T 1339/13 - Clarity and description

EPO T 1339/13

For the decision, click here

Key points

• The Opponent considers the claims to be unclear because of the phrase "the spring force increases only slowly"
• "The Board agrees with the appellant that the term "only slowly" is a relative term and that it is preferable not to use such a relative term in a claim. However, in the context of the claim at hand, this term imparts a clear teaching to a skilled reader. In addition, there is no basis in the disclosure for a more precise wording and this feature is not the only feature distinguishing the claimed invention from the prior art"
• It is interesting that lack of more precise wording in the description is a reason why the claim complies with Art. 84 EPC. 
• Also interesting analysis of whether a MSc thesis of 1985 put on the shelf of a library of a university department was publicly available. The Board accepts so, and also admits the document while only introduced in appeal (saying that it "could and should have been filed in the opposition proceedings"). 

Summary of Facts and Submissions

I. European patent No. 1 888 849 (in the following: "the patent") concerns a dredging vessel with a substantially vertical spud, typically a cutter suction dredger ("CSD").

II. The patent as a whole was opposed on the grounds of Article 100(b) and Article 100(a) EPC for lack of novelty and inventive step over an alleged prior use of a self-propelled CSD named "URSA".

III. The Opposition Division held that the prior use was not sufficiently proven and that, account being taken of the amendments made by the patent proprietor during the opposition proceedings, the patent and the invention to which it relates meet the requirements of the EPC (Article 101(3)(a) EPC).

IV. This decision has been appealed by the opponent (here the appellant).

[...]

IX. Cited evidence

In the statement setting out the grounds of appeal, the appellant referred to all documents that were filed in the opposition proceedings in support of the prior use and are cited in the decision under appeal, in particular: [...] Further, the appellant relied on evidence items D7 to D34c for the first time, whereby the following are relevant for this decision:

D8: C. Dekker, "Analyse van een spudsysteem voor een deiningsgecompenseerde snijkopzuiger", CO/85/153, Laboratorium voor de Techniek van het Grondverzet, TH Delft, 1985 [...]

Reasons for the Decision

[...] 5. Claim 1 - Article 84 EPC

5.1 The Board also considers that the amendments made in claim 1 meet the requirements of Article 84 EPC. In particular, the skilled reader would readily understand from the wording "the spring force increases only slowly while the spud carriage rotates" that the tension in the spring means can still rise, albeit only slightly, while the spud (carriage) tilts (see point 2.7 above).

5.2 The Board agrees with the appellant that the term "only slowly" is a relative term and that it is preferable not to use such a relative term in a claim. However, in the context of the claim at hand, this term imparts a clear teaching to a skilled reader. In addition, there is no basis in the disclosure for a more precise wording and this feature is not the only feature distinguishing the claimed invention from the prior art (see point 10 below).

5.3 The claim wording clearly defines a particular meaning for the term "piston accumulator": it comprises a cylinder with a free piston and an accumulator.

[...]

7. Consideration of D2 and D7 to D34c

7.2 D7 to D34c

7.2.1 Of these pieces of evidence submitted with the grounds of appeal, the appellant relied essentially on

- D8, D9, D15, D16, D23, D24 to establish the technical features of the alleged prior use and the public prior availability of D8; and

- D8, D9, D14, D17, D18, D26 and D34c to contest novelty and inventive step.

7.2.2 D14 documents the skilled person's common general knowledge at the priority date of the patent and is thus prima facie relevant for the case.

7.2.3 D17 and D26 are cited as closest prior art in paragraph 4 of the patent specification and thus are part of the proceedings (see e.g. Case Law of the Boards of Appeal of the EPO, 7th edition, September 2013, IV.C.1.5).

7.2.4 The Board sees no reason to disregard either D18 or D34c, in particular because these documents are prima facie relevant for the evaluation of inventive step when starting from D8.

