Sideloading patent claims… the Hammar comes down! A brief insight into patent claim construction in New Zealand
Article | May 30, 2023
Sideloading patent claims… the Hammar comes down! A brief insight into patent claim construction in New Zealand
Sideloading patent claims… the Hammar comes down! A brief insight into patent claim construction in New Zealand
- Like with all patent systems around the world, patent claims define the monopoly conferred by a granted patent in its specific jurisdiction. The scope of a patent’s claim(s) defines the closed ‘fence’ that barricades the valuable technological real-estate that its owner wants people to stay away from.
- The scope of the real-estate barricaded by the ‘fence’ is determined (or interpreted) by very structured principles that evolve in accordance with a jurisdiction’s jurisprudence, and which, necessarily, drives how patent claims are drafted.
- Patent claim construction principles are generally similar across New Zealand and Australia, but some differences do potentially exist. It does seem that New Zealand patent construction principles appear more willing to attribute meaning to claim terms by ‘reference to the object and description in the body of the description’, as compared in Australia. This provides comfort that well drafted detailed descriptions in patent documents can save the day if controversies arise as to the intended meaning of the language used in patent claims.
As was with me, it’s highly likely that you’ve never really had to consider too deeply about the daily life of a shipping container. Prior to needing to learn more about them, I knew that they were a freighting tool used to accommodate articles that were needed to be moved from destination A, to destination B. And that they were often carried by ships and stacked very high atop one another.
While a rudimentary understanding of sideloaders stood me well for many years, a cause developed requiring a need to know more about how they journey from A to B. What I hadn’t really appreciated was the pickup and drop off aspects of the journey, and how these were initially done.
Sidelifting… and their stabiliser legs… the back story
So, shipping containers are usually stored in a private compound in an empty state until needed. When a need arises, they are picked up and transported to a place where they are placed on the ground and loaded. The mode of transportation for this initial convey to the loading destination is by way of what are referred to as sidelifters or sideloaders – we’ll refer to them as sidelifters.
Once loaded, the shipping container is then picked up and transported to its next stop in its route to the ultimate delivery destination. Pickup following loading is usually by another sidelifter – which then transports the container to another transportation mode, such as a freight ship or train. A similar process is involved for unloading of the container.
This all seems straight forward. But how does the shipping container actually move between the ground and the carrying platform of the sidelifter? These movements are performed by crane mechanisms that are carried by the sidelifter vehicle.
Significant growth in the use of shipping containers has been experienced from about the 1970s, and has led to a dramatic growth and demand for sidelifters. This demand has been particularly noticeable in countries or cities with less developed rail systems, where sidelifters have significantly enabled road transportation of shipping containers. As noted above, sidelifters require the ability to load, and unload, to ground level (and also onto other vehicles). There is also a need to unload in confined areas.
To provide stability, the carrying platform of the sidelifter has two or more extending stabiliser legs used to stabilise the sidelifter vehicle. In use, these legs deploy during lifting operations in order to ensure that the carrying platform is appropriately stabilised for the lifting operation. Operational effectiveness of sidelifters is generally driven by the design and construction of their stabiliser legs. Where a shipping container is to be transferred from the sidelifter’s carrying platform to the ground, the stabiliser legs need to be positioned a distance out from the platform in order to provide adequate stability. In other situations, the stabiliser 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.
With the growth in the use of shipping containers came an increase in their size and weight. Shipping containers used to be 20 ft long, but today are up to 40 ft in length. The loaded weight of shipping containers has increased from around 33 tonnes, to around 40 tonnes. As the weight of a sidelifter vehicle itself is usually around 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.
There is therefore motivation to improve sidelifter technology, particularly in relation to stabiliser legs.
Sidelifters need to be adaptable – due to different shipping container sizes. A sidelifter’s crane mechanisms operate to lift loads onto and off the carrying platform to which they are associated. The crane mechanisms 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 legs being attached to the crane mechanism so that the two move in tandem.
