On 30 November 2022, the High Court found Siemens’ UK patent (EP 2 657 519 B1) invalid and that GE’s Haliade-X wind turbine did not infringe the patent. While the outcome of a related US action was an injunction on the sale of GE’s Haliade-X wind turbine in the US, the US action was based on different patent claims and was thus not relied upon in this decision.
Siemens’ patent contained two independent claims: claim 1 directed to a wind turbine including a rotor hub, and claim 9 directed to the rotor hub itself. The Judge found that GE did not infringe either of the independent claims, primarily because certain claim features were absent, but also because GE’s planned activities were considered not to be within the territorial ambit of the Patents Act. The Judge also found that the claims were obvious in view of an article in “Wind Energy”.
As discussed in more detail below, the decision includes three key points: the Judge elected not to rely on the examination history to interpret the claim language, despite UK patent law allowing for this; the territorial scope of the UK Patents Act was found not to include assembly of a wind turbine in UK coastal waters; and the skilled person in this particular field was considered to be willing to progress an untested design to arrive at the claimed invention.
In order to infringe a patent in the UK, it is necessary that all of the claimed integers or terms in an independent claim in the patent document are present in the alleged infringement. To assess whether a product or process infringes a patent, the first necessary step is to interpret or construe the claim language, within the context of the patent, to determine the scope of the claims.
In this case, independent claim 1 of Siemens’ patent was directed to a wind turbine and required inter alia that “an outer ring of the at least one bearing is integral with an annular member of the rotor hub”. Independent claim 9 included a similar limitation. The disputed issues on claim scope all concerned the “normal” interpretation of the claims; there were no issues on the doctrine of equivalence.
Issue 1 – “Integral”
Siemens (the patentee) argued that the term “integral” in claims 1 and 9 covered a press-fit connection between the outer ring of the bearing and the annular member of the rotor hub, which was present in GE’s Haliade-X wind turbine (the alleged infringing product). GE argued that the term was limited to situations where the annular member and bearing outer ring are of one piece, i.e. truly monolithic. Both Siemens and GE referred to Actavis v Lilly  and queried whether the file history should be used to help clarify the meaning of “integral”.
In response, Judge Meade said it would only be appropriate to consult the file history where (i) the point at issue is truly unclear if one confines oneself to the specification and claims of the patent, and the contents of the file unambiguously resolve the point, or (ii) it would be contrary to the public interest for the contents of the file to be ignored. Moreover, Meade noted that the first requirement will not be met merely because some point of interpretation is arguable both ways in the context of the specification, and that the second requires that the file provides a clear answer, and will not be met simply because the file may be relevant.
In the present case, during examination proceedings, Siemens filed amended claims limiting the independent claims to the outer ring of the bearing being “integral with” the annular member of the rotor hub, instead of the originally claimed language “firmly connected to or integral with”. This amendment seemed to be necessary to overcome a cited reference disclosing a bolted connection between an outer ring of a bearing and an annular member of a rotor hub, thus reading onto the deleted expression “firmly connected”.
Judge Meade found that the file history only established that Siemens saw a need to craft the claim to exclude a bolted connection, and that one can therefore clearly infer that a bolted connection would fall within “firmly connected” (the deleted expression) and would not fall within “integral”. However, one cannot resolve the precise boundary of “integral” based on the file history, and one cannot determine whether a press fit would provide it or not. Judge Meade acknowledged that the file history could be relevant if Siemens had alleged that a bolted connection infringed; however, press fit connections were not discussed at all, nor was the boundary of “integral” other than the very clear stance that it would not cover a bolted connection. Therefore, the file history was ignored.
In the end, this matter was decided in large part on the expert evidence provided during trial with the Judge concluding that the skilled person would consider “integral” to mean that the outer ring and the annular member were truly in one piece, or were so closely connected that they behaved for the purposes of transmitting a load as if they were in one piece. Therefore, an outer ring and annular member with a press fit connection were found to be “integral” on the basis of sharing a similar load transmission relationship.
The Judge’s decision on claim construction confirms the UK position that reliance on the file history is only useful if (i) the point at issue is unclear from the specification and claims of the patent, and can be unambiguously resolved from the file history; or (ii) ignoring the contents of the file history would be contrary to the public interest. Despite the Judge’s decision, patent applicants should still be mindful of comments made during examination as these comments may be deemed relevant if one of these conditions is met.
Issue 2 – “Of the rotor hub”
GE argued that the independent claims require that the annular member be “of the rotor hub”, that the rotor hub was well understood to be an identifiable part of a wind turbine, and that in the Haliade-X wind turbine the part relied on by Siemens for its infringement analysis is part of the generator, and not part of the hub. Siemens countered this by arguing that the rotating shaft rotates as one with the rotor hub, is connected via bolts to a flange of the rotor hub, protrudes into the interior of the rotor hub, and is of the same material of the rotor hub; and therefore that it was “fair to say” that it is “of the rotor hub”.
Judge Meade found that Siemens’ argument amounts to saying that the annular member is bound to be connected at least indirectly to the hub and to rotate as it does, and while that is true, it is not a reason to give no meaning to the words; otherwise the words “of the rotor hub” have no limiting function in the claim.
