Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (No 2)

The High Court of Australia considered an appeal by Lockwood Security Products Pty Ltd ("Lockwood") against a decision of the Full Court of the Federal Court concerning the validity of Lockwood's patent for a key-operated door lock. The dispute centred on whether certain claims within the patent lacked an inventive step, rendering them invalid. Lockwood's patent included both broad and narrow claims for a key-operated latch assembly.

The primary legal issue before the High Court was whether the Full Court had erred in finding that the patent specification contained an "implicit 'corollary' admission" regarding common general knowledge, which it used to infer obviousness and a lack of inventive step. The court was required to determine the correct application of the inventive step provisions of the *Patents Act 1990* (Cth), particularly in relation to the prior art base and the meaning of "common general knowledge" and "prior art information" when assessing obviousness.

The High Court held that the Full Court had erred in inferring an "implicit 'corollary' admission" from the patent specification. It reasoned that the combination of integers in claim 13, the subject of the appeal, involved an inventive step over the prior art. While acknowledging that the Full Court correctly identified the relevant art and construed certain statutory terms, the High Court found that the inferential leap from the perceived obviousness of claim 1 to the obviousness of claim 13 was erroneous. The court also noted that while claim 1 might be considered obvious in light of prior art, this did not automatically invalidate claim 13.

Consequently, the High Court allowed Lockwood's appeal, setting aside the orders of the Full Court. It restrained Doric Products Pty Ltd from infringing specific claims of the patent and remitted the matter to the Full Court to determine Lockwood's application to amend the patent claims, as well as other outstanding issues including costs, delivery up, and potential damages or an account of profits.