The decision X ZR 43/13 "Rotorelemente" relates to a complicated machine for punching out metal pieces. According to claim 1, the machine includes a die assembly including a first die member and a second die member for punching out different parts of the piece. The die members can be moved relative to each other in order to modify the shapes of the metal pieces, wherein the wording of claim 1 appears (at first sight) to define that the first die member is stationary and the second die member is moved.
The 1st instance (Bundespatentgericht) had ruled that this extends beyond the original disclosure, which covered only embodiments where the second die member was kept stationary. The draftsman of the claim must have confused the two die members and the Bundespatentgericht ruled that the patent must be revoked as the claime related to another invention (Aliud).
The Federal Court of Justice (BGH) did not follow this ruling. The confusion of the die members was found to be infelicitous wording (eine unglückliche Formulierung) and a proper construction of the claim in combination with the specification would have revealed that nothing but a movable first die member was meant to be claimed.
The error in judgement was due to the failure to properly define the meaning (Sinngehalt) of the claim in the light of the specification and the drawings prior to assessing whether this meaning extends beyond the scope of the original disclosure.