Infringement not proven under equivalents doctrine

The court ruled that SMC Corporation did not infringe Festo Corporation’s rodless cylinder. The US Supreme Court and the Court of Appeals for the Federal Circuit had already established the law in the case – specifying when a patent owner could claim infringement under the doctrine of equivalents. Festo sued SMC in 1988 under the doctrine of equivalents, which holds that if someone makes insubstantial changes to a patented invention, the new product still infringes. SMC\'s rodless cylinder uses one two-way sealing ring while Festo\'s uses two such rings. And Festo\'s product includes magnetised material, while SMC uses a non-magnetised alloy. Judge Patti Saris found that both elements would have been foreseeable to someone of ordinary skill in the art. ‘Because Festo has not rebutted the presumption of surrender for these asserted equivalents, it has not proven patent infringement under the doctrine of equivalents,’ the Judge wrote. Full report in The Recorder