T 0352/94 03-02-1998

Reasons for the Decision

1. Admissibility of the appeal

The respondent had made objections concerning the content of the statement of grounds of appeal and requested that the appeal be rejected as inadmissible. This request has been withdrawn and, since the objections in this respect have not been found convincing, the appeal is admissible.

2. Main request

2.1. Novelty

2.1.1. A manifold (270, 270') for a parallel path Coriolis mass flow meter is acknowledged in the patent in suit (see in particular column 5, lines 3 to 5 and column 7, line 42 to column 9, line 6; Figure 2). This Coriolis flow meter, which conducts a fluid to or from a pair of flow tubes (130, 130') utilized in said meter, has a transition piece (281, 281') having first and second ends and first and second orifices (280, 280') respectively disposed therein, and a passageway between said first and second ends.

However, contrary to claim 13 of the patent in suit, the acknowledged manifold illustrated by Figure 2 does not comprise features of the second part of said claim 13, for instance that said passageway has a cross-sectional area that gradually changes from a first value at said first orifice to a second value, different from the first value, at said second orifice.

2.1.2. Another manifold is known from E12 (see the whole document; see in particular column 1, line 5 to column 2, line 32); however, contrary to claim 13 in dispute, this other manifold is indicated as being a bifurcated tubing connector for joining discrete fluid streams into a single stream, more specifically for providing a smooth flow profile to blood in an extracorporeal blood handling system, and not as being for a parallel path Coriolis mass flow meter.

The appellant has argued that, at least with reference to the jurisprudence in one of the Contracting States, i.e. Germany, the words "for a parallel path Coriolis mass flow meter" of claim 13 in dispute do not result in any restricting effect on the scope of protection conferred by the patent and thus are not to be taken into account when assessing the patentability of the invention in suit. The same applied having regard to the above-mentioned decision T 287/86 (cf. in particular point 2.1(d) of the reasons), which stated that it is generally accepted that any indication of a purpose in a device claim has to be interpreted to the effect that the claimed device has indeed to be suitable for the indicated purpose, but not that it is limited to this purpose.

However, as convincingly argued by the respondent with reference to the Guidelines for Examination in the EPO, part C, Chapter IV, 7, 6, characteristics implied by the particular use of a device should be taken into account when e.g. deciding the novelty of the device, an example being given relating to hook for a crane as compared with a known fish hook of similar shape, the differences in size being implied by the difference in use. As further credibly argued by the respondent, in the present case, the use of the manifold for a parallel path Coriolis mass flow meter clearly implies that flow tubes are to be attached to a manifold compatible with the mechanical oscillations to which the flow tubes are submitted when measuring the mass flow of a fluid transiting through said flow tubes. Indeed, said necessary feature specifying how the flow tubes are attached to the manifold, and thus the resulting "suitability" of this other known manifold for a Coriolis meter, is not directly and unambiguously derivable from E12 and the respirators or anaesthesia apparatuses shown therein.

2.1.3. The further prior art documents are less relevant.

2.1.4. Therefore, the subject-matter of claim 13 in dispute is novel in the sense of Article 54 EPC.

2.2. Inventive step

2.2.1. It has not been disputed that the manifold for a mass flow meter illustrated in the patent in suit by Figure 2 represents adequately the closest prior art. As mentioned here above in paragraph 2.1.1, this manifold does not comprise features of the second part of claim 13.

According to the patent in suit (see column 4, lines 8 to 17, see also column 8, line 4 to column 9, line 6), the fabrication of the known meters of Figure 2, wherein in particular it is extremely difficult to weld the small mass of each flow tube to the large mass of each manifold while they are assembled, is time consuming and hence costly; moreover, at high flow rates, cavitation can occur in the fluid as it exits the meter, this, in turn, causing vibrations that could lead to measurement inaccuracies.

As specified by the patent in suit (see column 9, lines 7 to 34), the feature of claim 13 that the passageway (303) of the transition piece (110, 110') has a cross-sectional area that gradually changes from a first value at said first orifice (301) to a second value, different from the first value, at said second orifice (302), results in the elimination of abrupt change in the direction of the fluid flow and thus of the likehood that the pressure of the fluid will markedly drop anywhere within the transition piece.

