DeMarini argued before the district court that the EST accomplishes the same function (increasing the trampoline deflection), in substantially the same way (with a leaf-spring-like action), to achieve substantially the same result (improved hitting performance). Moreover, DeMarini contended that, like the accused infringing device in Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 9 USPQ2d 1962 (Fed. Cir. 1989), Worth's EST bat presented a classic example of transposition of two elements. Therefore, DeMarini argued that infringement under the doctrine of equivalents should be upheld on summary judgment just as it was in Corning Glass.

Ethicon argues that the district court's reliance on Dolly and Weiner, as well as USSC's reliance on Sage, is misplaced because those cases are factually distinguishable, and in any event no language in claim 6 "directly addresses and specifically excludes" a lockout positioned as in USSC's staplers. Ethicon also argues that the statements relied upon by the district court and USSC, if read broadly, would thoroughly undermine the doctrine of equivalents and specifically contradict Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1259, 9 USPQ2d 1962, 1968 (Fed. Cir. 1989) ("An equivalent must be found for every limitation of the claim somewhere in an accused device, but not necessarily in a corresponding component, although that is generally the case.").

"An equivalent must be found for every limitation of the claim somewhere in an accused device, but not necessarily in a corresponding component, although that is generally the case." Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 1259 (Fed. Cir. 1989) (adding negative dopant to the cladding is equivalent to adding positive dopant to the core in the context of the claimed invention). Since equivalency was not disputed, and we agree that the claimed test is met of substantially the same function, way, and result, the district court granted Festo's motion for summary judgment of infringement.

A "claim" set forth in a patent "provides the metes and bounds of the right which the patent confers on the patentee to exclude others from making, using, or selling the protected invention." Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 1257 (Fed. Cir. 1989) ( citing Graver Tank Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 607, 70 S.Ct. 854, 855, 94 L.Ed. 1097 (1950)). As the Federal Circuit has explained:

If the words of the preamble "give life and meaning" to the claim, then it may be interpreted to limit further the scope of the claim. Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 1257, 9 P.Q.2d 1962 (Fed. Cir. 1989); Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 866, 228 U.S.P.Q. 90 (Fed. Cir. 1985). Here, the '461 specifications indicate that the inventor was working on the particular problem of creating an effective splicing assembly to manipulate video magnetic tape and leader tape.

As a definitional matter, patent claims "are the numbered paragraphs which ‘particularly point out and distinctly claim the subject matter which the applicant regards as his invention.’ " Corning Glass Works v. Sumitomo Elec. U.S.A., Inc. , 868 F.2d 1251, 1258 (Fed. Cir. 1989) (quoting 35 U.S.C. § 112 (alterations omitted)). "The words of the claims themselves define the scope of the invention, and are given their ordinary and customary meaning, unless the patentee has chosen to use terms in some other manner."

98 F.3d 1563, 1572-73 (Fed. Cir. 1996); see also, e.g., Bicon, Inc. v. Straumann Co., 441 F.3d 945, 952 (Fed. Cir. 2006) ("[W]hether to treat a preamble as a claim limitation is determined on the facts of each case in light of the claim as a whole and the invention described in the patent."); Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 1257 (Fed. Cir. 1989) ("The effect preamble language should be given can be resolved only on review of the entirety of the patent to gain an understanding of what the inventors actually invented and intended to encompass by the claim."); In re Stencel, 828 F.2d 751, 754 (Fed. Cir. 1987) ("Whether a preamble of intended purpose constitutes a limitation to the claims is, as has long been established, a matter to be determined on the facts of each case in view of the claimed invention as a whole.").

Whether to treat a preamble as a limitation is a determination "resolved only on review of the entire . . . patent to gain an understanding of what the inventors actually invented and intended to encompass by the claim." Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1257, 9 USPQ2d 1962, 1966 (Fed. Cir. 1989); see also Applied Materials, Inc. v. Advanced Semiconductor Materials Am., Inc., 98 F.3d 1563, 1572-73, 40 USPQ2d 1481, 1488 (Fed. Cir. 1996) ("Whether a preamble stating the purpose and context of the invention constitutes a limitation of the claimed process is determined on the facts of each case in light of the overall form of the claim, and the invention as described in the specification and illuminated in the prosecution history."). In general, a preamble limits the invention if it recites essential structure or steps, or if it is "necessary to give life, meaning, and vitality" to the claim.

Where a patentee uses the claim preamble to recite structural limitations of his claimed invention, the PTO and courts give effect to that usage. See id.; Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 1257, 9 USPQ2d 1962, 1966 (Fed. Cir. 1989). Conversely, where a patentee defines a structurally complete invention in the claim body and uses the preamble only to state a purpose or intended use for the invention, the preamble is not a claim limitation.

The Snack Play stable rigid frame assembled from the panels is not the equivalent of the claimed stable rigid frame which specifically excludes the seat and back panels. Finally, Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 9 USPQ2d 1962 (Fed. Cir. 1989), does not support an application of the doctrine of equivalents to find infringement in this case. In Corning Glass, the inventions related to optical fibers which transmit light for optical communications.