Designs - electrically powered wheelchairs for the disabled - infringement - statement of monopoly sought protection for the design as a whole - obvious imitation - fraudulent imitation.

Patents - petty patent - infringement - revocation - obviousness or want of subject matter.

Computer Edge Pty Ltd v Apple Computer, Inc [1984] HCA 47; (1984) 54 ALR 767

Malleys Ltd v J.W. Tomlin Pty Limited [1961] HCA 77; (1961) 35 ALJR 352

Firmagroup Australia Pty Ltd v Byrne and Davidson Doors (Vic) Pty Ltd (1986) 11 FCR 415; (1987) 61 ALJR 495

Dunlop Rubber Company Ltd v Golf Ball Developments Ltd (1931) 48 RPC 268

Benchairs Limited v Chair Centre Limited (1974) RPC 429

Slazenger and Sons v Feltham and Co. (1889) 6 RPC 531

Claudius Ash Sons and Co. Ltd v Invicta Manufacturing Co. (1911) 28 RPC 597; (1912) 29 RPC 465

Wilson v Samuels (1913) 13 SR (NSW) 395

Australian Woollen Mills Ltd v F.S. Walton and Co. Ltd [1937] HCA 51; (1937) 58 CLR 641

Australian Guarantee Corp. Ltd v Sydney Guarantee Corp. Ltd (1951) 51 SR (NSW) 166

Ronson Products Ltd v James Ronson Pty Ltd [1957] VicRp 104; (1957) VR 731

Cadbury Schweppes Pty Ltd v Pub Squash Co. Pty Ltd (1981) RPC 429

L.J. Fisher and Co. Limited v Fabtile Industries Pty Limited (1979) 49 AOJP 3611

Turbo Tek Enterprises Inc. v Sperling Enterprises Pty Limited [1989] FCA 275; (1989) 88 ALR 524

Peter Pan Electrics Pty Limited v Newton Grace Pty Limited (1985) 8 FCR 557

Palmer v Dunlop Perdriau Rubber Co. Ltd [1937] HCA 43; (1937) 59 CLR 30

Commonwealth Industrial Gases Limited v M.W.A. Holdings Pty Limited [1970] HCA 38; (1970) 44 ALJR 385

Interlego AG v Toltoys Pty Limited [1973] HCA 1; (1973) 130 CLR 461

Populin v H.B. Nominees Pty Limited [1982] FCA 45; (1982) 59 FLR 37

Catnic Components Limited v Hill and Smith Limited (1982) RPC 183

Rehm Pty Limited v Websters Security Systems (International) Pty Limited (1988) 81 ALR 79

Nicaro Holdings Pty Limited v Martin Engineering Co. [1990] FCA 40; (1990) 16 IPR 545

Rodi and Wienenberger AG v Henry Showell Ltd (1969) RPC 367

Marconi v British Radio Telegraph and Telephone Co. Ltd (1911) 28 RPC 181

appellant (cross-respondent): Mr D. Shavin and Ms F. Low

instructed by Corrs Australia

Counsel and solicitors for the

Mr R. McCormack instructed by

Parker and Parker

That Orders 1, 2, 3, 4, 5, 8, 9 and 12 made by Lee J. on 24 October 1990 be set aside.

That other than as provided by Order 1, the appeal be dismissed.

That the respondent pay the appellant's costs (including reserved costs) of the:

(i) appeal;

(ii) cross-appeal; and

(iii) application.

Note: Settlement and entry of orders is dealt with by Order 36 of the Federal Court Rules.

This appeal from the judgment of a judge of the Court (Lee J.) relates to electrically powered wheelchairs for the disabled and involves questions under the Designs Act 1906 ("the Designs Act") and the Patents Act 1952 ("the Patents Act). His Honour's judgment is reported (1991) AIPC 90-755. Ultimately the appeal turns on the application of well established principles of law to the facts. Many of the facts found by the learned trial judge are not seriously or at all in dispute, though some of the facts found by his Honour resulted from his assessment of the credibility and reliability of certain witnesses, in particular on the issue of fraudulent imitation of the designs in suit.

2. A statement of the essential facts is necessary. The respondent, Avion Engineering Pty Limited ("Avion"), is the registered owner of two current Australian designs registered under the Designs Act, one (No. 97545) in respect of a wheelchair ("the wheelchair design") and the other (No. 97011) in respect of a wheelchair chassis ("the wheelchair chassis design"). Avion is also the grantee of petty patent No. 559106 issued pursuant to the Patents Act in respect of a wheelchair sub-frame ("the petty patent").

3. Avion lodged its applications for the registered designs and petty patent in August and September 1986. The petty patent was sealed on 5 March 1987. The wheelchair chassis design was registered on 16 July 1988 and the wheelchair design was registered on 27 August 1988.

4. Avion has manufactured electrically powered wheelchairs for some years in Western Australia and sells them throughout Australia. Since 1986 it has marketed its wheelchairs under the registered trade mark "Xplora".

5. The appellant, Fisher and Paykel Healthcare Pty Limited ("Fisher and Paykel"), is a company incorporated in Victoria which arranged for the importation into Australia of an electrically powered wheelchair manufactured in New Zealand.

6. In the early 1980's Avion was appointed as the Australian agent for Rehabilitation and Medical Engineering Limited, a company incorporated in New Zealand, which manufactured electrically powered three-wheeled vehicles (scooters) for use by disabled persons. The agency agreement was terminated in 1985. In 1986 the business, assets and undertaking of Rehabilitation and Medical Engineering Limited, including goodwill and all intellectual property rights, were purchased by a company controlled by a Mr N.E. Black. That company, as part of the sale, acquired the name "Rehabilitation and Medical Engineering Limited" ("RME"). RME commenced production of a new model of the disabled person's scooter and contacted Avion to negotiate an arrangement whereby Avion would market RME scooters in Australia. RME sent Avion a demonstration vehicle and Avion commenced to take orders for the scooter from various hospitals in Australia.

7. In about 1987 Avion and RME agreed to establish reciprocal arrangements under which RME would market Avion's wheelchair in New Zealand. In June 1987 Avion delivered two wheelchairs to RME. One wheelchair was described as a "Standard Model Xplora Series III" wheelchair and the other as an "Xplora Series IV Little Brother". The latter chair was designed for indoor use and had smaller wheels and motors than the former. The trial judge said that it was not made clear on the evidence whether those chairs were intended to be sold in New Zealand or only used as demonstration models. According to Mr Black's evidence neither chair was sold and each remained with RME. It was accepted that in New Zealand the cost of the "standard" Avion wheelchair was too expensive for that market. As a result Avion developed what it described as an "economy" model principally for sale in New Zealand.

8. Mr Black visited Perth in March 1988 and inspected the "economy" model wheelchair. He ordered from Avion five Xplora Series III Little Brother wheelchairs which were delivered to RME in New Zealand in about May 1988. Two of the chairs were sold by August 1988. In about August 1988 the arrangement between Avion and RME was terminated. It was agreed that each agent would continue to sell respective stocks on hand. The three remaining "economy" wheelchairs were not sold by RME.

9. In April 1989 Avion was an exhibitor at a national exhibition of rehabilitation and health care equipment held at Melbourne. Fisher and Paykel was also an exhibitor and it displayed, amongst other things, three RME scooters and an RME wheelchair. The wheelchair was endorsed with the name "Fisher and Paykel". A brochure relating to the wheelchair stated that the chair was manufactured in New Zealand by RME. Avion's Managing Director, Mr Coelho, who had dealt with Mr Black between 1986 and 1988, saw the RME wheelchair and Mr Black at the Fisher and Paykel stand and objected to the degree of similarity between it and Avion's product.

10. In about October or November 1989 a New Zealand company, Fisher and Paykel Limited (which is related to Fisher and Paykel), purchased the business and assets of RME. Mr Black was employed thereafter as the General Manager of the "RME Division" of "Fisher and Paykel Electronics".

11. Avion commenced these proceedings in August 1989 seeking an injunction restraining Fisher and Paykel from, amongst other things, importing or offering for sale such electrically powered wheelchairs as incorporate the designs protected by Avion's design registrations or infringe the petty patent.

12. In its defence Fisher and Paykel denied infringement of the designs and of the petty patent. By its cross-claim, it sought revocation of the petty patent and rectification of the designs register in respect of the wheelchair design.

