Dunlop v Cooper

The case involved two competing patent applications lodged on the same day for improvements to earth scoops. Walter Ernest Cooper and David John McClelland (respondents) applied for a patent for "improved earth scoops," while George Henry Dunlop (appellant) applied for "improvements in method and machinery for excavating." Dunlop opposed Cooper and McClelland's application on the grounds that they obtained their invention from him and that their complete specification described an invention different from their provisional specification. Conversely, Cooper and McClelland opposed Dunlop's application, alleging he obtained his invention from them. The Commissioner of Patents dismissed Dunlop's opposition and upheld Cooper and McClelland's opposition, leading to appeals to the High Court.

The High Court was required to determine several legal issues. Firstly, whether either party had obtained their invention from the other. Secondly, and crucially, whether Cooper and McClelland's complete specification described an invention that was other than that described in their provisional specification, as alleged by Dunlop. This involved interpreting the provisional and complete specifications and considering the state of the applicants' knowledge at the time of filing the provisional application.

The majority of the High Court (Griffith C.J., O'Connor and Higgins JJ.) found that neither party had obtained their invention from the other. However, they held, with Isaacs J. dissenting, that Cooper and McClelland's complete specification did indeed describe an invention different from that set out in their provisional specification. The majority reasoned that a provisional specification must accurately reflect an invention that the applicant is in possession of at the time of application. They found that the language of Cooper and McClelland's provisional specification was not apt to describe the invention detailed in their complete specification, and that evidence indicated the latter invention had not been conceived by them at the time of filing the provisional application. This disconformity meant that Dunlop's application, which did not suffer from this objection, should have been granted.

Consequently, the High Court allowed both appeals. The patent application by Cooper and McClelland was refused, and the patent application by Dunlop was granted.