The opinion of the court was delivered by: Matthew F. Kennelly, District Judge
MEMORANDUM OPINION AND ORDER
Liquid Dynamics Corporation ("LD") has sued Vaughan Company, Inc., contending that Vaughan's components for mixing systems used in certain wastewater treatment tanks infringes LD's U.S. patent number 5,458,414 (the "'414 patent"), and asserting antitrust and tort claims. Vaughan has moved for partial summary judgment, asserting an issue regarding construction of a term in claim 1 of the '414 patent and arguing that the doctrine of equivalents is unavailable to LD as a matter of law.*fn1 For the following reasons, the Court denies Vaughan's motion.
LD's invention aims to solve a problem inherent in long-term storage of wastewater or manure slurries in large tanks: the tendency of solid and liquid components of the waste compounds to separate, with the solid components settling at the bottom of the tank and forming a thick crust at the surface of the tank. Prior inventions that continuously mixed the contents to prevent the separation into liquid and solid components were generally expensive to operate and not entirely effective. The invention claimed in the '414 patent thoroughly re-suspends solid components just prior to use, using a minimum number of "submerged flow generating units" and avoiding altogether the use of flow generating units outside of the tank contents. LD Ex. B, '414 Patent, col. 2:39-55. In short, the system renders the liquid and solid tank contents sufficiently homogeneous (expending as little energy as possible) to allow liquid handling devices to unload the slurry from the tank for transport.
In its suit against Vaughan, LD alleges, among other things, that certain of Vaughan's Rotamix slurry mixing systems infringe claims 1 and 8 of the '414 patent, both literally and under the doctrine of equivalents. The disputed elements of those claims read as follows:
1. Apparatus for storing a slurry having solid and liquid components, comprising:
A storage tank defining a volume for holding a body of liquid and solid slurry components, including a floor of generally circular configuration and having a center, said storage tank further including an outer surrounding wall positioned generally at a radial distance from the center; at least two flow generating means positioned to be submerged within the liquid and solid slurry components for generating flow of at least one of the slurry components along a rotational direction, each of said flow generating means being disposed at distances from the center ranging between approximately 30 percent and 70 percent of said radial distance; . . . .
8. Apparatus for storing a slurry having solid and liquid components and for mixing the solid and liquid slurry components to form a substantially homogenous slurry, comprising:
a storage tank for holding a body of solid and liquid slurry components, said storage tank including a floor of generally circular configuration and having a center, said storage tank further including an outer surrounding wall positioned generally at a radial distance from the center; and at least a first and a second flow generating means for submersion within the solid and liquid slurry components for generating flows of the solid and liquid slurry components along respective directions, said flow generating means each being located at a position in a range between less than 75 percent of said preselected radial distance from the center of said storage tank and greater than 25 percent of said radial distance from the center of said storage tank;. . . .
Vaughan moved for partial summary judgment, contending that 133 of the mixing systems at issue in this suit do not literally infringe any claim of the '414 patent because the systems' nozzles are not located within the specific region of the tank Vaughan contends the patent requires. Vaughan also asserted that those 133 systems do not infringe the '414 patent under the doctrine of equivalents because LD, during its prosecution of the '414 patent, surrendered the right to assert that the claims cover mixers not having at least two nozzles within the claimed region. Vaughan further contended in its motion for partial summary judgment that forty of the mixing systems at issue do not literally infringe any claim of the '414 patent because they have rectangular, rather than generally circular, floors. According to Vaughan, allowing the application of the doctrine of equivalents with regard to the shape of the floors would improperly vitiate the "generally circular" element required by the patent.
Not all of these arguments are still before the Court, however, because on February 8, 2008, after this motion was partially briefed, the judge to whom the case was then assigned entered a stipulation and order limiting Vaughan's motion to the patent infringement claims made by LD under the doctrine of equivalents. See Jan. 7, 2008 Stipulation and Order ¶ A. Thus, the Court must construe claims 1 and 8 of the '414 patent and determine whether the doctrine of equivalents is available to LD as a matter of law. The order also limited the scope of Vaughan's motion to only one of its products-the system installed at Nashville Central-and stayed additional discovery relating to alleged patent infringement by the remaining systems. For purposes of the present motion, LD has agreed not to dispute that the actual nozzle locations of the Nashville Central system are as shown in the drawings attached to the declaration of Glenn Dorsch dated January 4, 2008 and are outside of a radial band extending between 25 and 75 percent of the tank radius. The Nashville Central system is a round tank 108 feet in diameter with eight nozzles located at 81.5 percent of the tank radius and four nozzles located at 22.2 percent of the tank radius.
