Welker Bearing v. PHD (CAFC 2008-1169)

The two relevant patents, in the same family, were 6,786,478 and 6,913,254.

The nub of means-plus-function is not the word, but whether the claim recites, or at least implies to one skilled in the art, sufficient functional structure to be self-standing without reference to the specification.

This court has consistently held that "[m]eans-plus-function claiming applies only to purely functional limitations that do not provide the structure that performs the recited function." Phillips v. AWH Corp., 415 F.3d at 1311 (Fed. Cir. 2005). Further, a patentee's use of the word "means" in a claim limitation creates a presumption that 35 U.S.C. § 112 paragraph 6 applies. TriMed, Inc. v. Stryker Corp., 514 F.3d 1256, 1259 (Fed. Cir. 2008).

In this instance, the '254 patent's claim language does not include the word "means," but instead the similar word "mechanism." This court has had several prior occasions to consider the applicability of means-plus-function treatment in the context of the claim term "mechanism." In Massachusetts Institute Of Technology v. Abacus Software, 462 F.3d 1344, 1354 (Fed. Cir. 2006) ("MIT"), this court considered the applicability of means-plus-function treatment to the term "colorant selection mechanism." This court noted that "[t]he generic terms 'mechanism,' 'means,' 'element,' and 'device,' typically do not connote sufficiently definite structure [to avoid means-plus-function treatment] . . . The term 'mechanism' standing alone connotes no more structure than the term 'means.'" Id. (emphasis added). Although "[c]laim language that further defines a generic term like 'mechanism' can sometimes add sufficient structure to avoid 112 ¶ 6," the adjectival modifier "colorant selection" was not defined in the specification and did not carry any generally understood structural meaning in the art. Id. Thus, this court read "colorant selection mechanism" as invoking treatment as a functional claim because it did not contain sufficient structure. Id.

By contrast, in Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580 (Fed. Cir. 1996), this court held that paragraph 6 did not apply to the term "detent mechanism," because "the noun '[d]etent' denotes a type of device with a generally understood meaning in the mechanical arts, even though the definitions are expressed in functional terms." Id. at 1583. This court examined several definitions of "detent," such as "[a] catch or checking device, the removal of which allows machinery to work such as the detent which regulates the striking of a clock." Id. Because these definitions connoted adequate structure that was reasonably well understood in the art, this court concluded that "detent mechanism" was not a mere functional placeholder. Id.

This court must assess the meaning of "mechanism for moving said finger" in light of this case law. In that context, the "mechanism for moving said finger" language includes even less structural context than the "colorant selection mechanism" in MIT. No adjective endows the claimed "mechanism" with a physical or structural component. Further, claim 1 provides no structural context for determining the characteristics of the "mechanism" other than to describe its function. Thus, the unadorned term "mechanism" is "simply a nonce word or a verbal construct that is not recognized as the name of structure and is simply a substitute for the term 'means for.'" Lighting World, 382 F.3d at 1360. Unlike the "detent mechanism" in Greenberg which had a known structural meaning, one of skill in the art would have no recourse but to turn to the '254 patent's specification to derive a structural connotation for the generically claimed "mechanism for moving said finger . . . ."

The CAFC intimated that the means-plus-function interpretation was necessitated by leaving the claimed mechanism "vague."

The applicant for the '254 patent could have supplied structural context to claim 1 in any number of ways. If claim 1 of the '254 patent had recited, e.g., a "finger displacement mechanism," a "lateral projection/retraction mechanism," or even a "clamping finger actuator," this court could have inquired beyond the vague term "mechanism" to discern the understanding of one of skill in the art. If that artisan would have understood such language to include a structural component, this court's analysis may well have turned out differently. Instead the applicant chose to express this claim element as "a means or step for performing a specified function without the recital of structure, material, or acts in support thereof." 35 U.S.C. § 112 ¶ 6. Therefore, this court must agree with the district court, which properly applied means-plus-function treatment to this term.

The skill of claim term construction is limiting the definition to the essential, without importing unnecessary baggage.

Because "mechanism for moving said finger" is a means-plus-function limitation, this court must next examine the trial court's identification of "the corresponding structure, material, or acts described in the specification and equivalents thereof." 35 U.S.C. § 112 ¶ 6. In doing so, "a court may not import functional limitations that are not recited in the claim, or structural limitations from the written description that are unnecessary to perform the claimed function." Wenger Mfg., Inc. v. Coating Mach. Sys., Inc., 239 F.3d 1225, 1233 (Fed. Cir. 2001).

While not explicit in asserted '254 claim 1, using the same term as claim '478 means that the finger moving mechanism necessarily involves rotation.

Other claim construction doctrines like claim differentiation, ordinary meaning, and clear disavowal of claim scope do not compel a different construction. With regard to claim differentiation, this court is aware that claim 1 of the '478 patent recites a rotating element, while claim 1 of the '254 patent does not. This difference between claims in different patents does not change the meaning of these means-plus-function limitations. By statute, this court must follow the directive to construe these limitations according to § 112 ¶ 6. Because both terms share the same specification with the same structure corresponding to the claimed function, this court cannot give these terms any different scope. This court finds no error in the district court's identification of corresponding structure, which includes a rotating central post.

The accused product didn't use rotation. Hence, no infringement.

Literal infringement of a claim limitation in means-plus-function format "requires that the relevant structure in the accused device perform the identical function recited in the claim and be identical or equivalent to the corresponding structure in the specification." Applied Med. Research Corp. v. United States Surgical Corp., 448 F.3d 1324, 1333 (Fed. Cir. 2006).

The record shows that PHD's Clamp II propels clamping fingers in and out of the locating pin without any rotational movement. Instead Clamp II's linear-moving mechanism for finger movement and the claimed "mechanism for moving said finger" with a rotating central post are "substantially different." SJ Opinion at 704.

Welker Bearing's argument that Clamp II might infringe under the doctrine of equivalents is equally unavailing. Indeed this case does not present a case for equivalents under the doctrine of equivalents at all. This case presents only the question of structural equivalents under §112 ¶ 6. Structural equivalents and the doctrine of equivalents are "closely related." See, e.g., Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus., Inc., 145 F.3d 1303, 1309 (Fed. Cir. 1998). They are related in the sense that both § 112 ¶ 6 and the doctrine of equivalents apply "similar analyses of insubstantiality of the differences" between a disclosed structure and an accused infringing structure. Id. at 1310. However, an important difference between the two inquiries "involves the timing of the separate analyses for an 'insubstantial change.'" Al-Site Corp. v. VSI Int'l, Inc., 174 F.3d 1308, 1320 (Fed. Cir. 1999). Namely, an equivalent structure under § 112 ¶ 6 "must have been available at the time of the issuance of the claim," whereas the doctrine of equivalents can capture after-arising "technology developed after the issuance of the patent." Id.

The record demonstrates that PHD's linear-moving mechanism for finger movement was well known in the prior art and cannot be classified as after-arising technology. SJ Opinion at 706. Thus, where, as here, a proposed equivalent has arisen before patent issuance, "a § 112 ¶ 6 structural equivalents analysis applies and any analysis for equivalent structure under the doctrine of equivalents collapses into the § 112 ¶ 6 analysis." Al-Site, 174 F.3d at 1321 n.2. Under any analysis, Welker Bearing cannot show equivalence between its disclosed mechanism and the Clamp II mechanism.

Affirmed.