Tuesday, 1 July 2014

T 754/13 - Clarity and scope of a claim, functional or just a wish?


The applicant has filed an appeal against the decision of the Examining Division to refuse the European patent application No. 06 708 833.6 MICROMIXING OF FLUIDS USING A REFLUX CELL
The appeal focused on two aspects:
  • Is the feature “thereby creating a reflux cell by the upstream penetration of the lower density fluid into the feeding tube of the higher density fluid” an allowable functional formulation in the context of the claim and description or does it define  a result to be achieved?The Board concludes that that is not the case: there exists an undue burden for the skilled person since he has to carry out at least a small research program based on seven parameters a) to g) to ascertain the boundaries of the scope of the claim.
  • Is the feature “sharp-edged” clear (in the claim as “wherein the shape of the exit of the feeding tube of the higher density fluid is sharp-edged”)?The Board also here concludes that this is not the case, since the Board sees two reasonable but rather different possible interpretations and the description is silent on the matters.

Reasons for the decision
[…]
2. Clarity (Article 84 EPC)
Article 84 EPC requires that "The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description".
2.1 First of all, the claims per se must be clear in themselves when read by a person skilled in the art without any reference to the content of the description. It is further constant jurisprudence of the Boards of Appeal that claims have to be clear for the sake of legal certainty since their purpose is to enable the protection conferred by the patent to be determined. Thereby a potential infringer of the subject-matter of the claims should be enabled to determine whether or not he is working within the scope of the claim. The latter brings with it that the skilled person should be able to establish to a sufficient extent the demarcation of the scope of the claim (i.e. its extent of protection) without undue burden. In the context of determining the scope of protection of a claim it has additionally to be considered that Article 84 EPC is not a ground of opposition (see Case Law of the Boards of Appeal, 7th edition 2013, sections II.A.1.1 to 1.5 and II.A.3.1) and therefore needs proper attention in examination proceedings.
[…]
2.2 Feature (d) of claim 1 defines amongst others that "the shape of the exit of the feeding tube of the higher density fluid is sharp-edged" (see point VIII above).
2.2.1 The description of the English translation of the application as originally filed (which in the following is always quoted) does not contain any definition of the feature that the shape of the exit of the feeding tube is "sharp-edged".
This definition "sharp-edged" has therefore to be interpreted by the person skilled in the art who will consider the complete specification of the application as originally filed but also his common general knowledge. Thus this definition could mean:
i) an edge having an angle equal to or smaller than 90° (i.e. a sharp or acute angle), or
ii) an edge that is "sharp", i.e. an edge which is suitable for cutting something.
2.2.2 Figures 1 to 4 of the English translation of the application as originally filed depict an axi-symmetric configuration of a mixing device wherein the exit of a cylindrical feeding tube of constant cross-section for the higher density fluid, i.e. a liquid, has the shape of an outwardly chamfered edge which forms an acute or sharp angle in the range of about 15°-30°. In the context of example 1 with reference to figure 1 the effect of this sharp-edged shape is described. Therein it is stated that it is responsible that the lateral ring-shaped passage section for the gas (which passage section is formed between the exit of the tube and a circular exit orifice having the same diameter (D) as the tube, being arranged in a parallel plane with respect to the plane of the exit of said feeding tube and being separated therefrom by an axial gap of the distance (H)) makes easier a prompt gas release with little or even no losses by friction (see page 8, line 20 to page 9, line 3).
2.2.3 When asked by the Board at the oral proceedings the appellant admitted that the sharp-edged shape of the feeding tube for the liquid could also have the form of an inwardly chamfered edge, i.e. the interior diameter of the tube continuously increases over a certain distance towards the exit of the tube where it ultimately has the exterior diameter. Claim 1, due to the definition in its feature (a) "the tube having an axis, a circular cross-section with an interior diameter (D), and an exit ..." allows for such an embodiment wherein the circular cross-section at the exit has an interior diameter (D) which is larger than an interior diameter of the feeding tube upstream of said exit.
2.2.4 It is therefore clear that claim 1 is not restricted to said first embodiment according to figure 1 and example 1 (see point 2.2.2 above) or to both aforementioned embodiments (see also point 2.2.3 above) since the exit of the feeding tube is only defined to be "sharped-edged" and does not contain any corresponding further restriction. Therefore the appellant's arguments to the contrary cannot be accepted.
2.2.5 The appellant's arguments based on the effect of the sharp-edged exit of the feeding tube of the device according to figures 1-4 used for the examples (see point 2.2.2 above) cannot hold either.
First of all, this is due to the fact that the application as originally filed nowhere discloses said sharp-edged exit of the feeding tube as an essential feature of the mixing device which would be responsible for creating a reflux cell in the feeding tube.
[…]
2.3 Feature (b) of claim 1 of the single request specifies that the lower density fluid is a gas while the higher density fluid is a liquid and that they meet in a specific manner in an area of confluence just opposite at the feeding tube exit wherein the gas flows with a velocity that is at least twice as high as that of the liquid and with a gas to liquid mass flow ratio between 0.05 and 200 and at its end defines "... thereby creating a reflux cell by the upstream penetration of the lower density fluid into the feeding tube of the higher density fluid" (see point VIII above). The Board thus considers that feature (b) defines a result to be achieved, namely that of a reflux cell inside the feeding tube.
2.3.1 The features (a) and (d) of claim 1 define amongst others an axi-symmetric mixing device including said feeding tube having a circular cross-section with an interior diameter (D) and said exit having a sharp-edged shape, and a circular exit orifice having the same diameter (D) as the interior diameter of the feeding tube which are opposite each other in two parallel planes that are separated by an axial gap (H) that is less than half of the diameter (D) (see points 2.2.2 and VIII above). The essential geometric dimensions (D) and (H) of this mixing device are thus not defined by absolute dimensions but only by relative dimensions.
The specification of the English translation of the application as originally filed is silent with respect to either general or preferred ranges for the diameter (D) and/or the axial gap (H). Only the example with reference to figure 2 discloses a single value for the distance (H) that is 90 mym (see page 7, line 29 to page 8, line 3 and figure 2).

