Lufthansa Technik AG v Astronics Advanced Electronic Systems & Anor

Patent claims are construed purposively, using the description and drawings to balance fair protection with reasonable certainty. A claim requiring a supply device to be provided “remotely” from a socket requires more than physical separation: the device must be kept away so that it does not present a source of danger to the passenger. Novelty requires a clear and unmistakeable disclosure of every claimed feature; a possible or ambiguous disclosure is insufficient. Obviousness is assessed by identifying the skilled person, common general knowledge, inventive concept and differences from the prior art, without hindsight. A supplier may be liable for indirect infringement where it supplies means relating to an essential element with the requisite knowledge. It may also be jointly liable where it participates in a common design under which customers assemble and use the infringing product.

These two actions concerned infringement and validity of EP (UK) 0 881 145 B1, relating to a high-voltage in-seat power supply system for aircraft cabins. The defendants challenged claims 1 to 3 and 7 for lack of novelty and inventive step over two earlier patents, Neuenschwander and Sellati. The court also had to construe the requirements of full plug insertion, remote positioning of the supply device, connected components and a central voltage source. Having upheld validity, the court considered infringement by Astronics, Safran and Panasonic, including indirect infringement and common-design liability.

1. Construction. Claim 1 required the plug pins to be inserted sufficiently far to contact the detectors at the bottom of the socket. Partial insertion was insufficient. “Remotely” meant more than “separate”; the supply device had to be kept away from the socket and arranged so that it did not present a source of danger to the passenger. The components of the claimed apparatus had to be connected when supplied. Claim 7 required a central voltage source which received the aircraft’s 115V, 400Hz supply, converted it to the relevant mains voltage, supplied the individual supply devices and could be deactivated by a control signal.
2. Insufficiency. The concept of remoteness was not conceptually uncertain. The fact that the patent left the skilled person to choose the particular design option did not make the claim insufficient under section 72(1)(c) of the Patents Act 1977.
3. Novelty. Applying the principles in Synthon BV v SmithKline Beecham plc (No 2) and General Tire and Rubber Co v Firestone Tyre and Rubber Co, neither Neuenschwander nor Sellati gave clear and unmistakeable directions for the required remoteness. Neuenschwander also did not clearly disclose full insertion or the timing feature in claim 2. Claims 1 to 3 were therefore novel over the cited prior art.
4. Inventive step. Applying the Windsurfing/Pozzoli approach, the skilled person had relevant aviation experience, the common general knowledge included a prejudice against high-voltage AC power at passenger seats, and the differences from Sellati and Neuenschwander were not technically obvious. The timing feature in claim 2 was a safety improvement and its straightforward implementation did not, without more, establish obviousness.
5. Infringement. Astronics supplied means relating to an essential element of claim 1 with the admitted knowledge required by section 60(2). Safran directly infringed by assembling the components into the claimed system. Panasonic participated in a common design with its customers to assemble the components into the system and was jointly liable for direct infringement under section 60(1)(a), applying Fish & Fish Ltd v Sea Shepherd UK. The patent was valid and infringed by all three defendants.