Please welcome with me: The mind willing to understand, not desirous of misunderstanding

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Case No. O2020_001 | Decision of 9 June 2021

BD logo

As mentioned earlier on this Blog here and here, Becton, Dickinson and Company had sued Ypsomed AG for infringement of EP 2 825 227 B1; see EPO Register and Swissreg for further bibliographic information.

The attacked embodiment is Ypsomed’s UnoPen™:

Ypsomed logo

The FPC’s judgment has meanwhile been published. Cutting a long story short: The FPC had to take a decision only on the unallowability of various amendments of EP 227, and dismissed BD’s complaint on this basis alone.

However, the most interesting aspect of the decision is claim construction. Accordingly, this is also mentioned in the FPC’s tweet:

Claim construction in good faith

With reference to an old Supreme Court decision, 107 II 366 (¶ 2), the jugdment holds that claims are to be construed in good faith; ¶ 24. This is what had been held in 107 II 366:

More recent judgments of the Supreme Court (in German language) did not explicitly refer to the good faith approch anymore, but rather only recited the sentence pertaining to the consequences of wrong, incomplete or contradictory definitions — which are to be borne by the patentee. However, this is apparently merely a shortened citation rather than a change of practice of the Supreme Court; a recent judgment in French language still refers to the good faith approach:

Now, what does ‘good faith’ mean when it comes to claim construction?

[drum roll]

You guessed it, didn’t you? Indeed, it’s the ‘mind willing to understand, not desirous of misunderstanding’ approach of T 190/99 to which the FPC now explicitly refers in ¶ 24 (fn 9):

T 190/99 is one of the most cited EPO decisions of all times. Sooner or later in any complex case at the EPO, the catchy headnote is cited by at least one party. Mostly, by the more desparate one.

The most interesting feature in terms of claim construction is feature 1.4.2:

According to the wording of the claim (emphasis added), the pen is configured such as

[…] to substantially prevent said driver (21) from rotating with respect to said dose set knob (2), […]

The parties fundamentally disagreed how this is to be understood. The defendant held that the claim wording is clear by and in itself; no claim construction even needed. On the other hand, the plaintiff argued that this should be understood as

[…] to substantially prevent said driver (21) from rotating with respect to said dose set knob (2), […]

in light of the specification — which is pretty much the opposite of the wording.

First, the judgment holds that feature 1.4.2 in isolation is indeed perfectly clear. However, the claim as a whole throws doubt on the linguistic interpretation of feature 1.4.2. In light of feature 1.4.3, this would mean that not only during an injection position, but also already during dose setting and dose correction a medicament would be ejected. This can’t be it; the claim as a whole would not amount to a credible technical teaching in such a reading.

Accordingly, in light of the specification, the skilled person would indeed understand feature 1.4.2 according to plaintiff’s interpretation, i.e. contrary to the mere linguistic interpretation.

Defendant further argued that one might well assume how a device with a literally interpreted feature 1.4.2 might work, e.g. with an additional (de)coupling arrangement. The FPC did not buy into that. In essence, this would mean to assume an additional feature to compensate for exactly the effect which is literally recited in the claim — which is counter-intuitive.

Finally, the judgment clarifies that this claim construction does not amount to a reduction of the scope of a claim to the disclosed embodiment(s). Rather, the claim as a whole does not provide a credible technical teaching (‘glaubhafte technische Lehre’) at all, and thus calls for proper construction in light of the specification. The proper construction of feature 1.4.2 is not narrower or broader than the literal interpretation; it is simply different.

Unallowable amendments

Allowability of amendments is always very case-specific and rarely of broader interest. This case is not an exception to the rule. However, I stumbled upon one of the various amendments that were held unallowable, i.e. the following feature (emphasis added; ¶ 49 et seq.):

[D]uring dose setting and dose correcting, stopping surfaces of said external teeth of said driver engage stopping surfaces of teeth of ratchet member to substantially prevent said driver from rotating with respect to said dose set knob.

The issue was whether there was disclosure in the application as filed for said engagement not only during dose setting, but also during dose correcting. Plaintiff argued that the feature would only mean, when properly construed in light of the specification, that during both dose setting and dose correcting the relative positions of the teeth of the driver and the teeth of the ratchet member are maintained.

The judgment holds that this is not the right approach: Allowability of amendments is all about clear and unambiguous disclosure in the application as filed, not about whether the skilled person could correctly construe or understand the feature.

On a quick read, this might be confusing. Claim construction surely matters; it has to go hand in hand with the check for proper disclosure in the application as filed; cf. e.g. Case Law of the Boards of Appeal, II.E.1.3.9. Else, the test for allowability of amendments would effectively only amount to a check for verbatim disclosure in the application as filed.

With respect to the specific feature recited above, the judgment holds that engagement of the stopping surfaces (if that may occur at all) in the correcting direction just cannot be such ‘as to substantially prevent said driver from rotating with respect to said dose set knob’:

Dies können die Stoppflächen bei einer Drehung in der entgegengesetzten Richtung als der bei der Dosiseinstellung auf keinen Fall; […]

The issue here was actually a classic non-disclosed feature: the engagement of the stopping surfaces as disclosed could not have the claimed effect; other configurations (which were not disclosed) could well have that effect, e.g. with rectangular teeth. Unlike the claim construction issue above where the claim as a whole did not make technically sense when taken literally. Accordingly, the amendment was unallowable. And, with a mind willing to understand, the judgment does not deny that claim construction matters when checking for allowability of amendments.


The judgment is a good reminder that expenses for assisting patent attorneys have to be substantiated. Expenses of more than kEUR 30 for involvement of a patent attorney on two days is not credible from the outset.

BD’s appeal has been dismissed by the Supreme Court with decision 4A_500/2021 of 31 January 2022 (published 9 March 2022).

Reported by Martin WILMING


Case No. O2020_001 | Decision of 9 June 2021

Becton, Dickinson and Company
Ypsomed AG

Panel of Judges:

    • Dr. Mark SCHWEIZER
    • Christoph MÜLLER
    • Dr. Lorenzo PARRINI


    • Christoph MÜLLER

Court Clerk:

    • Susanne ANDERHALDEN

Representative(s) of Plaintiff:

    • Dr. Simon HOLZER (MLL)
    • Louisa GALBRAITH (MLL)
    • Dr. Ulrike CIESLA (MLL), assisting in patent matters

Representative(s) of Defendant:

    • Dr. Christian HILTI (Rentsch)
    • Dr. Demian STAUBER (Rentsch)
    • Dr. Alfred KÖPF (Rentsch), assisting in patent matters
    • Dr. Axel REMDE (Rentsch), assisting in patent matters
    • Markus FRANTZ (SSM), assisting in patent matters




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