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Opportunity for inspection enough for anticipatory prior use – Federal Court of Appeal

On December 20, 2012 the Federal Court of Appeal, clarified what constitutes anticipatory prior use under the “new” Parent Act in  Wenzel Downhole Tools and National-Oilwell Canada Ltd et al.  The appeal came from a Judgment of Justice Snider that had dismissed Wenzel’s Infringement action finding that Claims 1 and 2 of Canadian Patent No 2,026,630 were invalid for lack of novelty and obviousness.  While the Court of Appeal dismissed the appeal on the basis that the relevant claims were obvious, the Court was divided on whether the 630 Patent was anticipated.


The 630 Patent is generally directed to a sealed bearing assembly used in the drilling of oil and gas well..At  trial, Justice Snider made the following factual findings:

  • Wenzel had rented a drilling motor bearing assembly  (the 3103 assembly) containing all of the essential elements of Claims 1 and 2 of the 630 Patent  and that assembly was used at an oil rig in Dilley, Texas more than one year before the filing date of the 630 Patent;
  • The 3103 assembly was encased in a steel tube that would have prevented the disclosure of the inner workings of bearing assembly;
  • The rented assembly was available for more that visual inspection and could have been dismantled; and
  • The 3103 assembly was intact when it was returned to Wenzel indicating the no physical inspection of the inner workings occurred in Dilley, Texas.

Anticipation by prior use

One of the main issues on the appeal was whether the rental and use of the 3103 bearing assembly in Texas  constituted made the subject matter of the invention available to the public.  Justice Gauthier, with whom Justice Nadon concurred, following the analogy of a book in a public library from Baker Petrolite concluded that the relevant test was whether there was an opportunity to access the relevant information:

[70] Again, I reiterate that it is my understanding of the law as it stands now that even if the library listed in a ledger all those who entered the library and recorded each book they reviewed, and a defendant would accordingly be able to prove that nobody had actually accessed the book in the library, my conclusion would be the same. The presence of the book in the library is sufficient to  make the information available, and thus to meet the requirements for anticipation within the meaning of section 28.2.

[77] The fact that such appropriate tool(s) may not have been usually available at the drilling site per se or that opening of the joints is not usually done at a drilling site is irrelevant. There is no evidence that Ensco was prohibited from bringing appropriate tool(s) to the drilling site or from bringing one of the drilling motors to the machine shop.

On the facts before them, Justices Gauthier and Nadon concluded  =that the Judge made no palpable and overriding error in  concluding to anticipation based on the rental of the drilling motors in Texas.

Justice Mainville, also following Baker Petrolite, held that prior use alone may not be sufficient for establishing anticipation:

[132] Prior use may still result in anticipation under subsection 28(1) of the Patent Act despite the legislative change of 1989. However, the legislative change means that prior use alone is now insufficient for establishing anticipation. Rather, anticipation by prior use requires positive proof that a disclosure occurred as a result of the use, and that this disclosure was such that the subject matter of the invention became available to the public: Baker Petrolite at para. 32.

Following the UK cases of Merrell Dow and Lux as well as recent decisions of the European Patent Office, Justice Mainville held that prior use that does not disclose information to the public is not anticipatory:

[150] The principles for finding anticipation by prior use are notably set out in Baker Petrolite, Merrell Dow, Lux and Fisons v. Packard, discussed above. Drawing from these principles, in order to succeed in their anticipation by prior use challenge in this case, the respondents had to adduce evidence establishing on a balance of probabilities that, under an objective determination, a person skilled in the art could have been in a position to understand and analyze the invention so as to allow that person to work the invention without undue burden.

Finding that the Defendants had not me the burden of showing an enabling s disclosure or that a skilled person would have been capable of accessing and analyzing the inner workings of the bearing without undue burden, Justice Mainville concluded that the trial judge erred in finding the 630 Patent anticipated.


Court of Appeal held that obviousness framework set out by the Supreme Court of Canada in Sanofi-Synthelabo was not a mandatory test to be rigidly applied in every situation:

[105] Finally, one must recall that the Supreme Court of Canada in Sanofi clearly indicated that there is no single or mandatory approach in the obviousness inquiry. Indeed, accepting that the  “obvious to try” approach might be useful depending on the circumstances was part of a move away from rigid rules that had limited the obviousness inquiry, towards a more flexible, expansive, and  fact driven inquiry (Sanofi at paragraphs 61-63). The Court only wanted to bring more structure, clarity, and objectivity to the analysis (Sanofi at paragraph 67).

Notwithstanding a lack of reasons judge justifying the “obvious to try” analysis from Sanofi-Synthelabo, the Court of Appeal held that Justice Snider was satisfied that the invention was  very plain or self-evident irrespective of her analytical approach and that claims 1 and 2 of the 630 Patent were obvious.

A copy of the Court of Appeal’s Reasons for Judgment may be found here.

A search of the Supreme Court of Canada’s dockets suggests that no application for leave to appeal the Federal Court of Appeal’s Judgment has been filed.