Sidelifters are often embodied as road-going vehicles and therefore must comply with road transport requirements, evokes a width limitation – generally 2.5 to 2.6m. This restriction becomes important in the design of the stabiliser legs. Efficiency requires that stabiliser legs are stowed (when not in use) across the width of the vehicle – which translates to a stowed length being limited to maximum of about 2.5m. This then limits the extended length of the stabiliser 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 a maximum height of about 4.25m.
Next time you are driving on a motorway, and see a shipping container being towed by truck, it is very likely a sidelifter. An even closer look should reveal one of two names presented on the body of either crane mechanism: Steelbro or Hammar – two leading innovators in the global sidelifter space.
Steelbro was founded in 1878 in Christchurch, as a general engineering firm, by two brothers who, it is told, aspired to produce innovative, high-quality solutions for the transport industry in New Zealand. The Steelbro story is a great example of iconic Kiwi innovation – I recommend anyone wanting to apprise themselves of a humble Kiwi innovator to look further into Steelbro’s story.
Today, now having a solid international presence, Steelbro design and construct sidelifters capable of lift capacities from 12 to 45 tonne.
Hammar emanates from Sweden and has been designing sidelifters since 1974. Hammar have also established themselves significantly across the globe and claim to be the leading supplier of sidelifter equipment.
Over the years both Hammar and Steelbro have developed new sidelifter models having increased capacity and sophistication in response to market demands.
I have not yet seen any other name on any sidelifting equipment during my motorway travels – the sidelifter market seems to be dominated by Steelbro and Hammar.
It should then be no surprise that both companies have gone one or two rounds in the patent boxing ring.
In the aged but still relevant matter that I discuss below, a Court of Appeal judgment serves to confirm New Zealand’s approach to the construction of patent claims and, in my view, provides an exemplary application of them.
The new concept and its patent…
In 1997 Hammar developed what was considered to be a breakthrough arrangement in stabiliser leg technology – this was based around the concept of a negatively inclined stabiliser leg. It was considered that by inclining the stowed leg in a negative position (as shown in the left hand image below), away from the side of its intended deployment, a gain could be made in the length of the leg without exceeding the vehicle width. Furthermore, if each end of the stowed leg was tapered or beveled, so as to fit in vertical orientation to the edges of the truck (or trailer), an additional gain in length could be made.
Once the leg was extended into its deployed position (as shown in the right-hand image above), the gain in length achieved in the stowed position could be almost doubled. By 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 also be achieved.
Prototype testing showed that a gain of 100 mm (from 2,500 mm to 2,600 mm) in the total length of the leg in its stowed position could be achieved. The beveled end also produced a gain of about 200 mm, being the extent to which the bevel protruded out from the side of the vehicle once the leg was moved to a horizontal position.
Thus, the total gain achieved when the stabiliser 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.
The inherent object of the concept was to provide vertical support close to the sidelifter vehicle, as well as “far away” support, whether such support was onto the ground or onto an adjacent elevated loading surface.
This new concept became the subject of a patent application lodged in Sweden in September 1997. A corresponding patent application was subsequently filed in New Zealand in 2000. That patent application matured to grant on 6 July 2000 as NZ 331591 (hereinafter, the Patent).
Steelbro also had a series of models of sidelifters, and from 1996 featured stabiliser legs which were stowed in a horizontal position. The change to a negatively inclined stowed position featured in a series of sidelifter models sold by Steelbro from early 2004.
The initial infringement matter…
Understandably, Hammar brought patent infringement proceedings against Steelbro in respect of one of its sidelifter models before the New Zealand High Court.
Despite challenges brought by Steelbro to the validity of the patent on a number of grounds (as any defendant is entitled to do in these types of situations), revocation of the Patent failed.
