In a decision concerning a stroller wheel locking mechanism, the Düsseldorf Local Division provided one of the UPC’s most detailed discussions of patent infringement by equivalence to date. The Court expressly endorsed the four-part test previously developed by the Hague Local Division and clarified important aspects of the assessment of technical equivalence.
The patent proprietor argued that several claim features were implemented by equivalent means because the accused products essentially reversed the arrangement of key components. The Court rejected the argument and held that infringement by equivalence had not been established. In doing so, it emphasised that a patentee must analyse the function of each substituted feature individually and that equivalence will generally not be obvious to the skilled person where the alleged equivalent requires a complete redesign of the claimed device.
The Court noted that the Court of Appeal has not yet established a definitive UPC-wide test for equivalence. It therefore turned to the approach previously developed by the Hague Local Division in Plant-e v. Arkyne and Washtower v. BEGA.
According to that approach, four questions must be answered in the affirmative:
The Düsseldorf Local Division expressly endorsed these criteria, holding that they form a coherent framework for assessing infringement by equivalence and that there was no reason in the present case to apply a different standard.
The Court's most important substantive statement concerns the assessment of technical equivalence.
The claimant argued at a relatively high level of abstraction that the accused design merely reversed the arrangement of various components while achieving the same overall objective of locking and unlocking the stroller wheel assembly.
The Court rejected this approach. It held that it is not sufficient to focus solely on the overall objective of the invention. Instead, the patentee must explain the role played by each substituted feature in achieving that objective and demonstrate why the replacement feature performs substantially the same function.
This is a significant clarification. The decision suggests that equivalence cannot be established merely by showing that the accused embodiment ultimately achieves the same result. The analysis must be tied to the specific claimed features that have been replaced.
The Court also addressed the second element of the Hague test, in particular whether it would be obvious to the skilled person how to apply the alleged equivalent.
The claimant's equivalence case was based on relocating and reversing several essential structural elements of the claimed locking mechanism. According to the Court, this was not a simple substitution of one known element for another. Rather, it involved a fundamental reorganisation of the claimed design.
Against that background, the Court stated that, as a general rule, it will not be obvious to the skilled person how to apply an equivalent element where doing so requires a complete redesign of the claimed device. Such a redesign points away from equivalence rather than towards it.
This part of the decision may prove particularly influential in future UPC equivalence cases. It indicates that structural complexity and the extent of the modifications needed to reach the accused embodiment remain highly relevant considerations when assessing whether an allegedly equivalent solution would be apparent to the skilled person.
The Court also found that the requirement of reasonable legal certainty for third parties was not met. Applying the approach developed in Plant-e v. Arkyne, the relevant question was whether the skilled person would understand from the patent that the teaching of the invention extends beyond the literal wording of the claims and leaves room for equivalent implementations.
The claimant argued that the invention was directed generally to providing a secure connection between the rotatable and non-rotatable elements of a stroller wheel assembly and that the patent did not prescribe any particular arrangement of the relevant components. In its view, the patent contained no indication that protection should be limited to the specific embodiments illustrated in the patent specification.
The Court disagreed. It held that a skilled person would not regard the extensive modifications relied upon by the claimant as falling within the scope of protection. In particular, the Court emphasised that the claims define a specific arrangement of the various components and that, according to the patent itself, it is precisely this arrangement that achieves the desired secure connection between the rotatable and non-rotatable elements. The skilled person would therefore not understand the patent as extending to substantially altered configurations in which the arrangement of those components is fundamentally changed.
As a result, the Court concluded that extending protection to the accused embodiment would not provide reasonable legal certainty for third parties.
The Court therefore rejected infringement by equivalence.
Although the defendants had also raised a Formstein defence, the Court did not analyse that issue in any depth because the equivalence claim already failed under the preceding requirements.
