Baygol Pty Ltd v Foamex Polystyrene Pty Ltd

Federal Court of Australia|2004-10-21|Before: Tamberlin J

REASONS FOR JUDGMENT 1 The applicant, Baygol Pty Ltd ("Baygol"), is the patentee of Australian Patent 584769 for an invention by Peter Koukourou entitled "Building Foundation" ("the Patent"). In two separate proceedings, Baygol sued the first respondent, Foamex Polystyrene Pty Ltd ("Foamex"), and the second respondent, Huntsman Chemical Co Australia Pty Ltd ("Huntsman"), for infringement of the Patent. On 24 September 2004, pursuant to O 29 r 3 of the Federal Court Rules ("the FCR"), the Court ordered that the proceedings against Foamex and Huntsman were to be heard together in relation to the determination of an agreed preliminary question. 2 The preliminary question concerns the construction of Claim 1 of the Patent. The Patent was filed provisionally on 24 December 1985 and assumed its final form, after amendment, on 19 February 1991. The Patent asserts a monopoly in a method of forming building foundations as a waffle raft concrete slab. 3 The agreed questions for separate consideration are: (a) Does the "concrete spacer" integer encompass the use of a plastic spacer? (b) Can the question posed as (a) be answered "yes" or "no"? 4 The claims defining the invention with the amendments marked up by reference to a comparison between the final version and the preceding version are as follows: "1. A method of forming a building foundation, comprising: firstly levelling the supporting ground on which the foundation is to be located, forming peripheral shuttering walls, positioning a plurality of box-like hollow members in rows on the levelled ground, placing concrete spacers on the ground between the hollow members to separate the hollow members into rows, separating the hollow members by spacers, Laying positioning lower reinforcing rods on the said spacers and between the hollow members, in a plurality of rows which intersect at right angles to each other, placing reinforcing bar spacers on the hollow members, and positioning a reinforcing mesh of upper reinforcing rods on the spacers over the hollow members, and pouring concrete into channels between the hollow members and over the hollow members so as to envelope said reinforcing rods, mesh and hollow members to envelope said concrete spacers reinforcing bar spacers, reinforcing rods, mesh, and hollow members and thereby form a the foundation with a reinforced slab and a plurality of intersecting reinforced beams and an overlying reinforced floor slab. 2. A method according to claim 1 wherein said spacers are of concrete, and comprising placing further concrete spacers on the ground externally of the hollow members, laying further lower reinforcing rods on the further spacers, and positioning shuttering walls adjacent the further concrete spacers to define the perimeter of the foundation, before said pouring of the concrete. 3. A methodaccording to either claim 1 or claim 2 wherein each of said box-like hollow members comprises four side walls and an upper wall one side being open, and is positioned concave open side down. 4. A building foundation constructed by the method of any preceding claim and comprising a plurality of said spaced inverted hollow members, lower reinforcing rods between the hollow members, concrete spacers spacing the hollow members and locating the reinforcing rods, mesh of upper reinforcing rods, reinforcing bar spacers on the hollow members locating the mesh above the hollow members and concrete enveloping all said concrete spacers, reinforcing bar spacers, reinforcing rods, mesh and inverted hollow members. 5. A method according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. 6. A building foundation according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings." (Original emphasis) 5 The infringement alleged in relation to Huntsman and Foamex is that each respondent has, without the authority of Baygol, been manufacturing infringing products and supplying them to customers. In each proceeding, the respondent has raised the defence that there is no infringement because their spacers are made of plastic and not concrete as referred to in Claim 1. The contention is that the use of plastic spacers is outside the terms of the relevant claim. 6 Baygol accepts that if, as a matter of construction of Claim 1, it is essential that the spacer be made of concrete and that a method in which the relevant spacer is made of plastic falls outside the claim, the use of plastic spacers by the respondents does not infringe the Patent and therefore Baygol cannot succeed in either of its infringement actions. In each case, the construction of Claim 1 of the Patent is in issue, in particular, the correct construction of the integer "concrete spacer" and whether this integer can be read to include a footing that uses a plastic spacer between the hollow members or is limited to a footing that uses "concrete spacers".

