Société des Usines Chimiques Rhône-Poulenc v Commissioner of Patents

Société des Usines Chimiques Rhône-Poulenc (the appellant) appealed to the High Court against the Commissioner of Patents' refusal to accept application no. 757 of 1954 and its accompanying complete specification. The dispute concerned the applicability of the Patents Act 1952-1955 to a divisional application lodged after the commencement of that Act, but originating from an application lodged under the repealed Acts, and the determination of the priority date for such an application.

The primary legal issues before the court were: (1) whether a divisional application lodged after the commencement of the Patents Act 1952-1955 was governed by that Act, despite its origin under the repealed Acts; (2) whether section 45(5) of the Patents Act 1952-1955, which deals with priority dates for divisional applications, was limited to cases where the subject matter of the later application had been specifically claimed in the earlier application; (3) whether section 45(5) was restricted to applications made before the publication of the original specification; and (4) the interpretation of the phrase "so as to" in section 45(5) regarding the purpose or consequence of an amendment.

The court held that a divisional application is a new substantive application and, if lodged after the commencement of the Patents Act 1952-1955, is governed by that Act. It was further determined that section 45(5) is not limited to situations where the subject matter of the divisional application was specifically claimed in the earlier application, nor is it restricted to applications made before the publication of the original specification. The court interpreted "so as to" in section 45(5) as referring to the consequence of an amendment, meaning it is sufficient if the amendment results in the specification applying to one invention only, regardless of the applicant's or Commissioner's intent at the time. The court also clarified that section 51 of the Act applies only to applications made under the Patents Act 1952-1955, not to applications made under the repealed Acts. The court found that the appellant's application no. 757 of 1954 fell within the scope of section 45(5), entitling it to the priority date of the original application. The court also affirmed that an applicant succeeding in an appeal against the Commissioner's refusal should generally be awarded costs, and that an examiner's report forwarded by the Commissioner to the applicant is admissible in proceedings between them.