The Federal Court of Appeal affirms patent valid and infringed, covers a lot of ground in so doing
The Federal Court of Appeal in Western Oilfield Rentals Ltd. v. M-I LLC, 2021 FCA 24 recently affirmed that several claims in a patent for certain drilling technology are valid and infringed. This appeal had everything: standard of review, claim construction (including section 53.1), infringement, inducement, the Gillette defence, anticipation, obviousness, insufficiency (including best mode!), ambiguity, inutility, overbreadth, and that thing where applicants are not supposed to add new matter during prosecution but it is not entirely clear what if anything will happen to a patent if they do. The Court of Appeal did not, however, view quantity as a