Australian Mud Company Pty Ltd v Coretell Pty Ltd

JUDGES: BENNETT, GILMOUR, YATES JJ DATE: 15 SEPTEMBER 2011 PLACE: PERTH

REASONS FOR JUDGMENT 1 The first appellant is registered as the owner of Australian Patent No. 2006100113 for an invention entitled "Core Sample Orientation" (the patent). 2 The patent is a certified innovation patent that was granted as a divisional application of Australian Patent Application No. 2005256104. 3 The appellants appeal from a judgment in which their claims of patent infringement by the respondents were dismissed. They also appeal from a judgment on the respondents' cross-claim granting relief against them for unjustifiable threats of infringement of the same patent. 4 As argued, the appeal centred on a single question of construction that related to all the claims of the patent. The parties accept that, if that question is answered in favour of the appellants, the appellants' claims of patent infringement would be made good and the respondents' claims of unjustifiable threats would fail, provided the patent is valid. 5 The respondents submit, however, that, in those circumstances, the patent would not be valid because, on that construction, the claims would not comply with s 40(3) of the Patents Act 1990 (Cth) (the Act): they submit that the claims would not be fairly based on the matter described in the specification. 6 The second and third appellants are licensees of the first appellant with respect to the exploitation of the patent in Australia. Their entitlements as licensees have been entered in the Register of Patents pursuant to s 187(2) of the Act. That status does not entitle them to sue for infringement. Their legal interest in the appeal arises from the fact that, together with the first appellant, orders were made against them in both the infringement proceeding and the proceeding for unjustifiable threats.

The patent 7 The invention claimed in the patent is an orientation device for providing an indication of the orientation of a core sample obtained through drilling operations in geological surveys. 8 The specification describes the general nature of the drilling operations that are involved. These operations are typically conducted using a drill with outer and inner tube assemblies. A cutting head is attached to the outer tube assembly to which rotational torque is applied. In the drilling operation a core is generated which progressively extends along the inner tube assembly as the drilling progresses. Once the sample is obtained, it is fractured from the surrounding subterranean area and brought to the surface where it is removed from the inner tube and analysed. Because the drilling operations are performed at an angle to the vertical, it is desirable, for the purposes of analysis, to have an indication of the orientation of the core sample within the ground prior to it being brought to the surface. 9 The specification describes, in a general way, prior art means of obtaining an indication of the orientation of the core sample. These include the use of an orientation spear, such as a marker (for example, a crayon) projecting from one end of a steel shank which is lowered into a pre-existing drill hole to strike, and thus to mark, the facing surface of the material from which the sample has been generated. When retrieved, the sample shows the mark, thereby indicating the orientation of the sample at the time it was in the ground. 10 The specification also refers, without elaboration, to mechanical core orientation devices for marking a core sample prior to its extraction from the drill hole. The specification identifies an example provided by the disclosures in patent application no. WO 03/038212. 11 The invention of the present patent is disclosed in the specification by a number of consistory statements corresponding to each of the five claims. Other preferred features are disclosed in the general description of the invention. 12 The best method of performing the invention is described in the specification by reference to a specific, but non-limiting, embodiment. It is common ground between the parties that the embodiment so described is an orientation device having a single, unitary assemblage. 13 The claims of the patent are as follows: 1. An orientation device for providing an indication of the orientation of a core sample relative to a body of material from which the core has been extracted, the orientation device comprising means for determining and storing the orientation of the device at predetermined time intervals relative to a reference time, means for inputting a selected time interval, means for relating the selected time interval to one of the predetermined time intervals and providing an indication of the orientation of the device at the selected time interval. 2. An orientation device as claimed in claim 1 attached to an inner tube assembly of a core drill and fixed against rotation relative thereto, the orientation device including means for attachment to the inner tube assembly. 3. An orientation device as claimed in claim 1 or 2 including means for comparing the orientation of the device at the selected time interval to the orientation of the device at any subsequent time and providing an indication of the direction in which the device should be rotated in order to bring it into an orientation corresponding to the orientation of the device at the selected time. 4. An orientation device for providing an indication of the orientation of a core sample relative to a body of material from which the core sample has been extracted, the orientation device comprising means for generating signals responsive to the orientation of the device, a processor for receiving the generated signals and for processing the signals to generate orientation data representative of the orientation of the device, means for storing the orientation data at predetermined time intervals, means for inputting a signal representative of a selected time interval to the processor, the processor operating to relate the selected time interval to the predetermined time intervals and output a signal indicative of the orientation of the device at the selected time interval. 5. An orientation device as claimed in claim 4 wherein data is generated representative of the orientation of the device at any subsequent time and the processor is operable to output a signal to a display means to provide a visual indication of the direction in which the device should be rotated at said subsequent time in order to bring the device into an orientation corresponding to its orientation at the selected time. 14 The appeal was argued substantially by reference to claim 1. This claim provides a convenient reference point to test the arguments that were raised.