the Patent 7 The Provisional Patent Application was lodged on 24 December 1985. This is the priority date of the Patent. A Complete Specification was filed on 24 December 1986. A second Complete Specification was filed on 27 February 1989 and a Notice of Opposition was filed by Mr Leonardis in September 1989. On 7 August 1990, a request was made to amend the second Complete Specification and a Patent based on the amended Complete Specification was granted on 19 February 1991 ("the Complete Specification"). 8 The title of the invention in the Complete Specification is "Building Foundation". The Introduction to the Complete Specification states that the invention relates to a building foundation which is suitable for use on both stable and unstable ground support and to a method of forming such a foundation. In the Background to the Invention, the usual practice for the construction of building foundations as at the priority date of 24 December 1985 is set out. This practice is to excavate a plurality of trenches, position reinforcing rods and reinforcing mesh in and over the trenches and then pour concrete to envelope the reinforcing rods, which are to be contained within the trenches, and to overlie the intermediate areas. This arrangement is described as "expensive" and as having the disadvantage that when unstable soil is required to support the foundation, there is a high degree of probability of the foundations cracking if the volume of soil varies as a result of changes in the moisture content. 9 There is then a brief description of the prior art, including that it was known to contain voids or hollows within conventional foundations to form a "waffle grid" within the deep foundation beams. The Complete Specification then continues with a summary of the invention. 10 The first consistory clause, which substantially accords with Claim 1, states that in the invention the method of forming a building foundation comprises levelling the supporting ground, forming peripheral shuttering walls, positioning a plurality of box-like hollow members in rows on the level ground between the shuttering walls, placing concrete spacers on the ground between the hollow members to separate these members into rows and laying lower reinforcing rods on the spacers, and between the hollow members, in a plurality of rows which intersect at right angles to each other. Reinforcing bar spacers are placed on the hollow members and a mesh of upper reinforcing rods is positioned on the spacers. Concrete is then poured so as to envelope the concrete spacers, reinforcing bar spacers, reinforcing rods, mesh and hollow members thereby forming a foundation with a reinforced slab and a plurality of intersecting reinforced beams. The second consistory clause describes a building foundation constructed by this method. 11 The Complete Specification then describes, illustrates and exemplifies a preferred embodiment of the invention with reference to figures. It is stated that a plurality of box-like hollow members are arranged in rows but spaced apart by concrete bricks so as to form a plurality of intersecting channels between the hollow members and support a plurality of lower reinforcing rods. The bricks firmly hold the hollow members in place and the upper surfaces of the bricks contain grooves to position the rods centrally. I note, at this point, that the evidence is that plastic spacers were not used in the form of "bricks". A mesh of upper reinforcing rods then overlies the hollow members being supported by support chairs and peripheral shuttering walls define the perimeter of the foundation. If, when the concrete is poured, there is any tendency for the hollow members to float, this is resisted by the grid, which applies a downward force that inhibits floating, and is further resisted by the spacers, which are located between the down-turned edges of the hollow members. After the assembly has taken place, concrete is poured into the channels to overlie the hollow members and envelope the reinforcing members. Since the bricks are formed of concrete, they are adhesive to the poured concrete and ingress of moisture or air to the reinforcing rods is inhibited and the foundation has considerable integrity from a structural point of view. 12 The Patent ends with six claims, of which the first three are relevant to these proceedings. The principal and widest claim is Claim 1, which is set out above and is the focus of this hearing. 13 The question for the Court in this case is whether the skilled addressee, with the knowledge relevant at the priority date would have understood the integer of "concrete spacers" in the Patent to mean that for the stated purpose of so separating the hollow members into rows, concrete, as the material for the spacers, was essential to the working of the invention.

