Criteria for national limitation in Switzerland and under the EPC

Case No. O2012_030 ¦ Decision of 17 September 2013 ¦ “Teilnichtigkeitsklage; Teilverzicht und Beschränkungsverfahren; Disclaimer”

1.  Background of the case

The main hearing in this matter took place on September 17, 2013; see the detailed report in an earlier post.

The patent-in-suit in this nullity case is EP 1 508 436. Initially, the patent was granted as EP 1 508 436 B1 by the EPO without any material objections during prosecution. The search report cited documents JP 8 311417 AWO 02/00802 AEP 1 279 695 AWO 99/48618 A and DE 200 22 503 U as belonging to the technological background (“A”) only. See the EPO file wrapper (6.2 Mb) and the European Patent Register for further details of the prosecution history.

Later-on, the patent-in-suit was subject to centralized limitation proceedings at the EPO in accordance with Art. 105a EPC and was re-published as EP 1 508 436 B3.

The only indenpendent claim 1 of EP 1 508 436 B3 reads as follows :

Self-adhesive tape for closing, sealing and adhering joints, more especially for use in house-building, and more especially joints in corners and edges, said tape having a carrier layer (1) on its upper side, an adhesive coating (2) of the carrier layer (1) on its underside and a removable covering film (3) on its underside, characterised in that at least a first fold portion (4) of the tape is folded-over in the transverse direction along a first folding edge (5) extending in the longitudinal direction of the tape, and in that at least one part of the adhesive coating (2) along a longitudinal portion of the tape is not covered with the covering film (3).

Embodiments of such a tape are illustrated inter alia as follows in the patent in suit (annotation added; click image to enlarge). The portions (4) and (6) can be folded outwards, i.e. upper and lower parts of the carrier layer (1) are not adhesively connected:

Patent in suit, Fig. 2 and 3 (annotated)

Patentee / defendant left the independent claim untouched in centralized limitation proceedings with the EPO. Rather, only dependent claim 16 and a corresponding part of the description was deleted; cf. EP 1 508 436 B1 with tracked changes. This deleted dependent claim related to embodiments wherein the adhesive coating (2) has a non-adhesive central strip.

Patentee / defendant argued that the person of routine skill in the art would understand claim 1 now such that the adhesive coating is devoid of a non-adhesive central strip, in order to distinguish the claimed invention from the prior art, namely document D3 (JP 8 311417 A) already cited in the search report. See Fig. 2 of D3 below (annotations added; click to enlarge):

D3, Fig. 2 (annotated)

In auxiliary requests, the absence of a non-adhesive central strip was even literally recited in claim 1; see below.

2.  Requests

Patentee / defendant requested maintenance of the patent as follows.

Main Request

Claim 1 of EP 1 508 436 B3, but further limited by the intended purpose for use in house building and the feature that the tape is rolled-up to form a roll of adhesive tape (click to enlarge):

Main Request

1st Auxiliary Request (AR1)

Similar to (1.), but reformulated as a use claim (click to enlarge):

1st Auxiliary Request

2nd Auxiliary Request (AR2)

Similar to MR, but with a further negative feature (let’s call it a disclaimer) clarifying that the adhesive coating (2) has no non-adhesive central strip (click to enlarge):

2nd Auxiliary Request

3rd Auxiliary Request (AR3)

Similar to AR1, but again with the disclaimer clarifying that the adhesive coating (2) has no non-adhesive central strip (click to enlarge):

3rd Auxiliary Request

3.  The decision of the FPC

Legal interest in the nullity action

The defendant had been served with a warning letter by the plaintiff. However, the warning letter was based on EP 1 508 648 B1, i.e. not the patent-in-suit here. The patentee thus put the legal interest of the defendant in dispute. The FPC clearly held that the — undisputed — competitive relationship between the parties is sufficient to establish a legal interest; see BGE 116 II 196, r. 2.

Differences between CH-PatA and EPC re limitation

This case highlights a potential pitfall in the interplay of centralised EPO limitation and yet further national limitation of the European patent in Switzerland.

In brief, this is how the FPC correlated the provisions of the PatA and the EPC:

According to the PatA, …
… a limited claim must refer to the same invention
(Art. 24(1) lit. c PatA)
Limitation and the same invention implies reduced scope (i.e. no shifted scope), essentially corresponding to the prohibition of Art. 123(3) EPC, i.e. that the patent may not be amended in such a way as to extend the protection it confers.
… define an embodiment that is included in the version of the patent application that determined the date of filing
(Art. 24(1) lit. c PatA)
Essentially corresponding to Art. 123(2) EPC, i.e. that the patent may not be amended in such a way that it contains subject‑matter which extends beyond the content of the application as filed
… define an embodiment that is included in the specification of the published patent
(Art. 24(1) lit. c PatA)
no corresponding provision in the EPC

Beyond the requirements under the EPC, limitation in Switzerland thus requires that the limited claim defines an embodiment that is included in the specification of the published patent. In particular, the FPC referred to BGE 95 II 364 (r. 4f) in this respect. This additional requirement under the PatA was decisive for AR2 and AR3, see below.

MR and AR1

Patentee argued that the person of routine skill in the art would understand the (limited) patent in a sense that the adhesive layer uninterruptedly covers the underside of the tape. The FPC was not convinced. In fact, there are even embodiments in the patent in suit that are perforated through the adhesive layer (see figures above). Thus, D3 was held to be novelty-destroying for both MR and AR1.