The accused apparatus 15 The accused apparatus functions to provide an indication of the orientation of a core sample relative to a body of material from which the core has been extracted. The apparatus has two components. The first component is a tubular unit described variously as "the down hole equipment", "the down hole unit", or "the bore hole component", amongst other expressions. For consistency, we will refer to this component as "the down hole component". This component is positioned within the inner tube assembly that is lowered into the drill hole from which the sample is to be taken. It has means for determining and storing the orientation of this particular component at predetermined time intervals relative to a reference time. 16 The second component is a handset. The handset is operated at the surface. It has means for inputting a selected time interval. 17 The down hole component and the handset, operating together, also provide means for relating the selected time interval to one of the predetermined time intervals, so as to provide an indication of the orientation of the down hole component at the selected time interval. 18 It was common ground at trial that the down hole component and the handset component work as described in the following statement tendered in evidence (which refers to the down hole component as "the down hole equipment"): (a) Prior to the lowering of the down hole equipment into the drill hole, the handset is turned on and wireless communication established with the down hole equipment. On establishing such communication, the operator may automatically initiate synchronisation of the real time clocks in both the handset and down hole equipment by way of an appropriate action button of the handset. (b) Following synchronisation, the down hole equipment can then be lowered into the drill hole at the back end of an adapted core tube ready for drilling operations. Of course, once down the hole such wireless communication ceases. (c) Down the hole, as drilling progresses, the accelerometers provide gravitational values relative to the x, y, z co-ordinates of the core tube at particular time intervals. These values are then calibrated and processed and, on an averaged basis at 10 second intervals, are then stored in a memory component. The stored values are representative of gravity values relevant to each accelerometer. As well, temperature values are stored. (d) Once a desired length of core sample has been achieved (as determined by the operator), drilling is stopped and the drill string and down hole assembly becomes [sic] rotationally inactive. At the surface, the operator then takes up the handset and presses a button on the handset described as "Take Measurement". This causes the clock in the handset to record the time the button the button [sic] was pressed. The handset also informs the operator to maintain the drill string inactive for a nominated period. (This is to achieve at least one orientation measurement during a period of down hole stability.) (e) Once the handset provides the operator with an indication that the down hole equipment can be moved, the operator then can bring the core tube and down hole equipment to the surface. (f) Once the down hole equipment is at the surface, real time communication is established between the handset and the down hole equipment by the Bluetooth wireless modules contained in the handset and down hole equipment. (g) Once communication is established, the handset queries the down hole equipment to provide it with the calibrated accelerometer data associated with a time that most closely matches the time recorded by the handset when the "Take Measurement" button was pressed. The down hole equipment then provides the calibrated accelerometer data and temperature data to the handset. The handset componentry then processes such calibrated accelerometer data and the temperature data to determine the orientation of the down hole equipment (and core tube) at the marked time at which the "Take Measurement" button was pressed. (h) At this stage, the handset and down hole equipment (at the back end of the core tube retaining the core sample) are in real time communication. The down hole equipment repeatedly transmits accelerometer data to the handset for processing. The handset processor then calculates the current orientation of the down hole tool and compares it to the orientation of the device at the time closest to that recorded by the handset. The results of these comparisons determine the direction in which the device must be rotated in order to realign the core device to its desired position and display this direction to the operator by way of the handset. (i) By visual referral to the handset, but manually independent of it, the core tube with retained sample then can be rotated (by the operator or other person) to achieve coincidence of down hole and surface orientation of the core tube and retained sample. Once the desired orientation is achieved, the retained core sample is then marked and then can be removed from the core tube. The core sample can then be placed into a core sample tray and the core tube and associated down hole equipment then can be returned for another cycle. (j) To be noted is that, usually, there are two down hole devices operating in sequence to maintain drilling efficiencies so that as one tool clears the surface, the second tool is then "started"/synchronised and lowered into the hole with the above described core orientation activity on the surface tool then to be undertaken in conjunction with the handset. 19 It can be seen from this description that not only is the accused apparatus one for providing an indication of the orientation of a core sample relative to a body of material from which the core has been extracted, but also one, through the operation and interaction of its two components, that fulfils the functions provided by each of "the means" identified and defined in claim 1 of the patent, in so far as those functions relate to the orientation of the down hole component.