13. The hearing of the matter before Lee J. was limited to questions of liability. His Honour's judgment was therefore interlocutory (see Computer Edge Pty Ltd v Apple Computer, Inc [1984] HCA 47; (1984) 54 ALR 767). Fisher and Paykel sought and was granted leave to appeal to the Full Court from the judgment of his Honour.

14. The trial judge held that registration of the wheelchair design was valid. In so holding, he rejected submissions made by Fisher and Paykel that there was no disclosure of design in the two photographs upon which the registration was based, it being claimed that the photographs were indistinct and did not adequately depict the features of shape and configuration of the design for which registration had been claimed, thereby rendering the design ambiguous and uncertain.

15. The trial judge found that the wheelchair design could be recognised in the Fisher and Paykel wheelchair and that the overall outline of the Fisher and Paykel wheelchair, constituted by the essential elements that combine to present the image of such a chair, reflected an obvious imitation of the wheelchair design. His Honour found, in the alternative, that the Fisher and Paykel wheelchair was a fraudulent imitation of the wheelchair design.

16. Turning to the wheelchair chassis design his Honour held that, although there were obvious similarities between the chassis depicted in that design and the Fisher and Paykel chassis, the differences were sufficiently distinct and perceptible to deny obvious imitation. His Honour found also that those differences resulted from the use of more economic materials or methods of construction; that the variations had the purpose of modifying functional features of the chassis without sacrificing the benefit of its overall function; and they were not made merely to disguise the use of the wheelchair chassis design. The differences between the two were substantial, and not merely disguises, so that the Fisher and Paykel wheelchair chassis was not a fraudulent imitation, notwithstanding that it might have been made with an intent to copy the design as closely as possible with knowledge that the design was or might have been protected by registration.

17. His Honour declared that Fisher and Paykel had infringed the wheelchair design, and granted injunctions restraining Fisher and Paykel from continuing to infringe it and certain ancillary injunctions.

18. His Honour found with respect to the petty patent that the claim was fairly based and that it had not been established that the claimed invention was obvious or did not involve an inventive step; so he dismissed the cross claim for revocation of the petty patent. His Honour also found that all of the essential integers of the petty patent, except one, were found in the alleged infringing wheelchair of Fisher and Paykel and that there was therefore no infringement. It will be necessary to return in more detail to the findings of the trial judge on the petty patent issues.

19. Fisher and Paykel appealed from his Honour's judgment with respect to the wheelchair design. Avion cross-appealed from his Honour's judgment that there was no obvious or fraudulent imitation of its wheelchair chassis design and that there had been no infringement of the petty patent.

20. Fisher and Paykel did not contend on appeal that the wheelchair design was invalid. The case on appeal with respect to the wheelchair design was confined to the questions of infringement by obvious or fraudulent imitation. There was no appeal against the dismissal of the attack upon the validity of the petty patent, save in respect of the assertion that the claimed invention was obvious.

21. It is convenient to consider the case first with respect to the wheelchair design, then to the wheelchair chassis design and finally to the petty patent.

22. The wheelchair design consists of representations of two black and white photographs showing perspective views of an electrically powered wheelchair from the front and rear. Copies of the photographs are attached to these reasons as figures 1 and 2. The certificate of registration of the wheelchair design includes a statement of monopoly (see s. 4 (1) of the Designs Act for the definition of "statement of monopoly") in these terms:

"Monopoly is claimed in the shape and

configuration of a WHEEL CHAIR as illustrated in

the accompanying illustrations."

The effect of the statement of monopoly was to seek protection for the design as a whole as depicted in the photographs. The statement of monopoly did not indicate any particular features of the illustrations in respect of which Avion wished to claim a monopoly or those features of the illustrations that are to be disregarded in considering the extent of monopoly protection. Nor were there any specific features of the representations in respect of which novelty or originality was specifically claimed because the "statement of novelty" merely contained the word "nil" (see s. 4 (1) of the Designs Act for the definition of "statement of novelty").

23. It follows that the protection afforded by the wheelchair design is with respect to the design as a whole as depicted in the photographs. In considering the question of infringement the trial judge compared the article depicted in the wheelchair design illustrations with the wheelchair imported from New Zealand by Fisher and Paykel and displayed at the exhibition mentioned earlier (Exhibit B). Exhibit B was manufactured in New Zealand after the date of registration of the wheelchair design. Avion tendered as an exhibit a wheelchair (Exhibit C) which was said to embody the application of the wheelchair design with minor modifications. Exhibit C was a product of Avion. His Honour applied the correct test of comparing the registered design with the alleged offending article, namely, Exhibit B. However, he was satisfied that Exhibit C did reflect the registered design and that the differences were ones of minor modification and did not impact upon the impression of similarity of design recorded by the eye. His Honour obviously found it convenient, as we do, to look at the two articles, namely, Exhibit B and Exhibit C and compare them.

24. The trial judge found, after comparing the wheelchair design with Exhibit B, that the latter showed "an obvious repetition of the essential features of the registered design". He noted that the essential visual elements of the registered design involved features of shape or configuration related to an integrated chair and supporting chassis which distinguished it from otherwise common features in other electrically powered wheelchairs. He found that while there were differences between the wheelchair design and Exhibit B, the differences were matters of style that did not deflect the eye from recognising the basic concept of shape and configuration of the registered design. His Honour said:

"The eye is able to discern the same mental

impression of the shape and configuration of the

chair as reflected in the representation of the

registered design, and in identifying the shape

or configuration of the chair depicted in the

illustrations the eye is not concerned with

items that are recognised as accessories or

accoutrements".

25. The trial judge identified the features of the wheelchair design and of the Fisher and Paykel wheelchair which caused him to conclude that the latter was an obvious imitation of the former, essentially because in his opinion they looked substantially the same in material respects. He accepted the evidence of Professor A.K. Russell, Head of the Department of Design at the Curtin University of Technology, that "the essential visual elements of the registered design involved features of shape or configuration related to an integrated chair and supporting chassis which distinguished it from otherwise common features in other electrically powered wheelchairs". He referred to the differences which he perceived between the wheelchair design and Exhibit B and said that the differences:

"played little or no part in the formation of an

impression of the shape or configuration

recorded by the eye in respect of that chair.

The overall outline of Exhibit B constituted by

the essential elements that combine to present

the image of such a chair reflects an obvious

imitation of the registered design. The

described differences are sufficient to show

that Exhibit B does not apply an entire copy of

the design of the chair illustrated in the

representations of the wheelchair design but the

differences are insufficient to prevent the eye

viewing the design of the article as an apparent

copy of the concept protected by the registered design.

Such variations as appear in the Fisher and Paykel

article, Exhibit B, concern matters ancillary to

the shape of the chair and they are not

important in the eye's registration of

recognition of a shape or configuration in that chair.

Furthermore, ... an examination of Exhibit B

from similar elevations showed an obvious

repetition of the essential features of the

registered design."

Earlier when dealing with the question of validity of the wheelchair design his Honour said:

"The wheelchair shown in the photographs (ie.

the registered design) shows an uncluttered

style and neatness of appearance to give the

article the stamp of the application of a design concept.

In some respects the requirements and function

of a wheelchair impose limitations upon the

scope for the application of individual design

concepts but I am satisfied that the photographs

of the article show a combination of elements of

integration, proportion and clean lines to

provide a shape and configuration which, to the

eye, provides an individual appearance."

His Honour appears to have considered that the registered design had certain "essential features" and that they included the shape of the seat, the shape of the seat frame and the shape of the armrests. He concluded that Exhibit B was an obvious imitation of the wheelchair design.

26. "Design" is defined in s. 4 of the Designs Act to mean "features of shape, configuration, pattern or ornamentation applicable to an article, being features that, in the finished article, can be judged by the eye, but does not include a method or principle of construction".

27. An infringement of the monopoly in a registered design occurs when a person, without the licence or authority of the owner of the design, "applies the design or any fraudulent or obvious imitation of it to any article in respect of which the design is registered": para. 30 (1) (a) of the Designs Act. The High Court in Malleys Ltd v J.W. Tomlin Pty Limited [1961] HCA 77; (1961) 35 ALJR 352 described the three categories of infringement in the following terms at 354:

"Turning to s. 30 it is apparent that there is

infringement in any one of three cases - that

is, where the design which has been applied is:

(i) the registered design (ii) an obvious

imitation of the registered design (ie, not the

same but a copy apparent to the eye

notwithstanding slight differences) and (iii) a

fraudulent imitation (ie, a copy with

differences which are both apparent and not so

slight as to be insubstantial but which have

been made merely to disguise the copying).

