14 December 2010

That’s a Wrap! Kimberly-Clark Patent Valid, but Not Infringed

Kimberly-Clark Australia Pty Limited v Multigate Medical Products Pty Limited [2010] FCA 1318

Construction – meaning of ‘sheet’ – Infringement – whether claims require ‘inner wrap sheet’ and ‘outer wrap sheet’ to be initially unconnected – Validity – whether priority claim valid – novelty – whether claims fairly based on specification – Rectification of Register – whether Register of Patents should be ‘corrected’ due to non-compliance of claims with unity requirement


Kimberly Clark Worldwide Inc is the proprietor, and Kimberly-Clark Australia Pty Ltd the exclusive licensee (collectively ‘Kimberly-Clark’), of three Australian patents (nos. 695238, 715940 and  758905), all entitled ‘Single Step Sterilization Wrap System’.  The three patents are related as divisional ‘grandparent’, ‘parent’ and ‘child’, respectively.

As the court (Justice Stone) describes it (at [3]):

The patents are for a single step sterilisation wrap system.  Sterilisation wrap systems are designed to facilitate the sterilisation and storage of instruments, generally surgical instruments, and other supplies, by wrapping them before the sterilisation procedure.  After sterilisation the sterile wrap remains in place protecting the items and allowing them to be stored without contamination until required for use. Sterile wraps are designed to allow the permeation of the sterilising agent but not contaminating agents.
Kimberly-Clark alleged that Multigate Medical Products Pty Limited (‘Multigate’) was proposing to market and sell an infringing sterile wrap product in Australia.

In the usual manner, Multigate denied infringement, and asserted various grounds of invalidity of the Kimberly-Clark patents, the most interesting being that the Register of Patents should be rectified to remove the ‘child’ patent, the ground that it claims more than one invention, contrary to section 40(4) of the Patents Act 1990.

The court found the patents valid, on all counts, but not infringed by the Multigate product.  A win and a loss for each party, and much money spent on legal fees for no change in the status quo!


The patents claim various methods and systems all characterised by the use of a sterilisation wrap comprising ‘an inner wrap sheet’ and ‘an outer wrap sheet’.

In the embodiments described in the Kimberly-Clark specifications, the inner and outer wrap sheets are initially separate items that are bonded together at multiple sites in a manner that leaves them visually distinguishable from one another.

Multigate denied infringement primarily on the basis that its product comprises a single sheet which is folded over to give two layers, and that this is not the same as the claimed ‘inner wrap sheet’ and ‘outer wrap sheet’.

The court agreed with Multigate (at [46]):

It may be that the “piece” is used for covering or wrapping as the applicant contends but, in so far as the word “sheet” is used to describe the article which is used for wrapping, in my view it describes a separate object. This meaning is supported when the use of the word is considered in the context of each of the claims.
As a result, none of the claims was infringed.


Multigate’s validity attacks – and their rejection by the court – are largely unremarkable.

One point of interest, however, is that the objections to the priority claim and lack of fair basis were run primarily as a defence against a finding of infringement.  In essence, Multigate’s argument was that if Kimberly-Clark was successful in arguing that the references to ‘inner’ and ‘outer’ wrap sheets encompass the single folded sheet of the Multigate product, then the claims would not be entitled to claim priority via the grandparent, and would not be fairly based on the description, because the originally-filed specification does not support this broad construction.

The court quite rightly opted for consistency, requiring the same construction for infringement and validity purposes.  Therefore, Multigate’s submissions in these grounds could not be accepted, insofar as they assumed a claim construction that the court had already rejected in relation to infringement (see [70]-[71] and [79]).


Subsection 40(4) of the Patents Act 1990 requires that ‘the claim or claims [of a patent specification] must relate to one invention only’ (the ‘unity of invention’ requirement).  The test for unity under Australian law is similar to that under the Patent Cooperation Treaty (PCT), and indeed in most jurisdictions with the exception of the USA.  Specifically, the claims must all share a ‘common inventive concept’.

However, it has always been widely understood that if the Patent Office does happen to grant a patent with claims that lack unity, this is not a basis upon which the patent is rendered invalid or unenforceable.  Subsection 138(3) sets out an exhaustive list of grounds of revocation of a granted patent, which includes failure to comply with subsections 40(2) or (3) (relating to matters such as clarity, sufficiency and fair basis), but not subsection 40(4).

Multigate alleged that the ‘child’ patent claims five distinct inventions.  However – presumably knowing that section 138 does not authorise revocation on the ground of lack of unity – adopted an alternative line of attack.  In particular, it attempted to use the provisions of section 192 to obtain an order that the Register be rectified so as to (at [104]):
  1. [remove] the grant of the Child from the Register insofar as the grant relates to more than one invention; and
  2. [endorse] on the Register that the Child is contrary to s 40(4) of the Act, and that accordingly the Child with the claims to the multiple invention claimed is void.
The Commissioner of Patents exercised her right to be ‘heard’ through written submissions, which the court found persuasive, to the effect that the Register is not the source of substantive patent rights, but rather is a public record of rights that may exist as a result of the operation of other part of the Patents Act.  As such, amendments to the Register can only be made in response to changes in the substantive rights, or for the purpose of correcting errors and the like.  Section 192 is not intended as a mechanism to effectively revoke a patent, where no ground of revocation exists under section 138.  (See paragraph [113].)


In our view, the most interesting aspect of this decision is Multigate’s bid for rectification of the Register of Patents.

In this respect, it is pleasing to see that the Commissioner and the court were both unprepared to allow section 192 to be used as a de facto revocation provision in cases where no ground exists under section 138.  This is clearly the correct outcome, and wholly consistent with historical practice.


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