December 4, 2012
Deere sued Bush Hog for infringing 6,052,980, claiming a rotary cutter for tilling soil. Bush Hog got off the hook with an ersatz claim construction leading to non-infringement by way of denying the doctrine of equivalents. On appeal, the CAFC gave a tutorial on the doctrine while rototilling the district court's summary judgment.
Deere & Company v Bush Hog et al (CAFC 2011-1629) precedential; Judges Rader (author), Newman, and Plager
The district court held Deere could not assert infringement under the doctrine of equivalents because the "into engagement with" limitation, as construed by the court, "is binary in nature"--either the upper deck wall is "in contact with the lower deck wall or it is not." Summary Judgment Opinion, slip. op. at 15 (internal quotation omitted). Further, the court held Deere's theory of equivalence was precluded by the doctrine of specific exclusion, "because the 'into engagement with' claim limitation specifically excludes structures where the deck walls are not engaged with each other." Id. at 16. Because the district court's analysis of this issue was based on its erroneous claim construction, this court also vacates the grant of summary judgment of no infringement under the doctrine of equivalents.
The district court's treatment of the doctrine of equivalents reveals a common misperception regarding "vitiation" that warrants some discussion. The concept of vitiation derives from the requirement that the doctrine of equivalents must be applied to the claims "on an elementby- element basis," so that every claimed element of the invention--or its equivalent--is present in the accused product. Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 40 (1997). Of course, in every case applying the doctrine of equivalents, at least one claimed element is not literally present in the accused product. The question is "whether an omitted part is supplied by an equivalent device or instrumentality." Id. at 32 (quoting Hubbell v. United States, 179 U.S. 77 (1900)). Thus, the doctrine of equivalents, by its very nature, assumes that some element is missing from the literal claim language but may be supplied by an equivalent substitute.
The test of the equivalence of a proposed substitute for a missing element is ordinarily a factual inquiry reserved for the finder of fact. Warner-Jenkinson, 520 U.S. at 38-39; Sage Prods., Inc. v. Devon Indus., Inc., 126 F.3d 1420, 1423 (Fed. Cir. 1997). It is the role of the court, however, to ensure that the doctrine of equivalents is not permitted to overtake the statutory function of the claims in defining the scope of the patentee's exclusive rights. Sage, 126 F.3d at 1424. Thus, for example, courts properly refuse to apply the doctrine of equivalents "where the accused device contain[s] the antithesis of the claimed structure." Planet Bingo, 472 F.3d at 1345. In such a case, application of the doctrine of equivalents would "vitiate" a claim element. Warner-Jenkinson, 520 U.S. at 39 n.8.
"Vitiation" is not an exception to the doctrine of equivalents, but instead a legal determination that "the evidence is such that no reasonable jury could determine two elements to be equivalent." Id. The proper inquiry for the court is to apply the doctrine of equivalents, asking whether an asserted equivalent represents an "insubstantial difference" from the claimed element, or "whether the substitute element matches the function, way, and result of the claimed element." Id. at 40. If no reasonable jury could find equivalence, then the court must grant summary judgment of no infringement under the doctrine of equivalents. Id. at 39 n.8.
Courts should be cautious not to shortcut this inquiry by identifying a "binary" choice in which an element is either present or "not present." Stated otherwise, the vitiation test cannot be satisfied by simply noting that an element is missing from the claimed structure or process because the doctrine of equivalents, by definition, recognizes that an element is missing that must be supplied by the equivalent substitute. If mere observation of a missing element could satisfy the vitiation requirement, this "exception" would swallow the rule. And, the Supreme Court declined to let numerous contentions bury the doctrine. Id. at 21, 40. Thus, preserving the doctrine in its proper narrowed context requires a court to examine the fundamental question of whether there is a genuine factual issue that the accused device, while literally omitting a claim element, nonetheless incorporates an equivalent structure.
In this case, the district court construed "contact" to require "direct contact," and thus found that allowing "no direct contact" would vitiate the court's construction. Yet, a reasonable jury could find that a small spacer connecting the upper and lower deck walls represents an insubstantial difference from direct contact. See TurboCare Div. of Demag Delaval Turbomachinery Corp. v. Gen. Elec. Co., 264 F.3d 1111, 1124 (Fed. Cir. 2001) (construing claim term "contact" to require "touching" but remanding question of whether "indirect contact" could be equivalent). Thus, the trial court erred by invoking the vitiation exclusion in this context.
This court has considered Defendants' other arguments against application of the doctrine of equivalents, but finds them unpersuasive. This court vacates the district court's determination that Deere is barred from asserting infringement under the doctrine of equivalents.
Reversed in part and remanded.
Posted by Patent Hawk at December 4, 2012 8:11 PM |