Opinion ID: 497896
Heading Depth: 3
Heading Rank: 2

Heading: Infringement of claims 3 and 5 under the Doctrine of Equivalents.

Text: 11 We also are not convinced by Propper's argument that the District Court erred in failing to find that the Surgicot pack infringed claims 3 and 5 of the Augurt patent under the doctrine of equivalents. In order to prove that the Surgicot pack infringed the '387 patent, it was incumbent on Propper to prove that each element of the accused STAR Pack did 'the same work in substantially the same way and accomplishe[d] substantially the same result' as the corresponding element in the claim. Hughes Aircraft Co. v. United States, 717 F.2d 1351, 1361, 219 USPQ 473, 482 (Fed. Cir. 1983); see also Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 608-09, 85 USPQ 328, 330 (1950). To overturn the District Court's finding on this matter, Propper has the burden to demonstrate affirmatively to this court that the District Court's findings were clearly erroneous. Fed. R. Civ. P. 52(a). 12 Even though the District Court recognized that the two inventions were similar, this does not mean that the accused invention necessarily infringes under the doctrine of equivalents. As this court has recognized, for two devices to be substantially equivalent, 'the element substituted in the accused device for the element set forth in the claim must not be such as would substantially change the way in which the function of the claimed invention is performed.' Perkin-Elmer Corp. v. Westinghouse Elec. Corp., 822 F.2d 1528, 1533, 3 USPQ2d 1321, 1324-25 (Fed. Cir. 1987). The District Court specifically found that the plastic laminated sheets of the Surgicot STAR Pack 'act contrary to the porous shell sheets of the '387 claims by blocking rather than permitting the passage of gas.' That is, the court acknowledged that those non-porous sheets caused a gas alignment different from the Augurt invention. The court further found that the two devices had different air/stream flow and bubble locations 3 and that the non-porous laminated sheets of the STAR Pack were substantially dissimilar to the porous paper sheets of the '387 patent. 13 The fact that the District Court found that the patent examiner had required Propper to submit amendments to define more specifically the porosity of the Augurt invention, before issuing a patent, also mitigates against a finding of infringement under the doctrine of equivalents. As a predecessor to this court stated: 'The doctrine of equivalents is subservient to file wrapper estoppel. It may not include within its range anything that would vitiate limitations expressed before the Patent Office.' Autogiro Co. v. United States, 384 F.2d at 400-01, 155 USPQ at 705. Since the PTO required appellants to delineate the porosity of the device during the prosecution of the patent, Propper cannot now claim that the non-porous sheet of the Surgicot device is equivalent to the porous sheets claimed in the Augurt patent. In these circumstances, and in light of the fact that there is testimony in the record to support those findings, we cannot say here that the District Court's findings on the doctrine of equivalents were clearly erroneous. See Preemption Devices, Inc. v. Minnesota Mining & Mfg. Co., 732 F.2d 903, 905, 221 USPQ 841, 842 (Fed. Cir. 1984).