The claim of the Patent defining the new concept can be paraphrased and divided into features as follows:
C1-A a structure which is adapted to support a wheel-mounted vehicle,
C1-B the structure consisting of at least two support parts which are relatively offset in the transverse direction of the vehicle,
C1-C and of which a first part is a support sleeve supported by a pivot pin connected to the vehicle chassis,
C1-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,
C1-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,
C1-F and at least one operative position with an opposite inclination,
C1-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,
C1-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.
Steelbro denied infringement contending that the sidelifter model complained of did not take:
(i) “a bearing” component within the support sleeve;
(ii) Steelbro’s support sleeve was not supported by a pivot pin connected to the vehicle chassis, and
(iii) “a longitudinal extent” which did not correspond to the width of Steelbro’s vehicle.
The High Court were ultimately not persuaded by Steelbro’s arguments in relation to features (ii) and (iii), finding that, based on the court’s interpretation, these features were indeed taken by Steelbro’s sidelifter.
The High Court, however, held that infringement was not made out in respect of feature (i) on the basis that Steelbro’s sidelifter did not incorporate a separate bearing component in its support sleeve. This conclusion was reached based on the High Court interpretating the “a bearing” feature as requiring a separate physical bearing component to be present, and not a bearing in the functional sense.
The highlighted text in the listed claim items above denotes the features of the claim that became the central focus of the appeal matter, described below.
The Appeal… bringing the ‘Hammar’ down…
Not unexpectedly, the finding of non-infringement by the High Court was appealed by Hammar to the New Zealand Court of Appeal.
Hammar, of course, challenged the High Court’s interpretation of the “a bearing” feature”.
Steelbro cross appealed on the interpretation leading to the finding in respect of feature (ii) (the connection between pivot pin and the chassis), possibly as a strategic move realising that the High Court’s reasoning founding the finding in relation to the “bearing” feature was vulnerable to attack.
Thus, in essence, and with reference to the highlighted sections of text in claim 1 recited above, the heart of the appeal case centered on only two real issues:
- In the context of feature C1-Cof claim 1 above: whether, in the phrase support sleeve supported by a pivot pin connected to the vehicle chassis requires a direct connection between the pivot pin and the chassis, or whether the connection can be achieved via another component, which was the case in the Steelbro sidelifter, and
- In the context of feature C1-Dof claim 1 above: whether, in the phrase an extension part which is movably arranged in a bearing in the first support part, the term “a bearing” requires the presence of a specific corresponding structural component, given that no such component was present in the Steelbro sidelifter.
These issues were needed to be reconsidered in view of established principles that define how patent claims are assessed in New Zealand.
How are patent claims interpreted?
Like with all patent systems around the world, patent claims define the monopoly conferred by a granted patent in its specific jurisdiction. The scope of a patent’s claims defines the closed ‘fence’ that barricades the valuable technological real-estate that its owner wants people to stay away from.
The scope of the real-estate barricaded by this ‘fence’ is determined (or interpreted) by very structured principles that evolve in accordance with a jurisdiction’s jurisprudence, and which, necessarily, drives how patent claims are drafted.
The principles of patent claim construction in New Zealand
The principles driving the general process by which patent claims are interpreted in New Zealand are paraphrased as follows:
NZ-1: The first step is to construe the claim(s) – this is a matter of law for the Court.
NZ-2: A patent specification is to be:
- read as a whole,
- given a purposive construction, and
- interpreted through the eyes of the person skilled in the relevant art.
NZ-3: 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 description.
NZ-4: The claims define the scope of the monopoly conferred by the patent. They limit what others may do. The claims must clearly define the protected field so that others may fairly know where they cannot go.
NZ-5: The description may assist interpretation of the claims, but it cannot modify the monopoly the inventor has clearly marked out.
NZ-6: If a claim is formulated too narrowly so that imitators do not infringe, or too widely, so that it is invalid, neither deficiency may be rectified by reading in additional content from the description.
NZ-7: The description of a preferred embodiment will not confine the scope of an invention that is claimed more broadly.
It is these principles by which a patent claim is interpretated under New Zealand law.
