from surface 18 of cylinder 12."

The drawing itself makes it clear that in the second sentence of the passage quoted the word "piston" designates the head of the piston which is in contact with the inner wall of the cylinder, or rather, would but for the seals be in such contact. The passage quoted thus shows the draftsman to be content, almost in the same breath, to assert that the isolating arrangement within the end assembly will electrically isolate the piston rod from the cylinder and to point out that it would not isolate the rod from the cylinder unless seals were provided at the piston head. In my opinion those circumstances strongly confirm the construction of claim 1 for which Mr. Macaw contends. Electrically the rod of the piston and the head of the piston are a single conductor, so that the claim in the first sentence of the passage quoted is of electrical isolation, by the isolating arrangement within the assembly, of the piston and its rod from the cylinder. Plainly the draftsman meant no such thing in the passage quoted. Nor, in my opinion, should he be understood to mean that in Claim 1.

It was a ground of revocation alleged that the invention, so far as claimed in the claims of the complete specification, was not novel on the priority date of that claim. The cross-claimant alleged that the priority date of each claim was the date of lodgment of the complete specification, 2 September 1986. But the applicant alleged that, each claim being fairly based on matter disclosed in a provisional specification lodged on 14 January, 1986, s.45(2) of the Patents Act 1952 accorded each claim the earlier priority date.
In or about 1983 the applicant manufactured, in Melbourne at premises where it carried on business as a manufacturer and supplier of, inter alia, air cylinders for use in actuating aluminium smelter pot crust breakers, air cylinder devices with a view to sale of those and similar devices for that use. They were manufactured in accordance with a drawing numbered 602 and several parts drawings (collectively, "the 602 drawings"). The cross-claimant alleged that a device so manufactured would, if the patent in suit were valid, constitute an infringement. Mr. Macaw submitted that a device so manufactured would, and the 602 drawings indicated that it would, lack two essential integers of the claims of the complete specification : that the "isolating arrangement within the end assembly" be one "by which the piston is electrically isolated from the cylinder"; and that "the arrangement include an annular air seal .... formed from a suitable .... electrically non-conducting material". (For the purposes of this submission the word "piston" in the preceding sentence is to be understood, on the construction I have given it, as that part of the piston which is at any time within the end assembly.) The 602 drawings disclose metallic structures beside and between the two annular structures each of which seals the space between rod and cylinder within the end assembly. These metallic structures, called adaptors, are so shaped as to maintain the deformable seal, against which they are pressed by some means such as a spring, in an effectively sealing configuration. And that is the reason adaptors are used. The need for adaptors is greater when the sealing structure is made of teflon than when the sealing structure is made of synthetic rubber or certain other compounds. Mr. Macaw's submission was that the expression "air seal" in claims of the complete specification comprehend any adaptor in contact with a sealing structure and that therefore neither of the air seals of the 602 drawings or of the air cylinders made in accordance with those drawings was an "air seal .... formed from .... electrically non-conducting material".
It is clear from a reading of the complete specification that the claims do not require that there be in the "isolating arrangement" no part other than the three which the claims require that the isolating arrangement should include. The evidence also made it clear that some of the sealing structures which those skilled in this art would be likely to use in the construction of an air cylinder would require the support of adaptors if they were to function effectively. It is clear also that a sealing structure might fall within the meaning of the expression "air seal" in the claims notwithstanding that it consisted of two or more separable parts. Claim 7, for example, reads:

"A device as in any one of claims 1 to 6, wherein the air seal has at least one of oppositely axially facing end surfaces provided with a groove, with a resilient "O" ring being provided in the groove and urging radially inner and outer circumferential lips into sealing engagement respectively with the rod and the encircling surface of the end assembly."

But there was no evidence which I am prepared to accept that usage of the expression "air seal", among those engaged in fields of endeavour which call for a nomenclature in respect of air cylinders, would comprehend an adaptor. (It may well be that the expression "air seal assembly" would comprehend an adaptor supporting the air seal.) The "O" ring of claim 7 is incorporated into the body of the sealing structure and, being physically part of it, may be comprehended by the expression in the usage of those persons. One witness whose evidence touched on usage gave this evidence:

"Now, the only parts of the assembly which the claim specifies shall be formed from a suitable heat resistant electrically non-conducting material, are the sleeve, the air seal and the body of the scraper member. So that I take it that when you speak of gun metal air seal adaptors as failing to satisfy the material requirements of the claim, you must, am I right about this, have a formed judgment that such gun metal adaptors would have the result that the isolating arrangement, as a whole, would not fulfil what is called the particular purpose of the whole device, namely by which the piston is electrically isolated from the cylinder. Do I - have I made myself clear in the question?---Yes, I - yes, I think so. I am using the word - as I - I think the air seal is used in several different senses. It can mean the air seal assembly or the air seal per se, meaning either the U-washer, the V-seal or some other actual physical component which is prevent the passage of fluid past that particular point within the assembly.