AR2 and AR3

As outlined above, the disclaimer in these requests pertains to an embodiment that initially was positively defined as an embodiment according to the invention. Such “disclosed” disclaimers were dealt with in G2/10 of the Enlarged Board of Appeal of the EPO. However, after EPO limitation the (formerly positively disclosed) embodiments were not part of the patent anymore. The criteria of G2/10 were thus no longer applicable here. Rather, the criteria set forth in decisions G1/03 and G2/03  of the Enlarged Board of Appeal of the EPO were to be applied. Since D3 is not “accidentially” novelty destroying but rather pertains to the very same technological field the criteria set forth in G1/03 and G2/03 were not fulfilled, either. The disclaimer in both AR2 and AR3 was thus held inadmissible.

4.  Personal remarks on “limitation of the patent”

Beyond the peculiarities of Swiss limitation requirements discussed above, yet another aspect of the present case is somewhat noteworthy (even though not decisive here): Was the patent indeed “limited by an amendment of the claims” in centralised EPO limitation proceedings, as Art. 105a(1) EPC requires?

As outlined above, independent claim 1 was not amended at all; only a dependent claim (i.e. the optional presence of an additional feature) and the corresponding part of the description was deleted. Can this result in a limitation of the scope of the patent? Generally speaking, I would say “no”. I did not conduct an in-depth literature and case law review, but evidently there is some support for this point of view, e.g.:

According to the EPO, a limitation must reduce the scope of protection of an independent claim by adding a feature. Dependent claims, description and drawings may only be amended in accordance with amendments of the independent claims.
(D. Visser, The annotated European patent convention, Nov. 2012, #1 to R. 95(2) EPC)

Eine Beschränkung setzt dabei stets voraus, dass zumindest in einen unabhängigen Anspruch eine Beschränkung aufgenommen worden ist. Nicht ausreichend ist es hingegen, dass lediglich ein abhängiger Anspruch  […] beschränkt worden ist, da damit der Schutzbereich der geänderten Ansprüche insgesamt nicht beschränkt wird.
(Fitzner · Lutz · Bodewig, Patentrechtskommentar, 2012, #17 to Art. 105 EPC)

This being said, I was quite surprised to see what the EPO Guidelines for Examination (D-X 4.3) say:

More particularly, the limitation of a dependent claim only, without any independent claim being limited, is acceptable.

Thus, limitation in the present case was apparently in conformance with the Guidelines. But, again: Can this be a limitation?

Giving this a second thought, there may well be situations where deletion of a dependent claim reduces the scope of the patent. Assume a patent with the following claims:

  1. Screw, made from steel.
  2. Screw according to claim 1, made from stainless steel.
  3. Screw according to claim 1, made from iron only.
  4. Screw according to claim 1, without any thread.

The description contains the following paragraphs:

[0001] As understood herein, the term “steel” also encompasses the raw materials used in the manufacture of steel, such as e.g. iron.

[0002] As understood herein, the term “screw” encompasses also nails (considered herein as screws without threads).

Evidently, claims 3 and 4 and the corresponding definitions given in para. [0001] and [0002] are contrary to the common understanding of a person of skill in the art of the terms “steel” and “screw”. And, of course, an application like this should not pass examination without an objection under Art. 84 EPC; see EPO Guidelines for Examination (F-IV 4.2). But once the patent is granted as such, definitions stand as they are. That means that — by unconventional definition — the scope of the claim is broader than the mere wording of claim 1 would suggest at first sight. If such an unconventional definition is deleted later on in limitation proceedings (in the claims and the description), it is again the common understanding of the person of skill in the art that counts (thus, steel is not iron anymore, and a nail is no longer a screw). I can only think of situations like these where deletion of a dependent claim reduces the scope of the patent. But in a perfect world, such claim sets should not be granted but rather be objected under Art. 84 EPC. Assuming that the Guidelines are not referring to cases that should not even have passed to grant if the examiner had acted in accordance with the Guidelines during prosecution, I am puzzled about the rationale behind this instruction to the examiners. In my perception this is plain wrong.

Reported by Martin WILMING


Case No. O2012_030 ¦ Decision of 17 September 2013 ¦ “Teilnichtigkeitsklage; Teilverzicht und Beschränkungsverfahren; Disclaimer”

Targo Specialty Products AG ./. Silu Verwaltung AG


  • Nullity

Composition of the Board of the FPC:

  • Dr. iur. Dieter BRÄNDLE (President)
  • Dr. Tobias BREMI (Reporting judge)
  • Dr. Christoph WILLI (Judge)
  • André WERNER (Judge)
  • Dr. Markus A. MÜLLER (Judge)
  • Lic. iur. Jakob ZELLWEGER (First Court Secretary)

Representative(s) of Plaintiff:

Representative(s) of Defendant:

  • Dr. Thierry CALAME (Lenz & Stähelin)
  • Marco ZARDI (Zardi), assisting in patent matters
  • Udo ALTENBURG (Bardehle, of counsel), assisting in patent matters

Full text of the decision right here:

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3 Replies to “Criteria for national limitation in Switzerland and under the EPC”

  1. The defendant lodged an appeal against the decision of the FPC. It will be interesting to learn how the Supreme Court construes Art. 24(1) lit. c PatA nowadays.

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