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Narrow Written Description Limits Broad Claim Term Despite Broad Statement in Prosecution

June 22, 2006

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Last Month at the Federal Circuit - July 2006

Judges: Mayer, Lourie (author), Dyk

In Honeywell International, Inc. v. ITT Industries, Inc., No. 05-1407 (Fed. Cir. June 22, 2006), the Federal Circuit affirmed the district court’s grant of SJ of noninfringement to ITT Industries, Inc.; ITT Automotive, Inc.; TG North America Corporation; TG Fluid Systems USA Corporation; and A. Raymond, Inc. (collectively “ITT/TG”).

The patent-in-suit, U.S. Patent No. 5,164,879 (“the ’879 patent”), describes a fuel injection system component for communicating fuel to the engine of a motor vehicle. The ’879 patent addresses a problem wherein fuel filters made of polymer began to break down and started leaking when motor vehicles began using electronic fuel injection systems. The patented invention solves this problem by providing an electrically conductive pathway between the fuel filter and the vehicle’s metal frame.

Honeywell International, Inc. and Honeywell Intellectual Properties, Inc. (collectively “Honeywell”) sued ITT/TG for infringement of the ’879 patent. The products accused of infringement were “quick connect” structures that join the various components of a fuel injection system together, such as a fuel line to a fuel filter. After construing the claims, the district court granted ITT/TG’s motion for SJ of noninfringement.

On appeal, the Federal Circuit rejected Honeywell’s argument that the district court improperly imported a limitation from the specification into the claims by construing “fuel injection system component” to be limited to a fuel filter. The Court held that the written description leads to the conclusion that a fuel filter is the only “fuel injection system component” that the claims cover, and that a fuel filter was not merely discussed as a preferred embodiment, as Honeywell argued. The Court pointed out that at least on four occasions, the written description referred to the fuel filter as “this invention” or “the present invention.” The Court explained that “[t]he public is entitled to take the patentee at his word and the word was that the invention is a fuel filter.” Slip op. at 11. The Court also noted that the written description did not indicate that a fuel filter is merely a preferred embodiment because the fuel filter was the only component that the written description discloses as having a polymer housing as claimed.

Nor was the Court persuaded by the patentee’s response to an indefiniteness rejection during prosecution in which he stated that the claims cover “all fuel components.” Id. The Court concluded that the statement was ambiguous and, regardless, such a broad and vague statement in the prosecution history could not contradict the clear statements in the specification describing the invention more narrowly. Furthermore, the Court reasoned that where the written description clearly identifies what his invention is, an expression by a patentee during prosecution that he intends his claims to cover more than what his specification discloses is entitled to little weight.

The Court also did not assign much weight to the patent examiner’s restriction requirement with respect to claims for a “fuel filter” and a “fuel system component” during prosecution of a related application. The Court concluded that in making the requirement, the examiner did not construe the claim term “fuel system component” or determine its meaning in light of the written description, but merely required election of one aspect of the invention for prosecution without applying it to the specification.

The Court, however, disagreed with the district court’s construction of the claim term “electrically conductive fibers” to the extent that it encompassed carbon fibers. The Court reasoned that, even though it was true that the written description did not expressly define “electrically conductive fibers” as it did for “fuel injection system component,” the written description disavowed carbon fibers from the scope of the ’879 patent because it demeaned the properties of carbon fibers. The Court noted that by listing all the reasons that metal fibers fare better than carbon fibers for use in the claimed invention, the patentee informed its readers specifically why carbon fibers would not be suitable as “electrically conductive fibers” in the claimed invention. The Court reasoned that contrary to the district court’s understanding, the written description went beyond expressing the patentee’s preference for one material over another.

The Court also affirmed the district court’s conclusion of noninfringement under the DOE as a matter of law. The Court explained that once it construed the fuel system component to be a fuel filter, the fuel filter became central to the patented invention. The Court concluded that if one utilized the conventional function/way/result analysis, it was beyond question that the accused quick connects did not perform the function of a fuel filter. Further, the Court reasoned that there could be no infringement under the DOE because the quick connect uses carbon fibers, and such fibers were disavowed from the scope of the “electrically conductive fibers” limitation.