The approach of the parties 20 The proceeding before the primary judge raised three main questions: whether the accused apparatus infringed the patent; whether the patent was valid; and whether the respondents, if liable for infringement, were joint tortfeasors. 21 The question of patent infringement raised four issues relating to the construction of the claims. All but one of those issues was determined in favour of the appellants. The issue determined adversely to the appellants, which was fatal to their case on infringement, was identified by the primary judge as "the device issue". 22 As apparently argued by the parties, and as determined by the primary judge, this issue concerned the meaning of the term "device" as used in the claims of the patent. The primary judge described the controversy as whether that term, as used in the claims, would encompass a core orientation tool (to use a neutral expression) in two or more separate and separated parts (as argued by the appellants) or whether it was limited to a unitary tool in a single assemblage (as argued by the respondents). 23 At trial the parties were in agreement that the term "device", as used in the claims, did not have a special or technical meaning, only its ordinary English meaning. 24 They accepted, however, that the words in a claim should be read through the eyes of the notional person skilled in the relevant art, in the context in which they appear, having regard to that person's own general knowledge and to what is disclosed in the body of the specification. 25 They accepted, also, that the construction of a specification, including the claims, is ultimately a question of law for the Court. 26 Nevertheless, the question of the meaning of "device" provoked a significant debate largely carried out through the evidence of expert witnesses called by the appellants (Professor Trevelyan and Dr Kepic) and the respondents (Dr Myers). There was no issue on appeal that each of these witnesses had expertise relevant to the attributes of the notional person skilled in the art. It seems doubtful, however, that all of their evidence was appropriately directed to the question of construction that fell for determination by the Court. This may be because, at trial, the debate focussed on the meaning of the term "device" used in engineering parlance rather than what the claims defined as the invention. 27 Thus Professor Trevelyan gave evidence about engineering objects comprising multiple, separate components, commonly referred to by engineers as a "device", such as an electric drill and its chuck, and the common car jack with detachable handle. 28 Dr Kepic gave evidence that those in the field of geophysics will refer to a number of physically separate components, which nevertheless work together to produce a result, as a "device". This evidence was exemplified by reference to data harvesting tools comprising a series of remote sensors and a separate hand held display unit, and differential GPS survey devices which comprised both a base station and a roving station. 29 The respondents criticised this evidence. They submitted that a broad understanding of the word "device" is not relevant to the words or text of the patent and cannot aid the task of construing the claims. 30 The primary judge rejected that submission, holding that, specifically in relation to the evidence given by Dr Kepic, such evidence was relevant to understanding "the point of view" from which the notional person skilled in the art would approach a reading of the patent. His Honour also reasoned that this evidence showed that Dr Kepic had a broad understanding of the term "device" outside his involvement in the present litigation which militated against an assertion that his evidence was contrived. 31 Dr Myers' evidence was similarly directed. The effect of his evidence was that, from a computer engineering perspective, a "device" refers to something that is physically interconnected, such as a semi-conductor device. Hence, according to Dr Myers' understanding, the word "device", as used in the claims, referred to "a physically integrated set of components capable of working together to produce some useful effect, such as an instrument". 32 The appellants criticised this evidence. They argued that this approach to the construction of the claims involved the erroneous adoption of a preconceived notion of the meaning of "device" that paid little regard to the text of the patent. 33 The primary judge accepted the force of this submission, to a point. His Honour accepted that Dr Myers approached the claims with an assumption as to how the word "device" was to be read, but checked this understanding against the text of the claims to see whether there was anything to challenge his view. It was not correct to say that Dr Myers had paid no regard to the text of the patent. 34 It can be seen, therefore, that the parties, although calling expert evidence on the question of claim construction, criticised the evidence of the other as being misdirected and, at least in certain aspects, foreign to the correct approach to claim construction.

