Liquid Dynamics Corp. v. Vaughan Co., __ F.3d ___, __ USPQ2d ___ (Fed. Cir. Jan. 23, 2004) (Lourie (dissent), GAJARSA, Dyk) (D. Ill.: Conlon)
KEY WORDS: CLAIM CONSTRUCTION (BROAD), DUAL RULE (BROAD), ORDINARY MEANING, MOOTNESS
Fed Cir vacates summary judgment of noninfringement as premised on a too-narrow claim construction. The patent related to stirring of slurry (e.g., manure) tanks using “flow generating means … at an angle to the radius” of the tank for “generating a substantial helical flow path” out along the floor, up the wall, across the top, and then down. The claims as filed merely recited a “flow,” and said nothing about its shape. The district court erred in concluding that “substantial helical flow path” was ambiguous and by imposing a numerical constraint from the written description that required perfectly helical flow, because “substantial” simply means “approximate” rather than “perfect.” The wording of other claim limitations was also consistent with this broader meaning. Liquid presented sufficient evidence to avoid summary judgment on literal infringement under the correct construction, but the Fed Cir noted for remand that Liquid presumptively surrendered under Festo all flows that are not literally “substantially helical.” The district court also did not abuse its discretion is dismissing Vaughan’s counterclaims as moot, but the Fed Cir took the opportunity to emphasize that Cardinal Chemical simply prohibits the Fed Cir from vacating a judgment of invalidity when the Fed Cir determines that a patent is not infringed.
A quote: “Courts construe claims by considering the evidence necessary to resolve disputes about claim terms and to assign a fixed, unambiguous, legally operative meaning to the claim…. We examine this intrinsic evidence [i.e., claims, spec, and prosecution history] seriatim.” [They've said to start with the claims before, and they've done seriatim analysis all the time, but I don't know if they ever made the seriatim point explicitly before]
In dissent, Judge Lourie believed that the language describing the flow path (out along the bottom, up the side, etc.) limited the claims scope. He also felt that the majority’s construction was essentially the same as the district court’s construction so that affirmance was proper. [This is disturbing, because the majority obviously intended its construction to be very different than the district court’s construction; this simply shows that claim construction often does not “assign a fixed, unambiguous” meaning to a claim, as the majority's quote suggests.]
Query: Is anyone bothered that the claim term is “substantial,” but the Fed Cir pretends that it is “substantially”?
Decision
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