Day v Perrott

The appellant, Alfred Carlyle Day, sought a patent for improvements in toys and construction elements. The respondent, James Perrott, opposed the grant of the patent, alleging disconformity between the provisional and complete specifications, and that the invention claimed in the complete specification had been the subject of an earlier application by the respondent. The Commissioner of Patents upheld the opposition. The matter proceeded to the High Court of Australia on appeal.

The central legal issue before the High Court was whether there was disconformity between the appellant's provisional and complete specifications, as contemplated by section 56(d) of the Patents Act 1903-1921. This required the court to determine if the complete specification claimed an invention that was not fairly described in the provisional specification.

A majority of the High Court, comprising Knox C.J., Isaacs, Gavan Duffy, and Rich JJ., held that disconformity existed. They reasoned that the provisional specification described an invention focused on eliminating bolts and nuts by using shaped elements with specific niches and a pronged key to lock them together. The complete specification, however, introduced a separate locking means that was independent of these shaped ends and niches, effectively claiming an invention beyond what was foreshadowed in the provisional specification. Starke J. dissented, finding that the modification in the complete specification was merely a substitution of obvious and equivalent means for achieving the same object of locking elements, and thus fell within the ambit of the provisional disclosure.

The appeal was dismissed with costs, upholding the Commissioner's decision that the patent should not be granted due to the disconformity between the specifications.