14 February 2017
In a recent EPO decision, T 1921/12, the Board of Appeal has considered the issue of corrections being made to the claims of a granted patent during Opposition proceedings.
In the case in question, the patent was directed to the superfinishing of planetary gear systems which undergo finishing to a surface roughness of approximately 0.25 microns or less to reduce wear on the bearings in the system.
During examination, Claim 1 was amended to omit the previously claimed limitation of the surface roughness of the gears being approximately 0.25 microns or less, so that the claims instead only defined the roughness value to be 0.25 microns. This was accepted and the patent was subsequently granted, before being opposed shortly afterwards.
During opposition, the patent proprietor twice requested corrections to be made to the wording of the claims. The first request related to alleged errors in the English-language translation of the patent specification at the time of grant (the ‘Druckexemplar’), while the second request was to reintroduce the statement regarding the roughness of the finishing being 0.25 microns “or less” into Claim 1. The Opposition Division, at the request of the patent proprietor who noted that relevant decision G 1/10 (relating to the correction of granted patents) was still pending, delegated this decision on correction to the Examining Division, which subsequently allowed the corrections to be made under Rule 139 and Rule 140 EPC. G 1/10 subsequently established that corrections to the text of a patent under Rule 140 EPC were inadmissible whenever made, including after the initiation of opposition proceedings.
The Opposition Division’s decision was that the patent was valid and could be maintained as corrected. The opponent then appealed, arguing that the corrections should not have been allowed, since this broadened the scope of the granted patent, contravening Article 123(3) EPC. It also argued that the corrections should not have been considered by the Examining Division once the patent had granted, and consequently those corrections should be considered null and void.
In reply, the patent proprietor argued that no procedural violation had occurred in allowing the Examining Division to decide upon the corrections, and that the corrections would equally have been allowed by the Opposition Division. Prior to oral proceedings before the Board, the patent proprietor submitted a request that included claims identical to those recited in the Druckexemplar.
The Board noted that the decision to correct the claims was taken by only one member of the Examining Division, thereby rendering the decision “non-existent”. The Board further stated that it was “rather disturbing” that the decisions relating to the corrections were not in the publically available part of the file. The decision permitting the correction of the Druckexemplar was signed by all three members of the Examining Division, but the Board held that the applicant had received the Druckexemplar prior to grant and had approved it, and consequently such a correction after this approval was not allowable in any case. Furthermore, since the patent proprietor had submitted a main request to the Board which related to the uncorrected Druckexemplar, the Board considered it unnecessary to refer this question to the Enlarged Board of Appeal.
Finally, the Board decided that the prior art rendered the patent obvious for all requests submitted, and therefore the patent should be revoked.
The Board did not cite G 1/10 in its decision on the corrections, thereby avoiding the question of whether it applied in this case where the correction under Rule 140 EPC had been allowed prior to G 1/10 being published. Nevertheless, it reached a conclusion which is in conformity with the G 1/10 decision in holding the post-grant corrections as inadmissible.