HIGH COURT OF AUSTRALIA 23 May 2007 Public Information Officer LOCKWOOD SECURITY PRODUCTS PTY LTD v DORIC PRODUCTS PTY LTD A deadlock in which a key unlocks the door from the inside as well as the outside so that people are not trapped in their homes involves an inventive step, the High Court of Australia held today. Lockwood filed its patent application in 1997 and the patent was registered in 2000. Lockwood said the new deadlock overcame the problems with existing deadlocks, which have a second key- operated lock inside which must be unlocked separately to exit the house. These were designed to prevent the removal of large items during a break-in. However if a key is left in the outside lock or misplaced without the inner lock being unlocked, occupants could be trapped inside. The patent is for a deadlock where the key would open the outside and inside locks simultaneously. In 2000 Lockwood’s lawyers accused Doric (and others) of infringing the patent. Doric commenced proceedings in the Federal Court of Australia alleging Lockwood had made unjustified threats of legal action. Lockwood cross-claimed for infringement of 19 of the 33 patent claims. Doric in turn cross-claimed seeking revocation of the patent, alleging the patented lock was not novel, that it was obvious and involved no inventive step, that the specification did not fully describe the invention, that certain claims were unclear, and that none of the claims were fairly based on the matters described in the patent specification. Justice Peter Hely rejected all Doric’s claims except lack of fair basis. He consequently found that 32 of Lockwood’s claims were invalid and ordered they be revoked and dismissed Lockwood’s cross-claim alleging infringement but granted a stay of judgment. The Full Court dismissed an appeal, upholding Justice Hely’s conclusion that claims 1 to 32 were invalid. Lockwood appealed to the High Court. In 2004, the Court unanimously allowed the appeal, declared that the patent claims were fairly based on the specification, and remitted the matter to the Full Court of the Federal Court to resolve remaining issues. In 2005, the Full Court dismissed the remainder of Lockwood’s appeal. It revoked many of the patent claims due to a lack of an inventive step with some claims also removed for lack of novelty. Lockwood again appealed to the High Court in respect of the Full Court’s reasons dealing with obviousness or lack of inventive step. The High Court unanimously allowed the second appeal. It held that the addition of a lock-release mechanism to unlock the deadlock inside a house (expressed in claim 1 as adding an extra integer to five existing integers of a deadlock) was an inventive step, as it was not obvious to a person skilled in the relevant art, namely lock design. The combination of integers was not common general knowledge, and it was also relevant that no-one had previously arrived at a solution to the known problem that inspired Lockwood’s design. The Court set aside various orders of the Full Court, including the order that certain claims of the patent be revoked for lack of inventive step. The High Court ordered that Doric be restrained from infringing particular claims of the patent and from supplying a latch assembly with the particular features of Lockwood’s deadlock. Issues still to be finalised were remitted to the Full Court.