The Board declined to institute inter partes review because Petitioner failed to identify adequate corresponding structure in the challenged patent that performed the function of claim limitation that was to be construed under 112(f).  According to the Board’s Rules, “[w]here the claim to be construed contains a means-plus-function . . . limitation as permitted under 35 U.S.C. 112(f), the construction of the claim must identify the specific portions of the specification that describe the structure, material, or acts corresponding to each claimed function.”  37 C.F.R. § 42.104(b)(3).

Here, the Board’s analysis turned on whether the Petition adequately showed that the cited prior art teaches the “adjusting assembly” limitation in the claims.  Both parties agreed, at least for the Institution stage of the proceeding, that the “adjusting assembly” limitation should be construed according to § 112(f).  The Board agreed that the limitation should be construed according to § 112(f) even though the word “means” does not appear in the limitation because the claim language itself does not recite structure that, performs the recited function of the “adjusting assembly.”  This conclusion was supported by Petitioner’s unrebutted expert opinion that the term “adjusting assembly” would not connote any specific structure, to a POSA.

Petitioner points to two structures (a “tilting spring” and a “weighing spring”) in the challenged patent as performing the recited function of the “adjusting assembly.”  Patent Owner pointed out deficiencies in Petitioner’s arguments, noting that Petitioner’s asserted structure was two disconnected springs that could not adjust anything, let alone perform the specifically recited functions in the claim.

The Board agreed with Patent Owner and found that Petitioner’s structure when standing alone, did not perform all of the functions of the “adjusting assembly” limitation of the claim. Thus, the Board found that additional structures beyond the “tilting spring” and a “weighing spring” would be required to perform the recited function of claim 1’s “adjusting assembly,” and stated that because of this Petitioner failed to show adequate corresponding structure under § 112(f).  Absent adequate corresponding structure in the challenged patent, Petitioner could not compare any such corresponding structure in the challenged patent to structures in the prior art references.  Without this comparison, Petitioner could not demonstrate that ether prior art reference disclosed the “adjusting assembly” limitation.

Accordingly, the Board denied institution because the Petition did not establish a reasonable likelihood of unpatentability for claim 1.

Takeaway: Very careful attention should be paid to any limitation that might be construed as a means-plus-function limitation in a claim challenged in an IPR.  Petitioners should make sure that the entirety of the function is accounted for in identified specification structure.