Visual comparison will establish (i) or (ii) but

a finding of fraudulent imitation must require

something more because in such a case visual

comparison is not of itself sufficient to

establish imitation; otherwise it would be an

obvious imitation."

See also Firmagroup Australia Pty Ltd v Byrne and Davidson Doors (Vic) Pty Ltd (1986) 11 FCR 415 at 423-424 (Full Federal Court), decision affirmed in the High Court (1987) 61 ALJR 495.

28. To establish obvious imitation the question must be looked at as one of substance by examining the essential features of the design: Firmagroup Australia Pty Ltd v Byrne and Davidson Doors (Vic) Pty Ltd ("Firmagroup") (supra) at 427-428 (Full Federal Court); Dunlop Rubber Company Ltd v Golf Ball Developments Ltd (1931) 48 RPC 268 at 281 and Benchairs Limited v Chair Centre Limited (1974) RPC 429 at 437. Those essential features must differ from the prior art. In Firmagroup, in the Full Federal Court, Lockhart J. said at 425:

"The scope of a registered design must be judged

against the background of the prior art at the

priority date. If the differences between the

registered design and the prior art are only

small then equally small differences between the

registered design and the alleged infringing

design will tend to lead to a finding of no

infringement. On the other hand the greater the

advance over the prior art in the registered

design then, in general, the greater the scope

of the protection afforded to the registered design".

29. We were referred in argument to points of similarity and difference between the representations of the wheelchair in the registered design and the Fisher and Paykel wheelchair. It is unnecessary to refer to them all, but we shall mention the principal differences. The armrest on the wheelchair design supports paddle shaped armrest cushions and in-fill panels whereas the armrest on the Fisher and Paykel chair has a central pillar, with no front support, and rectangular shaped armrests which are freestanding without any infill. The registered design has an angular pivoting front axle, but the Fisher and Paykel chair has a curved or round pivoting front axle. In the registered design there is a battery strap which protrudes downwards and on the Fisher and Paykel chair the battery support is on the bottom longitudinal member. The front of the chair depicted in the registered design has an angular finish whereas it has extended curves on the Fisher and Paykel chair. There is a larger control box on the chair depicted in the registered design than in the Fisher and Paykel chair which has a more compact control box. The registered design depicts pistol hand grips whereas there is a pushbar on the Fisher and Paykel chair. There are more visually obvious pins and hinges on the Fisher and Paykel chair than on the registered design chair, although the photographs which constitute the registered design are not entirely clear in this respect. The registered design chair has a battery cage shaped in the form of a basket whereas the Fisher and Paykel chair has a battery container that is more like a tray.

30. The overall appearance of the two chairs, one as depicted in the registered design and the other being Exhibit B, is, however, the critical measure of comparison and it is at this point that we part company from the trial Judge. We do this with some diffidence because his Honour had the benefit of hearing the evidence given before him with all the attendant advantages of the judge at first instance. Nevertheless at the end of the day the question is one of comparison of the chair as depicted in the registered design with the alleged offending article.

31. In its statement of monopoly, Avion chose not to designate any particular features of the representations in respect of which it claimed a monopoly and also chose not to specify any features of the representations which were to be disregarded in considering the extent of the monopoly protection. It is essential therefore that one compares the depiction of the chairs in the two photographs as a whole with the alleged offending chair, Exhibit B. When we do this we do not find that Exhibit B is a copy of the wheelchair design with only slight differences between the two. We find two chairs which convey overall a rather different impression of shape and configuration to the eye. When one analyses the overall impression by reference to points of detail, the features that we mentioned earlier spring to mind. We see in the wheelchair design a rather tightly structured, closely knit wheelchair whereas in Exhibit B we see a freer, more open chair. Uninformed by the issues in this case it would not have occurred to us that Exhibit B was an obvious imitation of the wheelchair design. Being better informed, we reach no different conclusion.

32. Reference to the prior art confirmed this impression. There are in evidence documents depicting various wheelchairs, (including electrically powered wheelchairs) available for sale from about 1977, as well as wheelchairs on the market from times which are not clear from the evidence. Having examined this material, what emerges is that the chairs differ from each other over the years in various respects including the design of the frames of the seats, the chassis, differing shape configurations, and varying degrees of simplicity, complexity and compactness. Frames of the wheelchairs involved in the prior art differ in shape or configuration as between themselves and as compared with the wheelchair design; but an analysis of this material establishes, to our satisfaction, that there are inherent in wheelchairs by their nature many elements of similarity dictated by the methods or principles of construction of such articles and their particular function. They all have seats, backrests, armrests, supports for the armrests, control panels, front and rear wheels, batteries and battery holders, motors, and methods of hand propulsion (whether hand grips or push bars). There are varying finishes at the front of the wheelchair from angular to curved and various shaped motor caps. Some have angular and others have curved or round pivoting front axles. Cast wheels in some are spoked and in others are filled. Different means are adopted for housing the battery, the stitching on the upholstery varies between them, and there is variation between the pins and hinges on the chairs. These are but some of the differences that one discerns from an examination of the visual representations of the wheelchairs in the prior art.

33. Although there is no issue of validity of the wheelchair design in this appeal, when considering whether there is an obvious imitation embodied in the Fisher and Paykel wheelchair (Exhibit B) of the wheelchair design, it is necessary to consider methods or principles of construction involved in an article of this kind and the constraints and limitations that they necessarily impose upon new or novel designs. With articles such as wheelchairs there is, in our view, limited room for new or original designs. Some of the differences between the designs of wheelchairs in the prior art differ only in immaterial details or (to use the words of s. 17 of the Designs Act) in "features commonly used in the relevant trade". Many of the features of shape or configuration, and pattern or ornamentation, that apply to wheelchairs are necessarily present because of the methods or principles of construction that must be applied to articles of this kind. We are unable to see the requisite degree of comparability between the wheelchair design and the product of Fisher and Paykel to support a finding of obvious imitation. To our mind the general features of shape or configuration embodied or inherent in both the wheelchair design and the Fisher and Paykel wheelchair arise from the fact that they are wheelchairs and necessarily involve the application of certain methods or principles of construction rather than any novelty in the design themselves. See Russell-Clark on Copyright in Industrial Designs, 5th ed, 1974; Firmagroup at 423 (Full Federal Court), and at 497 (High Court).

34. We have examined the evidence of the experts called by each party on this question. The trial judge said in his reasons for judgment that the experts differed in important respects from each other. We have had regard to the preferences expressed by his Honour in his reasons for the evidence of certain witnesses over the evidence of others; but in the end it does not seem to us that the evidence of the experts in the case carries the matter very far on the issues which arise under the Designs Act, as ultimately it is a matter of visual impression.

35. The monopoly provided for in the Designs Act is conferred by the Crown in recognition of the merit of a design and the monopoly is an incentive to the creation of attractive and useful designs. It is thought to be in the public interest that this monopoly be enjoyed. The Designs Act does not prevent the exercise of free market forces and competition except to the extent which the monopoly requires.

36. In our opinion, the wheelchair design and the Fisher and Paykel wheelchair (Exhibit B) are not sufficiently similar to support a finding that there is an obvious imitation by the latter of the former.