The primary judge's reasons 35 After identifying the three main questions arising in the proceeding, the primary judge discussed the legal principles relevant to the question of claim construction. 36 In his discussion of those principles, the primary judge referred to the need to give the claims a purposive construction. In that connection his Honour quoted the observations of Lord Diplock in Catnic Components Ltd v Hill & Smith Ltd [1982] RPC 183 at 242-243 and referred to the explanatory observations of Lord Hoffmann in Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2005] 1 All ER 667; (2004) 64 IPR 444 at [33]-[34] with respect to purposive construction. 37 In the present case, the primary judge at [25] said: I accept it is correct to take a purposive approach to claim construction, but I am mindful that it is not intended to widen the scope of construction to embrace alleged infringing articles that would otherwise be outside the plain words of a claim as read by a person skilled in the relevant art. The purposive approach is concerned with identifying the essential features of a claim and construing them from the perspective of a person skilled in the art. These features, as the Full Court of this Court noted in Populin v HB Nominees Pty Ltd (1982) 59 FLR 37 (Populin), at 43, "are to be determined not as a matter of abstract uninformed construction but by a common-sense assessment of what the words used convey in the context of then-existing published knowledge". 38 His Honour then noted the role of the skilled addressee in giving evidence on the question of claim construction and found that the evidence adduced from Professor Trevelyan, Dr Kepic and Dr Myers was relevant to the task of determining how the patent would be read by the notional person skilled in the art. 39 After discussing the configuration of the accused apparatus and its mode of operation (by reference to the tendered description quoted above), the primary judge turned to consider the four issues arising on the question of claim construction in the present case. For reasons we have explained, it is only necessary for us to discuss his Honour's consideration of "the device issue" and the conclusion to which he came on that issue. The primary judge noted that the parties had identified this issue as "the key issue" in the case. 40 At the outset the primary judge emphasised that the word "device" must be construed within the context of the claims as a whole and from the perspective of the relevantly skilled addressee of the patent, and not simply with an appreciation of what the word may mean in common parlance or in non-relevant fields of industry. 41 After summarising the main aspects of the evidence given by Professor Trevelyan, Dr Kepic and Dr Myers on this issue, and noting the parties' submissions in relation to that evidence, his Honour expressed the following view (at [80]): In my view, a literal construction of the claims and identified integers is open such that the "device" referred to is a single, physically interconnected thing, not separated into parts or components. In particular, the indication that it is the device that goes down a hole and is to be oriented suggested that there is only one device, part or component, at all times of its usage. 42 The primary judge then noted the arguments against that construction. His Honour noted that the arguments "appeal to common sense". It is clear that, in this part of the reasons, his Honour was rehearsing the arguments advanced by the appellants and describing the way in which those arguments were advanced, rather than signifying his considered acceptance of those arguments. 43 In summary, the arguments that were put against what his Honour described as "the literal construction of the claims" were as follows: The construction is pedantic and artificial. There is nothing particular in the word "device" or its dictionary meaning that suggests that it cannot be constituted by a number of components. The approach to the reading of the relevant claims adopted by Dr Kepic does not require any straining of language. The argument that the expression "the orientation of the device" must mean the orientation of all components of the device (where an apparatus is made up of separate and separated components), is not a view that the skilled addressee would ordinarily take, in light of the evidence of Dr Kepic, supported by Professor Trevelyan. 44 Although his Honour considered the resolution of this construction issue to be finely balanced, his Honour nevertheless came to the conclusion that the "literal construction" contended for by the respondents was "neither contrived nor in defiance of common sense". Indeed, his Honour concluded that this construction sat best with established construction principles. 45 His Honour supported this conclusion by reference to the following matters: Nowhere in the claims is there a reference to a device in two or more separate and separated components. In this connection his Honour referred to the use of the articles "the" and "an" in the claims. His Honour also observed that, read contextually, there was nothing in the claims to suggest that they encompassed multi-part tools. Claim 2, in particular, claimed the device of claim 1 attached to the inner tube assembly of a core drill. This is inconsistent with a device comprising multiple parts that are separate and separated. When resort was had to the specification to resolve any ambiguity, the specification itself did not suggest that the invention was to be construed as encompassing tools in more than one part. In this connection, the recitation of the background art in the specification suggested that the invention was intended to replace other unitary down hole systems for determining core sample orientation. The phrase "the orientation of the device" used in the claims suggested a whole device in a single part. Dr Kepic's evidence on the meaning of "device" was not determinative. In any event, when pressed in cross-examination, Dr Kepic accepted that the word "device" when read literally in the context of the claims, would not encompass orientation tools in two parts. On the other hand, Dr Myers' evidence showed that, construing the term "device" purposively in the context of the claims as a whole, the notional skilled addressee could read the term as being limited to a tool in one piece. 