Hammar Maskin AB v Steelbro New Zealand Lilmited [2010] NZCA 83 (24 March 2010)

Last Updated: 30 March 2010

IN THE COURT OF APPEAL OF NEW ZEALAND

CA692/2008 [2010] NZCA 83

BETWEEN HAMMAR MASKIN AB
First Appellant

AND BENGT-OLOF HAMMAR
Second Appellant

AND HAMMAR NEW ZEALAND LIMITED
Third Appellant

AND STEELBRO NEW ZEALAND LIMITED
Respondent

Hearing: 17 and 18 February 2010

Court: Glazebrook, Ellen France and Baragwanath JJ

Counsel: B W F Brown QC and A J Evans for Appellants
J G Miles QC and G W Hall for Respondent

Judgment: 24 March 2010 at 11.00 am

JUDGMENT OF THE COURT

1. The appeal is allowed and the cross appeal dismissed.
2. The respondent must pay the appellants’ costs for a standard appeal on a Band A basis plus usual disbursements. We certify for second counsel.

____________________________________________________________________

REASONS OF THE COURT
(Given by Glazebrook J)

Table of Contents

Para No
Introduction [1]
Background [7]

Sidelifters generally [7]

Genesis of the patent [13]

Models of sidelifters [17]

Infringement allegations [20]
The patent at issue [21]
Principles of patent construction [31]
The High Court judgment on infringement [37]
Does the patent require a separate physical bearing component? [41]

Parties’ contentions [41]

Expert evidence in High Court [43]

Panckhurst J’s conclusion on this issue [46]

Our assessment [47]

Hammar’s other arguments [57]
Must the pivot pin be directly connected to the chassis? [68]
Inutility [76]

Steelbro’s submissions [77]

Hammar’s submissions [79]

Our assessment [83]
Result and costs [84]

Introduction

[1] This appeal concerns the alleged infringement of a patent relating to stabiliser legs on sidelifters. Stabiliser legs are extendable to the side of trucks or trailers fitted with hydraulic cranes and provide stability when unloading and loading shipping containers. In 1997 Mr Hammar conceived what he believed to be a breakthrough modification to stabiliser leg technology. He filed a patent application in Sweden in September of that year. A corresponding application was filed in New Zealand and a patent granted in July 2000.
[2] Mr Hammar established the company, Hammar Maskin AB, in 1974. It is a Swedish company which designs, builds and sells sidelifters. That company is now owned by a parent company, the shares of which are owned equally by Mr Hammar and his wife. It has subsidiaries in Australia, Malaysia, the United States and in New Zealand (the third appellant, Hammar New Zealand Limited). In this judgment the appellants are referred to collectively as Hammar.
[3] Steelbro New Zealand Limited (Steelbro) is a New Zealand based competitor of Hammar. Steelbro was founded in 1878 at Christchurch as a general engineering company. However, since the early 1980s the company has specialised in the design, building and sale of sidelifters. Like Hammar, Steelbro has an international presence, exporting products to numerous countries.
[4] Proceedings were brought in the High Court[1] by Hammar claiming among other things that the Steelbro sidelifter models SB 361/401 infringe its patent. This claim was rejected by Panckhurst J on the basis that the Steelbro models do not incorporate a separate bearing component in the support sleeve. Steelbro had also sought revocation of the patent on a number of grounds all of which were rejected by the Judge.
[5] On appeal, the judge’s finding on infringement is challenged by Hammar. Steelbro in turn cross appeals against the rejection of its argument in the High Court that there was a second point of difference from the claims in the patent in that, on the relevant Steelbro sidelifters, the pivot pin is not connected directly to the chassis. Another aspect of Steelbro’s cross appeal is an argument in favour of revocation of the patent on the grounds of inutility. Hammar argues that Steelbro should not be permitted to raise this argument which differs from the revocation arguments heard in the High Court. It says that it has, in any event, no merit.
[6] We deal with each of these issues in turn but first provide more background. This is largely taken from Panckhurst J’s judgment, which the parties agree covered all relevant matters. We then set out a description of the patent and summarise the principles of construction of patents.

