Means plus Function Claims: The Federal Circuit’s Decision in Williamson v. Citrix Online LLC is Like Déjà vu All Over Again

It had all the elements of a pot-boiler thriller: a rogue government official orchestrating a mutiny against the rule of law, individuals in a plucky administrative body trying to stand up for what they believed was right, and a higher court deciding a closely watched case to bring justice to the people… but it wasn’t a story of gangsters from the 1930’s, it was the USPTO Commissioner, the Board of Patent Appeals, and the Federal Circuit, disagreeing in the 1990s over the literal scope of a means plus function claim. The Federal Circuit’s June decision in Williamson v. Citrix Online, LLC brings back memories – and some danger for applicants – from that era.

The law governing means plus function claims is set forth in 35 U.S.C. §112(f), the post-AIA version of §112 6th Paragraph:

(f) ELEMENT IN CLAIM FOR A COMBINATION.—An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. (Emphasis added.)

Thus, the literal scope of a means plus function claim is the embodiments specifically disclosed in the specification, “and equivalents thereof.” Doctrine of equivalents scope of such an element would be the equivalents – of the equivalents. While the courts have interpreted such claims in this manner (both for validity and infringement) for a long time, that was not always the case in the USPTO – before the above noted controversy. Instead, the Office took a more expansive view, holding that a means plus function element of a claim was met – thus anticipated – if any means which performed the function was shown in the prior art, sidestepping the analysis of whether that means was an “equivalent.” The PTO’s world began to crumble, however, with the Federal Circuit’s decision of In re Bond, 910 F.2d 831, 833, 15 USPQ2d 1566, 1568 (Fed. Cir. 1990) where the court took a different view: “The disclosed and prior art structures are not identical, but the claim may nonetheless be anticipated. … However, the Board made no finding that the delay means of claim 1 and that embodied in the Curtis device are structurally equivalent. Accordingly, its decision as to the anticipation of claim 1 is deficient and must be vacated.” In other words, the PTO can’t just assume any allegedly functionally equivalent structure is within the literal scope of the claim, without performing the analysis to determine structural equivalency.

The PTO was not amused.

Examiners were instructed by the Commissioner simply to ignore Bond, on the basis that it was allegedly inconsistent with an earlier decision of the Federal Circuit’s predecessor court, in 1957. However, the issue again came up just a couple of years later, and it seemed clear that the PTO’s own Board of Appeals intended to follow the Federal Circuit’s orders, and employ the narrower literal scope in assessing patentability of a means plus function claim.

The Commissioner took drastic action.

No less than 4 additional members were appointed to the panel deciding the case by the Commissioner, thus ensuring that the original 3 member panel could not decide in favor of Federal Circuit precedent. And so, the Federal Circuit once again received an appeal on the issue of claim scope in a means plus function claim, and once again schooled the PTO: [W]e hold that paragraph six applies regardless of the context in which the interpretation of means-plus-function language arises, i.e., whether as part of a patentability determination in the PTO or as part of a validity or infringement determination in a court.” In re Donaldson, 29 USPQ 2d 1845, 1849 (Fed. Cir. 1994).

Under the Federal Circuit’s rule, which in essence prescribes a narrow literal scope of a means plus function claim, it is often desirable to avoid invoking the 6th paragraph/section (f) as the result of avoiding the 6th paragraph is a claim with greater literal scope. Thus, as a claim reciting a “step for raising the pH” of a reaction is a means plus function claim, the literal scope of such a step is the methods in the specification – e.g., adding NaOH – and any equivalents thereof (KOH? What about buffers? Must raising be done by titration, the only method disclosed in an example?) – which is at best narrow, and further not particularly clear.

MPEP §2118 sets forth examiner instructions for determining when a claim is, in fact, a means plus function claim:

The claim limitation is presumed to invoke 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph when it explicitly uses the term “means” or “step” and includes functional language. That presumption is overcome when the limitation further includes the structure necessary to perform the recited function. TriMed, Inc. v. Stryker Corp., 514 F.3d 1256, 1259-60, 85 USPQ2d 1787, 1789 (Fed. Cir. 2008) (“Sufficient structure exists when the claim language specifies the exact structure that performs the function in question without need to resort to other portions of the specification or extrinsic evidence for an adequate understanding of the structure.”); see also Altiris, Inc. v. Symantec Corp., 318 F.3d 1363, 1376, 65 USPQ2d 1865, 1874 (Fed. Cir. 2003).

By contrast, a claim limitation that does not use the term “means” or “step” will trigger the rebuttable presumption that 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph does not apply. See, e.g., Phillips v. AWH Corp., 415 F.3d 1303, 1310, 75 USPQ2d 1321, 1324 (Fed. Cir. 2005) (en banc); CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1369, 62 USPQ2d 1658, 1664 (Fed. Cir. 2002). In examiner guidelines published by the PTO subsequent to Donaldson, examples were given of means plus function claims using the “step for” language.

The instructions in the MPEP, however, give applicants an easy way to avoid invoking the means plus function presumption –– by simply avoiding the “means” or “step” language. Until the Federal Circuit’s decision in Williamson.

According to the en banc Court, even if no “means” term is used, §112(f) (pre-AIA §112(6)) may apply if the claim fails to “‘recite sufficiently definite structure’ or else recites ‘function without reciting sufficient structure for performing that function.’” Use of the term “means” will continue to invoke a rebuttable presumption that §112(f) applies.” Williamson was the en banc reconsideration of an earlier panel decision upholding the Federal Circuit’s precedent that where “means” or “step” are not used, it is presumed that the 6th paragraph is not invoked. In Williamson, the claim recited a “distributed learning control module.” The en banc court reversed the precedent creating a “strong” presumption, holding that the standard is “whether the words of the claim are understood by person of ordinary skill in the art to have a sufficiently definite meaning as the name for structure.” Slip Op. p. 16. If the words of the claim do not meet that standard, § 112, para. 6 (now § 112(f)) applies.

Where does that leave the claim reciting “raising the pH of the reaction mixture” or even “hydrocracking the feedstream”? A disturbing hint can be found in the above noted Examiner Guidelines issued after the Donaldson decision, which guidelines characterize the following claim as invoking means plus function status:

“Raising the pH of the resultant pulp to about 5.0.”

The message is clear – not only should applicants avoid using “means for” or in chemical claims “step for” but revive an old practice of using a “form paragraph” that sets forth the intent to secure broad claim coverage: “In the specification and claims, unless the language means for or step for is specifically used, it is applicant’s intent not to invoke section (f) of 35 U.S.C. §112.” Otherwise, claim scope may be unduly limited by the creation of unintended means plus function elements.


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