On Monday, Justice Bennett held that Zetco's patent for hot water heater valves was valid, and infringed by Austworld Commodities.

The decision provides useful guidance on what is necessary for an anticipating disclosure.  At paragraph 93, her Honour notes that:

"A person of skill in the art examining a prior art valve may know of a component that equates to a missing integer, or the missing integer may be part of common general knowledge.  However, this does not necessarily mean that the prior art discloses that missing integer and that anticipation has occurred."

Claim 1 of the patent was for a prefabricated valve, that is, a single unit. After considering the prior art, her Honour held that a prior art valve involving parts that required manual connection would not be sufficient to anticipate the claims of the patent.