46 In coming to his conclusion, the primary judge observed: … While the (C)ourt should read the claims purposively and not with an eye for pedantry, even an appropriately liberal approach to construction should not permit the words of the claims to be stretched beyond their textual limits. 47 The primary judge thus concluded that the accused apparatus "in two separate and separated parts" was not within the scope of the term "device" as used in the claims, with the consequence that the appellants' case on infringement failed. 48 The sole issue that arises on this appeal is whether the primary judge erred in that conclusion.

The appellants' submissions 49 The appellants acknowledged in their submissions that the question of infringement in the present case turns on the proper construction of the word "device" as used in the claims. 50 The appellants accepted that it was correct for his Honour to take a purposive approach to claim construction and that this approach was not intended to widen the scope of construction to embrace allegedly infringing articles that would otherwise be outside the plain words of the claim: see [25] of the primary judge's reasons 51 The appellants submitted, however, that the primary judge put aside "the bedrock of claim construction in Australia". One could be forgiven for thinking that, by using that expression, the appellants were appealing to Lord Hoffmann's use of that expression to refer to the principle of purposive construction: Kirin-Amgen at [52]. In fact the appellants' submission was directed to a completely different principle, namely that it is not legitimate to narrow or expand the boundary of the monopoly fixed by the words of a claim by adding glosses drawn from other parts of the specification: Welch Perrin and Company Proprietary Limited v Worrel (1961) 106 CLR 588 at 610; Kimberly-Clark Australia Pty Limited v Arico Trading International Pty Limited (2001) 207 CLR 1 at [15]. 52 The appellant submitted that, by the construction he adopted, the primary judge had "read in" an integer that was not present in the claims, namely that the device was a single piece or unitary device. In light of the particular principle to which the appellants referred in that regard, the unstated premise for this submission must be that the primary judge imported this "gloss" from his reading of the specification, and not from the wording of the claims themselves. 53 The appellants submitted that even adopting a "literal interpretation", the word "device" can encompass orientation tools in two separate and separated parts. 54 In that connection, the appellants submitted as follows: The dictionary meaning of "device" does not define it as "a single thing", but focuses on "a particular function for the thing". The claims emphasise the function of the "device" by identifying various functional means which comprise the device. The primary judge was unduly influenced by the evidence of the experts. The appellants nevertheless advocated the views of Professor Trevelyan and Dr Kepic in preference to those of Dr Myers in relation to the meaning of the term "device". The claims would not be "impermissibly stretched" if the word "device" is read in the claims as referring to all the components of a thing which performs a single function (the "single function" here presumably referring to the function of providing an indication of the orientation of a core sample, rather than the various functions provided by the other means of which the device is comprised). Adopting this approach, the invention was defined "by specifying the function of its various single 'means', not their 'unitary construction'". When the claims refer to the "orientation of the device" they are referring to, and would be understood by the skilled addressee as referring to, only the down hole component (and not the orientation of the whole device) because that component performs this function and, indeed, was the only "functionally relevant part of the device", the orientation of the handset being irrelevant. Dr Kepic did not conclude that the word "device" read literally in the context of the claims could not encompass orientation tools in two parts. He said: "You would have to be very literal in the meanest sense, I think, to say [that the accused apparatus] is excluded from this claim". Even in claim 2 the "orientation of the device" would be understood by the skilled addressee as only referring to "the down hole part of the tool". Even if "a literal construction" of the word "device" does not encompass a thing in two parts, the word "device", purposively construed, can extend to an instrument in one or more parts. A purposive or common sense approach to the construction of the claims should have been adopted, by which the term "device" is not limited to unitary tools. 55 It is not clear from the two last mentioned submissions whether the appellants were contending that the primary judge erred by not adopting a purposive approach to claim construction or whether they were really contending that, in adopting a purposive approach to claim construction, the primary judge came to an erroneous conclusion.

