Opinion ID: 208069
Heading Depth: 2
Heading Rank: 1

Heading: Fibrous batt of fibers

Text: With regard to the term “fibrous batt of fibers,” Lydall argues that the district court incorrectly believed that there was only one embodiment disclosed in the ’260 patent. In making this error, Lydall contends, the district court applied its own Honeywell decision instead of following our decision in Phillips. Lydall asserts that the claim language is clear and unambiguous and does not suggest that the batt must be layered. Lydall argues that, in addition to describing the claimed invention, the specification uses the term “fibrous batt” to describe the prior art, which included single-layer batts. Lydall 2009-1135 8 contends that the specification expressly teaches that organic fibers may be used throughout the batt and that the binding fibers and the insulating fibers can be made of the same material, thus indicating that the term “fibrous batt of fibers” includes a homogenous batt made of one material. Lydall asserts that the specification expressly states that the drawing reference numerals used in the claims are not meant to be limitations and that the file history expressly indicates the same. Lydall also argues that the prosecution history indicates that the inventors intended to cover a homogenous batt in claim 1, which uses the same language as claim 45. Finally, Lydall asserts that claim differentiation of dependent claim 48, which includes a limitation for a three-layer, non-homogenous batt, requires a presumption, which Lydall argues is unrebutted, that claim 45 does not include such a limitation. In response, Federal-Mogul argues that Lydall has failed to acknowledge that this court upheld the district court’s decision, including its claim construction, in Honeywell after we issued the Phillips decision. Federal-Mogul asserts that, as in Honeywell, the ’260 specification disclosed only one invention: a multi-layered composite batt of fibrous materials with tufts of fibers formed on each side by two-sided needling. Federal-Mogul contends that all references in the specification to “batt” describe an insulating layer sandwiched between binding layers. Federal-Mogul argues that the broadest configuration in the specification is an insulating layer that is “at least in part” organic, but even that configuration, Federal-Mogul asserts, does not indicate that the term “fibrous batt of fibers” encompasses a single-layer, homogenous batt of all organic fibers. Federal-Mogul contends that Lydall cannot rely on its statements during the reissue prosecution to expand the scope of the ’260 patent when the specification 2009-1135 9 clearly limits the invention to a narrower scope. Finally, Federal-Mogul argues that claim 45 has only one interpretation, so claim differentiation does not apply because the written description and claims overcome the presumption of claim differentiation. Regardless, Federal-Mogul asserts that claim 48 also contains other limitations that distinguish it from claim 45. We agree with Federal-Mogul that the specification of the ’260 patent discloses a single embodiment of the invention, viz., an insulating shield that includes a fibrous batt consisting of an insulating layer sandwiched between two binding layers that is, as discussed infra, needled on two sides. Although Lydall is correct in saying that the claim language “fibrous batt of fibers” does not, in isolation, suggest a layered batt, Lydall’s arguments completely ignore the consistent use of the term “batt” in the specification. It is fundamental that we give due weight to the specification when construing this claim term. Phillips, 415 F.3d at 1315. We have stated that “when the preferred embodiment is described in the specification as the invention itself, the claims are not necessarily entitled to a scope broader than that embodiment.” Chimie v. PPG Indus., 402 F.3d 1371, 1379 (Fed. Cir. 2005); see Honeywell, 452 F.3d at 1318 (construing claim term to include fuel filter because “[o]n at least four occasions, the written description refers to the fuel filter as ‘this invention’ or ‘the present invention’”); SciMed, 242 F.3d at 1343 (construing term to include feature characterized as “the present invention”). In other words, when a patentee consistently describes one embodiment as “the present invention,” “[t]he public is entitled to take the patentee at his word.” Honeywell, 452 F.3d at 1318; see also SciMed, 242 F.3d at 1341 (“Where the specification makes clear that the invention does 2009-1135 10 not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”). Such is the case here. The specification identifies a three-layered batt as “the present invention.” ’260 patent col.6 ll.50. In addition, the specification repeatedly describes the batt as having an insulating layer disposed between two binding layers. See id. col.6 ll.53–55, col.9 ll.21–25, col.13 ll.19–23. Lydall’s consistent description of “the present invention” as including a three-layered batt makes clear that the claimed “fibrous batt of fibers” must have three layers, an insulating layer sandwiched between two binding layers. The fact that the specification discloses that the insulating fibers may “at least in part” be made up of the same organic fibers as the binding layers does not dissuade us from our conclusion. It may be that the insulating layer and the binding layers are made from the same material, but the batt still has three layers. It is not, therefore, a single, homogenous layer. We also agree with the district court that Lydall’s reliance on the prosecution history and the doctrine of claim differentiation is unpersuasive. “Representations during prosecution cannot enlarge the content of the specification.” Biogen, Inc. v. Berlex Labs., Inc., 318 F.3d 1132, 1140 (Fed. Cir. 2003). Thus, when the prosecution history appears in conflict with the specification, any ambiguity must be resolved in favor of the specification. See id. The specification is the “best source for understanding a technical term,” to be supplemented, “as needed, by the prosecution history.” Phillips, 415 F.3d at 1315 (quoting Multiform Desiccants, Inc. v. Medzam, Ltd., 133 F.2d 1473, 2009-1135 11 1478 (Fed. Cir. 1998)). Here, the specification is clear. The sole embodiment of the invention includes a batt that has three layers. The patentee’s efforts during the prosecution of the reissue patent to enlarge the claims beyond what the specification discloses also must fail. Similarly, Lydall cannot rely on claim differentiation to expand the scope of the claim term. See Nystrom v. Trex Co., 424 F.3d 1136, 1143 (Fed. Cir. 2005) (“[S]imply noting the difference in the use of claim language does not end the matter. Different terms or phrases in separate claims may be construed to cover the same subject matter where the written description and prosecution history indicate that such a reading of the terms or phrases is proper.”). In addition, as Federal-Mogul asserts, claim 48 can be differentiated from claim 45 by other limitations. Thus, we conclude that the district court properly construed “fibrous batt of fibers” as “a composite batt having a layer of insulating fibers sandwiched between layers of binding fibers.”