The construction of a patent claim is always decisive in opposition, revocation or infringement proceedings. A set of established principles - or “Rules of Claim Construction” (“Rules”) – have been established by judicial case law to assist with claim interpretation. Of course, these Rules equally apply in the Patent Office setting during the examination of applications, and when considering the allowability of amendments.

In particular, for amendments:

An amendment of a complete specification is not allowable after the relevant time1 if, as a result of the amendment:…a claim of the specification would not in substance fall within the scope of the claims of the specification before amendment (emphasis added)2

Amendments in such circumstances typically occur during re-examination proceedings of a standard or innovation patent, or during certification of an innovation patent. Since these types of amendment can be opposed by others, it is important to bear the Rules in mind when preparing such amendments.

Rules of Claim Construction in Australia

Australian case law calls for a purposive interpretation of claims rather than a strictly literal one,3 and several decisions have outlines appropriate principles.4

The Rules suggest an order in which the interpretation of a claim should be conducted:

  1. The words of a claim should be considered according to ordinary principles, i.e., their normal or plain meanings, albeit based upon a reading of the specification as a whole.
  2. If a claimed expression is unclear or ambiguous based upon ordinary principles, it is permissible to resort to the body of the specification to define or clarify the meaning.
  3. If an expression is still unclear or ambiguous, it is permissible to ascertain a meaning as would be understood by a person skilled in the art.

Some examples

The following decisions of the Federal Court and the Australian Patent Office provide guidance on the allowability of post-grant or post-acceptance amendments; i.e., whether the amended claims “in substance fall within the scope” of claims prior to amendment:

Bear Solutions:5 This recent decision by the Australian Patent Office concerned an opposition to an amendment of a certified innovation patent. The Patentee added a limitation from a dependent claim to independent claim 1, and Claim 1 was further amended to remove limitations that had provided the working inter-relationships between the recited integers. The Patentee’s written submissions suggested that the deleted working inter-relationships could be inferred by a purposive reading of the specification as a whole. The Commissioner’s Delegate found that: (i) the removed limitations were essential features of the invention, and (ii) as the plain meaning of the words of claim 1 was clear, inferring the deleted working inter-relationships from the specification would be drawing a gloss, contrary to the Rules. The amendments were found not to be allowable.

Aristocrat:6 The claims were amended to recite that a number of possible selectable paylines were greater than the “number of rows of the array”. Prior to amendment, the claims recited that the number of possible paylines was greater than “the number of rows plus a number of diagonals”. As the meaning of the term “diagonals” was unclear, and with varying definitions from each side, the Commissioner’s Delegate reviewed the specification to ascertain the meaning of this term. A meaning of “diagonal pay lines of a square array from one vertex to the opposite corner” was provided in the specification. On this basis, the amendment removing the limitation of “plus a number of diagonals” from the claims was found to broaden the scope and was not allowed.

Boehringer Ingleheim:7 The Federal Court considered a claim to a single component of a disclosed combination. The claims prior to amendment claimed the combination. The amendment was found not to be allowable.

Wimmera:8 The Federal Court contemplated amendments to claim 1 which firstly added the phrase “at a temperature of at least 900oC”. This amendment was found to relate to temperatures required to implement the process and thus not to broaden scope. Claim 1 was further amended replace the words “further leaching processes to form a residue” with “leaching with a solution of strong acid to form a residue”. Justice Sundabergread the specification as a whole in order to construct the scope of words before amendment, and found reading the phrase “further leaching processes” as “not involving two or more distinct steps” to accord with the description of the specification as a whole. The relevant step of claim 1 accordingly was considered not to be clear. The phrase “further leaching processes to form a residue” was thus qualified by a meaning provided in the specification as relating to a single step or process. The amendment to claim 1 was found not to broaden the scope of claim 1, and thus allowable.

Claim Scope May Differ in Other Jurisdictions.

The scope of a claim may vary according to differing principles of construction in other jurisdictions. In the United States, the Markman9 and Phillips10 decisions, as well as Section 2111 of the MPEP11, provide guidance on that jurisdiction’s approach to claim construction. According to our understanding, these guidelines provide – at a relatively high level – that the meaning of words or phrases in the claims should be determined as follows:

  1. The words of a claim should be considered according to the ordinary meaning the words would have to a person of ordinary skill in the art.
  2. It is permissible to resort to the specification as an aid in understanding the meaning of a word but it is improper to import claim limitations from the specification.
  3. An alternative meaning of a word clearly and deliberately defined in the specification overcomes the ordinary meaning to a person of ordinary skill in the art.
  4. Prosecution history can have a significant impact on claim construction.

A notable difference between claim construction in the US and Australia lies in the absence of a prosecution history estoppel doctrine in Australia.12

The US guidelines deal with similar issues to the Australian Rules but apply the principles of construction somewhat differently. Seemingly small differences in wording can make a world of difference to the results of claim construction – awareness of the aforementioned “Rules” is essential when preparing claim amendments for Australian purposes.