When does a technically modified product infringe a patent?, although it does not literally implement all patent features? The Düsseldorf local chamber of the Unified Patent Court dealt with this question (EPG) in their decision of 22. October 2026 in the CUP procedures&CINO versus ALPINA Coffee Systems (UPC_CFI_52/2025 und UPC_CFI_67/2025). The court expressly applied the four-stage equivalence test of the local chamber in The Hague and denied both literal and equivalent patent infringement in the specific case. The decision shows, how important a technically precise claim interpretation and a comprehensible justification are when enforcing European patents. <Cite refs={[“turn605697search0″,”turn605697search1”]}/>

The dispute over a patented milk frothing system

The subject of the proceedings was the European patent EP 3 610 762, this is a device for processing a liquid, especially milk, with an integrated flushing system and a corresponding flushing process.

The patent holder CUP&CINO Kaffeesystem-Vertrieb GmbH & Co. KG asserted, that the milk frother “ALPINA Latte Perfetto Duo” from ALPINA Coffee Systems GmbH violates its patent. The focus was on the design of certain check valves.

The patent claim required immediately closing check valves. The attacked device, on the other hand, used spring-loaded valves. This raised the question, whether the different technical design fulfilled the claimed features literally or at least fell within the scope of protection of the patent as an equivalent solution.

The Düsseldorf local chamber rejected both variants. The nullity counterclaim against the patent was also unsuccessful, so that the property right was valid in the proceedings. <Cite refs={[“turn605697search0″,”turn605697search1”]}/>

The four-stage equivalence test

The local chamber expressly adopted the criteria for assessing an equivalent patent infringement, which the local chamber in The Hague had developed. She viewed these as a coherent examination framework, which is suitable for assessing equivalence.

A modified embodiment can then be considered equivalent, if four questions are answered in the affirmative:

1. technical equality: The modified embodiment essentially solves the same problem and thereby performs essentially the same function as the claimed feature?
2. Adequate scope of protection: Is it justified given the technical contribution of the invention to the state of the art, to extend the scope of protection to the modified version?
3. Legal certainty for third parties: The person skilled in the art can recognize this from the patent, that the scope of protection should extend beyond the literal claim?
4. Novelty and inventive step: Is the challenged embodiment new and inventive compared to the prior art??

The questions must be considered in context. The mere statement, that two technical solutions achieve a similar overall result, is not enough. In particular, it must be explained in a comprehensible manner, what function the replaced feature fulfills and why the specific modification essentially also fulfills this function. <Cite refs={[“turn605697search0″,”turn605697search6”]}/>

Why the equivalence failed in this specific case

The attacked device used spring-loaded valves. However, the patent description highlighted certain disadvantages of spring-loaded solutions and interpreted the claimed design accordingly.

The local chamber came to this conclusion, that the valves used did not literally implement the relevant features of the patent claim. In the court's opinion, there was no equivalent violation.

Among other things, it was crucial, that the patent holder did not sufficiently explain, how the different valve design fulfilled the same technical function. In addition, according to the court's assessment, the expert could not draw any conclusions from the patent specification, that the protection area should also include the spring-loaded solution used.

This makes the decision clear, that the equivalence test cannot be reduced solely to an abstract similarity of the technical solutions. The content of the patent specification, The specific function of the exchanged feature and the legitimate interests of third parties must also be taken into account. <Cite refs={[“turn605697search0″,”turn605697search1”]}/>

Importance for the process strategy before the EPG

The decision is particularly relevant for patent holders, who want to enforce their intellectual property rights against technically modified products. A successful infringement claim should make a clear distinction in the statement of claim between the literal and equivalent realization of the claim features.

It is recommended if there is an alleged violation of equivalence, must be presented separately for each feature exchanged:

• which technical function the feature fulfills according to the patent,
• how the attacked execution implements this function,
• which is why the modification should have the same technical effect,
• why extending the scope of protection to this variant is appropriate and
• which is why the claimed scope remains compatible with the necessary legal certainty for third parties.

A blanket statement, the attacked version is functionally comparable, cannot replace this test. Rather, the technical argument should be coordinated with the interpretation of the patent claim and the description.

Plan requests for assistance and combinations of claims early on

In addition to the equivalence test, the Düsseldorf procedures illustrate the importance of forward-looking procedural planning. In another parallel procedure (UPC_CFI_47/2025 und UPC_CFI_68/2025) The board did not allow infringement applications in the form of auxiliary applications that had only been introduced in the interim proceedings. She also required a specific description of the combinations of claims, which should be maintained as part of the defense of the patent.

This means for patent holders: Anyone who would like to alternatively defend a patent with limited claims, should identify the possible combinations of claims at an early stage and tailor the injury argument accordingly. Changes to the claim wording may have an impact, whether and to what extent an attacked embodiment still falls within the scope of protection.

Consistent argumentation is also important for the defendant. The technical design, who is represented to defend against the accusation of infringement, should be coordinated with the objections to the legal validity of the patent. Conflicting interpretations can weaken the persuasiveness of your own presentation.

What companies and patent holders should consider now

Companies should take the decision as an opportunity, review existing patent portfolios and ongoing disputes for possible equivalence issues. At the same time, this must be taken into account when developing alternative technical solutions, that a deviation from the wording of a patent claim does not automatically lead to it leaving the scope of protection.

Patent holders, in turn, should investigate before initiating proceedings, whether the alleged infringement can be justified in a technically sound manner. This includes a precise analysis of the attacked embodiment, a careful interpretation of the relevant patent features and a clear presentation of the respective combinations of claims.

The decision of the local chamber in Düsseldorf from 22. October 2026 underlines the importance of a structured equivalence test in European patent law. A technically modified version is not covered by a patent for this reason alone, because it achieves a similar overall result. Rather, the relevant criteria of technical equality must be met, the appropriate scope of protection, the legal certainty of third parties as well as novelty and inventive step must be taken into account.

This follows for patent holders and litigants, that allegations of infringement should be technically precisely justified and coordinated at an early stage with the strategy for defending the patent portfolio. Careful preparation can make a decisive contribution to this, to realistically assess the chances of success of proceedings before the Unified Patent Court.

This post was created using artificial intelligence. The contents serve to provide general information and do not replace individual legal advice.