Blue Gentian Llc & Anor v Tristar Products (UK) Ltd & Anor

Patent claims must be construed objectively by reference to the characteristics of the claimed product. The assessment must remain realistic and fair; an abnormal example may still fall within the ordinary meaning of the claim, but something no skilled person would recognise as the claimed product does not.

Novelty requires a strict disclosure of the claimed combination. An invention is not anticipated by a document which merely suggests individual features or from which the combination is not inevitable. Obviousness must be assessed without hindsight, using the structured approach in Pozzoli v BDMO and considering the prior art through the eyes of the relevant skilled person.

The claimants marketed an expandable garden hose protected by UK Patent 2 490 276. They alleged infringement by the defendants’ competing hose. The defendants accepted infringement if claims 1 and 14 were valid, but challenged validity for lack of novelty and inventive step over two prior-art patent applications, McDonald and Ragner.

The principal issues were the construction of “garden water hose assembly”, whether either prior-art document disclosed the claimed combination of elastic inner and non-elastic outer tubes, and whether that combination was obvious to a garden water hose designer.

1. Construction. The expression “garden water hose assembly” was objective. The court focused on the characteristics of the product rather than the subjective intentions of the drafter, user or manufacturer. The construction had to be realistic and fair. A product which was too large, too small or otherwise not something a skilled person would call a garden water hose assembly would fall outside the claim. It was unnecessary to read “normally” into the claim.
2. Novelty over Ragner. Ragner disclosed a pressure-operated hose using a spring or other biasing means. It did not explicitly or implicitly disclose the required combination of an elastic inner tube coupled with a non-elastic outer tube. The combination was not inevitable. Applying the strict novelty test from General Tire v Firestone, claims 1 and 14 remained novel.
3. Obviousness over Ragner. The court applied the structured approach in Pozzoli v BDMO. The skilled person would consider the references to resilient cover material in Ragner, but the document did not link that teaching with the separate disclosure concerning freely sliding cover material. Combining those passages, and adding an inelastic outer layer to restrain radial expansion, involved the impermissible step-by-step reasoning criticised in Technograph. Claims 1 and 14 were not obvious.
4. McDonald. For novelty, McDonald had to be construed through the eyes of the aircraft-equipment manufacturer to whom it was addressed. That manufacturer could make the disclosed hose, so the document was enabling. Nevertheless, the assembly was not a garden water hose assembly: the mask was an aircraft oxygen component, the hose alone lacked the required flow restriction, and a suitable domestic fitting was neither disclosed nor inevitable.
5. For obviousness, McDonald was considered from the perspective of a garden water hose designer, who read the document with interest in accordance with Asahi v Macopharma. The designer would recognise the conceptual expansion principle but would not, without hindsight, regard the aircraft disclosure as a practical basis for a garden hose. Claims 1 and 14 were not obvious.
6. The patent was valid. Judgment was given for the claimants.