Construction - principles 14 In considering the appropriate approach to the construction of the claim, a useful starting point is the decision of the House of Lords in Catnic Components Ltd v Hill & Smith Ltd [1982] RPC 183 (Catnic), where the House of Lords held that the word "vertical", in relation to a lintel of a box girder structure, should be read to cover a situation where the relevant member was 6 to 8 degrees off the vertical. Lord Diplock delivered the decision of the House and made a number of well-known observations. Relevantly, for present purposes, his Lordship said at 242- 243. "… both parties to this appeal have tended to treat 'textual infringement' and infringement of the 'pith and marrow' of an invention as if they were separate causes of action, the existence of the former to be determined as a matter of construction only and of the latter upon some broader principle of colourable invasion. There is, in my view, no such dichotomy; there is but a single cause of action and to treat it otherwise, particularly in cases like that which is the subject of the instant appeal, is liable to lead to confusion. The expression 'no textual infringement' has been borrowed from the speeches in this House in the hay-rake case, van der Lely v Bamfords, where it was used by several of their Lordships as a convenient way of saying that the word 'hindmost' as descriptive of rake wheels to be dismounted could not as a matter of linguistics mean 'foremost'; but this did not exhaust the question of construction of the specification that was determinative of whether there had been an infringement of the claim or not. It left open the question whether the patentee had made his reference to the 'hindmost' (rather than any other wheels) as those to be dismounted, an essential feature of the monopoly that he claimed. It was on this question that there was a division of opinion in this House and in the Court of Appeal in the hay-rack case. My Lords, a patent specification is a unilateral statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of his invention (ie. 'skilled in the art'), by which he informs them what he claims to be the essential features of the new product or process for which the letters patent grant him a monopoly. It is those novel features only that he claims to be essential that constitute the so-called 'pith and marrow' of the claim. A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is: whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked. The question, of course, does not arise where the variant would in fact have a material effect upon the way the invention worked. Nor does it arise unless at the date of publication of the specification it would be obvious to the informed reader that this was so. Where it was not obvious, in the light of then-existing knowledge, the reader is entitled to assume that the patentee thought at the time of the specification that he had good reason for limiting his monopoly so strictly and had intended to do so, even though subsequent work by him or others in the field of the invention might show the limitation to have been unnecessary. It is to be answered in the negative only when it would be apparent to any reader skilled in the art that a particular descriptive word or phrase used in a claim cannot have been intended by the patentee, who was also skilled in the art, to exclude minor variants which, to the knowledge of both him and the readers to whom the patent was addressed, could have no material effect upon the way in which the invention worked." Emphasis added) 15 Catnic was considered and applied by Hoffman LJ in Improver Corporation v Remington Consumer Products Limited [1990] FSR 181 ("Improver"). His Lordship's approach to the application of the principles in Catnic is set out at 188-189 in the following terms: "If the issue was whether a feature embodied in an alleged infringement which fell outside the primary, literal or acontextual meaning of a descriptive word or phrase in the claim ('a variant') was nevertheless within its language as properly interpreted, the court should ask itself the following three questions: (1) Does the variant have a material effect upon the way the invention works? If yes, the variant is outside the claim. If no - (2) Would this (i.e. that the variant had no material effect) have been obvious at the date of publication of the patent to a reader skilled in the art. If no, the variant is outside the claim. If yes - (3) Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention. If yes, the variant is outside the claim." 16 The three questions posed by his Lordship have subsequently been applied in many cases where they are referred to as "the Improver questions". At 189, his Lordship noted that the question is always whether the alleged infringement is covered by the language of the claim, thereby emphasising the importance of the language as the Court's primary focus. At 190, his Lordship pointed out that the answers to the first two questions do not involve questions of construction. The answers to these questions are used to provide the factual background against which the specification must be construed and it is the third question which raises the question of construction. In his Lordship's view, even a purposive construction of the language may lead to a conclusion that, although the variant made no material difference, it would have been obvious that the patentee was confining the claim to the primary meaning in excluding the variant. Otherwise, there would be no point in asking the third question. 17 The status in Australia of thepurposive approach as formulated in Catnic is not settled. 18 In Populin v HB Nominees Pty Ltd (1982) 41 ALR 471 at 475-7, the Full Federal Court affirmed the well-settled "pith and marrow" approach. However, in Rhone-Poulenc Agrochimie SA & Anor v UIM Chemical Services Pty Ltd & Anor (1986) 12 FCR 477 (Rhone-Poulenc), the Full Federal Court did not draw any distinction between the "pith and marrow" approach and the approach taken in Catnic. Their Honours applied both approaches to reach their conclusion and did not analyse any differential application of the two approaches: see, for example, Lockhart J in Rhone-Poulenc at 498. 19 In Prestige (Australia) Group Pty Ltd v Dart (1990) 26 FCR 197 at 208-9, Gummow J expressed the view that the "purposive approach" had received an uneven reception in the Federal Court: see also Nicaro Holdings Pty Ltd v Martin Engineering Co (1990) 91 ALR 513 at 528-9 and Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 (Rehm). In Rehm, Gummow J stated that Catnic did not propound any novel principle or new category of "non-textual" infringement. At 92, he agreed that what is called for in the construction of claims is a common sense assessment of what the words used convey, in the context of the published knowledge at the priority date. The emphasis is on the language used to express the claim. It is the meaning of this language which must be ascertained. 20 In Olin Corporation Ltd v Super Cartridge Co Pty Ltd (1977) 180 CLR 236 at 246, Gibbs J accepted that the approach described by James LJ in Clark v Adie (1875) 10 Ch App 667 at 675 was good law. The statement of James LJ at that reference is as follows: "The patent is for the entire combination, but there is, or may be, an essence or substance of the invention underlying the mere accident of form; and that invention, like every other invention, may be pirated by a theft in a disguised or mutilated form, and it will be in every case a question of fact whether the alleged piracy is the same in substance and effect, or is a substantially new or different combination." (Emphasis added) 21 Justice Gibbs then went on to say: " … However, as was pointed out in C Van Der Lely NV v Bamfords Ltd [1963] RPC 61 at pp 78, 80, the principle that there may be infringement by taking the 'pith and marrow' or the substance of an invention does not mean that there will be an infringement where the patentee has by the form of his claim left open that which the alleged infringer has done. And it does not affect the fundamental rule that there will be no infringement unless the alleged infringer has taken all of the essential features or integers of the patentee's claim." (Emphasis added) 22 The respondents both rely on the qualification to the "pith and marrow" approach referred to by his Honour to support their submission that, in the present case, the patentee has, by the form of the claim, in selecting the adjective "concrete" as a criterion, left open the use of plastic spacers. 23 An overview of the patent construction principles is set out by Finkelstein J in Root Quality Pty Ltd v Root Control Technologies Pty Ltd (2000) 177 ALR 231 at [27] ff (Root Quality). That case was concerned with a patent for a container suitable for growing plants which were later to be transplanted. His Honour considered that the "purposive" approach set out in Catnic had been adopted in Australia but that cases such as Populin implied that the "pith and marrow" approach can still have application. His Honour considered that the "pith and marrow" approach is no longer necessary where the Improver questions are posed and answered and proceeded to analyse the facts on the basis of those questions. 24 In Root Quality, his Honour warned that the Courts should act with care before broadening a claim by applying a purposive construction because elements of the claim which would not appear to be essential for the invention may nevertheless have been regarded by the patentee as essential for some reason that is not evident. 25 At [47], his Honour said: "If the language of the claim is clear, then the meaning of that language cannot change by reference to what appears in the specification. But the words of the claim must be read in light of the specification as a whole and be given a meaning in that context. Once construed it is not permissible to extend or narrow the ambit of the claim by reference to the specification." (Emphasis added) 26 At [48], in relation to the use the Court may make of amendments to the specification, which is an important matter in this case, his Honour said: "The approach that I will adopt is to consider the claim in its unamended form to discern what was intended and then to consider whether the meaning has changed following the amendments. Usually, the task of construction is best undertaken by taking the claim as it currently stands and ascertaining its meaning, having regard to the nature of any amendments made. In this case, for reasons which will become apparent, a different approach is called for." ((Emphasis added) 27 At [50], in relation to expert evidence, his Honour said: "There will be cases, however, where expert evidence is not admissible on the question of construction. Sometimes the text of the specification will be couched in language with which all lawyers are familiar, containing no technical or trade terms calling for explanation. In that event the court of construction can determine for itself, unassisted by experts, the relevant meaning, as it does with any other instrument. In its unamended form the specification of the patent in suit falls into this category at least so far as concerns the issue presently under consideration." 28 In the present case, the respondents correctly submit that the word "concrete" is not a technical term. They submit that the Complete Specification is couched in words with which all lawyers are familiar and that these words should be given their natural meaning in the absence of any ambiguity. It is obvious that "concrete", whether used as an adjective or a noun, is not a word which is capable of including "plastic". The exercise in the present case is quite different from that undertaken in Catnic in relation to the word "vertical", which was clearly capable of being read differently depending on the experience and understanding of the practical reader. In Catnic, the expression was sufficiently ambiguous to include a member that was almost vertical so long as it provided sufficient support and strength to fulfil its purpose. In the present case, there is no such range or spectrum of permissible interpretation which could permit the word "concrete" to mean material other than concrete. 29 In Root Quality, Finkelstein J applied the Improver questions. In relation to the first question, his Honour thought it was evident that the variants would not affect the way in which the invention would facilitate the growth of the root ball in the desired fashion. On the second question, his Honour's conclusion was that it would have been obvious to a person who wanted to use the invention, namely, a horticulturist or nurseryman, that the variants did not have a material effect on the working of the invention. However, on the third question, particularly having regard to the amendments which had been made to the claim, his Honour reached the firm conclusion that the variants were not intended to be excluded from the claim, notwithstanding that they did not affect the working of the invention. 30 In Societe Technique de Pulverisation v Emson Europe Ltd & Ors [1993] RPC 513 at 522, Hoffman LJ, with whom Ralph Gibson and Leggatt LJJ agreed, rejected the evidence of witnesses as to the meaning of the expression "conduit means", saying: "… one has to construe the language of the claim. The judge allowed counsel to ask the expert witnesses what they understood words like 'conduit means'. These are not technical words having a special trade meaning and in my judgment the opinions of witnesses on their meaning were inadmissible. Construction was a matter for the judge. 'Conduit' is in my view a word which expresses a function. It is not merely something through which liquid flows but of which at least one purpose is to convey liquid from one point to another, however close those points may be." (Emphasis added) 31 In that case, his Lordship applied the clear and unambiguous meaning of the expression "conduit means" and found that there was no infringement because the ring in question was not "conduit means". No such appeal can properly be applied when considering the meaning of "concrete spacer". It is a spacer made of concrete. It is not something which can bear another meaning. 32 In Kirin-Amgen v Hoeschst Marion Roussel Ltd [2004] UKHL 46 (21 October 2004) (Kirin Amgen), Hoffman LJ sounded a caution as to the limitations on the use of the Improver questions as a formula for all cases, rather than as guidelines which will, in appropriate cases, help to determine how the skilled man would understand the patentee's intention. The limitations on the utility of the guidelines are most clearly illustrated by the complex pharmaceutical patent under consideration in Kirin-Amgen. 33 Lord Walker, with whom Hope LJ and Rodger LJ agreed, reinforced that qualification in the following terms: "138 … I particularly welcome Lord Hoffman's detailed explanation of the real significance of the Improver (or protocol) questions … and how they fit in with recent developments in continental patents jurisprudence. There is always a danger that any judicial summary of principle may, precisely because it is concise, practical and repeatedly cited, take on a life of its own, as if it were a statutory text with its own problems of construction to be resolved ('the way the invention works' in the first question is a striking example of this). 139 The fact is that neither Catnic Components Ltd v Hill and Smith Ltd [1982] RPC 183 nor Improver was concerned with anything approaching high-technology science Lord Hoffman has demonstrated that in a rapidly-developing, high-technology field the questions may have no useful function, and may be a distraction from the one compulsory question set by Article 69 and its protocol." 34 I do not consider that the reference to Article 69 in the above remarks diminishes the force of the observations made by their Lordships as to the limitations on the utility of the Improver questions and the making of a decision as to the type of case in which the questions are appropriate. 35 Lord Hoffman in Kirin-Amgen reaffirmed the purposive approach to the construction of patent claims. At [34] his Lordship points out that the reference is not to purpose in a vague generalised sense. Rather, Lord Diplock in Catnic was pointing out that a patentee may be taken to mean something different when he uses words for one purpose from what he would be taken to mean if he was using the words for another purpose. In the Catnic case itself, the question was what was meant by the word "vertical" and the distinction was between the meaning of the term "vertical" in a mathematical theory and the practical functional use of a lintel in the building trade. 36 In the present case, this question does not arise as the words "concrete spacer" are clear and unambiguous and do not admit of any definitional enlargement. 37 The principles relating to the construction of claims were recently considered and applied by Merkel J in PhotoCure ASA v Queen's University at Kingston [2005] FCA 344. At [168]-[175] and [195]-[208], his Honour carried out a comprehensive review of the relevant authorities. At the conclusion of this consideration, his Honour decided to consider the case on the basis of the Improver questions within the framework outlined by Lord Hoffman in Kirin-Amgen. His Honour was of the opinion that the first Improver question should be answered in the negative and accordingly proceeded to consider the second question, namely, the obviousness to a reader skilled in the art of the lack of material effect of the variant at the date of publication. His Honour concluded that the second question should be answered in the negative. In relation to the third Improver question, his Honour expressed the opinion that it may not be strictly necessary to address this question, as the answer to the second question has the consequence that, applying the purposive approach to the construction of the claims, there was no proper basis for concluding that the primary meanings of the phrases under consideration in the claims were not the intended meanings. In any event, his Honour considered that the answer to the third Improver question was that the reader skilled in the art would have understood that compliance with the primary meaning of the phrases was an essential requirement. As a consequence, his Honour dismissed the infringement claim.