Well, this is a matter then of terminology. We are in the world of words. How words are used?---Yes.

Are you aware of an adaptor component or member ever being called, or being referred to as part of the air seal?---Yes, I would certainly-because in order for the seal proper to function satisfactorily, it must be positioned correctly in space."

The last answer strongly suggests that the witness had, in giving it, slipped out of the world of usage into a conceptual world. In the description of one of what it describes as "alternative forms of air seal" shown on an accompanying drawing, the complete specification reads (page 8 lines 6-14):

"Figure 4 shows an alternative form of air seal 58 which, as with the seals of Figures 2 and 3, is shown in a typical cross-section. Seal 58 has a body 60 of which the circumferential surfaces flare radially therefrom as at 62,64. The adjacent side surface defines a groove 66, with the latter being lined with an annular metal spring member 68 of similar form. The respective side margins of member 68 urge adjacent lips 70,72 outwardly so as to provide a respective seal with surface 43 of assembly 14 and rod 20."

The expression "metal spring member" suggests that the metal spring is to be understood as a part - a "member" - of that which is called "an alternative form of air seal". If so, it might be concluded that such an air seal was not "formed from a .... electrically non-conducting material". Such an air seal could be said to have been "formed from" two materials, only one of which is electrically non-conducting. But in my opinion a fair reading of the complete specification requires the attribution to the word "formed" of a meaning which allows structures such as that described in the passage I have quoted to be comprehended by the expression "air seal" in claim 1. The word "formed" may be given the meaning : given its form, or external configuration, in an electrically non-conducting material. Alternatively, the words "air seal" may be construed as referring only to that member of the sealing assembly which by contact with the piston rod seals in the air in the cylinder. If that construction were adopted, the word "member" in the passage quoted could not be understood as meaning a part of the air seal. Why should not an air seal supported and "urged" into sealing engagement by a metal adaptor be held to be comprehended by the expression "air seal"? The adaptor and the ring and the spring have the same, or similar, functions. The answer is, in my opinion, that an adaptor is, and is recognisable as, a quite separate thing from the seal it supports, and there is no usage, in the speech of those who have occasion to talk and write about such things, or compelling contextual reason arising from a fair reading of the complete specification, to justify such a construction. In the cases of the structures incorporated into the seal when it is in use there is such a contextual reason, and usage allows the identification of such composite structures by the expression "air seal", and each of the composite structures is recognisable, in use, as a single thing. The clearest contextual indications occur in claims 7, 8 and 9 and between line 12 on page 4 and line 3 on page 5 and between line 12 on page 7 and line 21 on page 8 of the complete specification.

