Agne Augustinaite

June 2026

Background

The Claimant, Agathon, was the proprietor of a European patent relating to a mechanical system designed to improve alignment in industrial machinery. Particularly, the invention concerns the repeated opening and closing of heavy metal components where precise alignment is critical to prevent defects and reduce wear. To address this problem, the patent disclosed a guiding and cantering mechanism designed to ensure that the two halves of a machine align accurately each time they close. A key feature of the invention was the use of two sets of rollers or “rolling bodies”, which reduce friction and provide even distribution of forces during operation.

Agathon alleged that the defendants, Intercom and Knarr, infringed the patent. In response, the defendants filed a counterclaim for revocation, arguing that the patent lacked novelty and inventive step. While the court ultimately revoked the patent for lack of novelty, the central dispute between the parties focused on how a specific claim feature should be interpreted.

The Disputed Claim Feature

The key issue concerned the interpretation of the claim language “in the opened state … a rolling body abuts an edge.”

In simple terms, the claim requires that when the machine is in its “opened state,” a roller must be in contact with (i.e., “abut”) a corresponding edge of another component. The disagreement between the parties centred on two aspects of this feature:

1. What constitutes the “opened state” of the machine, and
2. Whether the requirement that the rolling body “abuts” the edge should be interpreted strictly.

The Proprietor argued for a broader interpretation. It argued that the “opened state” should encompass not only a fully open configuration, but also the transitional phase when the machine begins to close. Under this interpretation, it would not be necessary for the roller to be in direct contact with the edge at all times and slight positional variation during movement would still fall within the scope of the claim.

In contrast, the defendants argued for a narrower interpretation. They argued that the claim language clearly required actual physical contact, i.e. “abutting”, between the rolling body and the edge when the machine is in the opened state. Any broader interpretation would contradict the meaning of the claim. To support their interpretation, the defendants relied not only on the patent description and drawings, but also on statements made by the Proprietor during prosecution before the EPO. In particular, during the examination proceedings, the Proprietor stated that it was essential for the rolling body to abut the edge. This statement was made in response to objections raised by the EPO and was followed by the issuance of an intention to grant communication. The defendants argued that this constituted a clear representation of the invention’s scope, and that Agathon should not be permitted to depart from that position during litigation by pursuing a broader interpretation.

UPC Decision

The Milan Local Division agreed with the defendants’ narrower interpretation of the claim. The court emphasized that while statements made during prosecution are not formally binding on the Patentee, they may nonetheless play a significant role in claim interpretation. In particular, such statements can provide insight into how the skilled person would understand the claim language. The court also highlighted the importance of legal certainty. It stated that statements made by the applicant or proprietor must be taken into account, even if they are not binding.

Conclusion

Agathon v. Intercom and Knarr highlights that although prosecution history does not have the same formal estoppel effect as in some other jurisdictions, it can still play an important role in claim interpretation. The decision demonstrates that Patentees cannot freely depart from positions taken during examination, especially where such statements were essential for getting the patent granted.

For patent applicants the takeaway is clear – statements made before the EPO may later shape the scope of protection before the UPC, even in the absence of a formal doctrine of prosecution history estoppel.