SKILLED ADDRESSEE 38 The skilled addressee is not necessarily a specific individual or class of individuals but could be a member of a team: see Root Quality at [72] per Finkelstein J. The type of person who is skilled in the art depends on the nature of the invention, the industry concerned and the factual context in which the question is to be determined. The authorities refer to many formulations of the definition of the skilled addressee, including a non-inventive worker in the field and a person who has a reasonably competent knowledge of the subject matter of the invention. 39 In the present case, most of the witnesses have a particular educational or academic qualification in relation to either the area of professional engineering or aspects of building construction and design. The fact that these witnesses do not necessarily carry out the actual construction does not mean that they are not persons who can be regarded as skilled in the art. In my view, in this case, which concerns the concrete industry, it is proper to have regard to the views of those experienced in the industry as engineers or designers, provided they have experience in the concrete industry, as well as the experience, practices and knowledge of concreters or builders who carry out the operations on a regular basis or have some direct practical familiarity with the implementation of the construction process and the working of the method claimed in the patent. This is not a case where it is necessary to choose between the consulting engineers and the concreters themselves in deciding who is the skilled addressee. I have approached the matter on the basis that the views expressed as to the background of the invention and the surrounding circumstances are in a sufficiently broad range to encompass both the engineers and the concreters. I do not consider that any priority should be given to the views of concreters as opposed to engineers who are experienced in the industry. On the facts of this case, neither type of witness has any greater claim to be a skilled addressee. 40 There are, however, limitations on the role that can be played by the person claiming to be the appropriate skilled addressee. In the present case, I have relied on the evidence not as determinative of any question of construction but rather as providing the factual background against which to consider the proper construction of the claim.