Background

Sidelifters generally

[7] Trucks and trailers having a sidelifting capacity have existed for many years. Such vehicles, through the use of mounted cranes, can lift loads onto and off their carrying platform. To provide stability the vehicles have two or more extending stabiliser legs for deployment during the course of lifting operations.
[8] Because sidelifters (or sideloaders as they are also known), are road-going vehicles they must comply with road transport requirements of the countries within which they operate. These invariably include a vehicle width limitation, typically 2.5 to 2.6 metres. This restriction is of particular importance with reference to the design of stabiliser legs. Efficiency requires that they are stowed (when not in use) across the width of the vehicle. Accordingly, the stowed length of a stabiliser leg can only be a maximum of about 2.5 metres. This in turn restricts the extended length of the leg and the measure of stability which it can achieve in the deployed position. A further operational limitation is that stabiliser legs in the course of being deployed must not exceed the maximum height of 4.25 metres.
[9] The advent and exponential growth in the use of containers from about the 1970s led to a dramatic growth and demand for sidelifters. Particularly in countries with less developed rail systems, such as New Zealand, sidelifters enabled the road transportation of shipping containers. Flexibility of operation was demanded. Sidelifters required the ability to load, and unload, to ground level; but also onto other vehicles parked adjacent to the sidelifter. There was also a need to unload in confined areas, whether on wharves, in railway yards or the like.
[10] These operational requirements created demands with reference to the design and construction of stabiliser legs. Where a container is to be offloaded onto the ground the stabiliser legs need to be positioned a distance out from the deck of the sidelifter in order to provide adequate stability. But, in other situations the legs may need to be placed on, or beneath, the deck of another vehicle. In some situations the stabiliser legs may need to be deployed in a near vertical position, close to the side of the sidelifter, on account of some adjacent obstacle.
[11] With the growth in the use of containers came an increase in the size and weight of containers. Containers used to be 20 feet long. Today they may be up to 40 feet in length. The loaded weight of containers has increased, first up to 33 tonnes, and today to 40 tonnes. Given that the weight of a sidelifter itself is about ten tonnes (including the weight of the crane units and stabiliser legs), the vehicle is an inadequate counterweight to the weight of a container which is being offloaded. Hence, increased sophistication in the container industry has had to be matched by corresponding gains in sideloader development, particularly in relation to the development of improved stabiliser legs. Sidelifter cranes by contrast, apart from an increase in lifting capacity, have not required redevelopment to the same extent.
[12] On account of the variable size of containers, sidelifters also need to be adaptable. A sidelifting vehicle should ideally be able to lift both 20 and 40 foot containers. A mobile crane unit is required. Such units may be shifted along decking mounts or the vehicle chassis, so as to match the length of the container to be lifted. This means that stabiliser legs must also be mobile. In some sidelifters this is achieved by the stabiliser leg being attached to the crane unit so that the two move in tandem.

Genesis of the patent

[13] Mr Hammar explained in evidence that, during the summer of 1997, while working at his home one evening, the idea of a negatively inclined stabiliser leg occurred to him. Conceptual drawings were prepared. By inclining the stowed leg in a negative position, away from the side of its intended deployment, a gain could be made in the length of the leg without exceeding the vehicle width. If each end of the stowed leg was tapered or bevelled, so as to fit in vertical orientation to the edges of the truck (or trailer) an additional gain in length could be made.
[14] Once the leg was extended into its deployed position, the gain in length achieved in the stowed position could be approximately doubled. This was because stabiliser legs comprise an outer sleeve from which an inner sleeve is hydraulically extended. By also improving the configuration and placement of the heavy bracket by which the stabiliser leg is affixed to the vehicle itself, a better range of extension of the leg could be achieved.
[15] A prototype of the new stabiliser leg was developed and tested. In the meantime, on 4 September 1997, Mr Hammar filed a patent application through his Swedish patent attorney. Through the use of a negatively inclined stabiliser leg a gain of 100 mm (from 2,500 mm to 2,600 mm) in the total length of the leg in its stowed position was achieved. The bevelled end also produced a gain of about 200 mms, being the extent to which the bevel protruded out from the side of the vehicle once the leg was moved to a horizontal position. The total gain achieved when the leg was fully extended and placed in a deployed position was an increased reach approaching 300 mms. This improvement in reach translated to increased stability.
[16] On 28 August 1998 Mr Hammar filed the New Zealand patent application with a 4 September 1997 priority date. The New Zealand patent for the new style stabiliser leg was granted on 6 July 2000 as Patent No. 331591.

Models of sidelifters

[17] Over the years both Hammar and Steelbro have developed new models of increased capacity and sophistication in response to market demands. These were identified by different series numbers.
[18] Hammar built its first sidelifters in 1974. Since then a number of series have been launched. This case concerns the SL190 series which was developed from 1998. All previous series had featured stabiliser legs which were stowed in a horizontal position across the width of the sidelifter. The sale of the 190 series began with the release of three new units in late 1998. By 2000 models from the Hammar 190 series were sold in New Zealand.
[19] Steelbro has also had a series of models of sidelifters. All models through to the SB330 model in 1996 featured stabiliser legs which were stowed in a horizontal position. The change to a negatively inclined stow position occurred with the development of the SB361/401 series in early 2004.

Infringement allegations

[20] In early May 2005 the New Zealand patent attorneys acting on behalf of Hammar wrote to Steelbro alleging that the company had infringed copyright in engineering drawings and infringed the patent. Steelbro’s solicitors denied the infringement allegations. With reference both to the patent and copyright claims, Steelbro stated that it had been producing sidelifters since the early 1980s and that the company’s most recent model, SB361, incorporated improvements which were logical modifications of previous sidelifter arrangements. The judge’s finding rejecting the copyright infringement allegation is not the subject of appeal.

The patent at issue

[21] The specification begins by describing the invention as relating to a support structure for wheel-mounted vehicles of the type comprising at least two support parts extendable in the transverse direction to the vehicle (ie across the vehicle). The first part is said to be a support sleeve supported by a pivot pin connected to the vehicle chassis. The second part is said to be an extension part which is movably arranged in the first support part or support sleeve. It goes on to say that this type of support is usually pivotable between a parking position and an operating position.
[22] It then states that the space in which such support structures must be accommodated in a parked position corresponds to the outer transverse dimension of the vehicle (ie no more than the width of the vehicle). Previously, the specification continues, support structures had been inclined downwards when stowed to the operational side of the vehicle. This allowed the support structure to be “somewhat longer” than would be the case if parked in a horizontal position. However, in this inclined position it proved difficult to use the support structure when transferring a load to another surface at a similar level to the load surface of the subject vehicle.
[23] The object of the invention is stated to be two-fold. The support structure must be able to provide (at low design and production cost) vertical support (close to the subject vehicle, in order to avoid obstacles) and also “far away” support, whether onto the ground or onto an adjacent elevated loading surface. It is then stated that these objects are achieved by a support structure of the type described in the characterising clause of claim 1. This means that:

The two support parts are pivotable between a parking position in which they slope downwards to the side of the vehicle which is furthest away from the pivot pin of the support structure and an operative position with the opposite inclination. In maximal utilisation of the width of the vehicle by, for instance, bevelling the ends of the support sleeve so as to be located vertically in the parking position, there is obtained, compared with the prior-art structures, an increased distance between the support points of the extension part in the support sleeve, which reduces the load applied to the extension part, thereby making it possible to form the support with smaller cross-sectional dimensions or the extension part to be extended from the support sleeve further than was previously possible. The reversed inclination of the support in the parking position, in relation to prior-art constructions, implies that the entire support system when pivoting towards the operative position is efficiently moved sideways relative to the vehicle, which in turn gives the support structure a wider reach. [Emphasis added]

[24] Sub-claims 2 to 7 are stated to contain “[f]urther details and advantages of the invention”, while an embodiment of the invention is said to be described with reference to the accompanying drawings. Figure 1 depicts the vehicle from the rear with the support structure in its parked position.

[25] Figures 2, 3 and 4 depict the support structure deployed onto a neighbouring platform, the ground at a distance and the ground immediately beside the subject vehicle, respectively.

[26] In relevant part the numbers on the Figures 1 to 4 refer to the following components. The vehicle is designated 1. The chassis of the vehicle is designated 2, while 3 designates a wheel frame which is usually mounted on the chassis of the vehicle by means of spring suspension. A platform arranged on the vehicle is designated 4. A support structure “according to the invention” is designated 5 and is, in the embodiment illustrated, “pivotally connected to the platform of the vehicle or to the chassis thereof by means of a pivot pin 6.” The support structure is said to have “two parts which are telescopically movable relative to each other”: an outer sleeve marked 7 and an extension part 8 “which is displaceably guided therein”. A bracket 9 or pivot arm “rigidly connect to the sleeve part” [which] connects the support to the pivot pin 6.
[27] Figure 6 (copied below) is described in the specification as showing schematically the two parts which are displaceable relative to each other, ie the support sleeve 7 and the extension part 8 in a position which approximately corresponds to the position shown in Figure 3. Figure 5 (also copied below) illustrates a position which approximately corresponds to the parking position according to Figure 1. The specification goes on to say:

In Fig. 5 the two parts essentially coincide, while in Fig. 6 the extension part 8 extends out of the support sleeve 7. Fig. 6 illustrates clearly how the supporting points for the extension part 8 in the support sleeve 7 are located. In case of a reaction force F1 exerted by the ground, an upwardly directed force F2 will act on the support sleeve in the point 21, and a downwardly directed force F3 will act on the support sleeve in the supporting point 22. The distance L between the points 21 and 22 seen in the longitudinal direction of the support thus is considerably prolonged compared with the case where the support had been cut right off or even bevelled in the opposite direction, which would have been the case in an opposite inclination of the support. This means that the load exerted on the support sleeve as well as the extension is minimal; this advantage increases with an increased inclination of the support in the parking position. [Emphasis added]

[28] It is stated that the invention is not limited to the embodiment described above, which is an example only, and that it can be varied in all details within the scope of the claims without deviating from the basic idea of the invention.
[29] Turning to the claims, claim 1 can be divided into the following:

(a) a structure which is adapted to support a wheel-mounted vehicle,

(b) the structure consisting of at least two support parts which are relatively offset in the transverse direction of the vehicle,
(c) and of which a first part is a support sleeve supported by a pivot pin connected to the vehicle chassis,
(d) and the second part is an extension part which is movably arranged in a bearing in the first support part, i.e. the support sleeve,
(e) characterised in that the support, ie the two support parts, are pivotable between a parking position in which they slope downwards to the side of the vehicle which is furthest away from the pivot pin of the support structure,
(f) and at least one operative position with an opposite inclination,
(g) wherein the support sleeve has a longitudinal extent which, in the parking position of the support, essentially corresponds to the width of the vehicle,

(h) and wherein the ends of the support sleeve are bevelled to provide end faces that extend substantially vertically when the support is in the parking position. [Emphasis added]

[30] The phrases which have been italicised above in claim 1 are those with which this appeal and cross appeal are concerned. Sub-claims 2 and 7 are also material. They provide:

2. A structure as claimed in claim 1, characterised in that the pivot pin is arranged far down in the vehicle chassis, i.e. at least below the platform surface of the vehicle, preferably in level with the vehicle chassis.
   7. A structure according to claim 1 substantially as herein described or exemplified.

Principles of patent construction

[31] The Patents Act 1953 sets out the required contents of the specification in s 10. It provides:

Contents of specification

(1) Every specification, whether complete or provisional, shall describe the invention, and shall begin with a title indicating the subject to which the invention relates.

(2) Subject to any regulations made under this Act, drawings may, and shall if the Commissioner so requires, be supplied for the purposes of any specification, whether complete or provisional; and any drawings so supplied shall, unless the Commissioner otherwise directs, be deemed to form part of the specification, and references in this Act to a specification shall be construed accordingly.