I conclude that the presence of the metal adaptors in the 602 drawings does not constitute a lack of an integer of any of the claims.
There was expert evidence that, under the harsh conditions in which an air cylinder for use in actuating a crust breaking implement in an alumina smelting pot must operate, the electrical isolation of the piston rod from the cylinder of a device manufactured in accordance with the 602 drawings would not long continue. The metal components of the isolating arrangement, the adaptors, were separated from the piston rod by very small clearances, which would be reduced by lateral forces on the rod and by dust and moisture adhering to the rod. Mr. Clarke submitted that no period of time during which electrical isolation would continue was claimed in any of the claims and that the absence of an integer of any of the claims is not shown by showing that the period during which isolation continues is short.
There was no satisfactory proof of the period during which devices manufactured in accordance with the 602 drawings continued in use without failure of the isolating arrangement. The expert opinion evidence which I would be inclined to accept, by Hans Nicholas Verzijl, does not specify the period of use within which he would expect failure to occur, except by the phrases "following relatively moderate use" and "relatively quickly". There was evidence that cylinders made in accordance with a drawing numbered 598 and having clearances between metal parts of the isolating arrangement within the end assembly, as well as other features of that arrangement, similar to those ordained in the 602 drawings were sold by the respondent to Alcan Australia Ltd. for use in the potline numbered 3 at its Kurri Kurri aluminium smelter. Electrical arcing between the metal parts and the piston rod caused failure of some cylinders within a few months of installation. The plant services supervisor at that smelter, Gerard Van Acker, gave evidence that he expected failure of cylinders about 18 months after installation. But he also gave evidence that some of the 598 cylinders "lasted for years". On the whole of the evidence, which afforded limited assistance in the resolution of this question, I am persuaded to find that electrical isolation of the piston rod from the cylinder, in the sense which I think the claims should be understood in the expression of that integer, was achieved by devices manufactured in accordance with the 602 drawings. I think that the electrical isolation to which the claims refer is to be construed as such an isolation as will continue in use of the device for a period longer than a few months. But in the conditions of use prevailing in aluminium smelter potlines a brief life for some of a batch of air cylinders installed at about the same time can be expected, as I find. If some of the devices continue in use for years under those conditions, as I find that some of them did, the device falls, in my opinion, within the meaning of the phrase "(a) cylinder device ... having ... an isolating arrangement ... by which the piston is electrically isolated from the cylinder" in claim 1. I accept Mr. Clarke's submission that none of the claims defines the device by reference to any promised period of use, or to any promised period of electrical isolation, so that only a period which matched the general expectation of those skilled in the art could be implied. The whole of the evidence suggested that that expectation was of a period not ordinarily exceeding the 18 months stated by Mr. Van Acker, and often falling well short of 18 months.
I conclude that devices manufactured in accordance with the 602 drawing were an anticipation of the invention claimed in the patent in suit and the ground of want of novelty is made out.
It was contended for the cross-claimant that an isolating arrangement manufactured in accordance with a drawing dated 2 October 1985 ("the Festo drawing") by Alcan Australia Ltd., for use in the cylinders that company had bought from the respondent and had installed in the No. 3 potline at Kurri Kurri, constituted an anticipation of the invention claimed in the patent in suit. This was an arrangement in which the air seals and scraper member were each enclosed within the cylinder by which the rod was supported. Some witnesses called the cylinder a "bush" and a "sleeve". All seemed content to call the whole arrangement a "cartridge". Mr. Clarke submitted that the cylinder within which the air seals and the scraper member were enclosed was comprehended by the word "sleeve" in the claims because usage among those skilled in the art tolerated that meaning of the word and because those parts of the cylinder which were in contact with the piston rod, being all of the internal circumferential surface of the cylinder except where that surface accommodated air seals and the scraper member, performed the same function of supporting and restraining the piston rod in opposition to the lateral forces applied to it as did the separate cylinder disclosed by the drawing in the complete specification of the patent in suit and called therein "the sleeve".
In my opinion the word "sleeve" does not comprehend anything which encloses within itself the part called in claim 1 an annular air seal and the part called in claim 1 an annular scraper member. A reading of every part of the complete specification except the drawing in my opinion compels the conclusion (which the drawing confirms) that the three required parts of the isolating arrangement - sleeve, seal and scraper - are to be separately aligned along the axial extent of the bore defined by the isolating arrangement. Nowhere, perhaps, is that more clearly indicated than in the requirement of claim 1 that the seal be "intermediate the sleeve and scraper member". In the Festo drawing part of what in Mr. Clarke's submission is to be called the sleeve is intermediate the scraper member and one of the two seals, another part is intermediate the scraper member and the other seal and a third part lies beyond the scraper member and both of the seals. The evidence of usage does not persuade me that a cylinder of the kind shown in the Festo drawing would ordinarily be called a sleeve. But even if it had, the indications in the complete specification of a different usage are too clear to allow common usage to determine the meaning of the word "sleeve" in that document, in my opinion. For that reason I conclude that an essential integer of the claims in the complete specification was lacking in a device manufactured in accordance with the Festo drawing.
SMC Pneumatics (Vic.) Pty. Ltd. ("SMC") imported into Australia air cylinders manufactured by a Japanese company by which SMC was controlled. Five of the cylinders were to be installed in a potline of a smelter at Portland conducted by Alcoa of Australia Ltd. Before the cylinders reached Portland it was realised that the stroke of the cylinders was too short for use there. The cylinders were adjusted by SMC to enable them to be used at Portland, but that work was not undertaken, as I find, until after the priority date for which the applicant contends, 14 January 1986. Nothing that had occurred before that date amounted to prior use of the cylinders to justify the ground alleged of want of novelty by reference to the cylinders.
Shortly after 14 January 1986 the adjusted cylinders were delivered to Alcoa of Australia Ltd. ("Alcoa") at Portland and installed for use in a potline. SMC had offered the cylinders for trial and evaluation by Alcoa in furtherance of SMC's endeavour to sell cylinders to Alcoa for use at Portland. In April 1986 SMC tendered for the supply to Alcoa of 1050 of the cylinders. There was no evidence that any request had been made of Alcoa that the design of the cylinders be not disclosed to anybody other than employees required to disassemble them in the course of trial and evaluation, or required for the purposes of evaluation to consider the design. But Mr. Macaw submitted that the circumstances were such that the use of the cylinders, in which their delivery to Alcoa for trial and evaluation consisted, was a "secret use" within the meaning of that expression in s.100(2) of the Patents Act 1952, and accordingly a use of which account was not to be taken for the purposes of s.100(1)(g). He relied on evidence by Mr. Verzijl, who was employed by Alcoa as a plant engineer from 1977 until 1988, and whose duties included the design and evaluation of crust breaking equipment at Portland. Mr. Verzijl evaluated tenders from suppliers of the equipment and had taken part in arranging the delivery of the five SMC cylinders for trial and evaluation. The evidence was:

