Pages 322-327

INFORMATION FROM THE CONTRACTING / EXTENSION STATES

DE Germany

Judgment of the Bundesgerichtshof (Federal Court of Justice), 10th Civil Senate, dated 5 May 1998

(X ZR 57/96)*

Headword: "Regenbecken" (Rainwater reservoir)

Sections 1, 3, 4, 14 PatG (Patent Law)

Article: 52, 54, 56, 69 EPC

Keyword: "Interpretation of a patent and assessment of the prior art in opposition and appeal proceedings before the EPO - expert opinion - no binding effect on national revocation proceedings - European patent No. 211 058"

Headnote:

When interpreting a European patent, as when acknowledging the known prior art, the view of the European Patent Office in a decision rejecting an opposition should be taken into account as an expert opinion. It is not however binding in respect of subsequent revocation or infringement proceedings.

Summary of facts and submissions

The defendants are the proprietors of European patent No. 211 058 (patent in suit), which was granted with effect amongst others for Germany.

Claim 1 of the patent in suit, the sole claim contested in the revocation action, reads as follows:

"Liquid storage space (1), expecially a rainwater or stormwater run-off reservoir, having at least one scavenging chamber (1b) disposed in the region of a high point of the floor of the storage space and which can be filled with storage liquid, and which whenever the storage space has run dry allows the storage liquid to be discharged as a scavenging wave via at least one scavenging opening (10), characterised in that the scavenging chamber (1b) automatically fills with storage liquid as the level of the storage liquid rises, means (12) are provided which hold back the storage liquid that has collected in the scavenging chamber (1b), and the scavenging opening (10) is obturated and opened by a locking mechanism (13) controlled by the level of the storage liquid in the storage space (1)."

The plaintiffs claimed that the subject-matter of claim 1 of the patent in suit was not patentable in view of the prior art and requested that claim 1 of the patent be revoked with effect for the territory of the Federal Republic of Germany.

The defendants requested that the revocation action be dismissed.

The Bundespatentgericht (Federal Patent Court) allowed the action.

The defendants' appeal, with which they are pursuing their request for dismissal of the action, is directed against the Bundespatentgericht's decision. The plaintiffs request that the appeal be dismissed.

From the reasons

I. The defendants' appeal is unsuccessful. The subject-matter of claim 1 of the patent in suit is not patentable.

1. (...)

2. Claim 1 contains a very general teaching. With regard to the dispute between the parties in respect of the subject-matter of claim 1 the following should be noted.

(a) (...)

(b) According to the wording of claim 1, a scavenging chamber is provided with a scavenging opening which is obturated and opened by a locking mechanism controlled by the level of the storage liquid in the storage space (...). As stated by the Federal Patent Court and confirmed by the expert appointed by the court, a person skilled in the art would gather from the wording of the claim only that the scavenging chamber, scavenging opening and locking mechanism must be formed in such a way that the storage liquid can be discharged as a "scavenging wave" whenever the storage space has run dry.

The term "scavenging wave" is not defined in the patent specification. It is simply stated that the scavenging wave is "powerful" and that "complete scavenging" is guaranteed (...). As stated by the Federal Patent Court and the court-appointed expert, the person skilled in the art (...) would understand the term "scavenging wave" to mean a draining process in which a stored volume of water is suddenly released. This would produce a wave which would whirl up and carry off the deposited pollutants.

The Senate agrees with this opinion, which is documented in the specialist literature (...).

The defendants submitted in response (...) that, in the context of the patent in suit, a scavenging wave should be understood as meaning "a sudden, optimum scavenging wave with a lateral effect achieved by abrupt opening". This was also the view of the European Patent Office's Technical Board of Appeal 3.2.3 in decision T 892/90 of 12 January 1993. The "locking mechanism" in claim 1 of the patent in suit is thus a mechanism "which opens abruptly and thus permits a sudden scavenging wave". This also was the understanding of the EPO's Technical Board of Appeal.