Reference above is made to a “purposive construction” – which is a very important concept when seeking to find meaning in patent claims (generally globally). A “purposive” approach to patent claim construction requires that allowance be made for any inherent difficulties in, or unforeseen implications of, drafting, which have resulted in the literal construction not being the one the drafter has obviously intended. The underlying rationale for this approach is the provision of a fair exchange to inventors for the contribution made by their inventions.
However, while these principles exist, it is no easy feat to correctly apply them. As you will see with regard to the “a bearing” feature of claim 1 below, while seeking to follow the same principles, different results were reached by the New Zealand High Court and the Court of Appeal.
While on the subject of patent construction principles, lets look at the principles upon which patent claims in Australia are construed:
A-1: The claims define the invention which is the subject of the patent. These must be construed according to their terms upon ordinary principles. Any purely verbal or grammatical question that can be answered according to ordinary rules for the construction of written documents is to be resolved accordingly.
A-2: It is not legitimate to confine the scope of the claims by reference to limitations which may be found in the body of the specification but are not expressly or by proper inference reproduced in the claims themselves. To put it another way, it is not legitimate to narrow or expand the boundaries of monopoly as fixed by the words of a claim by adding to those words glosses drawn from other parts of the specification
A-3: Nevertheless, in approaching the task of construction, one must read the specification as a whole.
A-4: In some cases the meaning of the words used in the claims may be qualified or defined by what is said in the body of the specification.
A-5: If a claim is clear, it is not to be made obscure because obscurities can be found in particular sentences in other parts of the document. But if an expression is not clear or is ambiguous, it is permissible to resort to the body of the specification to define or clarify the meaning of words used in the claim.
A-6: A patent specification should be given a purposive construction rather than a purely literal one.
A-7: In construing the specification, the Court is not construing a written instrument operating inter partes, but a public instrument which must define a monopoly in such a way that it is not reasonably capable of being misunderstood.
A-8: The body, apart from the preamble, is there to instruct those skilled in the art concerned in the carrying out of the invention; provided it is comprehensible to, and does not mislead, a skilled reader, the language used is seldom of importance.
A-9: Nevertheless, the claims, since they define the monopoly, will be scrutinized with as much care as is used in construing other documents defining a legal right.
A-10: If it is impossible to ascertain what the invention is from a fair reading of the specification as a whole, it will be invalid. But the specification must be construed in the light of the common knowledge in the art before the priority date.
In addition to the above, three further rules have evolved from case law over the years:
A-11: There is a danger in considering the integers of a claim individually and in isolation. This could yield a literal rather than a purposive construction.
A-12: The court should avoid too technical or narrow construction of claims.
A-13: A construction according to which the invention will work is to be preferred to one according to which it may not do so.
I’ll be the first say it, that’s a lot to consider – especially in comparison with New Zealand’s list. But, Australia’s market is much larger than New Zealand’s and it makes sense that patent disputes are more likely – and it follows that this aspect of patent case law has evolved accordingly.
When we look at the New Zealand and Australian construction principles, they are largely in alignment. However, it does seem that New Zealand claim construction principles appear more willing to attribute meaning to claim terms by ‘reference to the object and description in the body of the description’ (ref principle NZ-3), as compared in Australia (ref principle A-2).
Does the pivot pin have to be “directly” connected to the chassis, or not…?
Back to Hammer and Steelbro.
Claim 1 of Hammar’s Patent requires that the support sleeve is “supported by a pivot pin connected to the vehicle chassis”.
In the Patent’s specification, the support structure is described as being “pivotally connected to the platform of the vehicle or to the chassis thereof by means of a pivot pin 6”, see Figure 1 of the Patent below.