(3) Every complete specification—

(a) Shall particularly describe the invention and the method by which it is to be performed; and

(b) Shall disclose the best method of performing the invention which is known to the applicant and for which he is entitled to claim protection; and

(c) Shall end with a claim or claims defining the scope of the invention claimed.

(4) The claim or claims of a complete specification must relate to a single invention, must be clear and succinct, and must be fairly based on the matter disclosed in the specification.

[32] In Lucas v Peterson Portable Sawing Systems Ltd,[2] Gault J, on behalf of the Court, said that s 10 of the Patents Act makes it clear that the applicant for the grant of a patent defines the scope of the invention, in respect of which the statutory monopoly is claimed, in a claim or claims at the end of the specification. Such claims must be clear and succinct and fairly based on the disclosure in the specification.
[33] He went on to say that conventionally there is a series of claims directed to aspects of the invention. These reflect the skill of the drafter who seeks to claim as widely as possible to encompass potential infringements but who also seeks to avoid such width that could render the patent invalid. Claims are usually drawn in increasing detail, often (in Peterson, as in this case) ending with a narrow claim to the specific embodiment described in the specification and any drawings.
[34] Gault J then set out the principles of construction of patents:

1. The first and essential step is to construe the claim. Construction is a matter of law for the Court.[3]
2. A patent specification is to be read as a whole and given a purposive construction. It must be construed as it would be understood by an addressee skilled in the relevant art.[4]

100. Each part of the specification is to be read objectively in its overall context and in light of the function of that part. The claims are to be interpreted by reference to the object and description in the body of the specification.[5]

4. The claims define the scope of the monopoly conferred by the patent. They limit what others may do. They must clearly define the protected field so others may fairly know where they cannot go.
5. The description in the body of the specification may assist interpretation, but it cannot modify the monopoly the inventor has clearly marked out.
6. If the claim is formulated too narrowly so that imitators do not infringe, that cannot be rectified by reference to the description. If it is too wide, consequent invalidity cannot be saved by reading in limitations appearing in the description.
7. The description of a preferred embodiment of the invention is just that and will not confine the scope of an invention claimed more broadly.[6]

[35] In the High Court, Pankhurst J referred as well to two United Kingdom cases. The first was Catnic Components Ltd v Hill and Smith Ltd where Lord Diplock said that, in giving a purposive construction to a patent, “the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge” was inappropriate, since it was what a person skilled in the art would understand from the use of a particular word or phrase which mattered. [7]
[36] The second was Kirin-Amgen Inc v Hoechst Marion Roussel Ltd where Lord Hoffman nevertheless recognised that the language the patentee has chosen is usually of critical importance. He said that the conventions of word meaning and syntax enable us to express our meanings with great accuracy and subtlety and the skilled man will ordinarily assume that the patentee has chosen his language accordingly. He noted that a number of judges have pointed out the specification is a unilateral document in words of the patentee’s own choosing. Furthermore, the words will usually have been chosen upon skilled advice. However, it was acknowledged that there will be occasions upon which it will be obvious to the skilled man that the patentee must, in some respect, have departed from conventional use of language or included in his description of the invention some element which he did not mean to be essential. Lord Hoffman noted, however, that one would not expect that to happen very often. [8]

The High Court judgment on infringement

[37] In its statement of defence Steelbro had denied infringement on the grounds that there were material points of difference between claims 1, 2, 4, 6 and 7 of the patent and the Steelbro models SB361/401, which were alleged to infringe the patent. However, in closing submissions in the High Court, the argument was confined to three of the agreed integers of claim 1 which Steelbro maintained were not infringed by its product. These were:

(a) The absence of a bearing component within the support sleeve;

(b) The support sleeve was not supported by a pivot pin connected to the vehicle chassis; and
(c) A longitudinal extent which did not correspond to the width of the vehicle.
[38] Panckhurst J held that the suggested differences at [37](b) and (c) were not sustainable. The interpretation he placed on the relevant integers meant that Steelbro’s SB361/401 models were seen to infringe the patent in relation to connection of the pivot pin to the vehicle chassis and in relation to the longitudinal extent of the support sleeve in the parked position.
[39] Panckhurst J also held that the interpretation he had reached in relation to [37](a) meant that infringement was not established with reference to this integer. The Judge held that the Steelbro SB361/401 models do not incorporate a separate bearing component in the support sleeve, which he held the patent claims required. It followed that, given the absence of this integer, infringement of the patent was not established.
[40] The appeal relates to the finding set out at [39]. The cross appeal relates to the finding with regard to [37](b).

Does the patent require a separate physical bearing component?

Parties contentions

[41] Hammar’s construction is that the description of the “bearing”[9] in claim 1 was intended to convey the concept of a “state of bearing”, that is of one component (the second support part, namely “the extension part”) bearing on the other component (the first support part, namely “the support sleeve”). This is essentially a functional view of the term “bearing”.
[42] Steelbro’s construction is that the description of the “bearing” is a reference to a discrete physical component which must be physically located inside the first support part, the support sleeve.

Expert evidence in High Court

[43] Mr Eaton, in giving evidence for Hammar, said that the use of the word “bearing” simply conveyed that the extension part bears on the support sleeve as it moves in and out, as shown in Figures 5 and 6 in the specification.
[44] Both of Steelbro’s experts concluded that claim 1 requires a separate bearing component. Mr Stevens’ analysis began with a review of the specification but this was of little assistance given that the words “movably arranged in a bearing in the first support part” are not defined in the description of the invention. He therefore focussed principally on the claim and made these comments:

What is being required by claim 1 of the Patent is that the inner support member (the extension part) must slide in and out of the outer support member (the first support part). The claim goes on to say that the “extension part ... is movably arranged in a bearing” and that the “bearing (is) in the first support part”.

