Wheatley v Drillsafe Ltd. (2001)
Wheatley v Drillsafe Ltd.
Wheatley (W), the proprietor and licensee of a European patent relating to a threaded hole cutting device, appealed against a decision holding that the patent was invalid on the ground of common general knowledge and accordingly should be revoked, and also that, in any event, there had been no infringement of the patent by Drillsafe (D) and others.
D maintained, inter alia, that its use of a semi-penetrating retractable probe within a cutting device in order to prevent the cutter from wandering did not infringe the patent on the ground that it was a permissible variant of the invention.
W contended that the judge had erred in his conclusion that the patent was invalid, and furthermore, he had failed to construe the words of the claim correctly and in accordance with the Protocol on Interpretation of the European Patent Convention 1973 Art.69 , as required under the Patents Act 1977 s.125(3).
1. Whether the patent of W was invalid?
2. Whether there was any infringement of W’s patent by D?
The appeal was allowed on the issue of invalidity of the patent. However, it was dismissed on the issue of infringement. It was observed that the judge had failed to adopt the correct approach when determining that the cutting tool was part of the common general knowledge. No distinction had been made between what was known and what formed part of the general knowledge. The judge in making his findings had erred by examining the question of inventive step from a position of hindsight. No evidence existed in support of his conclusion that a combined tap and cutter formed part of the general knowledge.
The three questions set out in Improver Corp v Remington Consumer Products Ltd. were of assistance to the court in construing and reaching the appropriate purposive and contextual interpretation of a claim pursuant to s.125 of the 1977 Act and the Protocol on the