In Steelbro’s alleged infringing sidelifter, the support sleeve was not supported by a pivot pin connected to the vehicle chassis, but rather was supported by a pivot pin that was connected to the crane base – which is moveably arranged on the vehicle chassis. Steelbro argued that this is materially different to that described in the Patent’s specification and, therefore, avoided infringement of claim 1. The High Court rejected this argument on the basis that the evidence established that sidelifters do not really have a platform or deck in the conventional sense. Instead, the High Court formed the view that, in effect, sidelifters have very minimal structure upon which shipping containers are able to rest while the crane and stabiliser legs are operational.
Hammar argued that the terms “platform” and “chassis” were used in the Patent’s specification in a general sense and are, in effect, interchangeable. The High Court accepted this view, concluding that the phrase “connection to the vehicle chassis”, as the words of claim 1 defined, did not require a “direct” connection, but that a connection to the chassis through the medium of the platform was sufficient.
On appeal, Steelbro argued that the Patent’s specification did not support any ‘interchangeability’ of the terms “platform” and “chassis” as the terms “platform” and “chassis” were identified as separate and different features. As such, Steelbro reasoned that a connection to a platform must be different, as compared to a connection to a chassis.
Hammar contended 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”, and the proper interpretation must have regard to function. This was reasoned on the basis that the function of stabiliser leg structures is to provide stability for the vehicle during the lifting operation, and therefore their deployment is essential as the vehicle itself is not weighted sufficiently to serve as an appropriate counterweight to the weight of the shipping 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 such, Hammar reasoned that the word “connected” must be interpreted functionally, as 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.
Hammar also referred to patent case law emanating from Australia in which the meaning of a patent claim term “connected to” was at issue. It was held in that case that “connected to” covered arrangements where:
- objects A and B were directly connected and fastened to each other, and where,
- objects A and B were connected by the medium of C
Hammar’s position on this point prevailed, with the Court of Appeal concluding that the “connection” be construed in a functional sense, and not in a literal sense.
As a result, Steelbro’s alleged infringing sidelifter was held to take this feature.
When is “a bearing”, not “a bearing”…
The issue concerning the interpretation of the term “a bearing” in claim 1 very simply centered around context: should use of the indefinite article drive its interpretation (as the High Court had favoured) over a functional interpretation.
Hammar contended that the description of the term “a bearing” 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”, refer feature 8 in the images below) bearing on the other component (the first support part, namely “the support sleeve”, refer feature 7 in the images below). Hammar’s expert submitted that the use of the term “bearing” conveyed that the extension part “bears” on the support sleeve during operation, as shown in Figures 5 and 6 of the Patent provided below. This is essentially a functional view of the term “bearing”.
Steelbro’s construction was that the description of the “a bearing” in claim 1 was intended as a reference to a discrete physical component which must be physically located inside the support sleeve. Steelbro’s experts considered that a separate bearing component was required at the interface between the inner telescoping component and the outer support sleeve – that would, in effect, facilitate a relative sliding of the two components.
However, no such additional bearing element was referenced or shown in the Patent’s specification or drawings.
The High Court found Hammar’s interpretation “strained”, and preferred the evidence of Steelbro’s experts – that the claim language, describing an extension part “moveably arranged in a bearing in the support sleeve … ”, could only be interpreted as referring to an additional bearing element intended to perform the function of “a bearing”, despite the Patent’s specification (and drawings) being silent as to an additional bearing element.
The Court of Appeal accepted that the claim language invited both interpretations to be found – the issue was which interpretation should be preferred in the total context of the Patent?
As a peripheral observation, it could have been that case that the claim language considered resulted from an inadvertent grammatical error during drafting, or an unfortunate consequence from translation of the original Swedish specification at the time the New Zealand application was filed. Nevertheless, the claim language, as it stands, requires interpretation by the established construction principles by the court. This clearly emphasis the close scrutiny that needs to be applied to patent specifications, by both inventors and their attorneys, during finalisation for filing.
