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When ‘No Means’ Means ‘Means’ in Functional Claim Language

Posted on Jun 24, 2015 in Articles

This article originally appeared in The Legal Intelligencer on June 24, 2015.

The preferred patent claim strikes a very fine line. When patent claims are broad, with fewer words, it is easier to find that they have been infringed. When claims are too broad, however, they may fail to meet the statutory requirements of patentability, for they may then fail to distinguish over the prior art (i.e., that which was already known before the patent was applied for). One way that patent attorneys draft broad claims, while at the same time differentiating over that which is already in the public realm, is to use something called functional claiming. Simply put, instead of writing a patent claim that describes what something is, a functional claim describes what something does (and hence the function that is performed).

One way to draft a functional claim is to use the word “means” (as in “means for” doing something). By using the word “means,” 35 U.S.C. Section 112(6) is invoked, which states: “An element in a claim … may be expressed as a means … for performing a specified function without the recital of structure … and such claim shall be construed to cover the corresponding structure … described in the specification … and equivalents thereof.”

35 U.S.C. Section 112(6) was created by Congress in 1952 to statutorily overrule the U.S. Supreme Court decision Halliburton Oil Well Cementing v. Walker. In that decision, a claim was invalidated because it included functional claim language. Congress, however, wanted to give patentees the right to claim inventions based on function, and thus created Section 112(6). (Note that the America Invents Act replaced Section 112(6) with Section 112(f); however, the two paragraphs have identical language.)

Section 112(6) was featured prominently in the intellectual property news this month when the U.S. Court of Appeals for the Federal Circuit replaced its previous opinion in Williamson v. Citrix Online LLC, 2015 U.S. App. LEXIS 10082 (Fed. Cir. June 16, 2015), with a new opinion decided by the court en banc. Before explaining the case, some background may be helpful.

The case law has held that the use of the word “means” in a claim creates a rebuttable presumption that Section 112(6) applies to the claim. This is significant because if Section 112(6) is applied to a claim then, as stated by Section 112(6), the claim is interpreted (in patent parlance, “construed”) to cover the corresponding structure disclosed in the specification and equivalents thereof. Furthermore, if there is no corresponding structure in the specification when Section 112(6) is applied, then the claim is indefinite and thus invalid.

Of greater interest are situations where the word “means” does not appear in the claim, and yet the claim language is very functional. The prior case law held that when the word “means” does not appear in a claim, a rebuttable presumption is created that Section 112(6) does not apply.

In 2004, the standard for claims lacking the word “means” changed when it was held that “the presumption [that Section 112(6) does not apply to a claim] flowing from the absence of the term ‘means’ is a strong one that is not readily overcome,” in Lighting World v. Birchwood Lighting, 382 F.3d 1354 (Fed. Cir. 2004). In Flo Healthcare Solutions LLC v. Kappos, 697 F.3d 1367 (Fed. Cir. 2012), the bar was raised even higher when the Federal Circuit stated “when the claim drafter has not signaled his intent to invoke Section 112(6) by using the term ‘means,’ we are unwilling to apply that provision without a showing that the limitation essentially is devoid of anything that can be construed as structure.” Thus, when the word “means” did not appear in the claims, while it was possible to show that Section 112(6) applied to the claims, it also was extremely difficult. In any event, if a party challenging a patent can show that Section 112(6) applied to claims lacking the word “means,” and further can show a lack of structure corresponding to the claim language, then the claim will most likely be held invalid.

The patent in Williamson claimed a “virtual classroom” and was asserted against a plethora of well-known companies, namely Citrix, Microsoft, Adobe, WebEx, Cisco and IBM. The district court found the asserted patent invalid. In the first Williamson opinion (decided by a three-judge panel of the Federal Circuit), the lower court was reversed and a ruling was made in favor of the patent owner. More particularly, the three-judge panel concluded that (1) the word “means” did not appear in the claims; (2) Section 112(6) did not apply to the claims; and (3) the lower court’s holding of non-infringement was vacated. The three-judge panel held that since Section 112(6) was not deemed to apply to the claims, the issue of whether the specification disclosed structure corresponding to the claim language should not have been considered.

In the Federal Circuit’s subsequent Williamson en banc opinion, things changed. The en banc panel took issue with the previous “strong” presumption that Section 112(6) did not apply to a claim when the word “means” was lacking. The en banc panel stated, “We abandon characterizing as ‘strong’ the presumption that a limitation lacking the word “means” is not subject to 112, para. 6. That characterization … has resulted in a proliferation of functional claiming untethered to 112, para. 6 and free of the strictures set forth in the statute. … We … expressly overrule the characterization of that presumption as ‘strong.’

“The standard is whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure. … When a claim term lacks the word ‘means,’ the presumption can be overcome and Section 112, para. 6 will apply if the challenger demonstrates that the claim term fails to ‘recite sufficiently definite structure’ or else recites ‘function without reciting sufficient structure for performing that function.’

Again, the Williamson claims lacked the word “means.” The en banc panel concluded, however, that (1) sufficiently definite structure was lacking from the claims in suit, (2) the presumption against Section 112(6) was rebutted, (3) Section 112(6) applied, and (4) by failing to disclose adequate structure the claims were invalid.

Patent owners often want functional claims, but Williamson teaches that such claims are fraught with danger if the accompanying specification does not include structure to perform the functions specified in the claims. The lack of the word “means” in a claim is not a guarantee that Section 112(6) will not apply. Based on the en banc decision in Williamson, there is no longer a┬ástrong presumption that a claim omitting the term “means” is not subject to Section 112(6). Sometimes, even “no means” means “means.”

– by Lawrence Ashery


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