37. It is a misconception to say that fraudulent imitation arises only if a court has held that there is no obvious imitation. The misconception arises because it is generally only necessary to consider fraudulent imitation when the conclusion has been reached that there is no obvious imitation. It is easier to prove imitation in most cases by examining the registered design and comparing it with the offending article, than by proving the intent of the defendant to copy the design. The authorities demonstrate (in particular Malleys, supra) that to support a finding of fraudulent imitation there may be greater differences between the registered design and the offending design than between the registered design and what could be held to be an obvious imitation. This is because the person who has deliberately set out to copy the registered design is presumed more readily to have achieved his object than the person who did so innocently. In this respect designs law, though having no common law base, is analogous to passing off: see Slazenger and Sons v Feltham and Co. (1889) 6 RPC 531 at 538 (CA); Claudius Ash Sons and Co. Ltd v Invicta Manufacturing Co. (1911) 28 RPC 597, (1912) 29 RPC 465 at 475 (HL); Wilson v Samuels (1913) 13 SR (NSW) 395 at 398; Australian Woollen Mills Ltd v F.S. Walton and Co. Ltd [1937] HCA 51; (1937) 58 CLR 641 at 657; Australian Guarantee Corp. Ltd v Sydney Guarantee Corp. Ltd (1951) 51 SR (NSW) 166 at 170-171; Ronson Products Ltd v James Ronson Pty Ltd [1957] VicRp 104; (1957) VR 731 at 739; Cadbury Schweppes Pty Ltd v Pub Squash Co. Pty Ltd (1981) RPC 429. Nevertheless, whether the imitation is obvious or fraudulent, in the final analysis, as the decision in Malleys, supra illustrates, the offending article must have the same fundamental or basic design as the article embodied in the registered design.

38. For reasons which we have already given with respect to obvious imitation, we conclude that no case of fraudulent imitation could be made out in the present case because it cannot be said that the Fisher and Paykel wheelchair is a copy of the wheelchair depicted in the registered design that is disguised with differences made merely to disguise copying.

39. It is plain that Fisher and Paykel had available to it more than one wheelchair of Avion. It is also plain that Fisher and Paykel examined those wheelchairs with care and no doubt took them apart to analyse points of difference and similarity. But it is plain that Fisher and Paykel did not wish to end up with a wheelchair that would place them in jeopardy of an action for infringement of the wheelchair design. Indeed, as the trial judge found, some of the variations occurred as a matter of necessity arising out of methods of construction which were limited by available materials or resources or which involved least cost. Also, there is some inherently credible evidence that some of the variations were brought about for commercial and manufacturing purposes. The Fisher and Paykel wheelchair was designed so that it could be assembled and disassembled in three parts, not two parts as with the Avion wheelchair. The three parts consist of the seat frame and a two-piece chassis. This enables the wheelchair to be more readily taken apart and placed in motor cars or other means for transporting the disabled. The two-piece chassis was also designed as such so the power unit of the wheelchair could possibly be used on a three-wheeled scooter, which RME manufactured as well, resulting in production advantages for RME and cost savings for a person who wished to have both a wheelchair and a scooter. The capacity for disassembly is not immediately apparent to the eye when viewing the Fisher and Paykel wheelchair in its assembled state (although it can readily be discerned by the informed observer), but it is important when considering the intent of Fisher and Paykel when designing and producing its wheelchair.

40. Accepting the correctness of the trial Judge's findings as to the credit and reliability of Mr Black and Mr Haagh (a fitter and turner employed by RME), neither of whom favourably impressed him, and accepting that it is plain that it was the intent of Fisher and Paykel to produce a wheelchair as close in design to the wheelchair design "as the law might be forecast to allow" (per Fullagar J. in L.J. Fisher and Co. Limited v Fabtile Industries Pty Limited (1979) 49 AOJP 3611 at 3621), we are nevertheless not persuaded that the product which emerged from their efforts and now embodied in the Fisher and Paykel wheelchair can be said to be one which embodies the registered design. Indeed, as we said earlier, the depiction of the wheelchair in the registered design and the Fisher and Paykel wheelchair do not strike us as being obviously similar.

41. The differences between the wheelchair design and the Fisher and Paykel article are both apparent and substantial and clearly are not mere disguises. Although the two are similar, the Fisher and Paykel wheelchair is not a fraudulent imitation notwithstanding that it was made with the intention of copying the registered design as closely as possible and with knowledge that the design was or may have been protected by registration: see Turbo Tek Enterprises Inc. v Sperling Enterprises Pty Limited [1989] FCA 275; (1989) 88 ALR 524 at 543.

42. The representations of the registered design of Avion's wheelchair chassis consist of three drawings being a perspective view, a plan view from the top and a side view. We have attached as figures 3, 4 and 5 the three representations as appearing on the register.

43. The statement of monopoly in relation to the wheelchair chassis design is a claim in the shape and configuration of the wheelchair chassis as illustrated in the drawings. The article which is said to infringe the wheelchair chassis design is a wheelchair chassis manufactured by RME and imported by Fisher and Paykel.

44. The trial judge described the various differences between the Fisher and Paykel wheelchair chassis and the representations of the registered wheelchair chassis design in these terms:

"The RME wheelchair chassis has a pivoting axle

of round steel tubing curved at each end; the

registered design is of square tubing with

angular extensions. The outline of the RME

wheelchair chassis formed by the principal parts

of the chassis frame is that of a square with a

tray mounted on the base of the square whilst

the outline of the registered design is that of

a rectangle with a bracket attached beneath. On

the RME wheelchair chassis, the rear wheel axle

mounts are part of a detachable sub-frame

whereas on the registered design the axle mounts

are single plates bolted to the frame of the

chassis. The front of the RME chassis has a

welded triangular section and a channel to

receive the pivoting front axle attached to the

front vertical support whereas on the registered

design there is no breaking of the lines of the

front vertical support where the pivoting front

axle is attached."

"It is obvious that the RME wheelchair chassis

owes much to all of the elements of the

registered wheelchair chassis design. Some of

the variations that have been made to the design

and applied to the RME article result from the

use of more economical materials or methods of

construction. Other variations such as the

detachable sub-frame which supports the rear

driving wheels, the electric motors and the

battery charging unit have been incorporated to

suit other purposes such as the standardizing of

units manufactured for the RME wheelchair and

RME scooters. Each variation had the purpose of

modifying functional features of the chassis

without sacrificing the benefit of its overall

function. However, they were not made merely to

disguise the use of the registered design."

Lee J. found that, having viewed from various angles and distances the modifications made by RME, the modifications provided an article which applied a new design and that he could not find that the RME chassis applied an obvious imitation of the registered design. His Honour also held that, because the differences between the registered design and the alleged infringing article were apparent and substantial, and not merely disguises, that article could not be a fraudulent imitation. His Honour said that, although he found that RME had every reason to believe that Avion had sought or obtained registration of the design or designs embodied in the wheelchairs in RME's possession, the evidence fell short of establishing that RME had reason to suspect that individual parts of an Avion wheelchair, for example the chassis, embodied a registered design. In those circumstances, the trial judge held that a finding of fraudulent imitation could not be sustained.

45. The principal attack made by Avion upon his Honour's judgment with respect to the wheelchair chassis design was that he erred in holding that the essential features of the wheelchair chassis design were not incorporated in the wheelchair chassis of Fisher and Paykel.

46. We have been through the same exercise as the trial judge engaged in, viewing from various angles and distances the alleged offending article, examining closely the representations of the registered design contained in the three drawings and comparing the drawings with the article. In our opinion, the trial judge correctly stated the differences between the wheelchair chassis of Fisher and Paykel and the three drawings that constitute the registered design. It is clear that the differences between the allegedly infringing article and the registered design are many and substantial; the Fisher and Paykel wheelchair chassis is not an obvious or fraudulent imitation of the registered wheelchair chassis design.

47. We agree with the conclusion reached by the trial judge on this issue and with the reasons which he gave in support of it.

48. Many of the salient facts for this branch of the case have already been outlined in dealing with the registered design issues and we shall not repeat them.

49. The procedures attending the consideration and acceptance of petty patent applications are more limited than those for applications for standard patents; see the discussion of the relevant statutory provisions by Lockhart J. in Peter Pan Electrics Pty Limited v Newton Grace Pty Limited (1985) 8 FCR 557 at 566. Section 40 of the Patents Act provides that a petty patent specification shall fully describe the invention, including the best method of performing it which is known to the applicant, and that the specification shall end with a single claim, defining the invention, which shall be clear and succinct and shall be fairly based on the matter described in the specification.

50. The body of the specification for the petty patent is in these terms:

"It is an object of this invention to provide a

means of reducing the individuality required in

the fabrication of a wheelchair in order to

reduce the costs thereof."

Some assistance in deriving a meaning for this awkward sentence is provided by the immediately preceding paragraph which is in these terms:

"A difficulty in current practice in

construction of wheel chairs resides in the

provision of individual requirements in a wheel

chair to accommodate for different body weights

and sizes of the user. As a result it is often

the case that a wheel chair needs to be

specially fabricated for a particular user which

increases the cost of manufacture."

