In-depth reporting and analytical commentary on intellectual property disputes and debates. No legal advice.

Unprecedented patent claim limitation has UPC perplexed in new judiciary’s first-ever full patent infringement trial

Context: The Unified Patent Court (UPC) started to accept complaints as of last June. Various preliminary injunction hearings have been held in different local divisions starting in the late summer, and there have been hearings in patent revocation proceedings. But prior to mid-April, no trial had been held in a main proceeding.

What’s new: On April 16, the Munich Local Division (Presiding Judge: Dr. Matthias Zigann) conducted the UPC’s first-ever full patent infringement trial in KrausMaffei Extrusion GmbH v. Troester (case number: ACT_528357/2023). The seven-hour trial was focused on claim construction and infringement, without anything very UPC-specific or non-technical defenses such as FRAND. The most intriguing aspect of the case is a claim limitation that was introduced in the parallel opposition proceeding before the EPO and will now be outcome-determinative. Even Judge Dr. Zigann, who has already decided a huge number of patent infringement cases, said he not previously seen anything like it. But validity was not discussed as the EPO will hold an appellate hearing in July, and the UPC will simply await the outcome of that one as opposed to deciding on a potential stay.

Direct impact: The outcome is difficult to predict, but the above-mentioned claim limitation raises serious issues, a fact that potentially helps the defendant.

Wider ramifications: If the unorthodox claim limitation on which the outcome of this case turns enabled the patentee to prevail, other parties would presumably propose similar claim elements during prosecution as well as at the stage of post-grant review. Apart from that, it’s also interesting to see that the UPC’s Munich Local Division is inclined to adopt the “cold stay” practice of German national courts, which simply delay decisions until after a parallel (in)validity determination has been made as opposed to ordering a formal stay of proceedings.

The patent-in-suit is EP3221117 on a “multiple extrusion head.” A typical use case for such devices is the production of running profiles for tires.

In order to salvage the patent before an opposition panel of the EPO, the patentee added a claim limitation that was modeled after paragraph 19 of the specification. The primary language in those proceedings is German. This is the German version of the unprecedented claim limitation, followed by an unofficial English translation:

“… wobei alle Fließkanaleinsätze jeweils einen Antrieb besitzen, mittels dem die Fließkanäle automatisch verschwenkbar ist, wobei jeder dieser Antriebe ausgebildet ist zum Aufbringen einer Zuhaltekraft auf den jeweiligen Fließkanaleinsatz, die größer ist als die Kraft, die vom im Fließkanal unter einem Druck von 2,5 MPa stehenden Gummi [eigentlich: Kautschuk] ausgeübt wird.”

Unofficial English translation:

“… wherein all flow channel inserts each have a drive by means of which the flow channels can be automatically pivoted, wherein each of these drives is designed to apply a locking force to the respective flow channel insert which is greater than the force exerted by the rubber under a pressure of 2.5 MPa in the flow channel.”

So what’s the unprecedented issue here?

The passage following the second “wherein” sets out a criterion for each drive: it must apply a sufficient locking force. But when is that locking force sufficient for the purposes of this claim limitation?

  • This here is neither a conventional means-plus-function approach of the binary kind (some means must perform a specified function) nor is it a straightforward quantitative criterion such as a voltage or, in a pharma patent, a dose.
  • There is a quantitative parameter: “a pressure of 2.5 MPa in the flow channel.”
  • But that one is not the answer all by itself. That one just describes the circumstances under which the rubber exerts a certain force, and each drive, as required by the patent, must be able to overcome that force (the one exerted by the rubber).
  • One thing is missing, and that makes it all so perplexing. 2.5 MPa is a pressure value, the patent talks about force, but what connects pressure and force is a third physical parameter: the area.
  • Pressure equals force divided by area; force equals pressure multiplied by area.
  • So, whether the “locking force” is greater than the force exerted by the rubber is highly dependent on the area. If the area is tiny, then the force (since area is one of the two factors) may be negligible, and even an objectively weak drive can overcome it. If the area is huge, even an objectively powerful drive may fail to do the job.

What happened in the infringement discussion is that the plaintiff’s lawyers built their infringement contentions on the assumption of a tiny relevant area. Theoretically, that’s possible. But the defendant’s lawyers urged the court to focus on the specific state in which the accused machinery is sold, and argued that it would not make technical sense (and would not even be possible) to narrow the relevant flow channels to the point where the relevant area would be as small as the plaintiff assumed in its computations.

What’s at stake here is a kind of claim limitation that is ultimately indefinite: it would lack any reasonable boundary.

Maybe that problem will be addressed by the EPO itself, at the appellate hearing in July, and the UPC won’t have to decide how to deal with this claim element.

The plaintiff is represented by Finnegan’s Dr. Dr. Jochen Herr, Dr. Moritz Meckel and Daniel Seitz, and the defendant by Wildanger’s Joerg Schmidt, Dr. Alexander Wiese (who became a partner of the firm earlier this year) and an associate, Antonio Alvaro.

The parties now have the opportunity to provide some post-trial briefing, the single most important part of which is presumably going to be a report on the outcome of the appellate proceedings in the EPO.