2.2.2. First, against appellant's argumentation that the subject-matter of claim 13 results in an obvious way from the common consideration of the device of Figure 2 of the patent in suit and of E12, the respondent has argued that, starting from a Coriolis mass flow meter according to Figure 2 of the patent in suit, the person skilled in the art would not take into account the teaching of E12 because this document does not relate to this specific technical field, but more in particular to the field of medical instruments. However, as convincingly argued by the appellant, E12 (see in particular column 2, lines 5 to 13) also relates to bifurcated tubing connectors in general and is thus a document which the skilled person would consult; since moreover this document indicates that in said general connector a smooth flowing is achieved and since the problem of cavitation which is observed in particular at the inlet and/or the outlet of many devices is general and always present to said skilled person, as can be seen from Dubbel, a textbook used by technicians in all fields, he would have taken advantage, in his meter, of this feature of the connector of E12 of a transition piece (12) having a passageway (24) with a cross-sectional area that gradually changes from a first value at a first orifice to a second value, different from the first value, at a second, opposed orifice, for preventing cavitation in particular at the outlet of his meter.

In this respect, it is to be noted that Dubbel, although submitted during the oral proceedings, i.e. at a late stage, has not been disregarded because it is in the form of a textbook and provided only to confirm, as an answer to written observations of the Board, previous arguments on general knowledge about cavitation (Article 114(2) EPC).

2.2.3. The manifold (10) known from E12 (see the whole document) is comprised in an apparatus and transports a fluid to or from a pair of flow tubes (18, 20) utilized in said apparatus; as mentioned here above, there is also a transition piece (12) having first and second ends and first and second orifices respectively disposed therein, with a passageway (24) between said first and second ends having a cross-sectional area that gradually changes from a first value at said first orifice to a second value, different from the first value, at said second orifice.

Said manifold also comprises a mounting block (14) having oppositely situated first and second surfaces thereon, said mounting block (14) being disposed in said transition piece (12) with the first surface in abutting contact with said second end; said mounting block (14) also has a first opening inwardly extending from said first surface which at said first surface is substantially identical in cross-sectional area with that of said second orifice and is aligned with said second orifice of the transition piece (12); said mounting block (14) also has a pair of second openings (32, 34) inwardly extending from said second surface to said first opening and in fluid communication therewith; each of said second openings (32, 34) has slidingly received an associated end of one of said flow tubes (18, 20).

Said mounting block further comprises projections (the concentric ridges or energy directors (58, 60), the projection (56) around said mounting block (14) shown in Fig. 2 as comprising the other ridges (58, 60)) formed in said mounting block (14) and radially extending inward into a corresponding one of each of said second openings (32, 34) so as to locally reduce the diameter of said corresponding second opening, wherein each of said projections (56) or a part (58, 60) thereof is located at a pre-defined depth from said first surface such that each of said projections abuts against an external wall of a corresponding one of said flow tubes (18, 20), in order to provide a substantially fluid-tight circumferential connection between the end of the corresponding flow tube (18, 20) and said mounting block (14).

2.2.4. The respondent has argued that the mounting block (14) of E12 is not formed of a weldable material in the sense of the patent in suit. However, as convincingly argued by the appellant, according to E12 (see column 3, lines 1 to 17; column 4, lines 6 to 68) energy directors (56, 58, 60) may be provided to the mounting block (14), in particular to the fittings (32, 34) therein where the tubes (18, 20) are fitted, this being done to facilitate welding, in particular ultrasonic welding, whereby ultrasonic welding energy is concentrated. Therefore, using a weldable material for the mounting block is obvious in view of E12.

The respondent has also particularly stressed that the feature of claim 13 in dispute, that each of said projections of the mounting block has a smaller mass than that of the remainder of said mounting block whereby during a welding operation each of said projections is capable of deforming before the remainder of said mounting block deforms in order to provide a substantially fluid-tight circumferential weld between the end of the corresponding flow tube and said mounting block, is not derivable from E12. However, as convincingly argued by the appellant, the text of E12 specifies the purpose of the projections (56; 58, 60) in the mounting block (14) as being "energy directors" which concentrate the ultrasonic energy to a part of said projections which, at least in the drawings of E12 and without any further information, are also derivable as having a smaller mass than that of the reminder of said mounting block and thus can also be considered as achieving the same result as the "sacrificial member" which is mentioned in the patent in suit (see column 10, lines 15 to 30).