A description is given of a preferred embodiment and it is then said that an object of the embodiment is to provide a wheelchair sub-frame whereby the wheel chassis can be mass produced and the chair frame may be constructed according to the individual requirements of the user; the sub-frame comprises a chassis and a seat frame which is removable from the chassis. It is also stated:

"The provision of a separate seat frame chassis

not only has the manufacturing advantage of

facilitating mass manufacture of the chassis and

individual manufacture of the chair frame but

also facilitates the ready disassembly of the

chair to enhance its portability."

51. It will be recalled that in April 1989 Avion participated in a national exhibition of rehabilitation and health care equipment, which was held in Melbourne and that Fisher and Paykel was also an exhibitor. Fisher and Paykel displayed an electrically powered wheelchair manufactured in New Zealand by RME which became Exhibit B in the present proceeding. A number of photographs of this exhibit and of particular sections of the wheelchair in question also were in evidence. RME is controlled by Mr N.E. Black, who gave evidence at the trial. His Honour found, inter alia, that at all material times Mr Black was aware that Avion manufactured wheelchairs with the protection of a patent, and that the extent of his knowledge was more than adequate to provide RME with notice of the likelihood that any design embodied in the Avion chairs was protected in this way. Mr Black did not cause any searches to be made to ascertain the specific terms of any intellectual property rights of Avion, lest he discover that which he would rather not know.

52. As we have said, at the trial there was a cross-claim by which Fisher and Paykel sought an order for revocation of the petty patent. Three grounds were relied upon; lack of fair basing, obviousness and lack of novelty. The third of these grounds was not pursued. His Honour rejected submissions by Fisher and Paykel that the claim in the petty patent was not fairly based on the matter described in the specification, within the sense of sub-s. 40 (2) of the Act.

53. The attack on the ground of obviousness was presented in two ways. First, it was submitted that what was claimed to be a combination of integers in truth was no more than a mere collocation of parts, and the essential integers lacked the necessary mutual inter-dependent working relationship for there to be a patentable combination, as described in Palmer v Dunlop Perdriau Rubber Co. Ltd [1937] HCA 43; (1937) 59 CLR 30 at 62, 65-66, 72-78. In particular, it was submitted that what we later identify as integer "b" of the claim did not have the necessary working relationship with the other integers. Secondly, it was submitted that the claimed invention involved no inventive exercise in combining integers, each of which was well known or used in the relevant trade, such that the making of the combination would have been obvious to a non-inventive skilled worker in the field. His Honour rejected both submissions. Only the first was pursued on the appeal.

54. The patentee, Avion, failed on the question of infringement. Various submissions as to the construction of the claim were put at the trial and pursued on the appeal. It is necessary first to set out the text of the claim. The trial judge said that witnesses and counsel had found it convenient to divide the features of the claim into seven integers numbered "a" to "g". On the appeal, this division of the claim was criticised by counsel for Fisher and Paykel as producing integers too few in number, but the submissions of counsel nevertheless proceeded, as they had at the trial, by using the division of the claim adopted by his Honour.

55. The text of the claim, divided in the manner we have described, is as follows:

"a A wheelchair comprising a chassis and a seat

frame, said chassis being supported at one end

by a pair of wheels spaced to each side of the

central longitudinal axis of the chassis being

supported at the other end by a pair of castor wheels

b each mounted at the opposite ends of a

transversely extending arm pivotally mounted at

its centre to the chassis to be pivotable about

a central longitudinal axis of the chassis

c said chassis having an upper transverse support

and an upper longitudinally extending support

d said seat frame providing a seat and back rest

e and being receivable on the chassis

longitudinally relative to the chassis by a

transverse element engagable with the upper

transverse support to prevent relative upward

movement there between

f and said seat frame having a longitudinal

element engagable with the upper longitudinally

extending support of the chassis to prevent

relative transverse displacement there between

g and a longitudinally extending stud on the

chassis and/or seat frame and engagable with an

aperture in the seat frame and/or chassis

respectively and having releasable locking means

engagable with the stud for preventing undesired

disengagement between the seat frame and chassis."

56. The issues as to infringement primarily concerned the construction to be given to those portions of the claim which have been isolated as integers "e", "f" and "g". We should set out, as regards each integer, the issues as they were presented on the appeal and the findings of the trial judge which were under challenge. However, we should first note that his Honour held that items "a", "b" and "d" were not essential integers; there was a caveat by his Honour as to integer "b", to which it will be necessary to refer later in these reasons.

1. Is the seat frame of Exhibit B, the RME wheelchair imported

by Fisher and Paykel, "receivable on the chassis

longitudinally"? His Honour answered "yes".

2. In Exhibit B, does the engagement of "a transverse element"

with "the upper transverse support" prevent "relative upward

movement there between"?

The "upper transverse support" is an element of the chassis

described in integer "c". The "transverse element", upon a

literal reading of the claim, engages with the chassis and

thus is an element in the seat frame. But in Exhibit B (as

illustrated by the photograph l in Exhibit "KHH6") the

relative upward movement of the seat frame is prevented by

two lugs which form part of the upper transverse support

element of the chassis. The seat frame slots in between the

lower surface of the lugs and the upper surface of the

transverse support element. The trial judge nevertheless

held that this element of integer "e" was found in Exhibit B.

3. If the submissions of Fisher and Paykel in issue 2 are correct

and there is not literal infringement, is there nevertheless

an infringement as a result of the application of the "pith

and marrow" principle, or what was said by Menzies J. in

Commonwealth Industrial Gases Limited v M.W.A. Holdings Pty

Limited [1970] HCA 38; (1970) 44 ALJR 385 at 388?

4. Is "relative upward movement" between the seat frame and the

chassis prevented, for the purposes of integer "e", only

where there is no such movement over the whole of these two

elements, so that it is not enough that prevention of

movement be limited to the site of the engagement? His

Honour held it was sufficient that movement be prevented at

the site of engagement.

1. Does the seat frame of Exhibit B contain "a longitudinal

element engagable with the upper longitudinally extending

support of the chassis"? His Honour accepted Avion's

submission that the "longitudinal element" was supplied by a

hole at the front of the front transverse member of the seat

frame which was "engagable with" the chassis by a removable

threaded bolt or stud passed through the hole, as

illustrated by photographs f, g, h and i in Exhibit KHH6.

On the appeal, there was further debate as to whether by

this means the seat frame was truly "engagable with" the

chassis in the sense required by the claim. It will be

necessary to refer further to that aspect of the matter.

2. If the answer to issue 1 is "yes", is there engagement "to

prevent relative transverse displacement therebetween"? The

trial judge rejected the submission that in Exhibit B such

displacement was prevented, not as described in issue 1, but

by fins or wings forming part of the seat frame which

engaged the lugs, as described above when dealing with

integer "e". These fins or wings also appear in photograph

l in Exhibit KHH6.

3. If the submissions for the appellant are correct as to

matters 1 and 2, so that his Honour was in error,

nevertheless is there infringement by reason of the

application of the "pith and marrow" doctrine or the

reasoning of Menzies J. in the Commonwealth Industrial Gases

Case, supra?

4. Despite his findings on issues 2 and 3, the trial judge held

integer "f" was not present in Exhibit B. His Honour so

decided on the ground that the locking device relied on as

providing integer "f" also incorporated integer "g", and the

claim required not two but three separate mechanisms, as

integers "e", "f" and "g", for prevention of relative

movement between and disengagement of the chassis and seat

frame. Is this correct?

1. Is the longitudinally extending stud used in Exhibit B "on"

the chassis within the meaning of the claim? The trial

judge held that the removable bolt was "on" the chassis when

screwed into the nut welded to the upper longitudinal

support of the chassis, and that it need not be permanently

affixed either to the chassis or the seat frame.

2. In Exhibit B, is there an "aperture" with which the

longitudinally extending stud is "engagable" within the

meaning of the claim? His Honour found that the aperture

was constituted by the nut into which the bolt was screwed.

