Is switching between systems the same as disabling one system and enabling the other?
On 22 March 2024, the Court of Appeal issued a judgment on the decision from the trial judge to revoke JCB’s EP(UK) Patent 2 263 965 for a safety control system for a telehandler. The safety control system relates to a method of preventing the movement of the telehandler arm when it is has sensed that the telehandler vehicle is about to tip over. This is achieved with the use of a longitudinal load moment control system (LLMC) which engages based on a sensed pivot on the rear axle of the vehicle. Such systems were known in the art at the priority date. The key feature of the invention is that the LLMC is disabled when the vehicle is traveling, thus preventing the LLMC from obstructing the driving of the vehicle.
In the decision from the trial judge, it was held that EP ‘965 was invalid in view of Japanese patent application No. 2000-329073 (Aichi). Aichi discloses a cherry picker that comprises two systems to prevent the vehicle from tipping over. A first system, referred to as a moment limitation device (MLD), prevents the vehicle from tipping over when the vehicle is stationary. A second system, referred to as a work range limitation device (WRLD), prevents the vehicle from tipping over when the vehicle is moving. The difference between a cherry picker and a telehandler is that the arm of a cherry picker can rotate around a vertical axis of the vehicle whereas the arm cannot rotate in a telehandler.
The key question of this appeal was whether either the MLD or the WRLD are LLMCs and, based on this, does Aichi disclose disablement of an LLMC within the claim when the vehicle moves? Depending on whether the MLD, the WRLD, or both systems are considered LLMCs would decide whether the switching from the MLD to the WRLD in Aichi discloses the disabling of the claimed LLMC in EP ‘965. Neither the MLD nor the WRLD sense the tipping point of the vehicle based on a measuring of a pivot on the rear axle of the vehicle.
Reviewing the evidence, the Court of Appeal held that the meaning of the term LLMC does not necessitate a limitation that it must use a load sensor on the rear axle. The Court states that “as a matter of common general knowledge LLMCs routinely used strain gauges on the rear axle but sometimes use other methods instead” and furthermore that “there is a safety limit or threshold of some kind. It has been predetermined in order to set in advance a limit beyond which the risk of instability associated with the longitudinal load moment is too high.”. Accordingly, it was held that both the MLD and the WRLD of Aichi fulfil the requirements of the LLMC and as such both the MLD and the WRLD of Aichi are LLMCs within claim 1 of EP ‘965.
The Court of Appeal reviewing the evidence of the Aichi control system also held that switching from the MLD (the first LLMC that prevents the vehicle from tipping over when the vehicle is stationary) to the WRLD (the second LLMC that prevents the vehicle from tipping over when the vehicle is moving) did not constitute disabling the MLD. In other words, Aichi does not disclose disabling an LLMC when the vehicle starts to move. Consequently, the Court of Appeal reversed the trial judge’s finding that the Patent was invalid.
This case teaches that in a very specific scenario, switching between systems is not the same as disabling one system and enabling another. However, this judgment could have gone the other way if Aichi had explicitly stated one additional word, namely, “disabling”.
This judgment is unlikely to have a large impact on the general approach to inventive step (be that during patent prosecution of a patent application or during validity and infringement proceedings of a granted patent). This is because the judgement relates to the interpretation of a specific system (load bearing when a vehicle begins to move) within a niche technical area (construction vehicles). It is unlikely that a blanket argument stating that “switching systems” does not equate to “disabling one system and enabling another system” would hold in all engineering systems.
One example where this would not apply is a switchboard comprising two lighting systems. In that scenario, switching between a first lighting system to a second lighting system could implicitly mean the same as ‘disabling’ the first lighting system, because the current is diverted (by the switchboard) from the first lighting system to the second lighting system. Thus, in that arrangement a switch occurs between a first system and a second system, disabling the first system.