"Where prototypes of that kind are provided for purposes of testing, did Alcoa have some policy about the way in which they should be treated?--- Alcoa and Bechtel, who were the managers at the time, I was unaware of any sort of written procedures or such, but there would have been an understanding that those people's cylinders would have been, remained confidential in the sense that other suppliers would not get to see the details of their design. If they wanted any other - you know, if there were any other things that they may have requested, we would have organised for them, like it is most probable that when the cylinders failed it would have been Alcoa's engineers curiosity to have a look at the mechanism of failure with the supplier and if they had requested that they did not want anyone to look at the cylinders, we would have met that requirements as well, but I can't - I am not aware of any of those sort of arrangements. I can't recall any of those sort of arrangements except that obviously we would not give a supplier's cylinder to someone else."

Mr. Verzijl gave evidence that at about the time when the SMC cylinders were being evaluated at Portland there were six different types of crust breaking cylinders which he was evaluating and that, in respect of confidentiality, there were no formal arrangements.

This is not a case of unconditional sale on the open market, as was in question in Bristol-Myers Co. v. Beecham Group Ltd. (1974) AC 646. Nor is it a case of trial and evaluation for the purpose of assisting the manufacturer to learn whether his product needs improvement, or to learn how it may be improved. This is a case of demonstration of a product to a potential buyer. I think that the application of the reasoning of the majority in the Bristol-Myers Case to a case of this kind requires that "secret use" cannot be found unless the supplier of the product for trial, first, intends that knowledge of the design be restricted to those of the potential buyer's employees and officers whose function it is to participate in making the trial or the evaluation, and second, has reasonable grounds for believing, either that his intention is known to the employee or officer of the buyer whose function it is to make his intention known to the participants in the trial and the evaluation, or for believing that those participants will assume that that is his intention. There was no evidence on which to base a finding of a belief, or of grounds for a belief, in the mind of any officer or employee of SMC that the relevant intention, if it existed, was known to any officer or employee of Alcoa, or that the participants in the trial and evaluation at Portland would assume that those who were in control of SMC had the relevant intention. The evidence of Mr. Verzijl which I have quoted might perhaps be said to justify a finding of an assumption by Alcoa's employees that SMC would not wish their cylinders to be made available for inspection by competitors. The evidence does not touch upon other means of dissemination of knowledge of the design of SMC's cylinders, as, for example, by employees of Alcoa who had obtained knowledge of the design in the course of trial and evaluation. It does not touch upon the question whether the "understanding" to which Mr. Verzijl refers had been one of which all those employees of SMC, or only some of them, were at the relevant time aware. It does not even justify a finding that all the participants in the trial and evaluation had been informed about the understanding.At the trial of the cross-claim a director of SMC requested that knowledge of the design of the cylinders which might be acquired by counsel and witnesses by inspection of parts of the cylinder tendered in evidence be not disclosed to the parties or to any officer or employee of the applicant because the parties were competitors of SMC. But that conduct is not satisfactory evidence in relation to the question of "secret use" in 1986. I conclude that the use of the cylinders at that time was not secret, within the meaning of s.100(2).
It was submitted by Mr. Macaw that the use of the SMC cylinders was no anticipation of the invention claimed in the complete specification because the isolating arrangement of those cylinders had not been proved -

(a) to have an air seal formed of a suitable heat resistant material;

(b) to have a scraper member of the description expressed in claim 1; or

(c) to have a sleeve which defined a substantial portion of the axial extent of the bore defined by the isolating arrangement.

