Meter-Tech Llc & Anor v British Gas Trading Ltd (Rev 1)

Patent claims must be construed purposively from the claims, description and drawings, without importing limitations based only on particular embodiments or alleged commercial objectives. A pre-payment meter may satisfy the relevant claim even where its pre-payment functionality is installed but not activated. For experimental use under section 60(5)(b) of the Patents Act 1977, the defendant must establish both that the acts were for experimental purposes and that those purposes had a real and direct relationship with the claimed subject matter. Obviousness remains the statutory question under section 3. The use of a meter-specific identifier in a remotely credited pre-payment system was obvious where such identifiers were common general knowledge and readily available.

Meter-Tech, the exclusive licensee, and Vanclare, the proprietor, sued British Gas Trading Limited for infringement of a patent concerning remotely credited pre-payment utility meters. British Gas counterclaimed for revocation. The dispute concerned construction, infringement of claims 1, 5 and 11, experimental use, added matter and a conditional amendment introducing an embedded identifier.

The court held that the installed and proposed British Gas systems would infringe if the claims were valid. The central issue was whether the claims were invalid for obviousness, particularly because the systems used a meter-specific identifier to direct remote credit to the correct meter.

1. Disposition. The Part 20 claim for revocation succeeded. Claims 1, 5 and 11 were invalid for lack of inventive step. The infringement claim was therefore dismissed. The proposed amendment was refused because it would not produce a valid patent, although the amended wording was sufficiently clear.
2. Construction. A meter with installed hardware and software enabling pre-payment operation was a pre-payment meter even if the facility was not activated. A system claim was satisfied where the system included at least one such meter. A remote communication unit could comprise multiple modules and need not be co-located or under a single control. A database could use intermediate mappings rather than a direct identifier-to-transceiver mapping.
3. The phrase “location identifier unique to the location” required an identifier specifically associated with the meter and sufficiently unique to enable credit to be directed to that meter. It did not require national uniqueness or independence from the supplier. A customer account number and MPxN did not satisfy that construction.
4. Experimental use. The defence under section 60(5)(b) of the Patents Act 1977 required the defendant to prove experimental purposes and a real and direct relationship with the subject matter of the claims. The court identified relevant factors, including whether the acts involved technical research, whether they tested a technical hypothesis or operation in different conditions, whether they mainly demonstrated suitability to customers or regulators, whether they generated revenue, and whether the extent of the acts was reasonably necessary. The Dual Prepay trial was genuinely experimental but was primarily a customer trial of a ready-made third-party system and lacked the required direct relationship with the claimed invention.
5. Validity. The use of a meter-specific identifier, including a meter serial number or equivalent, was technically obvious in the context of remotely crediting a particular meter. Claims 1, 5 and 11 were obvious over the cited prior art combined with common general knowledge. The court declined to base the decision on common general knowledge alone because that case had not been properly pleaded. The patent was not invalid for added matter.