THE EVIDENCE 41 Mr Appleyard is a chartered professional engineer with experience in design and specifying. He gave evidence that he had conducted a survey of the literature on concrete slab footings, including standard engineering publications, that existed at the priority date. By December 1985, the concept of waffle slab constructions for suspended floor slabs had been known for many years. In 1974, the Australian Standard entitled "The Use of Reinforced Concrete in Structures" included a statement that "reinforcement shall be supported by approved concrete, metal or other chairs, spacers or ties and be maintained in position within the permissible tolerance until the concrete has hardened". There was also reference in the Australian literature prior to 12 December 1985 to spacers and bar chairs being made from a range of materials including concrete, plastic, wire, steel sheets or asbestos cement. In addition, Mr Appleyard says that other footing systems had been developed prior to the priority date, but these had distinct disadvantages in that they still required the digging of trenches, which was expensive, and did not offer an optimal solution for tackling expansive soil problems. The use of the waffle raft construction method addressed the problems posed by reactive soil sites, made it possible to more accurately specify the amount of concrete to be used and reduced the construction time by removing the need to dig trenches. There is presently a market penetration in excess of 90% for waffle raft construction. However, Mr Appleyard considered that the weight of the blocks was not a relevant consideration, so that concrete had no advantage by reason of its greater weight. He therefore stated that a concrete spacer was not integral to the working of the invention. 42 Mr Fox, who was called for Baygol, is an experienced civil engineer who had been in the building industry for 32 years. He said that the principal function of the spacers in the invention is to maintain a gap between the waffle pods to form and maintain channels and therefore hold the waffle pods in position. Without spacers the waffle pods would move around when the concrete is poured. Concrete spacers have not been used for many years, particularly since plastic spacers have become readily available. Mr Fox did not consider that there was any functional engineering advantage in using concrete rather than plastic as the material for the spacers. On the other hand, he saw some benefits in the use of a plastic spacer, as plastic was an inexpensive and durable material, readily available and could be easily moulded into a mass-produced product such as a spacer, so that he said it was a logical progression to replace concrete spacers with plastic spacers. The fact that plastic spacers are mass-produced, light and easy to handle and perform the same function as concrete spacers makes them more attractive. Mr Fox said that moisture ingress would be prevented by a membrane around the spacers and not by the spacers themselves and that this was common practice at the relevant time. The use of concrete was the most common way of manufacturing spacers at the priority date but the function could be performed equally well by plastic spacers. 43 There was evidence from Mr Koukourou, the inventor, that the material from which the spacer was formed was not an essential feature of the invention and was irrelevant to the way the spacer worked. His evidence was that concrete bricks as spacers were more widely used than plastic spacers in the building industry prior to the priority date. He also referred to the fact that his invention still required the laying of plastic sheeting under the foundations system to prevent the risk of moisture ingress to the footing slabs. 44 Mr Beauchamp is a consulting engineer. Prior to giving evidence, he was given a copy of the Provisional Patent Application and the Complete Specification and was informed that the patent claims and specifications were filed initially in December 1985 and that the final form of the claims was settled on 19 February 1991. His evidence is attacked on the basis that these documents and instructions would have affected his opinion on the construction of the relevant integer in Claim 1 and that reduced weight should therefore be given to his evidence. I think that there is some substance in this submission. 45 Mr Beauchamp stated that the use of concrete spacers is an integral part of the working of the Patent because of the reference in the body of the Complete Specification to the function of concrete in inhibiting moisture ingress and, by adhering to the poured concrete, resisting the tendency of the hollow members to float when the concrete is poured. He said that he could not comment on whether the use of concrete spacers adds to the structural integrity of the completed slab. He acknowledged that the Australian Standard required the use of a vapour barrier under all slabs constructed on the ground. 46 Mr Beauchamp said that if he had read the Patent in 1985 he would have regarded the use of concrete as an essential integer in the process because of the repeated reference to concrete spacers and the benefits ascribed to them. He refers to some disadvantages of concrete, including that it was porous and could allow the ingress of moisture, although a vapour barrier would prevent the latter. In cross-examination, he doubted, as a matter of hindsight, the significance of these claimed disadvantages. His evidence narrowed to the one possibility that in circumstances where the concrete brick is porous and the vapour membrane around the concrete is punctured or torn, there is a possibility that there may be some ingress of moisture and rusting could occur to the steel reinforcing bars. This does not, in my view, provide a sufficient basis for an argument that concrete is essential to the working of the invention. 47 Mr Haworth, an engineer, was called for the respondents. He had had regard to the Provisional Patent Application and the Complete Specification and this, in my view, detracts from the weight to be given to his evidence. In his report, Mr Haworth referred to the alleged advantages of plastic over concrete and said that he read the Patent as consciously stipulating the use of concrete as opposed to plastic spacers. However, in cross-examination, he doubted the accuracy of the claimed advantages of concrete in the Complete Specification and said that he would have read the claims at face value. He conceded that the weight of the spacer would not make any difference in relation to the resistance of upward flotation but would merely retain the waffle pods in a longitudinal direction. 48 Mr Marchioro, a concreter with considerable experience, recalled that in 1985 A V Jennings used Boral Celtex concrete bricks as spacers. He said that he was not aware at this time of any spacers being available other than the Celtex concrete brick and if he had read the Patent at this time, he would have taken the reference to concrete to be a reference to the Celtex brick. Towards the end of the 1980s, a number of light-weight plastic spacers came on the market specifically designed to hold the pods in place in waffle footing frameworks. At that time, he did not believe that there was any substantial benefit in using plastic spacers in preference to concrete bricks. He confirmed that plastic spacers are almost exclusively used at the present time. 49 Mr Yttrup, a consulting civil engineer, was called by Huntsman. Mr Yttrup said that on a reading of the Complete Specification and the description of the method in the claims, his view was that the spacers must be made from concrete. He said that it would have been apparent to him in December 1985 that spacers performed three functions: (i) to hold reinforcing bars in the correct position; (ii) to hold the boxes securely in position during placement of the concrete; and (iii) to maintain the durability of the structure by preventing moisture and oxygen from reaching the steel reinforcing bars and causing them to corrode. He said that one option in 1985 was to use concrete bricks because they were widely used for a similar purpose of holding steel reinforcing in place in a variety of applications, including the construction of footings. Other material that Mr Yttrup said he would have considered using for the spacer instead of concrete included plastic or steel but these could not be used as solid bricks. His recollection was that, at the relevant date, concrete bricks were used between the pods as spacers but that plastic spacers became available soon after and they were more effective and efficient to use than concrete bricks. This is because they effectively held the boxes in place and were lighter and more convenient to use than concrete bricks. Mr Yttrup's evidence indicates that plastic spacers were available in 1985, but were not used to any significant extent, and provided a substitute for concrete in the manufacture of spacers. He agreed that everyone in the industry in December 1985 would have understood that vapour barriers would be used for all raft slab systems to prevent the ingress of moisture. Mr Yttrup contended that concrete would have an adhesion advantage over plastic becasue the surface of a plastic spacer is less porous than that of a concrete spacer. This adhesion advantage means that a concrete spacer would prevent the ingress of moisture more effectively than a plastic spacer. Mr Yttrup's evidence in this regard was contrary to that of all the other witnesses. Mr Yttrup also gave some anecdotal evidence about the pouring of a concrete slab in October 1985 when spacers were used in the form of Celtex concrete bricks. However, this does not diminish the force of the evidence that as at 1985 there were known to be options other than concrete for spacers.