57. The specification is to be read not in the abstract but in the light of common knowledge in the art before the priority date, which in the present case is the date of lodgment of the specification, 12 September 1986. In ascertaining the width of the claim, it is impermissible to vary or qualify by reference to the body of the specification any plain and unambiguous meaning of terms used in the claim; but if an expression in the claim is not clear, then resort may be had to the body of the specification to define or clarify the meaning of the words used in the claim; Interlego AG v Toltoys Pty Limited [1973] HCA 1; (1973) 130 CLR 461 at 478-479. The Court must bear in mind that what is being construed is a public instrument which must, if it is to be valid, define a monopoly in a way that it is not reasonably capable of being misunderstood; construction is a matter of common sense assessment of what the words used convey in the context of the then existing published knowledge. Authority for those propositions, which are not controversial, is to be found in Populin v H.B. Nominees Pty Limited [1982] FCA 45; (1982) 59 FLR 37 at 41-43.

58. In the present case, the prior art shows various examples of motorised wheelchairs which were capable of disassembly for carriage in motor cars. In particular, there were examples of seat frames detachable from the chassis, and some provided for seats of varying designs which were adapted for use with the one chassis. It also is to be borne in mind that whilst the embodiment described in the petty patent is of an electrically powered wheelchair, there is no claim for a wheelchair whose wheels are propelled by any particular means.

59. There was some discussion before us as to the principles by which infringement is adjudged. In the Commonwealth Industrial Gases Case, supra, the defendants admitted infringement of the letters patent in question up to the time which they had acted upon advice given by their patent attorneys. The advice had been given after the defendants had received a letter alleging infringement of the patent in suit, which was identified in that letter by its number. The defendants then modified the equipment they subsequently manufactured. Menzies J. held that the modification so made did not prevent the equipment manufactured and sold thereafter from infringing the plaintiff's patent. His Honour acknowledged that there can be no infringement if what the defendant has done differs materially from an essential feature of the claimed invention. Later authorities, affirming the fundamental rule that there will be no infringement unless the alleged infringer had taken all of the essential features or integers of the patentee's claim and that the "pith and marrow" doctrine does not affect that fundamental rule, are collected in Populin v H.B. Nominees Pty Limited, supra.

60. Menzies J. had before him a modification of what was an essential feature of the patent in suit. Nevertheless, his Honour held that the modification did not avoid the essential feature because what was produced was so close to what was claimed as still to take the invention of the plaintiff. His Honour said, supra at 388:

"Patent rights are not to be set at nought by

such a subterfuge which I am satisfied added

nothing to the equipment and was made merely in

an attempt to take full advantage of the

invention while avoiding infringement of the

plaintiff's letters patent by a modification so

small as to be insignificant."

61. In Catnic Components Limited v Hill and Smith Limited (1982) RPC 183, the House of Lords was concerned with the question of whether the defendant escaped infringement because, whereas one of the integers of the claimed invention spoke of a rear support member "extending vertically", the alleged infringement included a member inclined at 6 degrees or 8 degrees from the vertical. This variation had a negligible effect upon function. It had been made with a view to avoiding infringement. Therefore, as we have pointed out elsewhere, the finding of infringement by the House of Lords would, in an Australian court, have caused no great surprise in the light of the earlier decision of Menzies J. We would not treat the House of Lords as having propounded any novel principle or new category of "non-textual infringement": Rehm Pty Limited v Websters Security Systems (International) Pty Limited (1988) 81 ALR 79 at 91-92; Nicaro Holdings Pty Limited v Martin Engineering Co. [1990] FCA 40; (1990) 16 IPR 545 at 560-561. On the present appeal, the submissions of counsel proceeded essentially in accordance with the views expressed above.

62. It has become the practice in a claim for a combination of common integers, to set out in considerable detail the elements or integers. Failure to do so may result in want of compliance with s. 40. Also, those drafting such claims should do so in the light of the prior art; this may make them rightly fearful of claiming too much, as Lord Upjohn pointed out in Rodi and Wienenberger AG v Henry Showell Ltd (1969) RPC 367 at 392. Accordingly, as his Lordship also emphasised, there is a need for caution in accepting in an infringement suit the suggestion by the patentee that what appears to be a limitation upon the claimed subject matter is merely the product of a slip of the pen and thus not to be held too readily against the patentee.

63. What then are the essential integers of the claim of the petty patent? This is a question of construction upon which no general principles, other than those already mentioned, can be laid down. Even in an apparently closely limited combination claim, there may be, on its proper construction, an inessential integer which may be omitted altogether or may be substituted by a mechanical equivalent, so that there still is an infringement; see, for example, Populin v H.B. Nominees Pty Limited, supra at 45.

64. As we have said, the trial judge held that integers "a", "b" and "d" were inessential; this was subject to a caveat as to integer "b". For ourselves, we should have thought that the claim for a wheelchair comprising a chassis and seat frame, supported as described by two pairs of wheels, contained integers which were essential to the combination claimed; without them there would be no point to the assembly of the seat frame and chassis in a manner to prevent relative upward movement, transverse displacement and undeserved disengagement, as dealt with in essential integers "e", "f" and "g". But a serious question does arise as to the nature of integer "b".

65. In the body of the specification, it is stated that the provision of the pivoting transverse arm in the embodiment "provides for a degree of articulation between the front and rear wheels of the wheel chair which facilitate movement of the wheel chair over rough grounds and the negotiation of modulating (surfaces)".

66. It is apparent from the terms of the claim that the wheelchair has a rigid chassis and seat frame which are engaged in such fashion as to prevent movement between them. This is emphasised by integers "e", "f" and "g". It is important for a rigidly framed wheelchair to have some means of assisting its passage over undulating or irregular surfaces. There were various means by which this might have been achieved. In his evidence, one of the experts, Professor Hunt, gave as an example the use of sprung caster wheels. But the claim singles out one particular means, which is integer "b". Without this integer, the wheelchair, as otherwise claimed, with its rigid frame, would be incomplete or inadequate in its structure and function. These considerations support the conclusion drawn from the terms of the claim itself that integer "b" is essential.

67. But then it was submitted for Fisher and Paykel that the claimed combination, if so interpreted, would be bad because this essential integer "b" was functionally independent of the other integers, so that there was no working inter-relation brought about by the collocation of the integers. We have already referred to the passages in Palmer v Dunlop Perdriau Rubber Co. Ltd, supra, in which, with reference to English authority, the applicable principles are discussed. On this point, and on the hypothesis that integer "b" was essential (the caveat to which we have earlier referred), the trial judge held that it was "part of the inspiration of the design that a disengagable chassis be able to incorporate a pivoting axle".

68. Counsel for Fisher and Paykel criticised this passage as falling short of a finding as to working inter-relation as required by the authorities. But if the matter be approached by bearing in mind the reasons which support the conclusion that integer "b" is essential to the claim, the answer becomes clearer. Plainly, the pivoted axle has a working relationship with the chassis with which it is engaged, in that without it, the chassis could not serve as usefully its function as part of the assembly of a chair which is a wheelchair. It is not the point that because this method of wheel mounting has been adopted as an essential integer, the adoption of an alternative means, such as spring caster wheels, might not infringe. The wheelchair with its rigid frame, given by the combination as claimed of a seat frame and chassis, should desirably have a means to assist its operation readily and effectively to cross modulated or irregular surfaces. That is provided by the inter-action between the pivoting axle, the chassis and the seat frame.

69. In our view, by the adaptation in this way of each integer to the working of the others, there is provided an entirety which is a patentable combination, within the meaning of the authorities. The attack on validity thus fails.

70. We turn now to consider the various submissions upon the issues of infringement. We have already summarised these and deal with them in the same order.

71. There is a vertical restraint welded to the front of the transverse member of the chassis of Exhibit B. The restraint comprises two parallel elements as shown in photograph d of Exhibit KHH6. The front square shaped longitudinal member of the seat frame is put into position between these two elements before the application of a threaded bolt to secure the seat frame and the chassis (steps which require further consideration in dealing with integers "f" and "g"). Photograph f in Exhibit KHH6 shows this application of the bolt. In the course of its reception onto the chassis by engagement of the transverse element at the rear of the seat frame with the upper transverse support at the rear of the chassis, the seat frame has to be held at an angle of some 10 to 15 to surmount the vertical restraint at the front of the chassis.