The interpretation of granted claim 1 in opposition proceedings and appeal proceedings following opposition before the EPO is not binding on the revocation proceedings. In the case in suit this is clear from the fact that the opposition and the appeal against the grant of the patent in suit were rejected/dismissed in full, with the result that granted claim 1 was maintained without amendment. The interpretation must thus be based solely on the granted version of claim 1 with reference to the patent description and drawings. The comments made in the grounds for the decision in the opposition proceedings and the appeal proceedings following opposition on the subject-matter of the invention are, regardless of whether they are to be understood as restrictive or broadening, important expert opinions which as such must be taken into account - no more and no less - when interpreting claim 1. Moreover, it is clear from Article 69 EPC that it is not the task of the opposition proceedings and the appeal proceedings following opposition to determine the scope of protection of a patent by interpreting the content of granted claims.

In patent revocation proceedings, the examination as to patentability of a European patent should include the entire prior art without restriction, in particular the prior art which has already been the object of examination in the proceedings for grant (see BGH GRUR 1996, 862, 864 - "Bogensegment" (Bend segment)). A European patent may be revoked (solely) on the grounds of such prior art which has already been taken into account in the proceedings for grant as well as in the subsequent opposition proceedings and the appeal proceedings following opposition before the European Patent Office (BGH GRUR Int. 1996, 56 ff -"Zahnkranzfräser" (Gear rim cutter)). The fact that in revocation proceedings the entire facts of a case must be taken into account without restriction is the necessary consequence of the function of these proceedings and their relationship to the opposition proceedings. The assessment of the prior art in the proceedings for grant, opposition proceedings and appeal proceeedings following opposition cannot legally have a binding effect on the revocation proceedings. The decisions taken in these proceedings are however expert opinions of considerable importance which must be acknowledged when assessing patentability in revocation proceedings. They have no further legal effect beyond this.

In agreement with the Federal Patent Court and the court-appointed expert the Senate is unable to follow the interpretation of granted claim 1 given by the EPO in the opposition proceedings and appeal proceedings following opposition, as this opinion is supported neither by the wording of claim 1 nor by the description of the patent. The court-appointed expert stated that (...) a scavenging wave "with a lateral effect" apparently related to the geometric shape of the floor to be scavenged. However, nothing is said about this in either claim 1 or the description. Furthermore, the skilled person would be unable to deduce such a lateral effect as being a particular characteristic of the scavenging wave according to the patent from the patent in suit because claim 1 expressly includes stormwater run-off reservoirs which have a large, mostly circular cross-section and mostly a very narrow floor.

Neither does claim 1 reveal anything to the skilled person about the constructional design of the locking mechanism. (...)

(c) The (...) term "storage liquid" also requires explanation. The patent specification does not contain a definition of this term. It is reasonable to assume that the "storage liquid" is simply the liquid which flows (from the outside) into the storage space. Linguistically speaking, "storage liquid" could also mean the liquid that is removed from the storage space.

The court-appointed expert stated that on simple examination the skilled person would understand "storage liquid" to be the liquid that flows into the storage space. This opinion is supported by the description and drawings.

The patent specification is silent on the fact that the "storage liquid" is of special importance for the teaching of the patent in suit (...). These general remarks support the opinion of the court-appointed expert that the skilled person would basically understand "storage liquid" as being the liquid that "arrives in the run-off and is directed into the storage space". (...)

II. Looked at in this way, the teaching of claim 1 is undeniably new. It would, however, have been obvious to the skilled person on the priority date of the patent in suit from the prior art and his general knowledge (...).

The idea of controlling the scavenging process in some way in relation to the level of the storage liquid by way of the locking mechanism of the scavenging chamber would have been obvious to the skilled person (...) as a result of his general knowledge and from the prior art. No inventive step can be seen to be involved. Actual means to implement this control are not mentioned in claim 1 and cannot therefore be used to substantiate its patentability (...).

DE 1/99