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Commercial Success of Embodiments Having Features Not Recited in the Claims May Be Considered When Determining Obviousness

November 30, 2012
Rodkey, Kevin D.

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Last Month at the Federal Circuit - December 2012

Judges: Dyk (author), Clevenger, Wallach (dissenting-in-part)

[Appealed from: D. Del., Judge Robinson]

In ArcelorMittal France v. AK Steel Corp., No. 11-1638 (Fed. Cir. Nov. 30, 2012), the Federal Circuit affirmed-in-part and reversed-in-part the district court’s claim construction of U.S. Patent No. 6,296,805 (“the ’805 patent”), reversed the jury’s finding of anticipation, and remanded for a new trial on the secondary consideration of commercial success with respect to obviousness and literal infringement under the Court’s new claim construction.

ArcelorMittal France and ArcelorMittal Atlantique et Lorraine (collectively “ArcelorMittal”) own the ’805 patent, which relates to a boron steel sheet having an aluminum-based coating. The ’805 patent discloses that the steel can be processed by rapidly heating the steel for “hot-stamping” and then rapidly cooling the steel by “quenching,” which increases its mechanical strength, resulting in parts that are thinner and lighter. The ’805 patent discloses that the aluminum-based coating prevents undesirable oxidation of the steel during processing.

ArcelorMittal sued AK Steel Corporation, Severstal Dearborn, Inc., and Wheeling-Nisshin Inc. (collectively “AK Steel”) in the District Court for the District of Delaware, alleging that AK Steel’s aluminum-coated steel sheets infringed the ’805 patent. The district court construed the term “hot-rolled steel sheet” to mean “a steel sheet that has been reduced to its final thickness by hot-rolling,” and construed the term “the steel sheet has a very high mechanical resistance” to mean “the flat-rolled steel has been subjected, after rolling, to additional controlled heating and cooling and has an ultimate tensile strength of 1500 MPa or greater.” Slip op. at 5-6 (citations omitted). A jury found that AK Steel’s products did not infringe these claims under the DOE, and that the asserted claims were both anticipated and obvious. ArcelorMittal appealed.

On appeal, the Federal Circuit first reversed the district court’s construction of “hot-rolled steel sheet,” which excluded hot-rolled steel sheets that were also cold-rolled during processing. The Court explained that the claim term “comprising” contemplates the use of unstated steps, such as cold-rolling. The Court acknowledged that the term “hot-rolled steel sheet” refers to a term that is not cold-rolled, but explained that the ’805 patent’s disclosure demonstrates that additional processing steps, such as cold-rolling, may be applied to the steel. Specifically, the Court noted that the ’805 patent refers to an optional cold-rolling step throughout the description, such as describing the purpose as including the production of a cold-rolled steel sheet. The Court also observed that several exemplary sheet thicknesses disclosed in the specification could only be achieved by cold-rolling. Because claim terms are not normally interpreted in ways that exclude examples disclosed in the specification, and because “the specification unambiguously contemplates cold-rolling,” the Court reversed the district court and held that the proper construction of “hot-rolled steel sheet” is “a steel sheet that has been hot-rolled during its production.” Id. at 9.

Next, the Federal Circuit affirmed the district court’s construction of “very high mechanical resistance.” The specification describes a “high” or “substantial” mechanical resistance as 1500 MPa. Because the term “very high” was not defined, the Court reasoned that a “very high” mechanical resistance must exceed a “high” resistance of 1500 MPa. The Court rejected ArcelorMittal’s argument that the specification also discloses mechanical resistances as low as 1000 MPa, noting that the specification did not refer to 1000 MPa as either “high” or “very high.” The Court also examined a prior art article coauthored by one of the inventors of the ’805 patent that described steels with “high mechanical characteristics” as having an ultimate tensile strength of greater than 1500 MPa after heat treatment. Id. at 11. The Court stated that although an inventor’s subjective understanding of patent terminology is irrelevant to claim construction, “when an inventor’s understanding of a claim term is expressed in the prior art, it can be evidence of how those skilled in the art would have understood that term at the time of the invention.” Id. Accordingly, the Court affirmed the district court’s construction that “very high mechanical resistance” means a resistance of 1500 MPa or greater. The Court then remanded for a new trial on infringement based on the proper claim constructions.