72. It was submitted for Fisher and Paykel that in integer "e", "receivable" refers to the whole of the movement preceding the final destination of engagement of the two members at the rear of the wheelchair, and reference was sought to be made to the preferred embodiment to support that interpretation. Avion submitted, in our view correctly, that the correct approach was to compare Exhibit B with the terms of the claim itself. We accept the submission for Avion that whilst the phrase "longitudinally relative to the chassis" in conjunction with "receivable on the chassis", requires the seat frame to be in such a relationship to the chassis throughout the movement for reception of the seat frame, the claim does not require the longitudinal relationship to be fixed or constant. The relationship may vary in the course of this movement provided that throughout it answers the description of "longitudinal". "Longitudinal" has an ordinary meaning of extending or proceeding lengthwise; thus the seat frame may have a longitudinal relationship to the chassis, even though it is not horizontal in the sense of parallel to the plane of the chassis. Accordingly, in our view, his Honour correctly decided issue 1 upon integer "e" in favour of the patentee.

73. Then it was pointed out by Fisher and Paykel that in Exhibit B the engagement did not prevent relative upward movement between the seat frame and chassis as a whole, and that the prevention of such movement was limited only to the site of engagement described in integer "e". As a matter of fact, this may be conceded. Then it was submitted that the expression "to prevent relative upward movement" in integer "e" was not satisfied by the prevention of relative upward movement in this fashion.

74. In dismissing this submission, the trial judge held that integer "e" has to be read in context with the whole of the claim, and that the construction contended for by Fisher and Paykel would neither be consonant with that context nor feasible. We agree with that conclusion. Integer "e" has to be read with the final stipulation in the claim, in integer "g", that there be a releasable locking means for prevention of undesired disengagement between the seat frame and the chassis. This serves to support the construction of the claim so that the total prevention of relative upward movement need not be achieved prior to the engagement of the releasable locking means provided for in integer "g", provided that the end result is a wheelchair comprising a chassis and the seat frame in such a fixed relationship which follows from the taking of a series of sequential steps.

75. Accordingly, we would decide issue 4 as to integer "e" favourably to the patentee.

76. There remain issues 2 and 3. It will be recalled that the "upper transverse support" identified in integer "e" is an element of the chassis described in integer "c", and the "transverse element" which engages with the chassis is an element of the seat frame; however, in Exhibit B, and to adopt the words used by the trial Judge, "the pair of elements comprising the joint which engaged the seat frame and the chassis was inverted by placing the transverse element on the transverse support of the chassis to receive the transverse support of the seat frame". His Honour also said:

"I accept Professor Hunt's evidence that in

Exhibit B the nature of that engagement involved

a kinematic inversion of the joint described in

the claim as a means by which that engagement

was to be effected. Kinematic or mechanismal

elements of machinery refer to reciprocal pairs

in which the exchange of an element of the pair

with the other involves no alteration in the

motion belonging to the pair of elements". (see

Reuleaux, The Kinematics of Machinery, Dover

Publications Inc., pp 42-43, pp 94-95). The

application of a kinematic inversion may be

distinguished from the use of a mechanical

equivalent or substitute. The latter involves a

choice of some other mechanical means to achieve

the purpose described in the claim, whereas the

former retains the elements of the mechanical

joint described in the claim and merely inverts

their reciprocal functions".

77. It was submitted for Fisher and Paykell that this acceptance of a distinction between kinematic inversion and the use of mechanical equivalents has no foundation in law; it followed, so it was submitted, that integer "e" being an essential integer, not an inessential integer, it was possible to escape infringement by use of a mechanical equivalent. We accept that submission. As earlier mentioned, if the alleged infringement does not possess one of the essential features or integers of the claim, there is no infringement, and the doctrines of "pith and marrow" and as to the use of mechanical equivalents have no application where the alleged infringement differs from the claimed invention in such a respect.

78. We also accept the submission that contrary to what was said by the trial Judge, the application of a kinematic inversion, as explained by him, is not to be distinguished from the use of a mechanical equivalent or substitute. The latter is a legal concept and the former an engineering term for a species of the legal genus "mechanical equivalent". To invert the reciprocal functions of the elements of the mechanical joint described in the claim is, within the sense of the authorities, to use a mechanical equivalent; see the discussion by Parker J. in Marconi v British Radio Telegraph and Telephone Co. Ltd (1911) 28 RPC 181 at 215-219.

79. Further, there is no infringement where the variation from the claimed integer would have a material effect upon the way in which the invention works: Catnic Components Limited v Hill and Smith Limited (1982) RPC 183 at 243. There was evidence before the Court that a seat frame having an under-frame free of protuberances (as is the case with Exhibit B) will have an advantage in that the frame may be slid over surfaces such as a car boot or van floor without the need for the attachment to the lower ends of the vertical seat frame members of rollers or other gliding means to assist the passage of the frame over the surface. Downwardly projecting transverse elements, or lugs, affixed to the under-side of the seat frame, and answering the terms of the claim of the petty patent, would lack this advantage. Indeed, in Exhibit C, which was an Avion wheelchair, the downwardly projecting lugs as we have described them were accompanied by two caster wheels, one placed in front and extending beneath the lower surface of each lug.

80. It also follows from what we have said that this was not the class of case described by Menzies J. in the Commonwealth Industrial Gases Case where the variations were so small as to be insignificant and added nothing to the equipment, so that one could say that they were made merely in an attempt to take full advantage of the invention whilst avoiding infringement.

81. For these reasons, it follows that issues 2 and 3 should have been decided by his Honour against Avion with the result that there was no infringement of the claim. That conclusion is in itself sufficient to dispose of the appeal insofar as it relates to patent infringement. Nevertheless, we should express our conclusions upon the other grounds that were debated before us.

82. The first issue is whether the seat frame of Exhibit B contains "a longitudinal element engagable with the upper longitudinally extending support of the chassis". As we have indicated, the trial judge held that the "longitudinal element" was supplied by a hole in the front of the front transverse member of the seat frame which was engagable with the chassis by a removable threaded bolt or stud passed through the hole. Photograph i in Exhibit KHH6 provides a clear illustration of the hole in question. His Honour's reasoning appears in the following paragraph:

"Although Fisher and Paykel conceded that the

words 'longitudinal element' were capable of

being used to include the mechanical device of a

hole, it was contended that . . . the words as

used in the claim did not carry that meaning.

The reasoning behind that submission was to the

following effect, namely that the audience to

which the claim was addressed, the hypothetical

non-inventive skilled worker in the art, would

have expected the words to mean a physical item

rather than an abstract notion such as a hole.

It was agreed that although it was not necessary

to look for a technical meaning to the words

'longitudinal element' to include a hole-element

within them, it was said that a skilled worker

in the art would not be expected to refer to any

dictionaries to discover the field of meaning

the words were capable of covering.

I do not accept that argument. Once it is

accepted that the words bear their ordinary

meaning and no technical sense and that the

ordinary meaning of the words includes within it

the use of a hole-element, it is not to the

point that the hypothetical skilled worker may

not have that meaning in the forefront of his

mind. It may be expected that if such a worker

had any difficulty with the term in either

employing it or in ensuring it was not used, he

or she would go to a usual source to better

inform him or herself as to the extent of the

meaning of the term."

83. In Exhibit B, the seat frame has a transverse member constituted by a square section tube, and there are, consistently with the above interpretation, two longitudinal elements being the two apertures or holes, one on each of the opposing sides of the square section tube. There is no significant difficulty in describing each of these apertures as "a longitudinal element" thus complying with the claim.

84. The longitudinal element must be "engagable with" the chassis to prevent relative transverse displacement. The term "engagable with" appears once in integers "e" and "f" and twice in integer "g". There is no doubt that the "engagable with" element of integer "e" is present in Exhibit B in the sense that the lugs engage with the upper transverse support of the chassis to prevent relative upward movement at the point of engagement; no further step is required to bring about that engagement, the working relationship of the integers being of itself sufficient to achieve the claimed result.

85. Fisher and Paykel submitted on the appeal, and we accept, that the situation, as regards the presence of integer "f" in Exhibit B, is quite different. On the footing that the apertures are longitudinal elements, they are engagable with the chassis so as to prevent relative transverse displacement; but this is not simply as the result of the working relationship between these two integers. Something more is required. In Exhibit B this is the insertion of a threaded bolt through the apertures, and thus across the square section tube constituting the transverse member of the seat frame and into a nut which is welded to a plate, being part of the upper longitudinally extending support of the chassis. Only when the bolt has been inserted in this way, are the apertures in the seat frame engaged with the chassis.