A director of SMC, Kevin Hulton-Smith, gave evidence that the air seals were made in Japan to a design provided by SMC or the Japanese company which controls SMC. (The evidence does not show clearly which company.) The seal is composed in part of what was described in evidence as a high temperature fluorine rubber and in part of teflon. Teflon is suitably heat resistant, but Mr. Macaw submitted that there was no evidence of the capacity of the other substance to resist the very high temperatures which prevail in the cylinder during use, and that the SMC design drawing of the end assembly specifies a temperature range for that assembly of 5-150 degrees, whereas other evidence, which I accept, showed that temperatures above 200 degree C. were common. However, the cylinders operated in a potline at Portland for two years and I am prepared to infer from that circumstance, in the absence of evidence of deformation of an air seal in any of those cylinders by heat, that the seals were formed of a "suitably heat resistant material", within the meaning I give that expression in Claim 1.
There were two parts of the isolating arrangement which might be regarded as the scraper member. One, called in evidence a coil scraper, consisted of a teflon annulus the inner circumference of which was grooved. In the groove was seated a metal coil, part of which projected radially beyond the inner surface of the teflon housing. The coil had some freedom of movement radially within its housing and there was evidence that the coil would be displaced by some of the material adhering to the retracting piston rod. By that means the slidable engagement of the scraper fin with the surface of the piston rod which the claims of the complete specification require would be discontinuous, and the scraper would fail in performance of its function to the extent that some of the material on the piston rod would be carried within the isolating arrangement. Mr. Macaw's submission was that such a failure in performance of what he identified as a function required by an essential integer of the claims precluded a conclusion of anticipation by the SMC cylinders.
I do not read the claims as promising, or as requiring, complete and continuous engagement of scraper and piston rod surface, nor any particular degree of force maintaining the engagement. I find that the matter to be scraped was, except in the most extraordinary circumstances which were not in the contemplation of those skilled in the art in 1985 and 1986, in pieces of no greater diameter than one millimetre, and that the solid matter did not have strong adhesive properties, although it was abrasive. There was evidence of scraper members likely to perform the function of excluding that matter more effectively than the SMC scraper. But the efficiency of the SMC scraper in operation, which I infer from the operation of the cylinders for two years at Portland, was in my opinion sufficient to satisfy the requirement of the integer, on failure of compliance with which Mr. Macaw relied. It is unnecessary in those circumstances to consider the submissions about the other part suggested to be a scraper member of the description specified in the claims.
The third essential integer of the claims which Mr. Macaw submitted was lacking in the SMC cylinders was the requirement that the sleeve should define a substantial portion of the axial extent of the bore defined by that which claim 1 calls the "isolating arrangement within the end assembly". The length of the SMC sleeve is 48 per centum of the length of the whole assembly. When regard is had to the context which is supplied by the complete specification and by the expert evidence concerning the function which the sleeve is required to perform in operation of the device, the word is in my opinion seen to be used in the seventh sense given by the Oxford English Dictionary (2nd. ed) : "of ample or considerable amount, quantity or dimensions". (Cf. Palser v. Grinling (1948) AC 291; Monsanto Company v. Commissioner of Patents (1974) 48 ALJR 59; Tillmanns Butcheries Pty. Ltd. v. Australasian Meat Industry Employees' Union (1979) 42 FLR 331.) Although the claims of the complete specification do not exhaustively specify the component parts of the isolating arrangement, they clearly contemplate that the three components specified in claim 1, together with any adjuncts essential to the effective operation of those components (such as adaptors and springs) will be sufficient to enable the air cylinder to function effectively. Two of those three components are quite small in comparison with the end assembly, of any of the air cylinders which the evidence disclosed as useful for actuating crust breaking implements, within which the isolating arrangement must be housed. And I do not think that I am required to put wholly out of mind the relative lengths of sleeve, seal and scraper in the drawing to which the complete specification refers in giving meaning to the word "substantial" in claim 1.

