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PATENTS - Claims - Construction - Defences to infringement

Thursday, April 08, 2021 @ 6:16 AM  


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Appeal by Western Oilfield and FP Marangoni Inc. (FPM) from a Federal Court decision finding they infringed certain claims of the respondent’s 173 Patent related to shale shakers. The 173 Patent described a continuing desire for shakers having increased fluid capacity, increased fluid flow-through rates across the screens and improved fluid removal efficiencies. The appellants argued that the Federal Court erred in construing the claims, in dismissing the appellants’ arguments regarding invalidity and in finding the appellants liable for infringement. The appellants argued that FPM stopped doing business in 2014, prior to the issuance of the 173 Patent, and thus could not be liable for infringement. The appellants also argued that there was no direct evidence of Western’s customers receiving instructions and being induced to infringe.

HELD: Appeal dismissed. The Federal Court did not err in construing the patent claims. The construction of the claims was based on the evidence of the respondent’s expert which the Federal Court was entitled to accept. The Federal Court understood the expert evidence and explained why it reached the conclusion that it was entitled to reach. The Federal Court did not err in finding FPM liable for infringement. Nothing in s. 55(2) of the Patent Act suggested that a pre-issuance infringer could avoid liability by discontinuing its activities prior to issuance of the patent. There was no indication in the text that the infringing activity must continue after issuance of the patent. There was no basis for Western to avoid liability based on the timing of its instructions or based on any lack of evidence that its customers were induced by the instructions. The description of the decision of the interactions with customers was sufficient to support the conclusion that Western’s influence had been effective. The Federal Court did not err in finding the 173 Patent valid. The Federal Court made no reviewable error in distinguishing the prior art references on the basis that they were not directed to the recovery of liquid, and in finding therefore that they did not anticipate the 173 Patent. The prior art did not include reference to adjusting pressure differential to prevent stalling of slurry. The Federal Court did not fail to consider any of the evidence. The evidence was not such that it was a reviewable error not to find the 173 Patent insufficient or in refusing to find the specification of the 173 Patent insufficient for failure to comply with the best-mode requirement. The Federal Court made no error in law or misunderstood or failed to consider the evidence or the appellants’ arguments on inutility. There was no breach of procedural fairness. The appellants’ right to cross-examine was constrained by their undertaking to the Federal Court to call their experts as witnesses. This undertaking was voluntary. The Federal Court gave the appellants the option of withdrawing their undertaking instead of complying with it. Not only was it appropriate for the Federal Court to require the appellants to choose, but it was necessary to ensure a fair trial. Failing to require the appellants either to comply with their undertaking or withdraw their expert reports would have discouraged the kind of co-operation that led the parties to agree to submit expert reports to the Federal Court before trial and to alter the normal order of evidence for the sake of efficiency.

Western Oilfield Equipment Rentals Ltd. v. M-I L.L.C., [2021] F.C.J. No. 105, Federal Court of Appeal, M.J.L. Gleason, G.R. Locke and A.L. Mactavish JJ.A., February 9, 2021. Digest No. TLD-April52021006