Patents

Case Note Buchanan v Alba Diagnostics Limited

Jane Lambert

24 June 1999 , Updated 14 Apr 2004

This article formerly appeared on the Old Colony House website

To English eyes this was an extraordinary case. The pre-proof hearing (equivalent to an application for directions) in an action for infringement of a mechanical patent required 3 separate sessions in June, August and October 1997. The proof (equivalent to the trial) of the issues of title to the patent in suit and infringement stretched over 19 days with sittings in February, June, July and October 1998 and March 1999. When judgment was delivered on the 24 June 1999 the action was decided on the construction of an assignation (assignment) of a patent. Everything that the judge said on the issue of infringement was therefore superfluous and his lordship addressed it only because so much time had been devoted to that issue. Had D failed on the issues that were before the court there might have been further hearings on validity. Further expense was incurred in unsuccessful appeals appeals to the Inner House and House of Lords.

The Facts

D was the assignee of a patent for a device for indicating the boiling point of brake fluids. It had lent money to a company controlled by the inventor on the security of that patent. The assets charged included "all improvements" to the patent as well as the patent itself. The assignor had agreed that the patent would become the assignee's property absolutely should it be wound up. P, the inventor, refined his invention and applied for a patent for a new device (the patent in suit). The assignee also developed a device from the invention. The assignor went into liquidation whereupon the invention and all improvements became D's property. P sued D for infringement of the patent for the refined invention. D denied infringement and counterclaimed for declaratory relief that it was beneficially entitled to P’s patent on the ground that it was an "improvement" within the meaning of the deed or, alternatively, revocation. Title to the patent in suit and infringement were determined as preliminary issues.

The Decision
Lord Hamilton decided both issues in D's favour. In addressing whether the patent in suit was an improvement his lordship considered first what had been changed and what had been retained disregarding any common elements derived from the prior art. Although the patent in suit constituted an important advance it was not so radical as to make it quite distinct from P's original invention. Next, the judge analysed the charge and concluded that the patent in suit would have been within the contemplation of the parties when they entered that deed. On the question of infringement, Lord Hamilton referred not just to the well-known English authorities, Catnic Components Ltd. v Hill & Smith Ltd. [1982] RPC 237 and Improver Corporation v Remington Consumer Products Ltd. [1990] FSR 181 but also to Lord Sutherland's decision in Conoco Speciality Products Inc. v Mepro Montassa Ltd. 1992 SLT 444. He dismissed P's submission that the onus was on D to disprove infringement once a material difference had been alleged. His lordship found that P had failed to prove that D's device operated in the way described in the specification which excused his considering the second and third Improver questions.

The Appeals

The Inner House came to the same conclusion as the trial judge as indeed did the House of Lords.