Inconsistency Remains The Key To Unlocking The File History. The Federal Court Of Appeal Cautions Against An Over Broad Interpretation Of Section 53.1 In Bauer Hockey Ltd. v. Sport Maska Inc.

• Published date: 26 August 2021
• Subject Matter: Intellectual Property, Litigation, Mediation & Arbitration, Real Estate and Construction, Patent, Trials & Appeals & Compensation, Construction & Planning
• Law Firm: Bereskin & Parr LLP
• Author: Mr Adam Bobker

To what extent is the extrinsic evidence found in the prosecution history of the patent relevant context for the purposive construction of a Canadian patent claim? In an obiter speech in Bauer Hockey Ltd. v. Sport Maska Inc., 2021 FCA 166 ("Bauer"), the Federal Court of Appeal has once again cautioned (as it had in Canmar Foods v. TA Foods, 2021 FCA 7) against an expansive view of Section 53.1 of the Patent Act. In his Bauer trial judgment (2020 FC 624), Justice Grammond held that the enactment of Section 53.1 of the Patent Act meant that the prosecution history is always relevant context and can be considered by the Court in all cases in which claims construction is at issue. On appeal, the Court of Appeal has repeated that Section 53.1 should only allow for consideration of the prosecution history when there is evidence of inconsistent positions being taken by the patentee - one before the patent office and another before the Court. Otherwise, the rule from Free World Trust that extrinsic evidence such as the prosecution history should not be admitted should govern.

The Bauer case involved a patent claim for a one-piece quarter for a lasted skate boot, with a "foxing portion". The "quarter" is the main component of the skate boot that wraps around the foot. It had traditionally been made in two pieces that were sewn together to form the "upper" of the skate boot. The inventive concept of the patent was held to be a quarter in one piece instead of two. The claims at issue were held to be obvious at trial, which finding was upheld on appeal. The construction of the claimed "foxing portion" of the quarter had been relevant at trial, at least in part, to the issue of whether certain prior art anticipated the claims.

In paragraphs [47]-[52] of his trial decision, Justice Grammond explained his view that Free World Trust and Whirlpool mandate that a purposive construction of patent claims should consider the text, context, and purpose of the claims while keeping in mind that the patent "bargain" requires that the interpretation of a patent claim must be fair to both the patentee and public and that patents are drafted in accordance with particular rules and conventions. The resulting goal of the purposive construction approach is to "search for a claim's essential elements", namely those elements that "cannot be substituted without affecting the working of the invention".

In paragraphs [53]-[72], Justice Grammond explained his view of the law relating to four...