DLP Limited v Coram UK Holding Limited

A patent claim is construed purposively, in context and as a whole, but ordinary words retain their ordinary meaning where no term of art is established. A claimed pump and control unit may require a single, complete and self-contained product. A removable housing cover must directly connect with and close the housing; an external wall cannot supply that closure. For obviousness, the court applies a structured inquiry using the common general knowledge and avoiding hindsight. The skilled person is not obliged to pursue a document merely because it has been read. Technical obviousness is distinct from commercial attractiveness. The alleged pumps did not infringe, and the patent was not shown to be obvious over any of the three cited disclosures.

At a liability-only trial, DLP alleged that Coram’s Premium Pump and Bluetooth Pump infringed selected claims of a patent for an electric shower-waste pump and control unit. Coram counterclaimed for invalidity for lack of novelty and obviousness over Grumbach, Gontar and Quantum, and opposed proposed amendments as added matter. The novelty attack was abandoned. The issues were the construction of the claims, infringement, obviousness and, if necessary, amendment allowability. The central questions were whether the products fell within claim 1 and whether the patent was obvious in light of each prior-art citation.

1. Construction. The court applied purposive construction in context and construed the patent as a whole, giving terms their ordinary meaning where none was a term of art. It relied on Virgin Atlantic Airways v Premium Aircraft Interiors [2010] RPC 8, Icescape Limited v Ice-World International BV & Ors [2018] EWCA Civ 2219 and Brugger v Medic-Aid [1996] RPC 635. A “unit” meant a single, complete and self-contained shower-waste pump and control unit. A removable housing cover had to connect directly with and touch the housing, although it need not latch or form a watertight seal.
2. Infringement. The backplates of the Premium Pump and Bluetooth Pump were fixed to the wall and did not provide access to the internal components as required of a removable housing cover. The Premium Cover did not touch the backplate, and the Bluetooth Pump’s clip connection was insufficient. The wall performed part of the closure and was not part of the claimed unit. Claim 1 was therefore not satisfied, and the dependent claims also failed. The court additionally observed, unnecessarily to the result, that the second chamber had to be watertight against leakage including spray.
3. Obviousness. The court applied the structured approach in Generics (UK) Limited v H Lundbeck [2007] EWHC 1040 (Pat) and Pozzoli SPA v BDMO SA [2007] EWCA Civ 588. The analysis required identification of the skilled person and common general knowledge, the inventive concept or construed claim, the differences from the prior art, and whether those differences were obvious without knowledge of the invention. The court applied the cautions in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59 and Fisher & Paykel Healthcare Limited v Flexicare Medical Limited & Anor [2020] EWHC 3282 (Pat) against hindsight. A skilled person was not obliged to pursue prior art which supplied no reason to act, applying Vernacare Limited v Environmental Pulp Products Limited [2012] EWPCC 41. Obviousness was technical, not commercial, applying Hallen Company v Brabantia (UK) Limited [1991] RPC 195.
4. Prior art and result. Grumbach was not a suitable starting point and required impermissible hindsight. Gontar disclosed only features within the common general knowledge and did not prompt the skilled person to create the claimed unit. Quantum did not make it obvious to add a further watertight chamber and then make the original enclosure non-watertight. The patent was therefore not invalid for obviousness over Grumbach, Gontar or Quantum. The proposed amendments were not necessary to decide, although the court stated that it would have allowed them. The claim and counterclaim were dismissed.

not stated in the judgment.