The Court next reversed the jury’s finding of anticipation based on a reference referred to as the Bano article. The Federal Circuit noted that Bano states that it is advisable to protect heat-treated parts with coatings, but does not disclose any particular coating compositions. The Court determined that Bano’s disclosure of paint coatings could support a jury finding that Bano discloses precoating the steel, but rejected the jury’s finding that Bano discloses either aluminum or aluminum alloy coatings. The Court also rejected the district court’s holding that aluminum is a member of a small class of metals that are suitable for coating boron steel and is therefore inherently disclosed by Bano. The Court observed that Bano’s disclosure of paint coatings does not support a finding that both paint and metal coatings fit into a general formula of coatings, or that they are a definite and limited class of coatings for a steel sheet. The Court further explained that one of ordinary skill in the art would not envision each member of the class of paint and metal coatings upon reading Bano, even if such a class existed. Because the Court held that Bano does not disclose aluminum coatings and that there was no substantial evidence that aluminum belongs to a definite and limited class of possible coatings, the Court reversed the jury’s verdict of anticipation and the district court’s denial of JMOL.

The Federal Circuit then turned to whether the ’805 patent was obvious over Bano and French Patent No. 1,297,906 (“the French ’906 patent”). The Court first noted that ArcelorMittal conceded that each element of the claimed invention was known in the prior art. The Court then explained that Bano and the French ’906 patent could support a jury finding a prima facie case of obviousness. First, Bano’s disclosure was sufficient to support a jury finding that it discloses applying a coating before heat treatment. Second, the French ’906 patent discloses coating steel with aluminum during hot-forging. The Court considered ArcelorMittal’s argument that hot-stamping and hot-forging are not analogous art, but concluded that this was a question of fact to be resolved by the jury. The Court determined that there was also sufficient evidence that a person of ordinary skill could have combined Bano and the French ’906 patent, and that the jury properly concluded that AK Steel established a prima facie case of obviousness.

Finally, the Court considered whether the erroneous construction of “hot-rolled steel sheet” required a new trial on obviousness. Because the district court had instructed the jury to only consider commercial success of products covered by the asserted claims, the jury did not consider products made by both hot-rolling and cold-rolling. The Court rejected AK Steel’s argument that even if the claims included both hot-rolling and cold-rolling, the hot-rolled embodiment is obvious and, therefore, the entire claim is obvious. The Court stated that this is not a situation when the claims describe distinct alternative embodiments and where the obviousness of one embodiment invalidates the entire claim. The Court explained that the claim recites only hot-rolled steel, but also contains “comprising” language permitting the performance of additional cold-rolling steps. Under these circumstances, the commercial success of an embodiment with an additional unrecited feature may be considered when evaluating the obviousness of the claim, provided that there is a nexus between the embodiment’s success and the claimed and novel features of the invention. The Court held that the commercial success of ArcelorMittal’s cold-rolled embodiment must be considered to the extent that its success results from the claimed invention rather than solely from the cold-rolling which was not claimed. The Court remanded for a new trial to consider secondary considerations of nonobviousness on the cold-rolled embodiment.

Judge Wallach dissented-in-part from the majority’s construction of “very high mechanical resistance.” Judge Wallach argued that this term should be construed to mean in excess of 1000 MPa. Judge Wallach pointed to the stated purpose of the invention to produce a coated steel sheet with a mechanical resistance in excess of 1000 MPa after thermal treatment. Judge Wallach also observed that the specification used the terms “high,” “very high,” and “substantial” interchangeably, and that these terms did not help to shed light on the scope of the claims. Instead, Judge Wallach focused on the purported increase in mechanical resistance in excess of 1000 MPa, as recited by the ’805 patent.

Summary authored by Kevin D. Rodkey, Esq.