In its decision in Wonderland v Cybex (UPC_CFI_807/2024 and UPC_CFI_334/2025, Local Division Düsseldorf, 27 May 2026), the Düsseldorf panel addressed — in detail — the assessment of patent infringement by equivalent means under Art. 69 EPC and the Protocol.
The decision is of broad interest because it confirms a methodological approach to equivalence and illustrates the evidential burden on a claimant seeking to rely on equivalence.
Key findings on equivalence
Adoption of The Hague’s four-step framework
The panel noted that the Court of Appeal had not yet ruled on the criteria for assessing equivalence at the UPC.
The Düsseldorf Local Division expressly adopted the four questions previously formulated by the Local Division The Hague (Plant-e v Arkyne; Washtower v BEGA). These questions are as follows, and if all four questions are answered affirmatively, equivalence is present:
- Technical equivalence: Does the variation solve (essentially) the same problem that the patented invention solves and performs (essentially) the same function in this context?
- Is extending the protection of the claim to the equivalent proportionate to a fair protection for the patentee? This needs to be assessed in view of the patentee’s contribution to the art and taking into account the question whether it is obvious to the skilled person from the patent publication how to apply the equivalent element (at the time of infringement).
- Reasonable legal certainty for third parties: Does the skilled person understand from the patent that the scope of the invention is broader than what is claimed literally?
- Is the allegedly infringing product novel and inventive over the prior art?
Step (1): Technical equivalence: claimant must explain the function of each substituted feature
On step (1), the panel answered the technical equivalence question in the negative. The reasoning is notable as it insists on a structured analysis: although a claim must be considered as a whole, equivalence requires determining “the function of each substituted feature” in relation to the claim, in order to compare the technical functions of the claimed means and the substitute means.
The claimant’s submissions were held insufficient because they were too general and focused on the overall objective of the claim (a stable connection and swivel lock functionality) without explaining why the claim specifies particular locations/arrangements of key components and how those locations contribute to the teaching of the patent.
Step (2): Fair protection and obviousness: “reversing” the arrangement was not obvious
For step (2), Düsseldorf Local Division likewise answered in the negative, holding that it was not obvious for the skilled person to apply the alleged equivalents from the patent publication at the time of infringement. Given the patent’s specific arrangement requirements, arriving at the challenged design would require rearranging several components, amounting to a “fundamental redesign”, which the panel considered not obvious.
Steps (3) and (4)
On step (3), the panel also found against equivalence, reasoning that a skilled person would not understand that “significant modifications in almost all parts” would be covered where the claim’s specific arrangement is presented as the means by which the secured connection is achieved. Because the analysis failed at the earlier steps, the panel considered it unnecessary to address step (4).
Conclusion
Düsseldorf’s decision confirms that, pending Court of Appeal guidance, first-instance panels may converge on The Hague’s four-step framework. Practically, it underlines that equivalence arguments must be pleaded and evidenced feature-by-feature: it is not enough to assert that overall the same technical purpose is achieved when the claim defines a specific arrangement of key components and the challenged design substantially differs from it.
