HPM Industries Pty Ltd v Gerard Industries Ltd

HPM Industries Pty Ltd (HPM) sued Gerard Industries Ltd (Gerard) for infringement of its letters patent for improvements relating to switch cover plates. Gerard denied infringement and counterclaimed for revocation of the patent, arguing the invention lacked novelty and an inventive step, having regard to prior knowledge and use in Australia.

The court was required to determine whether Gerard's switch cover plates infringed HPM's patent, and if so, whether HPM's patent was valid. Specifically, the court had to consider whether the invention, as claimed, was obvious and lacked an inventive step in light of what was known or used in Australia before the patent's priority date of 10 October 1952, and whether it was novel.

The court found that Gerard's cover plates did infringe both claims of HPM's specification, applying the principle that a mechanical equivalent can substitute for a described integer in a combination claim. However, the court held that the invention claimed by HPM was obvious and did not involve an inventive step under section 100(e) of the Patents Act 1952-1954. This conclusion was reached by considering all information disclosed by prior use of switch cover plates, even if not part of common general knowledge, and determining that every integer of HPM's claim, except possibly the dimensional requirement, had been disclosed prior to the priority date. The court noted that section 100(e) widened the law by requiring consideration of all that was "known or used" in Australia, not just common general knowledge.

Consequently, HPM's suit for infringement was dismissed, and Gerard's counterclaim for revocation of the letters patent was successful.