T 0100/15 - Sufficiency of disclosure

Key points

• This opposition appeal is about sufficiency of disclosure.
• " when a patent does not give any information on how a feature of the invention can be put into practice, and the opponent has plausibly argued that common general knowledge would not enable the skilled person to put this feature into practice, it is for the patent proprietor to show otherwise". The Board refers to CLBA III.G.5.2.2.

EPO T 0100/15 -  link

3. Auxiliary request 5 - Article 83 EPC

3.1 Claim 1 of auxiliary request 5 is directed to a process wherein the articles are produced using gammaTiAl intermetallic compounds and wherein the method step h) refers to a controlled cooling.

According to paragraph [0036] of the contested patent (corresponding to page 6, lines 26 to 30 of the application as filed) the controlled cooling below 1200°C does not influence the microstructure of the articles produced using gammaTiAl intermetallic compounds.

Hence, it is essential for the skilled person to know how to achieve the controlled cooling in order to obtain articles with the desired microstructure and thus with the required mechanical properties.

3.2 In this context the proprietor argues that the opponent has not demonstrated that the skilled person is unable to repeat the standard "metal 3D printing" process disclosed in the contested patent.

The Board agrees with the argument of the proprietor in that the burden for establishing insufficiency of disclosure lies with the opponent in inter-parte proceedings.

However, when a patent does not give any information on how a feature of the invention can be put into practice, and the opponent has plausibly argued that common general knowledge would not enable the skilled person to put this feature into practice, it is for the patent proprietor to show otherwise, see Case Law of the Boards of Appeal, 8th edition, 2016, Chapter III.G.5.2.2.

3.3 In the present case, an undue burden for the skilled person seeking to put the invention into practice arises from the the addition of the term "controlled". into the wording of claim 1 as granted.

It is undisputed that the contested patent does not provide a definition for the controlled cooling. The argument of the proprietor, that the term should be interpreted as a control of the atmosphere and not of the temperature reduction, is not persuasive (see points 1.4.2 and 1.4.3 above).

In this context it can be accepted that cooling in an inert gas atmosphere is faster than cooling under vacuum due to the heat conduction provided by the gas atmosphere. However, reducing the total cooling time is not the same as controlling the cooling, since the article can still cool in an uncontrolled manner.

Furthermore, monitoring the threshold temperature from which the controlled cooling can start does not inherently define a controlled cooling step, but only defines the point in time when to start the controlled cooling.

Therefore it has been rendered plausible by the opponent during the appeal proceedings, that the skilled person does not get the required information from the contested patent as to how to perform the controlled cooling.

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3.6 It follows that the skilled person is not taught by the contested patent how the controlled cooling defined in amended claim 1 can be performed, in particular the patent does not disclose which parameter has to be monitored and how it is to be adjusted during the controlled cooling. The skilled person has to guess what is meant by this term and whether, for example, the cooling rate or the temperature gradient within the article should be controlled.

Even if the skilled person could be expected to arbitrary select a suitable parameter, the contested patent does not give any information to which extent and how it should be controlled, for example which cooling rate could be tolerated in order to achieve articles with the required stability of the microstructure.

3.7 Also in the example of the contested patent no indication concerning the controlled cooling is presented. Paragraphs [0084] and [0085] disclose that approximately 30 hours are required to produce 30 turbine blades under vacuum and cool them in helium.

The example does not disclose that a controlled cooling has to be performed and does not indicate a time frame for the cooling step itself. Moreover, the example does not correspond to the embodiment described in paragraph [0074] of the patent, according to which a flow of inert gas is fed until the desired temperature is achieved.

3.8 In the absence of any teaching of how to control the cooling, the skilled person has to set up its own research program to find appropriate conditions which do not have an influence on the microstructure according to paragraph [0036] of the contested patent.

This amounts to an undue burden for the skilled person.

3.9 In summary, the Board reaches the conclusion that the subject-matter of claim 1 of auxiliary request 5 does not fulfil the requirements of Article 83 EPC.