The respondents' submissions 56 The respondents submitted that, as a matter of construction, the claims of the patent do not comprehend the assemblage of the accused apparatus, being an apparatus in two parts which, the respondents submitted, provided an improved form of orientation equipment (which they claimed as their achievement). In this latter connection, the respondents pointed to what they said were improvements in the mode of operation of the apparatus which allowed the handset component to be operated at a distance from the down hole component under a range of operating conditions. 57 The respondents submitted that a central theme of the appellants' submissions, both at trial and on appeal, was an incorrect focus on what was, ultimately, an irrelevant issue, namely whether the word "device" can embrace componentry in two or more parts, as in the accused apparatus. The respondents submitted that, by adopting this focus, the appellants ignored significant defining words in the claims surrounding the word "device". Thus, the respondents submitted, a proper construction of the claims involves looking at all words appearing in each claim, not merely focussing on the term "device". 58 The respondents accepted that, in general usage, the word "device" can embrace componentry of one or several parts. They submitted, however, that that was not really the point, because the word "device" does not stand alone but is only part of the "phraseology of the claims" chosen by the first appellant to define its monopoly. Thus, resort to the broad meanings of the word "device" by Professor Trevelyan and Dr Kepic did not really assist in interpreting the claims. 59 The respondents directed attention to particular aspects of the language and syntax of the text employed in the claims. They pointed to the use of articles ("An orientation device …" and "… the orientation device …") and the phrase "the orientation of the device", which, on the respondents' argument, signified that each of the claims was directed to, and confined to, a unitary assemblage. 60 In particular, the respondents pointed to the phrase "the orientation of the device" as showing that it was the orientation of the whole device (comprising the three means in combination) that was referred to in the claims, not some component part of the device used to provide the orientation of the core sample. 61 The respondents submitted that the accused apparatus simply did not fall within the definition of the invention provided by each of the claims, according to language of the first appellant's own choosing. 62 They submitted that the primary judge took the correct view that, in the present case, a literal construction of the claims would also be the proper purposive construction of the claims.

Consideration 63 We approach this matter on the basis that the parties agreed that the primary judge identified and correctly explained the appropriate principles with respect to the construction of patent claims. 64 The catch-cry of "purposive construction" purportedly based upon Catnic and the application of the "Improver" questions derived from Improver Corporation v Remington Consumer Products Ltd [1990] FSR 181 in the context of claim construction was comprehensively discussed by Bennett J in Sachtler GMBH and Co KG v RE Miller Pty Ltd (2005) 221 ALR 373 at [43] - [67]. The primary judge applied those principles and it is not necessary for us to repeat them. We would, however, make the following observations. 65 In Catnic, Lord Diplock (with whom the other members of the House of Lords agreed) referred to a patent specification as "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 … 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 was in this context that his Lordship said that "a patent specification should be given a purposive construction rather than a purely literal one …". In saying that a patent specification should be given a purposive construction, his Lordship was not suggesting that the words of the claim function other than as a definition of the invention. That, after all, is the task that the Act requires the claims to perform. In performing that task the claims must not only define the invention; they must be clear and succinct: see ss 40(2)(a) and 40(3). 66 In Nicaro Holdings Pty Ltd v Martin Engineering Co (1990) 91 ALR 513 Gummow J (when in this Court) observed (at 528-529) that, for an Australian court dealing with patent infringement, Catnic did not propound any novel principle or new category of "non-textual infringement": see also Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 at 92; Fisher & Paykel Healthcare Pty Ltd v Avion Engineering Pty Ltd (1991) 22 IPR 1 at 19. 