Concerning the further arguments of the respondent that the materials mentioned in E12 for the manifold for medical purposes would not be adequate for a Coriolis meter, it is not relevant in that sense that, as convincingly argued by the appellant, the patent in suit does not disclose any particular material and that, moreover, a plurality of materials are used in existing meters of this type.

2.2.5. For the person skilled in the art of manifold for parallel path Coriolis mass flow meters starting from the manifold of this type of Figure 2 of the patent in suit, it was obvious to take also into account the teaching of E12 since a solution to the constant problem of cavitation is disclosed therein in form of a connector with gradually changing cross-sectional area providing a smooth flow between one end thereof connected to two parallel tubes and the other end thereof connected with only one tube. By doing this, additionally, the welding energy is directed to the parts to be united, thereby solving the other problem, concerning manufacturing, mentioned here above. Thus, the skilled person will arrive to a manifold which comprises all the structural features which are indicated in claim 13 in dispute and which, if necessary with some adaptation based on general knowledge of Coriolis manifolds, is suitable for the indicated purpose of equipping a parallel path Coriolis mass flow meter.

2.2.6. Consequently, the subject-matter of claim 13 in dispute does not involve an inventive step in the sense of Article 56 EPC.

Therefore, the grounds of opposition mentioned in Article 100 EPC prejudice the maintenance of the main request, i.e. the patent in the form as granted, so that this main request is not allowable (Article 102(1) EPC).

3. First auxiliary request

Claim 13 of the first auxiliary request concerns a manifold arranged for a parallel path Coriolis mass flow meter, i.e. a manifold which consists of structural parts of adequate materials assembled in an adequate way in view of its use as a manifold for a Coriolis meter. Indeed, such a manifold is "suitable" for this purpose. However, there can be manifolds which are not arranged for this purpose, but for another purpose, and which yet, either by chance or by minor adaptation measures based on general knowledge, are found to be "suitable" for this purpose. Therefore, the subject-matter of claim 13 of the first auxiliary request represents a more restricted scope of protection than the manifold of claim 13 as granted, which was for a parallel path Coriolis mass flow meter, i.e. in accordance with the above-mentioned decision T 287/86, "suitable" for said purpose. For the reader of claim 13 of the first auxiliary request, it is directly and unambiguously derivable that the features of the manifold are specifically designed for the mentioned purpose, as well with respect to the structural features of the parts of the manifold as with respect to the way they are assembled. This manifold has been adequately disclosed in the patent as granted and in the patent application as filed, and it is clearly defined in said claim 13 (Article 123(3), 123(2) and 84 EPC).

Since claim 13 of the patent as granted has been found novel, claim 13 of the first auxiliary request, which concerns a more restricted type of this manifold, is also novel in the sense of Article 54 EPC.

The skilled person starting from the manifold of the parallel path Coriolis mass flow meter of Figure 2 of the patent in suit and trying to solve the problem of cavitation in this known device would be aware of the general teaching of E12 concerning the smooth flow profile presented by the hollow contoured configuration of the transition piece (12). Moreover, he would be aware that he could find in this document, with the projections (58, 60) of the mounting block (14), some solution of his problem of the difficulty for assembling the manifold, i.e. the difficulty to weld the small mass of each flow tube to the large mass of each manifold, which are time consuming and hence costly. Thus, as mentioned here above with respect to the main request, he could arrive to a device "suitable" for a Coriolis flow meter. However, as convincingly argued by the respondent, the skilled person starting from the manifold of the flow meter of Fig. 2 of the patent in suit and arranging it, i.e. specifically designing it, would not, in view of the oscillations to which the flow tubes are to be submitted, take into consideration the tube connection of E12 because it is not directly derivable as being adapted for this purpose. Therefore, the subject-matter of claim 13 of the first auxiliary request is not obvious having regard to the state of the art and thus involves an inventive step in the sense of Article 56 EPC.

Claim 1 of the first auxiliary request is identical with the text which had been agreed by the proprietor and respondent for granting the patent and only differs from the text of the printed specification, which is erroneous, by the amendment provided now. Claim 1 concerns a Coriolis meter equipped with a manifold having the features of the manifold of claim 13, and is thus also novel and involves an inventive step for the same reasons as those mentioned in relation to claim 13 (Articles 54 and 56 EPC).

Therefore, taking into consideration the amendments made by the proprietor and respondent and resulting in the first auxiliary request, which meets the requirement of the Convention, the patent can be maintained on this basis (Article 102(3) EPC).