Steelbro submitted that use of the indefinite article makes the meaning of the phrase clear – and that under New Zealand law, recourse to the body of the specification can only be had if the claims are ambiguous. The Court of Appeal rejected this argument, pointing clearly to the principle NZ-3 of New Zealand patent claim construction noted above, in which claims must always be interpreted in their overall context and by reference to the object and description in the body of the specification. But with the caveat of NZ-5 above, in that reference to the totality of the specification cannot be used to modify the scope of the monopoly defined in the claims.
The Court of Appeal accepted Hammar’s contention that, in the context of the specification ‘as a whole’, there is no teaching of a “bearing” being a discrete physical component situated in the outer support sleeve. Additionally, there is no separate physical “bearing” shown in the drawings. Hammar argued that such references would have been present in the specification and drawings had a separate physical component been intended. Instead, the specification resonates the functional concept of bearing.
Again, the Court of Appeal favoured a purposive approach to the construction of the “bearing” feature, therefore finding that Steelbro infringed claim 1 of the Patent.
All in all, the confusion arising from the confusing presence of the indefinite article in claim language describing the “bearing” feature, sensibly in my view, was resolved by having allowable recourse to the what was described in the specification and shown in the accompanying drawings.
This outcome therefore provides comfort that patent claims, at least under New Zealand principles, enables the court licence to find some consistency with what the specification teaches the skilled reader. It is unfortunate that this conclusion was not reached by the High Court, but did eventually prevail and the approach confirmed in New Zealand law.
On a practical note, this finding confirms the value of the detailed description and drawings in patent documents. While their purposes serves to educate the public on the disclosed technology for free use when the patent expires, it also provides context to the intended meaning of the claims which define the monopoly conferred to the patent owner.
Patent drafting is a complex exercise, and subject to the usual errors when preparing legal documents – especially for situation requiring translation (given that around 90% of patents in New Zealand and Australia originate from foreign jurisdictions, inadvertent errors which might result from translation can be curable rather than being judged on a literal meaning – which could invalid the patent, or allow an infringer to escape). This decision provides comfort that well drafted detailed descriptions in patent documents can save the day if controversies arise as to the intended meaning of the language used in patent claims.
With the view to extracting some learnings from the matter, I think the following points are useful when interpreting claims under New Zealand law:
- This decision provides comfort that well drafted detailed descriptions in patent documents can save the day if controversies arise as to the intended meaning of the language used in patent claims. Given that around 90% of patents in New Zealand and Australia originate from foreign jurisdictions, inadvertent errors which might result from translation can be curable rather than being judged on a literal meaning – which could invalid the patent, or allow an infringer to escape.
- The appeal finding affirms that words are not be imported into the existing language of patent claims. Steelbro’s efforts in seeking to limit the claimed requirement for a “connection” between two items to one that was “direct” was rejected. This finding lacks is consistent with the established principles of claim construction under New Zealand law, notably that ‘the claims are to be interpreted by reference to the object and description in the body of the description.’ Here, the limitation sought by Steelbro was not something that was suggested in the body of the specification.
- Comfort can surely be taken that any identified tension between the wording of a claim and the teaching in the specification can be resolved by reference to the specification ‘as a whole’. While the claim language defining the requirement for “a bearing” could have been better formulated, and which possibly resulted from translation of the original Swedish specification into English, the Court of Appeal correctly drew assistance from the body of the specification to apply the correct intended meaning to the term. Unfortunately, the High Court, it seems, may have placed too much weight on the testimony of Steelbro’s experts in trying to find meaning in the literal claim language – especially, given that no additional bearing element was referenced or shown in the Patent’s specification or drawings
- The principles of claim construction under New Zealand law are generally aligned with those in Australia. However, in New Zealand, there does seem to be more weight placed on interpreting the claims with reference to the body of the specification, specifically the object and description. This does invite difficulties when working to not modify the scope of the plain meaning of the claim language by content in the body of the specification, as in Australia. In this case, adoption of a functional interpretation of the term “bearing” resulted from a second review where a more pragmatic approach having recourse to the teachings in the specification was taken – this might not have happened so readily under Australian law, as it did in the first consideration by the High Court.