The opinion of the court was delivered by: ZIEGLER
Pending before the court are the cross motions of the parties for summary judgment pursuant to Fed.R.Civ.P. 56(c). Plaintiff, Kress Corporation, seeks summary judgment with respect to its claims of patent infringement under 35 U.S.C. §§ 271. Defendants, Alexander Services, Inc., Alexander Mill Services, Inc. and Liftking Incorporated, also seek summary judgment with respect to the asserted claims. For the reasons that follow, we will grant defendants' motion for summary judgment and deny plaintiff's motion for judgment.
This civil action arises from the alleged infringement by defendants of Kress's patent, U.S. Patent Number 4,063,658 ('658 patent). The patent in question describes a carrier capable of transporting slag pots full of molten steel waste from a steel mill to a slag dump. When full, the slag pots weigh from 35 to 200 tons.
The first three of the patent's four claims are relevant to this action. Claim one, which is independent of the other claims, describes the carrier itself. It consists of a large U-shaped cradle, which holds the slag pot, resting horizontally atop a similarly-shaped wheeled frame. The cradle and frame are attached at the open ends, allowing the cradle to pivot up and over the end of the frame. A series of levers and linkages attached to both the frame and the cradle control the arc of the cradle as it pivots. Finally, a pair of "linear actuators" or pistons are attached from the frame to the levers. When the actuators are extended, the cradle pivots up and along an arc from the horizontal position, through a second "carrying" position, and finally beyond vertical to a dump position. The actuators can swing the cradle up to 140 degrees from the horizontal to the dump positions.
Claim two describes "struts" attached to the frame, which support the cradle while in the carrying position. The struts remove some of the weight from the main actuators, levers and links. The third claim calls for the struts to be in the form of linear actuators, which also support the cradle while in the carrying position.
Kress alleges that defendants designed, built and sold four carriers that infringe its patent. The Alexander companies produced two of the carriers, and sold them to Washington Steel Company. Liftking similarly produced two carriers, which were sold to the Darlington Steel Company. Defendants admit that their carriers contain many of the components and structures described in the '658 patent. However, defendants assert that (1) their carriers require an auxiliary set of linear actuators to move the cradle to the second, or carrying position, and (2) that the patent, as properly construed, does not cover their carriers. Both sides have moved for summary judgment as to the infringement claims.
Summary judgment will be granted if the pleadings, depositions, answers to interrogatories, and admissions on file, together with any affidavits, show that there is no issue of material fact and that the moving party is entitled to judgment as a matter of law. Celotex v. Catrett, 477 U.S. 317, 322, 91 L. Ed. 2d 265, 106 S. Ct. 2548 (1986). In considering a motion for summary judgment, the court must examine the evidence in the light most favorable to the nonmoving party and draw all reasonable inferences in favor of that party. Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255, 91 L. Ed. 2d 202, 106 S. Ct. 2505 (1986).
In determining whether an accused product infringes a patent, we must apply the following procedure recently announced by the Court of Appeals for the Federal Circuit:
An infringement analysis requires two separate steps. First, the court must construe the claims asserted to be infringed as a matter of law in order to establish their meaning and scope. Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S. Ct. 1384, 134 L. Ed. 2d 577 (1996). Second, the claims as construed are compared to the allegedly infringing device. Id. To literally infringe, the accused device must contain every limitation of the asserted claim. Laitram Corp. v. Rexnord, Inc. 939 F.2d 1533, 1535 (Fed. Cir. 1991).
Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1105 (fed. Cir. 1996). Even if the accused device does not literally infringe, it may infringe under the doctrine of equivalents if the differences between the elements of the claimed invention and the accused device are 'insubstantial.' Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 137 L. Ed. 2d 146, 117 S. Ct. 1040, 1997 WL 84999 (U.S. 1997).
Where a dispute concerns the scope of the patent claims, we must consider three sources, including the claims themselves, the specification and the prosecution history. Markman v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed. Cir. 1995) aff'd, 517 U.S. 370, 116 S. Ct. 1384, 134 L. Ed. 2d 577 (1996). Claim terms are given their "ordinary and accustomed meaning unless examination of the specification, prosecution history and other claims indicates that the inventor indicated otherwise." Transmatic, Inc. v. Gulton Industries, Inc., 53 F.3d 1270, 1277 (Fed. Cir. 1995).
First, we will examine the scope of the claims themselves. Here, the patent claims refer to only one set of linear actuators capable of moving the cradle.
Although claim three refers to another set of actuators, the claim discusses only the manner in which the actuators support the cradle once it is lifted into the second position.
We therefore find that the "ordinary and accustomed meaning" of the claim language does not allow for coverage of secondary linear actuators that move the cradle to the carry position.
Kress argues that language from the patent's specification should be construed to cover devices that have such structures. Defendants rejoin that the specification language does not support such a finding, and that the prosecution history of the patent similarly limits the patent coverage.
Both sides agree that the patent's specification section discusses the role of the second pair of actuators, mentioned in claim three, in lifting the slag pot to the "carry," or second, position. However, they ...