I therefore consider the notional skilled addressee would understand this to mean that the support sleeve (the first support part) is fitted internally with an additional bearing surface of some kind. That is, “bearing” is not being used in this sense to imply only the regions of moving contact between the inner and outer sleeve. It is in fact being used to refer to a distinct component present in the first support part (the support sleeve) within which the extension part is movably arranged.”

[45] Dr Stark focussed less on the specification but had no difficulty in construing the fourth integer as requiring “a component such as, for example, a bearing bronze rubbing strip or strips that would facilitate a relative sliding of the two components”. In replying to Mr Eaton’s evidence Dr Stark stated further:

Mr Eaton conveniently omits the indefinite article “a”. Claim 1 refers to “a bearing” not “bearing”. A bearing conveys to me a separate bearing component, at the interface between the inner telescoping component and the outer support sleeve, and does not mean one component simply sliding on the other without “a bearing” component separating them at the interface.

Panckhurst J’s conclusion on this issue

[46] The Judge accepted that there was no reference in the specifications to a separate or additional bearing component. Nor was the existence of a separate element described in the specification or shown in the drawings. However, he pointed out that the wording of the claim describes an extension part “movably arranged in a bearing in the [support sleeve]”. This description, to his mind, could only be read as referring to an additional element which performs the function of a bearing. He considered that Mr Eaton’s contention, that the words convey that one part bears on the other when the stabiliser leg is extended, was strained. For these reasons it was his view that the evidence of Mr Stevens and Dr Stark was to be preferred.

Our assessment

[47] There is no doubt that the word “bearing”, taken alone, is capable of describing both a separate physical bearing component and also the state of bearing. The issue is which meaning should be preferred in the total context of this patent. In that regard, Hammar pointed to the wider context and, in particular, the lack of a separate bearing component elsewhere in the specification or in the embodiment as shown in the drawings. By contrast, Steelbro concentrates on the indefinite article (“in a bearing”) in claim 1.
[48] Mr Miles QC, on behalf of Steelbro, submitted that the use of the indefinite article makes the meaning of the phrase clear and that is the end of the matter. In his submission, under New Zealand law, recourse can be made to the body of the specification only if the claims are ambiguous. We reject that submission. As noted at [34](c) above, claims must always be interpreted in their overall context and by reference to the object and description in the body of the specification. That said, we accept that the specification can only assist interpretation. It cannot modify the monopoly the inventor has clearly marked out in the claims: See at [34](d) above.
[49] Mr Miles also stressed that this case involves an infringement claim, implicitly suggesting that this affects the rules of construction. We reject that submission too. As Panckhurst J noted, the construction of a claim is inelastic, in that the construction remains the same whether the validity or infringement of the patent is being considered.[10]
[50] Having said this, we agree with Mr Miles that, looking at the phrase “in a bearing” in claim 1 in isolation from its context, the more natural meaning is that it denotes a separate physical bearing component. However, even with the use of the indefinite article the meaning contended for by Hammar is tenable. If the Hammar meaning is taken, then what is being said is that the extension part is in a bearing relationship in the support sleeve. We thus do not agree that the Hammar interpretation would involve “modify[ing] the monopoly the inventor has clearly marked out” in the claim.
[51] Mr Miles argued further that, if Hammar’s construction is preferred, the term “in a bearing” becomes otiose. We do not accept that submission. This is because to remove those words would remove the reference to one of the functionalities. Not only is the extension part moveable in the support sleeve. That extension part also has a bearing relationship with the sleeve.
[52] We accept Mr Brown’s submission that such a bearing relationship is implicit and inevitable in the description of the prior art stabiliser legs in the specification. Consistent with the existence of such a bearing relationship, the specification, in its description of the invention, proceeds to explain how that bearing relationship is enhanced and how the magnitude of the load exerted by the legs is minimised by the invention disclosed.[11] We do not accept Mr Miles’ submission that it is significant that the specification describes the “load” relationship between, and the “forces” affecting, the extension part and the support sleeve but that it does not employ the term “bearing”. It is the function described which then carries through to claim 1 which is more important than the precise wording.
[53] In our view Hammar’s interpretation of the claim, which adopts a functional view of the term “bearing”, provides an orthodox description of the relationship between two parts which interact by the movement of one against the other and/or where one bears some of its load on the other. As Hammar pointed out, Steelbro’s witness, Mr Stevens, accepted that an outer sleeve is capable of acting as a bearing. He also said that when, in the case of the Steelbro SB361 product, the inner leg moves relatively within the outer part, it is moving within the structure, although he did note that there is no device called a bearing fitted in the structure.
[54] Looking, as we must, to the interpretation of the word, “bearing” in the context of the specification as a whole, we also accept Mr Brown QC’s submission that it is noteworthy that, despite the word “bearing” appearing in claim 1 prior to the characterising clause, there is no reference in the specification to a “bearing” of the nature contended for by Steelbro, namely a discrete physical component situated in the outer support sleeve. This applies both to the description of prior art in the specification and to the description of the invention.
[55] Further, there is no separate physical bearing shown in the drawings and, in particular, in Figures 5 and 6. If there was intended to be an additional integer in the form of a separate physical bearing then, as Mr Brown submitted, one would expect that to appear in the specification and the drawings. Instead, what permeates the whole of the specification is the functional concept of bearing.[12]
[56] For all the above reasons, we consider that, taking a purposive approach to the construction of the patent and construing claim 1 in the context of the specification as a whole, the term “bearing” in claim 1 is used in a functional sense. This means that Hammar’s construction is the correct construction. No separate physical bearing component is required.