7.2.5 The Board considers that D8, D9, D15 and D16, as well as the offer to hear Messrs Heidekamp, Kimmann and/or Albers as witnesses, could and should have been filed in the opposition proceedings. Indeed all this newly filed evidence was within the power/sphere of influence and knowledge of the appellant, and the Opposition Division had made it clear in its communication annexed to the summons to oral proceedings dated 13 September 2012 that it considered the prior use of the apparatus shown in A4 to A7, i.e. the technical features of the URSA, as not sufficiently proven. Thus, the Board decided not to hear the proposed witnesses nor to take any of D9, D15 and D16 into account (Article 12(4) RPBA).

D8, however, is prima facie highly relevant for the evaluation of inventive step (see point 10 below) and cannot be disregarded. Consequently, this document has been taken into consideration, despite its late-filing.

7.2.6 The rest of the newly submitted evidence is essentially related to facts which are not in dispute among the parties, e.g. that the URSA existed and was publicly accessible prior to the priority date or that, at that time, it was a standard practice to use a pressure relief valve as an overpressure safety means in hydraulic systems. For this reason, the Board decided not to consider this evidence.

9. Availability of D8 to the public 

The evidence adduced allows the following conclusions regarding the chain of events in respect of this issue:

9.1 D8 is one of three graduation papers written in Dutch by a Mr Chris Dekker, as part of a master's degree in mechanical engineering at the TH Delft (renamed TU Delft in 1986), specialising in dredging technology (see D8, pages 4 and 5 and D23, point 6), which comprises the analysis of a spud system for an undulation compensating CSD (see title).

9.2 The front page of D8 carries the number CO/85/153, where "CO" stands for "Constructieve Opdracht", i.e. "Construction Assignment", "85" refers to the year when D8 was finished, i.e. 1985, and "153" refers to the fact that D8 was the 153rd graduation paper written at the Department of Dredging Technology (Laboratorium voor de Techniek van het Grondverzet) of TH Delft (D23, point 5; library's register D23c, pages 3 and CO-26).

9.3 D8 was put, along with all graduation papers and handbooks on dredging technology, in the library of this department (D23, points 7 and 8). This is a public university library, i.e. one that should normally be accessible to a broad audience, in particular from the offshore and dredging industry (D23, points 9, 12 to 16).

9.4 D8 figures in a register dated 1986 listing all graduation papers of students in this department (D23c, page CO-26), which was circulated to members of the staff and, upon request, to interested institutions and companies (see D23c, letter dated 11 January 1984).

9.5 D8 is cited, and its content is discussed, in a MSc thesis (D24) written in 1994 by a Mr Dresen, then student in the Department of Dredging Technology at TU Delft. D24 comprises an inventory of past studies on CSDs working in waves (see title and page ii), in particular an overview of graduation works written by former students at TU Delft (page vii and Chapter 2). On pages 35 to 38 and 68 of D24, there is an explicit reference to D8 and its disclosure regarding the spud carriage system of O&K as mounted on the CSD Bilberg I.

9.6 Normally, at TU Delft, a graduation paper will be made public after its assessment by the graduation committee, unless it has been sponsored by a company or an institution which requires some parts of the paper to be kept confidential. In such an exceptional case, the paper will not be published for a maximum of 2 years (D23, point 11). This does not appear to have taken place for D8 and, even if it had, D8 would have been made public at the latest in 1987.

9.7 The respondent argued that, up until the priority date, D8 might have been put in a part of the library which was not publicly accessible, or that the relevant part of D8 might have been kept confidential, even though it was referred to in D24. However, the respondent did not furnish any evidence in support of these allegations except for the compte-rendu of an unsuccessful attempt to locate the paper in May 2015. However, the mere fact that on 21 May 2015 D8 was neither digitally nor physically obtainable from the TU Delft library is irrelevant in respect of assessing the document's accessibility at the relevant time. As there is sufficient evidence on file to this end (see in particular points 9.5 and 9.6 above), the Board is convinced that this document was publicly available before the priority date of the patent.

[...]

10.14 In conclusion, when starting from D8, the claimed invention involves an inventive step in the sense of Article 56 EPC.

[...]

11. Prior use URSA

11.1 As acknowledged by the appellant, the alleged prior use is not more relevant than Figure 3.5 of D8 for assessing the inventive step of the claimed invention.

11.2 In light of the conclusions reached when starting from D8 as the closest prior art, there is no need to investigate the prior use any further.