2.3.2 Taking account of the above, the person skilled in the art is taught by claim 1 that he has to select the following parameters for carrying out the mixing process defined in claim 1 of the single request:
a) a gas (any gas or a mixture of gases such as air);
b) a liquid (any liquid which may be chosen within a very large range of possible viscosities and which additionally can be a mixture of liquids, see page 8, lines 1 and 2);
c) a diameter (D);
d) a height of the axial gap (H) that is less than half of said diameter (D);
e) a velocity of the gas in the confluence area that is at least twice as high as that of the liquid (which implies a certain pressure of the selected gas);
f) a gas to liquid mass flow ratio between 0.05 and 200 (which represents a very large range); and
g) a "sharp-edged" shape of the feeding tube exit.
Thus in order to ascertain the boundaries for the scope of claim 1 the person skilled in the art has to select embodiments in accordance with these seven parameters a) to g) and additionally he has to vary the same. In this context it is clear to him that the parameter e) (likewise the implied pressure or pressure difference necessary for creating the gas velocity) is influenced by parameter g).
The appellant did not dispute at the oral proceedings that the selection of a gas (which can be one-atomic, two-atomic, three-atomic, etc. or a mixture of gases) represents an individual parameter that influences the creation of a reflux cell.
[…]
2.3.5 Also the examples of the English translation of the application as originally filed are considered not to be particularly helpful to the person skilled in the art in this context. Contrary to the appellant's arguments they do not give the skilled person much guidance to create said reflux cell, let alone establish where the boundaries lie.
[…]
2.3.6 Considering the disclosure of the specification of the English translation of the application as originally filed the skilled person, most presumably, will start from the parameters given in the first example of the application and will use said specified height (H) to select a diameter (D) for the exit of the feeding tube and the exit orifice of the mixing device that is at least the double of this height (H).
However, already when trying to repeat these two examples on the basis of the disclosed parameters the person skilled in the art has to make additional selections for the missing unspecified parameters - namely the parameters a), c), f) and g) and only for the second example additionally the parameter d) - and as a consequence thereof has to carry out a large number of additional experiments to verify these two examples in order to create a reflux cell.
[…]
2.3.8 Taking account of the above, the Board considers that, although the experiments described in the application appear to be very simple, there exists an undue burden for the skilled person since he has to carry out at least a small research program based on said seven parameters a) to g) to ascertain the boundaries of the scope of claim 1 of the main request.
The Board further considers, as mentioned at the oral proceedings, that the very broad subject-matter of claim 1 of the main request, which encompasses all kinds of gases and liquids, is not supported - as required by Article 84 EPC - by the description of the English translation of the application as originally filed with respect to the small number of only two examples which were only made with water (optionally in combination with a small amount of a surfactant, i.e. Tween 80) as said liquid in combination with an unspecified gas (see point 2.3.5 above).
2.3.9 The appellant's arguments to the contrary cannot hold for the following reasons.
[…]
Likewise, the arguments based on decision T 68/85 (see OJ EPO 1987, 228) cannot hold. First of all, this decision dealt with an application containing a functional definition (or a result to be achieved) was considered admissible under Article 84 EPC. However, the Board pointed out in this respect: "On the other hand, the effort to define a feature in functional terms must stop short where it jeopardises the clarity of a claim as required by Article 84 EPC. That clarity demands not only that a skilled person be able to understand the teaching of the claim but also that he be able to implement it. In other words, the feature must provide instructions which are sufficiently clear for the expert to reduce them to practice without undue burden, if necessary with reasonable experiments" (see point 8.4.3 of the reasons; emphasis added by the Board).
Hence, already this decision sets the standard at preventing undue burden. Furthermore, since the issuing of this decision the jurisprudence concerning clarity has been further developed with respect to establishing the boundaries of the claim (see Case Law of the Boards of Appeal, 7th edition 2013, sections II.A.1.1 and II.A.3.4).
[…]
Order: The appeal is dismissed.
  
This decision has European Case Law Identifier: ECLI:EP:BA:2014:T075413.20140513. 
The whole decision can be found hereThe file wrapper can be found here.

No comments :

Post a Comment

Statcounter