Hydraflow asks this Court to find that the '745 patent teaches that there are two sources for the radial loads applied to the seal lips, the loads which result from stretching and compressing the respective lips, and the loads which the wedge applies. (Soom Dec. P 6.) The specifications do clearly contemplate such an "interference fit" of the sealing lips. (Ralabate Aff. P 2, exh. 1, Col. 3, lines 48-61; P2. Facts, exh. E, Col. 3, lines 48-61.) The question is what bearing, if any, this has on the teachings of Claim 1.
Claim 1 calls for a wedge, cooperating with a circular recess, "for applying radial loads to said inner and outer sealing lips." Hydraflow submits that loads which result from the stretching and compressing of seal lips are applied "to" the seal lips. Enidine responds that loads generated by seal lips are applied "to" something else, not to the seal lips themselves. Even if someone skilled in the art would understand that loads generated by the lips are applied "to" the lips as Hydraflow contends, the issue is not dispositive. Whether lips in an "interference fit" apply loads "to" themselves or "to" something else, the language of Claim 1 teaches that the wedge must apply loads to the inner and outer lips. Claim 1 speaks of radial loads that a wedge applies to the sealing lips, not radial loads the lips may apply to themselves. The specifications fully support this teaching. They depict a wedge applying radial loads to both the inner and the outer lips, which themselves are stretched and compressed.
Contrary to Hydraflow's contention, the teachings of Claim 1 clearly require that the source of the load on the inner lip include a load applied by the wedge element. Since Hydraflow concedes that a wedge must contact a sealing lip to apply a load to it, Claim 1 does exclude a structure in which the wedge contacts only one of the two sealing lips.
2. Comparison of Claim to Accused Device
Having interpreted Claim 1 of the '745 patent, this Court must now compare the claim with the accused device. See Stiftung, 945 F.2d at 1178-79. The patentee has the burden of proving infringement by a preponderance of the evidence. SRI International, 775 F.2d at 1123; Envirotech Corp. v. Al George, Inc., 730 F.2d 753 (Fed. Cir. 1984); SSIH Equipment S.A. v. United States International Trade Commission, 718 F.2d 365 (Fed. Cir. 1983). "Infringement of a claim requires that the accused device meet every limitation of the claim, either literally or by equivalents." Stiftung, 945 F.2d at 1178 (citing Builders Concrete, Inc. v. Bremerton Concrete Products Co., 757 F.2d 255, 257 (Fed. Cir. 1985)). Literal infringement is a question of fact, as is infringement by equivalents. Intel Corp. v. United States International Trade Commission, 946 F.2d 821, 841 (Fed. Cir. 1991) (citing Moleculon Research Corp. v. CBS, Inc., 793 F.2d 1261, 1269-70 (Fed. Cir. 1986); D.M.I., Inc. v. Deere & Co., 755 F.2d 1570, 1575 (Fed. Cir. 1985)).
a. Literal Infringement
"Literal infringement may be found when an accused device falls within the asserted claims as properly construed." In re Hayes Microcomputer Products, Inc. Patent Litigation, 982 F.2d 1527, 1541 (Fed. Cir. 1992) (citing Palumbo, 726 F.2d at 974). Hydraflow does not dispute that the wedge in the Enidine snubber contacts only the outer seal lip and applies no radial load to the inner sealing lip while at rest. (P2. Memo, p. 13; P2. R.Memo, p. 4.) Andres Soom, a Hydraflow expert engineer, testified that the inner side of the wedge does not touch the inner sealing lip of the Enidine device in a static condition. (Perlman Aff. P 13, exh. 5, p. 36.) James E. Brunton, Hydraflow's expert patent lawyer, agreed that the inner side of the wedge applies no radial load to the inner sealing lip of the Enidine snubber in the static condition. (Perlman Aff. P 13, exh. 6, p. 42.) Two Enidine engineers, Brian C. Bucholtz and Benjamin T. Houghton, opined that the Enidine wedge does not touch or apply any load to the inner lip. (Perlman Aff. P 13, exh. 4, p. 8; Perlma
Aff. P 4, exh. 2, p. 17.)
In fact, no contrary proof has been presented that the Enidine wedge ever contacts or otherwise applies any radial load to the inner sealing lip. An accused infringer "is entitled to summary judgment, on the ground of non-infringement, by pointing out that the patentee failed to put forth evidence to support a finding that a limitation of the asserted claim was met by the structure in the accused devices." Johnston, 885 F.2d at 1578. Mr. Brunton conceded that the Enidine device does not have a seal assembly in which a single, integral, annular wedging element applies radial loads to the inner and outer lips of a seal. (Perlman Aff. P 13, exh. 6, p. 52.) With no genuine issue as to that fact, Enidine is entitled to summary judgment that its device does not literally infringe the '745 patent.
b. Structural Equivalents
The parties have also construed Claim 1 of the '745 patent as including means-plus-function limitations. Plaintiff argues that if a seal assembly in which the wedge only touches the outer sealing lip is not within the disclosure, there is a triable issue of fact as to structural equivalents. (P2. R.Memo, p. 9.)
The Patent Act provides explicit guidelines for claim elements expressed in means-plus-function terms:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification or equivalents thereof.