Primary approach - Language of claim 1 50 Having regard to the wording of Claim 1, the use of "spacers" is an essential integer, because it is one of the eight steps which comprise the method which is the subject of the claim. The question is whether the material used to manufacture the spacers must be concrete. 51 The starting point for the construction of the claim is the language chosen. The express requirement in steps four and seven of Claim 1 of the Complete Specification is that the spacers be "concrete spacers". The final step in the claim also confirms this and uses not only the expression "concrete spacers" but also "the said" concrete spacers. This emphasises the reference to concrete. 52 The word "concrete" is not one which has been shown to be ambiguous or to raise questions of fact and degree within a spectrum as to its interpretation, as was the case in Catnic in relation to the word "vertical". No reasonable connotation of the word "concrete" could include "plastic". The word "concrete" is one of ordinary English usage. For present purposes, it does not have any particular or industry meaning as distinct from the primary literal meaning. Expert evidence on the meaning of the word is therefore irrelevant. The applicant's submission is that the word "concrete" should be ignored and the express requirement of "concrete" spacers should be replaced with a requirement which simply provides for the spacers to be made of plastic or of any material which could make the invention work. There is no contextual justification for doing such violence to the language of the claim or ignoring the language chosen to express the claim. 53 As a matter of first impression, one would expect a person directed to implement the method set out in the claim to follow the wording and use concrete spacers. If the patentee had intended to refer to spacers made of other materials, then, given the simplicity of the requirement, it would have been easy to simply omit the reference to "concrete" or to designate a range of other suitable materials. This step was not taken by the patentee. The evidence does not disclose any reasons for the patentee not taking such an obvious course if he regarded the word "concrete" as too restrictive. It must be borne in mind that patent claims are not drafted by inexperienced or unqualified authors. They are usually the result of considered and deliberate choice, using the English language, with all its subtleties and precision, to delimit the boundaries of the claimed monopoly. The drafting of patent claims is an arcane and sophisticated art. As Lord Hoffman pointed out in Kirin-Amgen at [34], it will be an infrequent case in which it can be said that a patentee departed from the conventional use of language by including an element which was not meant to be essential. 54 Further support for the view that concrete was intended to be an essential integer can be derived from the wording of Claim 2, which refers to "a method according to Claim 1 comprising placing further concrete spacers" and "all said concrete spacers". Claim 4 also refers to "concrete spacers". Whatever else may be said, it is obvious that the word "concrete'" was not an oversight on the part of the patentee. I am satisfied that there is no ambiguity in the use of the word "spacers" and that the word "concrete" was not intended to be ignored but rather it was intended to delimit the essential limits of the claim. The exact reason for the use of the word "concrete" is not clear but this does not mean that it can be ignored.