67 In Olin Corporation v Super Cartridge Co Pty Ltd (1977) 180 CLR 236 at 246 Gibbs J, when dealing with the so-called "pith and marrow" principle of infringement, cautioned that the application of that principle did mean that there would be infringement where the patentee has, by the form of his claim, left open that which the alleged infringer has done. 68 Indeed, in C Van der Lely N.V. v Bamfords Ltd [1963] RPC 61, on which Gibbs J based his observation in Olin, Viscount Radcliffe (at 78) said: When, therefore, one speaks of theft or piracy of another's invention or says that it has been "taken" by an alleged infringer and this "pith and marrow" principle is invoked to support the accusation, I think that one must be very careful to see that the inventor has not by the actual form of his claim left open to the world the appropriation of just that property that he says has been filched from him by piracy or theft. After all, it is he who has committed himself to the unequivocal description of what he claims to have invented, and he must submit in the first place to be judged by his own action and words. See also the discussion in Populin v H B Nominees Pty Ltd (1982) 41 ALR 471 at 476-477. 69 To give a purposive construction to a patent specification, and in particular its claims, is not to engage in a process of reasoning that extends the patentee's monopoly to the "ideas" disclosed in the specification. Nor does it extend the patentee's monopoly to products or processes that the patentee did not, by the claims, define as the invention, even if those products or processes can be seen to perform the same function as the invention or to be based on the patentee's "ideas". 70 It is clear that, in the present case, the primary judge was well apprised of the fact that it was necessary for him to give the claims a purposive construction (as that expression is correctly used in the cases), and not merely a purely literal construction. 71 In adopting that approach his Honour concluded that a purposive construction of the claims did not result in a construction that was at variance with the plain text of the claims themselves. 72 At [87] of his reasons, the primary judge observed: … there is no warrant for adopting a method of construction that gives a patentee what it might have wished or intended to claim, rather than what the words of the relevant claim actually say. While the Court should read the claims purposively and not with an eye for pedantry, even an appropriately liberal approach to construction should not permit the words of the claims to be stretched beyond their textual limits. 73 In making that observation his Honour had particular regard to what had been said in H Lundbeck A/S v Alphapharm Pty Ltd (2009) 177 FCR 151 at [60]. We agree with his Honour's statement. 74 We can see no error in the primary judge's approach or in the construction of the claims to which he came. Indeed, in our view, the construction to which his Honour came was not only open to him, but correct. 75 We accept the respondents' submission that the appellants' contentions focus too intently on the various meanings of the word "device" considered alone, rather than on the particular use of the word "device" in the claims themselves. 76 The construction for which the appellants contend requires a differential meaning to be placed on the word "device" in various parts of the claim, at one stage meaning the whole device (when referring to the three means of which the device is comprised) and at other times (when referring to the "orientation of the device") meaning not the "device" as such, but only a component of the "device" (in the case of the accused apparatus, the down hole component). The appellants' approach to construction is really one that can be seen to have been taken with the accused apparatus in mind. 77 On the other hand, the construction for which the respondents contend gives a consistent meaning to the word "device" as used throughout the claims and, indeed, throughout the specification as a whole. As the primary judge observed, to construe the claims in the way that the respondents contend is "neither contrived nor in defiance of common sense". It is simply giving force and effect to the words chosen by the first appellant in defining the invention that is claimed. 78 In our view the primary judge did not import any reference from the body of the specification into his construction of the claims. Rather, his Honour properly construed the claims in the context of the specification. The limitations which his Honour observed in the word "device" were those coming from the text of the claims themselves. The body of the specification does not suggest a different construction. 79 As we have noted, the respondents' notice of contention was raised contingently, on the basis that it is only necessary to consider the question of fair basing should the appellants prevail in their appeal. 80 In our view the contention raised by the respondents could only succeed if we were to construe the consistory statements in the body of the specification differently from the claims based on those consistory statements. 81 Although it is strictly unnecessary for us to consider the respondents' contention, we can see no reason for construing the claims differently from the consistory statements on which those claims are based. The position is not the one presented by cases such as Atlantis Corporation Pty Ltd v Schindler (1997) 39 IPR 29; the consistory statements do describe the invention that is claimed: see the discussion in Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (2004) 217 CLR 274 at [87].

Disposition 82 For these reasons, the appeal must be dismissed. The appellants should pay the respondents' costs. I certify that the preceding eighty-two (82) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justices Bennett, Gilmour and Yates.