Giving the word the meaning I have indicated, I am not persuaded as a matter of fact that the sleeve in the SMC cylinders does define a substantial portion of the axial extent of the bore defined by the isolating arrangement. And that is the case whether or not I have regard, as the expert witnesses said that one should, to the proportionate relationship between the axial extent of the bore defined by the sleeve and the diameter of that bore, in determining whether the axial extent of that bore is a substantial portion of the axial extent of the whole isolating arrangement.
The design drawing of the SMC cylinders was furnished to Alcoa at the time when SMC tendered for supply fo 1050 cylinders in April 1986. It is not of such detail that what is essential to the invention claimed in the complete specification of the patent in suit can be read out of it, and Mr. Clarke did not in final address submit that it was.
My conclusion being that the SMC cylinders did not constitute an anticipation of any of the inventions claimed in the complete specification of the patent in suit, it is unnecessary to consider Mr. Macaw's contention that each of those claims was fairly based on matter disclosed in the provisional specification lodged on 14 January 1986 and so by force of s.45(2) of the Patents Act 1952 to be accorded that priority date.
The validity of the patent in suit was denied also on the ground, specified in s.100(1)(e) of the Patents Act 1952, that the invention, so far as claimed in any of the claims, was obvious and did not involve an inventive step having regard to what was known or used in Australia on and before 2 September 1986.
I find that in and for several years before 1986 those responsible for aluminium smelter production were concerned to procure air cylinders, for use in association with the point feeder technology which had been introduced into Australia at the beginning of the decade, which had effective and durable electrical isolation of the piston rod within the end assembly, notwithstanding that what was called in evidence primary insulation was interposed between the feeder assembly (including the air cylinder) and the super-structure from which it depended. And they were making known that concern to those whose business it was to supply air cylinders for that use. The non-inventive skilled workers in the field had before 1986 appreciated that in order to achieve that isolation the three essential component parts of the end assembly which had to touch the piston rod in operation - the sleeve, the air seal and the scraper - must either be of non-conductive material or be themselves electrically isolated by non-conductive housing. They appreciated also that between the piston rod and any other component of the end assembly which was made of metal, and was not housed in non-conductive material, there had to be a space, a clearance, of sufficient magnitude to eliminate electrical arcing. What had not become obvious, as I find, to those workers was, first, that a clearance sufficient to maintain electrical isolation for workshop testing and for some period of operation on a potline was insufficient to maintain that isolation on a potline for a period of years; and, second, that the longer the sleeve the greater the probability that such a clearance would maintain isolation for such a period, because the longer the sleeve the shorter would be lateral displacement of the piston rod.
Mr. Macaw submitted that by the words of claim 1 - "an isolating arrangement .... by which the piston is electrically isolated from the cylinder" - that claim and the other, dependent claims were defined by result. But the claims cannot be understood to state that result in terms which other, prior isolating arrangements, not conforming with all the other requirements of claim 1, would not satisfy. Many such isolating arrangements would achieve electrical isolation. If it be said that an isolating arrangement conforming with the requirements of claim 1 will last longer than one not so conforming, claim 1 states no criterion of durability.
Mr. Macaw's principal submission on this issue was that the inventive step lay in the selection of a combination of integers which, not being a combination at all obvious to non-inventive skilled workers in the field, significantly increased the duration of electrical isolation and thereby lengthened the period during which the cylinder device would operate without requiring dismantling for maintenance or repair. I accept that submission.
One means of ensuring prolonged electrical isolation the claims of the patent in suit did not specify : the housing of all metal components within the isolating arrangement in non-conductive material. Although the complete specification makes no mention of unhoused metal components within the bore defined by the isolating arrangement, as distinct from unhoused metal components at either end of that bore which retain the components of the isolating arrangement within the end assembly, the claims do not define the components of the isolating arrangement exclusively.
The combination of integers selected by the patentee was first, that components in contact with the piston rod be, as to two of them made of non-conductive and suitable heat resistant material and as to the third either made of or housed in such material, second, that the sleeve constitute in length a substantial portion of the length of the isolating arrangement, third, that the scraper have an annular fin which projects radially inwardly to slidably engage the surface of the piston rod. The first of the three was at the earlier priority date obvious, as I find. But I do not find either of the other two obvious to non- inventive skilled workers in the field. The combination was I find a step of sufficient inventive merit to be patentable. It achieved a significant advance in satisfying the need of a more enduring electrical isolation, by selecting the best available means, first, of excluding matter likely to wear the piston rod and the components of the isolating arrangement and likely to diminish by its deposition the clearances between any metal components of that arrangement and the piston rod, and, second, of restricting lateral movement of the piston rod, which movement also tends to cause that same wear and to diminish those same clearances.
The objection of obviousness is not established. But, the ground of anticipation having been proved, the patent must be revoked.
If the patent had not been revoked, its infringement would have been established Proof was made of several infringements by the respondent. In his final address Mr. Clarke made no submission against a finding of those infringements.
The proceeding and cross-claim will be adjourned so that the parties may consider the question of costs and the terms of the orders to be made.

[1993] FCA 285

07 MAY 1993