the amendments 55 Although, in my view, it is not permissible to use the whole of the Patent Office file in order to assist in the construction of the claims, s 116 of the Patents Act 1990 (Cth) does enable the Court, in interpreting a Complete Specification which has been amended, to refer to the specification without the amendment. This could provide a basis for an inference as to what was intended by the patentee or at least cast some light on the construction of the claim. 56 In this case, the amendments are of some significance in determining whether the patentee intended that the reference to "concrete" would act as a restriction on the extent of the claim. 57 The first Complete Specification included, as part of the third step in Claim 1, a reference to "placing concrete spacers on the ground … to separate the hollow members into rows." Claim 2 also contained multiple references to "further concrete spacers". A second Complete Specification was filed on 27 February 1989, which deleted the reference to concrete before the word "spacer" in Claim 1. Claim 2 referred to "[a] method according to Claim 1 wherein said spacers are of concrete and comprising placing further concrete spacers on the ground …". Thus, Claim 2 proceeded on the basis that the spacers did not have to be exclusively constructed of concrete. 58 Amendments were proposed to the second Complete Specification on 7 August 1990. After further amendments were made, the final Complete Specification was published on 15 August 1991. As discussed in [51 and [54] above, the Complete Specification contained a number of express references to "concrete spacers". These amendments support the conclusion that a considered choice was made by the patentee to claim "concrete" as the exclusive material for the spacers and that the expression was meant to be essential to the claim. The omission of the requirement of concrete, coupled with its subsequent reinsertion, is very significant in pointing to a conclusion that concrete was intended to be essential. 59 The evidence does not disclose the precise reasons for the variations in wording concerning the material out of which the spacers were to be made. However, in accordance with the observations of Lord Hoffman in Kirin-Amgen at [35], when adopting a non-textual or purposive approach, it is important to keep in mind the limitations of that approach and the gaps in the Court's knowledge of the background which led to the patentee choosing the restrictive language, given the range of possible explanations available for taking this course. 60 After endeavouring to determine the meaning of the language selected by the patentee and taking into account the above matters and the history of the claim, I consider that the word "concrete", where appearing before the word "spacer" in Claim 1, was intended by the patentee to delimit, and does delimit, the extent of the claim. Accordingly, there is no infringement in this case.

