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.
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