Hammar’s other arguments

[57] For completeness, we deal briefly with Hammar’s other arguments in favour of its position.
[58] The first argument was that the words which precede the characterising clause in clause 1 (including the word “bearing”) describe the state of the prior art.[13] The pre-patent stabiliser legs, as described in the specification, all comprised at least two support parts, with the first being connected to the vehicle in some fashion and the second being an extension part, which moved within the first part. The second part was consequently in a bearing relationship with the first part. Significantly, there was no mention of a separate physical bearing component in the description of the pre-patent stabiliser legs in the specification.
[59] In answer to this submission, Steelbro submitted that, even if the words preceding the characterising clause are descriptive of prior art (which it did not accept), this does not assist Hammar’s argument. This is because prior art which included a separate bearing component was identified in the proceeding by Dr Stark (although this is disputed by Hammar). In fact, in Dr Stark’s opinion, such a feature is so common place that when Dr Stark prepared his evidence, he assumed that when he saw sliding telescopic elements they would incorporate bearing bronzed rubbing strips.
[60] We accept Mr Brown’s submissions for Hammar on this point. As we understood it, the point made by Mr Brown was that the description of prior art in the specification does not include any reference to a separate bearing component. The description concentrates on bearing relationships. This is thus effectively confirmation that, read in context, the term “bearing” in claim 1 was used in a functional sense.
[61] Hammar’s next argument was that the Steelbro witnesses and the Judge were in error in entertaining Steelbro’s argument that it was legitimate to have regard to the form of Hammar’s sidelifter as subsequently manufactured when construing the patent claims.[14] Mr Brown submitted that it is not appropriate to seek to construe a specification by reference to extrinsic material in the form of actual products. Thus, Steelbro’s heavy emphasis on the actual construction of the 190 series sidelifter, in particular on the presence of stainless steel material to reinforce the inner surface of the support sleeve adjacent to the mouth of that sleeve, was a red herring.
[62] Mr Brown submitted that in one sense this is simply a manifestation of the broader principle that subsequent conduct is not available as an aid to the interpretation of a written document: Glaverbel SA v British Coal Corporation.[15] However, it is submitted the patent specifications are an a fortiori instance, as reflected for example in the observation of Laddie J in Telsonic AG’s Patent:[16]

Patents and their claims are meant to be statements made by the patentee to the relevant public. Their meaning and effect should be discernible from the face of the document.

[63] Mr Miles did not contend that the embodiment of the patent can be used to resolve an ambiguity in a claim. However, where, as here, a patentee has incorporated in his product a component which is precisely described in a particular integer (namely a bearing in the support sleeve of the stabiliser), then, it is submitted, the general rules of construction relied upon by Hammar do not prohibit reference to that fact merely as corroborative evidence.
[64] We do not need to resolve the issues between the parties on this point. Nor do we need to consider the extent to which, if any, the principles outlined by Mr Brown as set out at [62] above, have been modified by the decision of the Supreme Court in Wholesale Distributors Ltd v Gibbons Ho[17]ings Ltd.17 This is for two reasons. The first is that we have come to a different view of the interpretation of claim 1 than Panckhurst J. The second is that we accept Steelbro’s submission that Panckhurst J acknowledged Hammar’s evidence of the embodiment of the patent (the SL190 sidelifter), but merely noted that Steelbro argued this was confirmatory of the fourth integer. The finding claimed by Hammar was not made.
[65] Hammar’s final argument was that when claim 1 is interpreted in light of omnibus claim 7, it is clear that claim 1 was intended to encompass the exemplified embodiment described in the specification. For instance, in the arrangement illustrated in Figures 1 to 6, the existence of a separate bearing component is neither described in the specification nor shown in the drawings. Omnibus claim 7 is dependent on claim 1 and thus narrower: David Kahn Inc. v Conway Stewart & Co. Ltd.[18] Because omnibus claim 7 is dependent on claim 1 and therefore narrower in scope, as stated by Peter Gibson LJ in Glaverbel, guidance on the true construction of claim 1 can be obtained by looking at the scope of claim 7.[19]
[66] Steelbro’s submission is that claim 7 has to be read down to be limited to the embodiment shown in the drawings, but containing all of the integers of claim 1. The fact the specification does not describe, and the drawings do not show, a separate bearing component is immaterial. Hammar’s evidence was that the drawings contained in the specifications are conceptual only. In Mr Miles’ submission they would thus not necessarily be expected to show all of the components or details in the patent.
[67] We accept Hammar’s submission that the scope of claim 7 does provide some added support for its interpretation of claim 1, for essentially the same reasons as set out above at [52] – [20] above. .20

Must the pivot pin be directly connected to the chassis?

