16 August 2010

Claims Under Construction in New Zealand

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

Claim construction – principles of construction – whether "a bearing" requires a specific structural component or is used to define a functional relationship – whether "connected" implies "directly connected".


This recent decision of the New Zealand Court of Appeal provides a useful summary of the current law relating to claim construction, along with two simple examples of its application.


Hammar Maskin AB ("Hammar") is the proprietor of New Zealand patent no. 331591, which relates to stabiliser legs on sidelifters. Stabiliser legs are extendable to the side of trucks or trailers fitted with hydraulic cranes to provide stability when loading and unloading shipping containers.

Steelbro New Zealand Limited ("Steelbro") is a New Zealand based competitor of Hammar.

Hammar brought proceedings against Steelbro in the High Court of New Zealand alleging that Steelbro infringed its patent. Steelbro denied infringement on the basis that a number of features in the Hammar claims were not present in the accused sidelifter models. In essence, Hammar and Steelbro advanced alternative constructions for three contested features. Although the High Court found in favour of Hammar on two of the three features, it found for Steelbro on the third, such that there was no infringement.

Hammar appealed this latter finding, while Steelbro cross-appealed in relation to the High Court’s finding on one of the other two features.


The Court of Appeal was required to decide on two claim construction issues:
  1. 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 is present in the Steelbro sidelifter; and
  2. whether 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, as in the Steelbro sidelifter.
Steelbro also sought to raise a new ground of inutility against the Hammar patent. The Court refused to allow introduction of a new ground on appeal, but also expressed a view that it considered Steelbro was unlikely to succeed in any event.


The Court of Appeal set out the principles of construction of patents, as established by the New Zealand Supreme Court in Peterson Portable Sawing Systems v Lucas [2006] NZSC 20. These may be summarised as follows:
  1. claim construction is a matter of law for the Court; patent specifications are to be read as a whole, given a purposive construction, and interpreted through the eyes of the addressee skilled in the relevant art;
  2. each part of the specification is to be read objectively in its overall context, and in light of the function of that part, and the claims are to be interpreted by reference to the object and description in the body of the description;
  3. the claims define the patent monopoly, and limit what others may do, so they must clearly define the protected filed so that others may fairly know where they cannot go;
  4. the description may assist interpretation of the claims, but cannot modify the monopoly the inventor has clearly marked out;
  5. 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; and
  6. the description of a preferred embodiment will not confine the scope of an invention that is claimed more broadly.
Additionally, the primary judge had referred to the decisions of the House of Lords in Catnic Components Ltd v Hill and Smith Ltd [1982] RPC 183 and Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2005] RPC 169, [2004] UKHL 46. The first of these emphasises the purposive construction approach, warning against “the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge”. The second emphasises the primacy of the words chosen by the patentee to define the scope of the monopoly while acknowledging that there will be occasions on which it will be obvious to the skilled person that the patentee must have departed from a conventional use of language. It appears that the Court of Appeal approved of the guidance in these UK authorities.


"A bearing"

The presence of the indefinite article ("a bearing", as opposed to simply "bearing") could certainly be read as implying a reference to a separate component.  Steelbro's experts in the High Court certainly thought so.

The Court of Appeal conceded (at [47]) that the word "bearing", taken alone, was capable of describing both a separate physical bearing component and also the functional state of bearing, and noted that "[t]he issue is which meaning should be preferred in the total context of this patent."

Hammar's principal argument in favour of a functional interpretation was the complete absence in the specification and drawings of any embodiment comprising a separate bearing component.

Steelbro submitted that "under New Zealand law, recourse can be made to the body of the specification only if the claims are ambiguous", presumbly on the basis that even if the term "a bearing" is inconsistent with the description, it is nonetheless unambiguous.  The Court of Appeal rejected this submission, noting that "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" (at [48]).

The court also rejected a submission by Steelbro implicitly suggesting that the fact that the case involved an infringement claim would somehow affect the rules of construction, stating that "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" (at [49]).

While various other arguments were advanced on both sides, the final nail in Steelbro's coffin appears to have been the court's acceptance that "even with the use of the indefinite article the meaning contended for by Hammar is tenable" if "what is being said is that the extension part is in a bearing relationship in the support sleeve" (at [50]).  The court rejected Steelbro's submission that this interpretation renders the term "in a bearing" otiose, because "to remove those words would remove the reference to one of the functionalities" (at [51]).

The court therefore concluded 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" (at [56]).


The question of whether "connected" requires a direct attachment, or encompasses indirect connection required less extensive submission and consideration.  Steelbro relied upon the specification describing the support structure as being "connected to the platform of the vehicle or to the chassis thereof by means of a pivot pin 6" (at [68], emphasis added).  The Steelbro sidelifters employed a different arrangement in which a pivot pin was connected to a crane base which was moveably arranged on the vehicle chassis.

Hammar, for its part, submitted that "connected" should be interpreted functionally, and that the claim was not limited to directly-connected arrangements.  Counsel for Hammar referred (at [74]) to the Australian case of Rescare Ltd v Anaesthetic Supplies Pty Ltd [1992] FCA 537, in which the construction of the term "connected to" was similarly at issue.  In that case, the court found that "connected to" encompassed an arrangement in which objects A and B are directly connected and fastened to each other, and also an arrangement in which A and B are connected by the medium of C.

The Court of Appeal agreed, holding that it did "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" (at [75]).


With regard to the term "a bearing", it appears to us that this is a case of unfortunate drafting.  While it does not seem to have been an error as such (the phrase "arranged in a bearing in the first support part" does not make sense if the indefinite article "a" is simply dropped) the claim could certainly have been drafted to avoid possible ambiguity.  It is hardly plausible that the draftsperson intended to draft a claim that did not actually encompass any of the disclosed embodiments of the invention.

With regard to "connected", the result seems unsurprising.  Steelbro was asking the court to read into the claim a limitation (ie the word "directly") which is not present, and which is not even clearly derivable from the description.  We are inclined to conclude that Steelbro felt that it should cross-appeal on at least one of the two points it lost in the High Court as a form of "insurance" against success by Hammar in its appeal.

Finally, we note that while the principles of construction in New Zealand are broadly similar to those applying in Australia, there may be some subtle differences. 

Firstly, it appears that greater deference may be given in New Zealand to the conventions of patent drafting, in that each part of a specification is read "in light of the function of that part".  This seems to suggest that the skilled addressee has at least some notion of the conventions of patent drafting, although perhaps not to the extent of the UK addressee described in Virgin Atlantic Airways Limited v Premium Aircraft Interiors UK Limited [2009] EWCA Civ 1062 (in which the skilled person was held to understand the import of an application being a divisional, and to be familiar with the rules and conventions of claim drafting, at [7]-[21]).

Secondly, there may be a greater emphasis in New Zealand on interpreting the claims with reference to the object and description in the body of the specification.  There is, however, often a tension between giving the words of the claims their "plain meaning" without impermissibly modifying their scope by reference to the description, and ensuring that the claims are construed appropriately in the context of the specification as a whole.  It is therefore possible that the balance between these principles varies more from case-to-case than it does between Australian and New Zealand law.

20 AUGUST 2010

In a decision issued on 11 June 2010 (Steelbro New Zealand Limited v Hammar Maskin AB [2010] NZSC 65) the Supreme Court of New Zealand refused Steelbro leave to appeal from the decision of the Court of Appeal.


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