86. The patentee sought to escape this difficulty by submitting that the term "engagable with" in integer "f" was to be read as meaning "capable or susceptible of engagement"; this would allow for the necessary action of another, unidentified, member or element to achieve the result of engagement. In our view, the phrase "engagable with" is used in the claim to describe fastening or attachment of the stated integers, in their working inter-relation and as a step in the assembly and disassembly of the integers which in combination provide a wheelchair with the characteristics claimed in the petty patent. The phrase "engagable with" is not to be read so as to omit the identification of another means necessary to bringing about the fastening or attachment in question. So to read the claim would be to expose the patentee to challenge under s. 40 of the Act. It follows, in this respect, that we would not accept the submissions for the patentee as to the meaning of the phrase "engagable with". This has the result that, although for reasons which do not appear to have been fully argued before his Honour, issue 1 should be decided adversely to the patentee. This then is another ground for the conclusion that there was no infringement by Exhibit B.

87. It was then submitted (as issue 2) that, in any event, although the insertion of the bolt may achieve engagement between seat frame and chassis, and may inhibit transverse displacement between the seat and the chassis, it does not prevent such displacement, as required by the claim. It was submitted that in Exhibit B transverse displacement is only prevented by the wings or fins forming part of the seat frame when engaged with the lugs, as described when dealing with integer "e".

88. The trial judge held that the claim does not require the absolute prevention of movement between the seat frame and the chassis to be effected solely at any one particular joint; the concern is with prevention of relative movement, and the claim speaks of that being effected at two separate joints described in integers "e" and "f" and, whilst the claim does not speak of the same result in integer "g", such relative movement would be part of the "prevention of undesired disengagement" provided by the joint described in integer "g". With respect, we agree with that reasoning as to the proper construction of the claim. Accordingly, we would decide issue 2 in the same way as his Honour, that is to say favourably to the patentee.

89. Issue 3, raises the question, in the light of what we have said above as to issue 1, and as to non-infringement, of whether nevertheless there is infringement by virtue of the "pith and marrow" doctrine, or the reasoning involved in the Commonwealth Industrial Gases Case. Integer "f" is, on any footing, an essential integer, and the doctrine of "pith and marrow" will not apply. Further, it follows from what we have said that we would not regard the use of a threaded bolt in Exhibit B as something that added nothing to the equipment in question, and as no more than an insignificant modification of the integer. Thus, there is no room for the operation of reasoning such as that employed in the Commonwealth Industrial Gases Case, supra. Issue 3 thus should be determined adversely to the patentee.

90. The remaining issue upon integer "f", issue 4, concerns his Honour's finding that, despite his other findings, integer "f" was not present in Exhibit B because the locking device relied on as providing integer "f" also incorporated integer "g", and on its proper construction the claim required not two but three separate mechanisms for the prevention of relative movement between and disengagement of the chassis and the seat frame.

91. His Honour referred to the speech of Lord Upjohn in Rodi and Wienenberger AG v Henry Showell Ltd, supra at 394, for the proposition that, whilst it may be possible for two integers to be incorporated in a single mechanism "if the intended separate function of each is carried out in that mechanism", the contrary is so "if the function of one is absorbed in (the function of) the other or an additional function provided by the single mechanism . . .". We would not read as what is said by his Honour in this passage as propounding any principle of law concerning infringement of combination claims; nor would we read what was said by Lord Upjohn as propounding any such principle.

92. We accept the submission for the patentee that whether or not one element in the alleged infringing combination answers the descriptions of two or more integers of a combination claim is first a question of construction of the claim. It may be that on its proper construction the claim is not infringed unless each integer can be separately identified in the alleged infringing combination as a mechanism which performs no function other than compliance with the description of one integer in the combination claim.

93. We accept as the proper construction of the claim in question in this proceeding that it is concerned with prevention of movement and displacement between the chassis and the seat frame by providing for engagement of integers to prevent relative upward movement, transverse displacement and undesired disengagement. But, in our view, it does not follow that there will be no infringement if the alleged infringing article provides for such prevention of movement, displacement and disengagement by the one means which nevertheless answers the description of the integers "e", "f" and "g". Accordingly, although in the light of the conclusion we have reached as to the absence of integer "f" it is unnecessary to do so, had the occasion arisen, we would not have concluded that the patentee failed for the reasons given by his Honour on issue 4.

94. The trial judge held that the removable bolt was "on the chassis" of Exhibit B when screwed into the nut welded to the upper longitudinal support of the chassis, and that the bolt need not be permanently affixed either to the chassis or the seat frame.

95. We accept the submission that the phrase "on the chassis and/or seat frame" in integer "g" provides greater clarity as to the function of the integer without signifying the requirement that the stud be permanently affixed either to the chassis or to the seat frame. As his Honour pointed out, the expression "a longitudinally extending stud" (emphasis supplied) indicates that the stud may be affixed either to the chassis or to the seat frame, but that it does not necessarily follow that the stud be permanently affixed, or that it is to be treated as other than an integer of an operating mechanism which will require the extension of the stud so that it is, in accordance with the balance of the claim, "engagable with" the appropriate aperture. Accordingly, we would reach the same conclusion as his Honour as to the first issue upon integer "g".

96. The second issue is whether, in Exhibit B, there was an "aperture" with which "a longitudinally extending stud" was "engagable". One of the dictionary meanings of "stud" is a short rod or pin fixed in or projecting from something and serving as a support or stop. In Exhibit B, the threaded bolt to which we have already referred is engagable with the opening in the vertical restraint welded to the front of the transverse member of the chassis, with each of the oppositely placed apertures in the square-shaped longitudinal tube forming part of the seat frame, and with the inner of the vertical restraints welded to the chassis, being the plate containing the nut we have earlier described. The seat frame is placed between the vertical restraints and engagement is then secured by the operation of the bolt in the manner we have described. The bolt is engaged with the nut. In our view, this nut is the "releasable locking means" described in integer "g", and the stud is the bolt which is "engagable with an aperture" in the chassis of Exhibit B, being the aperture of the encircling plate.

97. The trial judge found that the aperture was constituted by the nut into which the bolt was screwed but, as counsel pointed out, if that was so, there would be no separate "releasable locking means engagable with the stud". That difficulty disappears if the integer is construed in the way we have suggested, which is in accord with the submissions for the patentee. Accordingly, were it necessary to do so, we would decide both issues concerning integer "g" favourably to the patentee.

98. The primary Judge, by his orders made 24 October 1990, dismissed the cross-claim in which it was alleged that the petty patent was invalid. We would dismiss the appeal against that order. His Honour also gave a certificate under s. 169 of the Patents Act that the validity of the claim of the petty patent specification came into question. It follows that we would not disturb that order. It follows also that we would dismiss the appeal against his Honour's finding against the patentee on the issues of infringement, though not entirely for the same reasons.

99. It follows that there should be set aside those of the orders made by the trial judge which were founded upon the holding as to infringement of the wheelchair design. Otherwise the appeal and the cross-appeal should be dismissed. Fisher and Paykel should have its costs of the appeal and Avion also should pay Fisher and Paykel's costs of the cross-appeal. The trial judge ordered that Fisher and Paykel should pay Avion's costs of the cross-claim. That order should not be disturbed. His Honour also ordered Fisher and Paykel to pay 90% of Avion's costs of the Application before him. In oral reasons given on 19 October 1990, Lee J. noted that whilst Avion had succeeded as to infringement of the wheelchair design, it had failed upon patent infringement and there was a discernible area of the trial which related to specific patent infringement issues. Hence his Honour made the reduction of 10%. The result of this appeal is that Avion should have failed below upon all infringement issues which it pursued on its Application. Thus, this order as to costs of the Application should be set aside and Fisher and Paykel should have its costs (including any reserved costs) of the Application.

100. The orders made by this Court should provide for:

(1) Orders 1, 2, 3, 4, 5, 8, 9 and 12 of the Orders made by Lee

J. on 24 October 1990 to be set aside.

(2) Otherwise the Appeal to be dismissed.

(3) The Cross-Appeal to be dismissed.

(4) Avion to pay Fisher and Paykel's costs (including reserved

costs) of the Appeal and the Cross-Appeal and of the trial

of the Application.