OBVIOUSNESS - GAS BURNERS

Sabaf SpA v MFI Furniture Centres and Meneghetti SpA (High Court, 31 July 2001)

The claimant was the registered proprietor of expired Patent GB 2,100,440 in respect of burners for gas hobs. It brought an action against the second defendant for infringement of its patent and sought damages and an account of profits. The claimant's burner pre-mixed gas together with "primary" air drawn from above the hob unit in order to "promote complete mixing and distribution of the gas and the primary air". Pre-mixing was improved by increasing the pressure of the mixture by slowing its speed, the so-called Venturi effect, in a funnel-shaped radial mixing passage located under the flame spreader of the burner. The claimant maintained that the method of drawing in primary air and the means of production of the Venturi effect were inventive steps. It thus argued that since the second defendant's burners also draw in primary air and used a funnel shaped radial mixing passage to achieve a Venturi effect, it had infringed its patent. The latter pointed to a number of features which it argued avoided infringement, and also contended that the claimant's patent was invalid for obviousness. It said that the method of drawing in primary air taken together with the method of produce the Venturi effect comprised a collocation of two known or obvious integers. It now said that such a collocation could not constitute an inventive step.

The court ruled that the second defendant's burner had infringed the claimant's patent. The differences pointed to by it were not insufficient to avoid infringement of the claimant's patent. The methods of drawing in primary air and creating the Venturi effect were sufficiently similar for the second defendant's burner to fall within the scope of the claim and infringe the claimant's patent.

The court also ruled, however, that the claimant's patent was invalid for obviousness. The evidence showed that the patent was a mere collocation of two existing pieces of prior art. If there was no inventive step in the use of one device and no inventive step in the use of a second device, and in the absence of the interaction of their features, there could be no inventive step by the use of the two devices together: "The law of patents was set on a public policy foundation that a skilled man in the art could not be stopped by a subsequent patent from using one or more known or obvious devices".

"Intellectual Property Newsletter" 2001