For the reasons discussed above, the Judge found that the press fit connection in GE’s Haliade-X wind turbine was within the scope of “integral”. Regarding the feature, “of the rotor hub”, Judge Meade sided with GE and found that the annular member was of the generator, not “of the rotor hub”. Therefore, the Judge concluded that there was ultimately no infringement of Siemens’ patent.
Territorial scope – the Dogger Bank point
For a UK patent to be infringed, the infringing act (e.g., making, using, selling or importing a product) must have taken place in the UK. However, the UK Patents Act 1977 goes further to clarify territorial scope in respect of the continental waters of the UK stating the Patents Act 1977 applies to acts done in areas designated under the Continental Shelf Act 1964 or the Petroleum Act 1998.
Despite finding the Haliade-X wind turbine did not infringe the claims of the patent, Judge Meade went on to consider whether GE’s activities at Dogger Bank, when the Haliade-X wind turbines are installed on the seabed, would be “activities connected with the exploration of, or the exploitation of the natural resources of, the shore or bed of waters to which this section applies or the subsoil beneath it” as stated in Section 11(1)-(2) of the Petroleum Act 1998.
The Judge concluded GE’s acts at Dogger Bank would not be “exploitation” of the kind required; noting that “exploration” is not relied on and would be a much weaker argument. Judge Meade said no natural resources of the shore or bed of waters as referred to are exploited, instead what is taken advantage of is the mere existence of the sea bed and subsoil beneath it. In particular, the Judge stated,
“One can of course understand that taking living or non-living resources like hydrocarbons or seaweed and doing something with them is “exploitation”, but drilling out some rock and doing nothing with it is not, in my view”.
Therefore, Judge Meade found that GE’s planned activities at Dogger Bank would not be within the territorial ambit of the Patents Act 1977 and that GE would not infringe the patent even if all of the features of the independent claims were present in GE’s Haliade-X wind turbine.
The Judge’s interpretation of exploitation appears to open the door for offshore use of patented technology in wind turbines without the risk of infringement. The decision brings into focus the importance of being mindful of the jurisdictional scope of protection afforded by a patent, and ensuring claim language captures infringement at all stages of deployment.
Kit of parts
As an aside, Siemens also made arguments that having all the parts of the Haliade-X wind turbine at port in the UK, but not assembled, infringed claim 1 of the patent by virtue of being a “kit of parts” (despite a “kit of parts” claim not being in the patent). However, Judge Meade declined to decide this point as it was deemed not relevant to the outcome of the action. Thus, it remains unclear if a “kit of parts” claim would have resulted in a different outcome in respect of infringement.
Obviousness and the “skilled person in the art”
In the UK, for a patent to be valid it must be novel, inventive and sufficiently described to allow a person skilled in the relevant field to put the invention into practice. GE argued that the patent was invalid for anticipation and obviousness.
The main prior art reference relied upon by GE was a wind turbine design disclosed in an article in “Wind Energy” published just before the application was filed, entitled “Review of direct-drive radial flux wind turbine generator mechanical design”. The article included a table illustrating a number of wind turbine designs, some of which were considered to form part of the common general knowledge (CGK) while others did not; the design relied upon by GE was not part of the CGK.
The article provided little detail on the bearing types in these designs, other than saying they were “mechanical/magnetic”. While it was acknowledged that press fit connections were part of the CGK (which if combined with the design relied upon by GE would anticipate the claims), Judge Meade considered that there was insufficient teaching in the article on the bearing types for the article to be novelty destroying.
Turning to obviousness, Judge Meade found the relevant question boiled down to whether or not it would be obvious to progress the non-CGK design into actual development. In this regard, Meade said it was necessary to consider the attitude of the skilled person, in particular their degree of conservatism and approach to designing wind turbines. Judge Meade noted that while safety was especially paramount in the industry, the industry needed to react to changing external requirements as they arose and that there was no sign that the players in the field hesitated to implement new designs. Therefore, the skilled person would not be deterred from progressing newer, untested designs, but would assess them on their merits while taking into account their relative lack of use.
For this reason, as well as the expert evidence given during trial, Judge Meade concluded that the patent was invalid for being obvious based on a combination of the wind turbine design in Wind Energy combined with the skilled person’s CGK.
The Judge appeared to ascribe the skilled person operating in this particularly industry with a greater willingness to progress an untested design on the basis of rapid technological development in this sector. As such, this decision may impact other patents in the field and effectively make an obviousness attack more difficult to defend.
Finally, GE argued that the patent was insufficient because its claims covered very large turbines in which the annular member is truly integral with the outer ring of the bearing, and that – according to expert evidence provided during trial – it would not be possible to make a bearing outer ring for a very large turbine that was truly integral with the annular member, but that it would be possible to secure the bearing outer ring to the annular member via a press fit connection.
As press fit connections were found to be part of the CGK, the skilled person would know they could use press fitting or the like and so they would not think they needed to make a very large, truly integral assembly. As such, Judge Meade did not find the claims to be insufficient.
It will now be particularly interesting to see if Siemens appeal this decision and whether any of the Judge’s conclusions are overturned. Further, the Judge’s comments on the appetite of the skilled person to progress an untested design in the wind turbine industry, and the territorial reach of a UK patent, may impact the strength of patents in this field.