[68] Claim 1 states that the support sleeve is “supported by a pivot pin connected to the vehicle chassis”: see at [29](c) above. In the specification the support structure is described as “pivotally connected to the platform of the vehicle or to the chassis thereof by means of a pivot pin 6”: see at [26] above. Figure 1 identifies the chassis (by the number 2) and the moveable platform (by the number 4) as distinct, if connected, components.
[69] In the Steelbro models, the support sleeve is not supported by a pivot pin connected to the vehicle chassis but rather is supported by a pivot pin connected to the crane base which is moveably arranged on the vehicle chassis. It was argued in the High Court and this Court that this is materially different to the patent specification, and thus that the Steelbro models do not infringe Hammar’s patent.
[70] Panckhurst J rejected that argument. He said that the evidence established that sidelifters do not have a platform or deck in the conventional sense. Rather, there is a minimal structure upon which containers may rest and which is moveable but hydraulically fixed to the chassis while the crane and stabiliser legs are operational. As a result, he accepted Hammar’s submission that the terms platform and chassis are used in a general sense and, because of their association and practice, are interchangeable.[21] On that basis, he concluded that the description in claim 1, namely connection to the vehicle chassis, did not require a direct connection but that

a connection to the chassis through the medium of the platform sufficed.

[71] In Mr Miles’ submission, Panckhurst J erred in that conclusion. In his submission there is nothing in the patent to suggest that the terms “platform” and “chassis” are used interchangeably. The specification identifies the platform and chassis as separate and different components. They are shown separately in Figure 1 and designated 2 (chassis) and 4 (platform). The platform is clearly different to the chassis. Further, connection to a platform must be something different to connection to a chassis. Otherwise, the specification would not refer to the pivot pin as being connected to one “or” the other of them.
[72] Mr Brown submitted that it would be apparent to the skilled addressee that the word “chassis” in claim 1 was used in a general sense and was interchangeable with or subsumed the word “platform”. In his submission, this proper interpretation must have regard to function. The function of stabiliser leg structures is to provide stability for the vehicle during the lifting operation. Their deployment is essential where (as is invariably the case with loaded containers) the vehicle is an inadequate counterweight to the weight of the container. In order to provide stability to the vehicle and a sufficient degree of counterweight the stabiliser leg structures must be integrally connected to the vehicle itself. As Dr Stark said, when cross-examined in the context of the platform, if the platform was not connected to the chassis then “the whole thing would fall off”.
[73] In Mr Brown’s submission, whether the connection is directly to the vehicle chassis, or via another component of the vehicle which is itself directly connected to the vehicle chassis, is not material to the functioning of the stabiliser legs in providing support for the vehicle in the lifting operation. Mr Brown submitted that the word “connected” must be interpreted functionally. This means that it is not confined to direct connection but extends to connection to the chassis via an interconnecting component.
[74] Mr Brown relied upon Rescare Ltd v Anaesthetic Supplies Pty Ltd[22] in support his proposition. Claim 1 of the patent in suit in that case used the phrase “connected to”. These words, it was held, may be used in two senses. Objects A and B may be connected in the sense of an immediate physical relationship, each being fastened to the other. Equally, however, A and B may be connected by the medium of C. The sense in which “connected to” has been used in a particular context is a matter of construction, to be answered in the context of the document as a whole. [23]
[75] We accept Mr Brown’s submissions. We do not consider that the term “connected” imports the connotation in the context of this patent of “directly attached”. It is a functional connection that is at issue and there is such a connection on the Steelbro models, as the Judge held. We consider that Hammar’s argument that the term chassis in claim 1 is used in a functional rather than literal sense is supported by the fact that the pivot pin is not directly connected to the chassis in the diagrams in the specification and also by the wording in the specification itself referred to at [68] above.

Inutility

[76] Section 41(1)(g) of the Patents Act provides that a patent may be revoked on the grounds that the invention, so far as claimed in any claim of the complete specification, is not useful. As outlined in Patents for Inventions, what the invention is intended to do is a matter to be gathered from the specification itself. So where the patentee promises (expressly or impliedly) the attainment of a certain result and this is not obtained, or what is stated as the main object of the invention is not obtained, the patent will be invalid.[24]

Steelbro’s submissions

[77] In the present case, Mr Miles submitted that the invention, insofar as it is claimed, is not useful in that it includes embodiments that do not achieve the stated objective of the invention. That objective is set out at [23] above. In Mr Miles’ submission, the invention as it is described in the patent, must achieve at least three positions, each of which are referred to in the claims as “operative positions”. This object, however, is not achieved by the invention as it is claimed in all claims. Claim 1, which forms the basis for the remaining claims 2-7, requires only that the support structure can be deployed to “at least one operative position with an opposite inclination” to the inclination of the support structure when in a parked position.
[78] In these circumstances, Mr Miles submitted that a support structure that is incapable of achieving more than one operative position will infringe the claims but will not achieve what the patent description says is the object of the invention. It follows that the claims include embodiments that are not useful and therefore the patent should be revoked. He said that this argument was not addressed by Panckhurst J, though the case law on which the argument is based was referred to in Steelbro’s closing submissions.

