I first came across the "no functional equivalents" doctrine in the Appellant's brief for a mechanical case, Ex parte Konstant. One of the claim elements at issue in Konstant was a "flange ... with the entire upper width that defines an upper support for at least one cross bar." Citing to a dictionary, the Examiner asserted that a flange was "a projection used for strength or attachment," then asserted that "the 'steps' or 'lips' of [the reference] perform this function." The Appellant cited Suzuki v. Richardson for the proposition "for anticipation, 'almost' is not enough; there is no such thing as 'anticipation by equivalents'."
I thought it was an interesting argument, though the Board in Konstant didn't mention the doctrine and instead reversed on other grounds. (Namely, it's improper for Examiner to rely on the same structure to disclose two separate claimed elements; see my Ex parte Konstant post here).
I was excited to see the BPAI using what seems to be the same "no functional equivalents" doctrine in Ex parte Kershaw. I found out about this decision on the Florida Patent Lawyer blog. You should read Mike Terry's post (here) for the details, but here's my take on it. The Appellant claimed a memory management unit, and the Board found that the Examiner's reliance on software components that perform memory management was misplaced since the claimed unit was a structure (i.e., hardware):
[T]he Examiner appears to be relying on certain memory management function performed by various software components in Ledebohm (e.g., Driver Program 136, and/or Resource Manager 138). (See FF2.) We agree that Ledebohm is directed to performing management functions. However, we note that functional equivalence is not enough to show anticipation of a structural component (such as the claimed memory management unit). See In re Ruskin, 347 F.2d 843, 846 (CCPA 1965) (“the functional equivalent is not enough to be a full anticipation of the specific device claimed by appellant.”)While most of the applications I work on involve a lot of function rather than structure, when I do have a structural element I'm definitely going to watch out for an opportunity to apply In re Ruskin.
(Ex parte Kershaw, p. 8.)