improver questions 61 Given my conclusion, it is not strictly necessary for me to apply the Improver questions. However, in case I am wrong in the above conclusion, I will briefly indicate my views and reasoning on the Improver questions, having due regard to the cautionary remarks made by their Lordships in Kirin-Amgen. Question 1 - Does the variant have a material effect on the way the invention works? If yes, the variant is outside the claim. 62 The weight of the evidence is that the use of plastic as a material for the spacers does not have a material effect on the way the invention works. 63 The first claimed functional advantage of concrete spacers, namely, the closer adhesion of concrete spacers with the poured concrete as compared with plastic spacers, has not been made out. I accept the evidence that it was standard practice in 1985 to use vapour barriers. The function of vapour barriers was to prevent corrosion of the steel reinforcing bars by the ingress of moisture. The better view is that the adhesive value of concrete spacers is no greater than that of plastic spacers having regard to the three-dimensional shrinkage effect of the poured concrete when it dries. That is, when the concrete dries, it would tend to shrink away from the spacer. There would therefore be no greater gap which would permit moisture to penetrate between the poured concrete and a plastic spacer than between the poured concrete and a concrete spacer. 64 It was suggested by Mr Beauchamp that plastic had an advantage over concrete in relation to the ingress of moisture. However, this practical advantage would only exists in the unlikely situation that the concrete was porous and the vapour barrier ruptured so that there was an ingress of moisture. This is a remote possibility and does not amount to a material difference in respect of the way in which the invention works. 65 The second claimed functional advantage of concrete spacers, namely, the weight of concrete, as opposed to plastic, in resisting the upward flotation of the waffle pods, has also not been made out. This view was shown in the evidence to be based on a misunderstanding as to the function of spacers, which is to hold the pods apart. This is evident from the description in the Complete Specification of "placing the concrete spacers on the ground between the hollow members to separate the hollow members into rows." This is a purposive function. I prefer the evidence of Mr Appleyard on this point. 66 It is evident that plastic spacers have considerable collateral or incidental advantages so far as cost, availability, weight, flexibility in manufacture and ease of transportation are concerned. However, these are, in my view, merely incidental advantages which do not go to the working of the invention. 67 For these reasons, I am of the view that the first Improver question should be answered in the negative. It is therefore necessary to proceed to consider the second Improver question. Question 2 - Would it have been obvious, as at the date of publication of the patent, to a reader skilled in the art, that the use of the plastic variant had no material effect on the working of the invention? If no, the variant is outside the claim. 68 In my view, the evidence strongly supports the conclusion that, as at the publication date, it was known that there were other alternatives to concrete bricks which could perform the function for which spacers are designed in the Patent. The evidence discloses that plastic spacers were not generally used at that time but Australian Standards which were known in the industry referred to other alternatives such as plastic, wire, steel or asbestos cement. 69 Mr Appleyard gave evidence of earlier literature concerning spacers and to the general industry knowledge of engineers and builders involved the design and implementation of residential footings prior to the publication date which indicates that the terms "spacer" and "bar chair" are interchangeable. In particular, Mr Appleyard refers to the Australian Basic Guide to Concrete Construction (1975) issued by the Cement and Concrete Association of Australia, which contains the following statement in relation to reinforcement: "To ensure the correct concrete cover to reinforcement, spacers can be used to hold the reinforcing steel a fixed distance from the forms. Spacers are available in the form of bar chairs which may be made from: 1 Concrete 2 Plastic 3 Wire (may be galvanised or plastic coated) 4 Steel sheet (zinc coated or similar) 5 Asbestos cement. The specified concrete cover is essential in order to protect the reinforcement from either rusting or chemical attack." In October 1980, the Concrete Institute of Australia published Recommended Practise - Reference Specification for Concrete Work, which contained the following statement in relation to reinforcement: "5.4.2 Supports for reinforcement. Chairs, spacers, stools, hangers and ties may be used as supports for reinforcement and shall be made of metal, concrete or plastics, but pieces of wood, aggregate, brick or the like shall not be used." 70 Mr Marchiori indicated that he commenced using plastic spacers towards the end of the 1980s. In 1985, he was not personally aware of spacers other than concrete spacers being available. This does not directly address the question of whether an experienced builder or engineer would have considered it obvious as at December 1985 that plastic spacers would have had a material effect on the working of the invention. 71 It is difficult, if not impossible, to project back over more than 18 years and recollect with any accuracy what was happening as at late 1985, when this issue had no obvious significance to the witnesses who have been called. I am satisfied, on the basis of the literature to which I have been directed and the evidence of Mr Appleyard, that a person skilled in the art would have been of the opinion at the priority date that plastic spacers had no material effect on the way in which the invention worked. For this reason, I answer the second question in the affirmative. It is therefore necessary to consider the third question. Question 3 - Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention? If yes, the variant is outside the claim. 72 This question focuses on the language of the claim and the patentee's intention as to whether there should be strict compliance with the primary meaning of the claim. 73 There may be many practical reasons for a patentee to limit the extent of the monopoly claimed. Examples are where the patentee seeks to avoid possible problems as to prior art or where there is a commercial need for the early grant of a patent. As pointed out by Lord Hoffman in Kirin-Amgen, these practical considerations reduce the scope for a conclusion that the patentee could not have intended the meaning which the words convey on their face. The words of the claim will usually have been chosen upon skilled advice and with a view to the greatest degree of precision possible in order to achieve definition and clarity. It is not a matter in respect of which broad allowances must be made for statements of general intent under the guise of the purpose of construction. 74 In my view, there is no escape from the clear, precise and specific statement in Claim 1 that the spacer must be made of "concrete". Having regard to the wording of the Complete Specification and the emphasis it places on "concrete", not only in Claim 1 but also in the other Claims, together with the amendment history of the application, I am satisfied that a reader skilled in the art would conclude that the patentee had specifically imposed that restriction as being an essential requirement of the invention. It is difficult to see any other explanation for the omission and subsequent insertion of the limiting term "concrete" in the final Complete Specification. This indicates that the patentee has left open in formulating the claim that which the infringer has done, namely, the use of plastic spacers. The wording of the claim, in my view, is not reasonably capable of misunderstanding and the claim does not encompass the alleged infringement. 75 Accordingly, I answer the questions as follows: "(a) Does the "concrete spacer" integer encompass the use of a plastic spacer?" No "(b) Can the question posed as (a) be answered 'yes' or 'no'?" Yes I order the applicant to pay the costs of the first and second respondents. I certify that the preceding seventy-five (75) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Tamberlin.

Associate: Dated: 18 May 2005 NSD1530 of 2003 A Franklin SC and J Rawlings Counsel for the Applicant:

Solicitor for the Applicant: Griffin Vincent Lawyers

Solicitor for the Respondent: Rigby Cooke Lawyers Aitken McLachlan & Thorpe

NSD 1581 of 2003 A Franklin SC and J Rawlings Counsel for the Applicant:

Solicitor for the Applicant: Griffin Vincent Lawyers

Counsel for the Respondent: J Emmerson QC and SCG Burley

Solicitor for the Respondent: Freehills Date of Hearing: 14 and 15 December 2004 1 and 2 March 2005

At a glance

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Judgment (15 paragraphs)

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Legislation Cited (1)

Cases Cited (8)

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