Hammar’s submissions

[79] Hammar submitted that the Judge directly addressed the point on inutility as it had been advanced to him by Steelbro. In the High Court, Steelbro had argued that Hammar’s sidelifter design could not achieve a vertical deployment as described in claim 6 but merely a near to vertical position. The issue was whether this sufficiently met the promise contained in the patent that the stabiliser leg was pivotable to a vertical position beside the sidelifter. Panckhurst J held that ‘vertical’ is not to be construed literally.[25] The express object described in the specification is that the stabiliser leg can function in a confined space alongside the sidelifter. This object, or promise, is achieved so long as the leg can be placed in a near to vertical position. It followed that inutility was not demonstrated and this finding has not been challenged on appeal.
[80] Mr Brown submitted that the Judge did not address the new point but this was because it was never put to him (and he could not therefore fairly be said to have “missed” it). The new point first emerged in the Notice of Cross-Appeal. Furthermore, the new argument is raised by Steelbro both without leave of this Court and without amending the particulars of invalidity, the requirements for which are addressed in rr 22.19, 22.24 and 22.25 of the High Court Rules.
[81] In any event in Mr Brown’s submission the point is without merit. Although the object clause describes three distinct positions of deployment (which correspond to the illustrations in Figures 2, 3 and 4), neither the object clause nor any other part of the specification refer to “operative positions” in the plural. The skilled addressee would understand that a support structure can only be in one operative position at one time and that the object of the invention is to provide a support structure in which the three described positions are “possible”, that is, capable of being achieved at some point in time depending upon the circumstances. It is clear from the object clause and the specification as a whole that an obstacle in the path of the support structure may prevent the support structure from achieving the second and third described positions. It is also clear that a loading surface needs to be located beside the vehicle for the third described position to be achievable.
[82] In a similar manner, the skilled addressee would not interpret claim 1 as seeking to claim a sidelifter with a pivotally mounted support which can only ever achieve a single operating position. A sidelifter with a pivotally mounted support will move through a number of potential operating positions during deployment. To manufacture such a sidelifter but permit only a single operating position would be of no commercial use and would never be marketable. Instead, the skilled addressee would interpret claim 1 as claiming a sidelifter with a support structure that can achieve at least one operative position in the circumstances pertaining. This interpretation is consistent with the description of the preferred embodiment of the invention.

Our assessment

[83] This ground of inutility was not pleaded. We reject the submission that it was argued in the High Court. Nor was there any opportunity to lead evidence on the issue. The argument in the High Court was limited to the issue of verticality and the finding of the Judge on that issue is unchallenged in this Court. We decline leave to amend the pleading and raise this issue on appeal. In any event, it seems to us that the argument would not succeed for the reasons given by Hammar.

Result and costs

[84] The appeal is allowed and the cross appeal dismissed.
[85] The parties are to confer and file on or before 9 April 2010 a joint memorandum setting out agreed orders to give effect to this judgment. In the event orders cannot be agreed the joint memorandum should identify the points of difference and explain the reasons for those differences. The memorandum should also note if there is any reason for the matter to be referred back to the High Court.
[86] The respondent must pay the appellants’ costs for a standard appeal on a Band A basis plus usual disbursements. We certify for second counsel.

Solicitors:
Henry Hughes & Co, Wellington for Appellants
Buddle Findlay, Auckland for Respondent

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[1] Hammar Maskin AB & Ors v Steelbro New Zealand Ltd HC Christchurch CIV-2006-409-0977, 8 October 2008.
[2] Lucas v Peterson Portable Sawing Systems Ltd [2006] 3 NZLR 721 (SC).
[3] At [25].
[4] At [26].
[5] At [27].
[6] The matters set out at [34](d) – (g) are set out at [28] of Peterson.
[7] Catnic Components Ltd v Hill and Smith Ltd [1982] RPC 183 (HL) at 243.
[8] Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2004] UKPC 6; [2005] RPC 169 (HL) at [34].
[9] See at [29](d) above.

[10] At [29]. See Simon Thorley and others Terrell on the Law of Patents (16th ed, London, Sweet and Maxwell, 2006) at [6-06]. See also Susy Frankel and Geoff McLay Intellectual Property in New Zealand (Wellington, Lexis Nexis Butterworths, 2992) at 353.

[11] See in particular the part of the specification described above at [23] and [27].

[12] Compare Société Nouvelles des Bennes Saphem v Edbro Ltd. [1983] RPC 345 (CA) and the interpretation of “slide” and “slidably” in a functional sense: at 361.

[13] Virgin Atlantic Airways Ltd v Premium Aircraft Interiors UK Ltd [2010] RPC 8 (CA) at [20] - [21].
[14] See [53] - [54] of Panckhurst J’s judgment.
[15] Glaverbel SA v British Coal Corporation [1995] RPC 255 (CA) at 268-270.
[16] Telsonic AG’s Patent [2004] RPC 744 (HC) at 754.
[17] Wholesale Distributors Ltd v Gibbons Holdings Ltd [2007] NZSC 37, [2008] 1 NZLR 277.
[18] David Kahn Inc. v Conway Stewart & Co. Ltd. [1974] RPC 279 (HC) at 308.
[19] At 281.

[20] For completeness, we note that the parties were given leave to file further submissions on a point relating to fair basis which arose during the hearing. This point is only tangentially relevant and thus we did not find it necessary for the purposes of this case to make any finding on this issue.
[21] At [50].
[22] Rescare Ltd v Anaesthetic Supplies Pty Ltd (1993) 25 IPR 119 (FCA).

[23] At 129. The decision in the case was subsequently overturned by Lockhart, Sheppard and Wilcox JJ in Anaesthetic Supplies Pty Ltd v Rescare Ltd [1994] FCA 1065; (1994) 122 ALR 141 (FCA) but on another point.

[24] T.A. Blanco White Patents for Inventions (4th ed, Stevens and Sons, London, 1983) at [4-4-403].
[25] At [124].