T 0986/13 (Fuel cell filter/Donaldson) 17-02-2016

1. Main request - allowability under Article 100(c) EPC

1.1 For the board, the features "clean oxidant" and "dirty oxidant" as defined in the subject-matter of claim 1 as granted have no basis in the application as filed, and so claim 1 extends beyond the content of the application as filed for the following reasons.

1.2 The features "clean oxidant" and "dirty oxidant" have no literal basis in the application as filed.

1.3 The term "oxidant" is in fact disclosed only twice in the application as filed. Once under the heading "background of the disclosure", wherein it is disclosed that fuel cells typically operate with a fuel source being supplied to the anodic side of the cell and an oxidant being supplied to the cathodic side. Obviously this passage cannot be the basis for the features "clean oxidant" and "dirty oxidant" because this passage relates to the prior art and not to the invention as disclosed in the application.

The second occurrence of the term "oxidant" is in the paragraph bridging pages 2 and 3 as originally filed, which describes the invention as providing "an air filter assembly for filtering the intake air used in low temperature catalytic reactions, such as fuel cells. The assembly provides either particulate filtration, chemical filtration, or both, to the incoming air stream to provide a purified oxidant to the cathodic side of a catalytic reactor, such as a fuel cell" (emphasis added).

1.4 For the board this passage does not mean - as alleged by the appellant - that the words "air" and "oxidant" are to be considered synonymous over the entire application as filed. It merely means that air - not any oxidant - is mandatorily purified by the filter assembly according to the invention and that the purified air exiting said filter assembly serves as an oxidant for the cathodic side of a catalytic reactor. Thus the word "oxidant" indicates the function to be achieved by the purified air, not that any oxidant is to be filtered by the filter assembly, as argued by the appellant.

1.5 The board furthermore notes that the two independent claims 1 and 13 as originally filed do not use the term "oxidant" either, but relate to an "air filter assembly comprising a housing having an inlet and an outlet, the inlet receiving dirty air into the filter assembly, and the outlet receiving clean air from the filter assembly" (emphasis added). No trace of the generic term "oxidant" could be found in dependent claims as originally filed either.

1.6 It follows from these considerations that there is no basis in the application as filed for the amendment by which the specific term "air" was systematically replaced by the generic term "oxidant" in claim 1. The subject-matter of claim 1 therefore extends beyond the content of the application as filed (Article 100(c) EPC) and the main request is thus not allowed.

2. Auxiliary request I - allowability of the amendments

2.1 In the claims of this request the term "oxidant" was systematically replaced by "air".

For the board, as indicated in point 1.5 above, the features "dirty air" and "clean air" have a basis in the application as filed, in particular in independent claims 1 and 13 which explicitly disclose an air filter assembly having an inlet receiving dirty atmospheric air and an outlet receiving clean air.

2.2 The subject-matter of claim 1 of this request thus has its basis in claim 1 as originally filed and in the passages at page 2, lines 30 and 21, page 8, lines 19 to 22 and page 9, lines 5 to 7. For the board, these passages disclose directly and unambiguously the chemical filter portion including an adsorbent which can be shaped into a pleated or honeycomb structure, as presently defined in claim 1 at issue.

The board does not in this respect adopt the view of the opposition division that the feature "adsorbent shaped into a pleated structure" was not directly and unambiguously derivable from the above-mentioned expression at page 9, lines 5 to 7, which discloses that the adsorbent could be a "pleatable or honeycomb structure that optionally can be further shaped". Admittedly, this expression literally means that the pleatable structure can be shaped in any kind of structure. In the context of the technical field of the patent in suit, however, pleated filter structures are commonly known to the skilled person. It would therefore be too academic to suggest that the expression "pleatable structure that can be further shaped" would not disclose the feature in claim 1 at issue, i.e. a "pleated structure". For the board, the skilled person would construe the above passage to imply that the pleatable structure can be further shaped into a pleated structure, because the pleated structure of filters is one of the most common filter structures in the field of air filters and he would therefore directly and unambiguously infer from the above passage that the pleatable structure can be further shaped into a pleated structure.

2.3 The remaining claims of this request have a basis as follows in the application as filed:

- Claim 2: in claim 2 as filed;

- Claim 3: in the passage at page 12, lines 18 and 19 as filed;

- Claim 4 to 6: in claims 6 to 8 as filed, respectively;

- Claim 7: in claim 13 as filed;

- Claims 8 and 9: in claims 10 and 11 as filed, respectively;

- Claims 10 and 11: in claims 14 and 15 as filed, respectively;

- Claim 12: in claim 1 and the passages at page 8, lines 19 to 22 and page 9, lines 5 to 7 as filed.

2.4 With respect to claim 3, the board does not accept the opposition division's view that the subject-matter of this dependent claim was an unallowable intermediate generalisation of a specific embodiment disclosed in the description as filed. Indeed, the feature that "the physical portion is upstream from the chemical portion" is part of the particular embodiment in which the filter assembly is defined as having one layer of particulate media as the physical filter portion and three layers of adsorptive media as the chemical portion. However, it is manifest for the skilled person that these specific features of the embodiment disclosed at page 12, lines 14 to 18 are independent from the position of the physical and chemical portions of the filter assembly, and so they are not inextricably linked with each other.

2.5 The scope of protection conferred by claims 1 to 12 of this request having furthermore not been extended over that of the claims of the patent in suit, the board is satisfied that the claims of this request meet the requirements of Article 123(2) and (3) EPC.

3. Remittal

The board notes that the patent was also opposed on the grounds of insufficiency of disclosure, lack of novelty and lack of inventive step and in the annex to the summons to attend oral proceedings, the opposition division expressed its preliminary opinion that the invention was sufficiently disclosed but lacked novelty. In view of this, the board exercises its discretion pursuant to Article 111(1) EPC and remits the case for further prosecution.