Patents in toilet fresheners

The claimant held a patent for units for cleansing and freshening toilet bowls. The units had the dual purpose of spreading a fresh odour in the toilet area, and also of introducing an active substance into a toilet, such as a disinfectant, by means of a block overhanging the toilet rim.

A reservoir in the unit held perfume that was released from a porous member via a "liquid-permeable closure". The Claimant alleged that two of the defendant's products infringed its patent. The defendant's products achieved the transfer of perfume via an impermeable shelf or plate with a three inch circular hole. The High Court had ruled against the claimant.

This decision was upheld by the Court of Appeal. It said that, though the phrase "liquid-permeable closure" was an oxymoron, it was nonetheless clear that some restriction or regulation of flow of liquid was envisaged by the patent claim. The evidence indicated that, in the defendant's products, liquid could pass from reservoir, through the hole onto the porous pad without such restriction or regulation. The impermeable shelf or plate could not be described as "liquid permeable", and the hole through which liquid was passed was not a "closure" since the liquid flowed freely. It was, the court concluded, an "impermissible use of language" to construe "liquid-permeable closure" to cover the defendant's products, and any such interpretation would go beyond the provision of fair protection to the patent holder.

"Intellectual Property Newsletter" January 2002