Wind Turbine patent revoked because of matter added during patent prosecution
Background to the Decision
In case T1650/14, a large technology company was granted a patent (EP1956375) on 12 Jan 2011. This patent related to a wind turbine and a method of determining at least one rotational parameter, for example the rotation speed of the rotor or the phase of a blade. The full decision is available at:
https://www.epo.org/law-practice/case-law-appeals/recent/t141650eu1.html
Opposition
Following the Grant of a European patent, there is a 9-month window in which the patent can be opposed. The criteria for opposing a patent are limited exclusively to the following:
- the subject-matter of the European patent lacks novelty, inventive step or is excluded material;
- the European patent does not disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art [the patent does not allow for a skilled person to read the document and then perform the invention – something important is missing from the explanation];
- the subject-matter of the European patent extends beyond the content of the application as filed [during the prosecution phase, amendments were made which included new information, not previously present in the application as filed].
In this case, the company Vestas Wind Systems A/S raised an opposition on the grounds of (a) and (c). They were successful at least with respect to ground (c), and the patent was revoked on 9 April 2014. It was found that the subject-matter of the European patent did indeed extend beyond the content of the application as filed.
The Appeal
The company which owned the patent were understandably disappointed by this decision, and decided to appeal.
The Board of Appeal reviewed the application as originally filed, and the patent as granted. Claim 1, which defines the scope of the monopoly being claimed by the patent, had indeed become longer and more complex. This is not necessarily a barrier to patentability – many patents are amended during the prosecution process to narrow their scope in light of prior art cited by Examiners against them. The test whether “new” material has been added is whether a notional skilled person in the field would “directly and unambiguously” derive any amendments being made as present in the specification as filed. For example, if the original specification claimed device X, but in the description disclosed that feature Y may be incorporated, then an amended claim for device X incorporating feature Y is likely to be acceptable.
However, the key issue here is that according to the Board of Appeal, the skilled person would infer from the specification that the phase of the rotor relative to the Earth in the global reference system is completely determined once the direction of the gravitational force in the rotating reference system is determined. As a result, it is not directly and unambiguously derivable from the earlier application that the phase is established by considering both the variations for effective forces due to gravitational force and the direction of the gravitational force, as required by the modified claim 1.
The Board of Appeal therefore concluded that even though the scope of the claim was narrowed by this amendment, the amendment itself extended beyond the content of the earlier application as filed. Therefore the appeal was dismissed, and the patent remained revoked.