Summary judgment is appropriate in a patent case, as in any other case, when there is no genuine issue as to any material fact and the moving party is entitled to judgment as a matter of law. Fed. R. Civ. P. 56(c); Avia Grp. Int'l, Inc. v. L.A. Gear Calif., Inc., 853 F.2d 1557, 1561 (Fed. Cir. 1998). In determining whether there is a genuine issue of fact, the Court views the evidence and draws all reasonable inferences in favor of the party opposing the motion. Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255 (1986).
A patent infringement analysis entails two steps. The first, claim construction, is a question of law requiring the Court to determine the meaning and scope of the patent claims alleged to be infringed. See Markman v. Westview Instruments, Inc., 52 F.3d 967, 970-71 (Fed. Cir. 1995). Second, the Court must compare the properly construed claims to the device accused of infringing-a question of fact. See, e.g., Bayer AG v. Elan Pharm. Research Corp., 212 F.3d 1241, 1247 (Fed. Cir. 2000). A court may resolve the issue of infringement on summary judgment only if "no reasonable jury could find that every limitation recited in the properly construed claim either is or is not found in the accused device." Frank's Casing Crew & Rental Tools, Inc. v. Weatherford Int'l, Inc., 389 F.3d 1370, 1376 (Fed. Cir. 2004). Infringement may be shown under the doctrine of equivalents if the plaintiff makes "a showing that the difference between the claimed invention and the accused product [i]s insubstantial." Stumbo v. Eastman Outdoors, Inc., 508 F.3d 1358, 1364 (Fed. Cir. 2007).
For purposes of claim construction, the parties dispute only the proper construction of the term "approximately" in claim 1, contained in the phrase "between approximately 30 percent and 70 percent." The remainder of the terms in claims 1 and 8 are straightforward and unambiguous. LD asserts that the term "approximately" permits variations in each direction of at least ten percent of the total radial dimension of the tank.*fn2 Vaughan, on the other hand, argues that the term "approximately" cannot logically be construed in a way that extends the claimed range of claim 1 beyond the band extending from 25 percent to 75 percent of the radial distance, or in other words, beyond the range claimed by claim 8.
There is a "'heavy presumption' that a claim term carries its ordinary and customary meaning." CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366 (Fed. Cir. 2002) (citing Johnson Worldwide Assoc., Inc. v. Zebco Corp., 175 F.3d 985, 989 (Fed. Cir. 1999)). The ordinary and customary meaning of a term is the meaning that the term would have to a person with an ordinary level of skill in the relevant field at the time of the invention. Phillips v. AWH Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005) (en banc).*fn3 The person with an ordinary level of skill "is deemed to read the claim term . . . in the context of the entire patent, including the specification." Id. The intrinsic record "usually provides the technological and temporal context to enable the court to ascertain the meaning of the claim to one of ordinary skill in the [relevant field] at the time of the invention." V-Formation, Inc. v. Benetton Grp. SpA, 401 F.3d 1307, 1310 (Fed. Cir. 2005).
For some time, the Federal Circuit, at least in some of its decisions, recommended that district courts "resort initially to the relevant dictionary definitions to determine the ordinary meaning of the [disputed] term." See, e.g., E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1367 (Fed. Cir. 2003). Its decision in Phillips made clear, however, that dictionaries may be helpful in claim construction involving "little more than the application of the widely accepted meaning of commonly understood words" but that in the majority of cases, courts should look first to "'the words of the claims themselves, the remainder of the specification, the prosecution history, and extrinsic evidence concerning relevant scientific principles, the meaning of technical terms, and the state of the art.'" Phillips, 415 F.3d at 1314 (quoting Innova/Pure Water, Inc. v. Safari Water Filtration Sys., Inc., 381 F.3d 1111, 1116 (Fed. Cir. 2004)).*fn4
Specifically, the Court should first examine the intrinsic evidence: the context in which the term is used in the asserted claim; the differences between the claims; the written description contained in the patent specification; and, if it is in evidence, the patent's prosecution history, for the purpose of excluding an interpretation that the patentee disclaimed. Id. at 1314-1317. "To avoid importing limitations from the specification into the claims," however, the Court must bear in mind "that the purposes of the specification are to teach and enable those of skill in the [relevant field] to make and use the invention and to ...