Flo-Con Systems, Inc. v. Leco Corp.

• Decision Date: 11 May 1993
• Docket Number: Civ. A. No. CV193-028.
• Parties: FLO-CON SYSTEMS, INC., Plaintiff, v. LECO CORPORATION, Defendant.
• Court: U.S. District Court — Southern District of Georgia

845 F. Supp. 1576

FLO-CON SYSTEMS, INC., Plaintiff, v. LECO CORPORATION, Defendant.

Civ. A. No. CV193-028.

United States District Court, S.D. Georgia, Augusta Division.

May 11, 1993.

Edward L. Speese, Warlick, Tritt & Stebbins, Augusta, GA, Gail Duffie Stebbins, Martinez, GA, for Flo-Con Systems, Inc.

Ted Hamby Clarkson, Joseph Hixon Huff, Kilpatrick & Cody, Augusta, GA, for Leco Corp.

ORDER

BOWEN, District Judge.

Before the Court is Plaintiff Flo-Con Systems, Inc.'s, ("Flo-Con") Motion for a Preliminary Injunction, filed pursuant to 35 U.S.C. § 283. Flo-Con seeks to enjoin Leco Corporation's ("Leco") continued manufacture, use, promotion, and sale of three Leco products that allegedly infringe on Flo-Con patents. The parties presented their arguments at the April 27, 1993, hearing on this matter. For the reasons stated below, Flo-Con is granted limited relief through the requirement that Leco deposit into the registry of the Court a percentage of its gross sales of specified products.

I. BACKGROUND

Flo-Con, a company involved in the research, development, and manufacture of steel industry equipment, filed this action against Leco to enforce two patents: U.S. Patent 4,545,512 — originally issued October 8, 1985, (the "Original '512 patent") and reissued January 12, 1993, after reexamination and modification ("the '512 patent") — and U.S. Patent 5,174,908 ("the '908 patent"). The allegedly infringing Leco products are three versions of a tundish valve slide gate.

A tundish valve slide gate is a component of a valve used to control the flow of molten steel in a four container, continuous casting, steel manufacturing system. The four component containers are (1) the furnace, (2) the ladle, (3) the tundish, and (4) the mold. When the system is in operation, molten steel flows from the furnace, through the ladle and tundish, and into the mold. The valves used to control the flow from the tundish to the mold employs a rectangular metal plate, known as a slide gate, through which a hole is bored. To open the valve, the slide gate hole is aligned with the valve's opening; similarly, the valve is closed by sliding the gate until its solid portion is aligned with the valve's opening. Also, because the slide plates wear quickly, they must be replaced approximately every six to eight hours of operation.

Flo-Con's '512 patent and its '908 patent describe slide gates designed for use in the Flo-Con 11T Tundish Valve. The distinguishing feature of the gate described in the '512 patent ("the '512 gate") is that its hole is offset from the plate's center a distance greater than the radius of the hole. According to Flo-Con, an offset hole is advantageous because it allows the valve operator to throttle the flow of molten steel; that is, he is not limited to on and off only.

The gate described in the '908 patent ("the '908 gate") is an advanced version of the '512 gate whose distinguishing feature is asymmetrical ledges that prevent it from being inserted into the tundish valve backwards. Because of that feature, the '908 gate is known as a nonreversible gate.¹ One problem with the '512 gate is that if it is inserted backwards, the full-on and full-off positions are reversed. Thus, if an operator selects emergency shut-off and the '512 gate in the valve is installed backwards, the valve goes to full open instead of closed. To remedy this problem, the '908 gate employs asymmetrical ledges on its sides (the gate has shoulders that slide on rails in the valve) so that the gate can be inserted into the valve only one way.

According to Flo-Con, three slide gates manufactured and sold by Leco infringe on its patents. The first is virtually identical to the Flo-Con '512 gate and allegedly infringes on the '512 patent. Each of the two remaining Leco gates allegedly infringe on both the '512 and '908 patents because they employ an offset hole like that found in the '512 gate and an asymmetrical guide feature similar to that found in the '908 gate. The distinction between the two Leco nonreversible gates, however, is that one has asymmetrical ledges like those used on the '908 gate while the other has ledges of equal width and a groove cut into one ledge.

II. ANALYSIS

Injunctive relief may be granted in patent cases "in accordance with the principles of equity to prevent the violation of any right secured by patent, on such terms as the court deems reasonable." 35 U.S.C. § 283. The standard for granting preliminary injunctions under § 283 is no different than that applicable in other cases, H.H. Robertson, Co. v. United Steel Deck, Inc., 820 F.2d 384, 387 (Fed.Cir.1987) — it requires analysis of the usual four factors: (1) reasonable likelihood of success on the merits, (2) irreparable harm, (3) the balance of hardships between the parties, and (4) the injunction's impact on the public interest, Hybritech, Inc. v. Abbott Laboratories, 849 F.2d 1446, 1451 (Fed.Cir.1988). Significantly, none of these four factors are dispositive, each must be weighed against the others and against the relief requested. Id.² Applying these factors, Flo-Con is entitled to limited relief as to Leco's reversible and nonreversible tundish slide gates.

A. Likelihood of Success on the Merits

1. Leco's Reversible Gate

Flo-Con asserts that the Leco reversible gate is a direct copy of the '512 gate. Leco counters with three arguments to show Flo-Con likely will not succeed on the merits concerning its '512 patent: (1) that there is no infringement of the '512 patent, (2) that the '512 patent is invalid, and (3) that the '512 patent is unenforceable. Despite these arguments, however, Flo-Con probably will succeed in showing the Leco reversible gate infringes on its '512 patent.

Leco admits that its reversible gate directly infringes if the '512 gate is covered separately by the '512 patent; however, it denies infringement by arguing the '512 patent covers only the valve-gate combination and that, under the repair doctrine, consumable parts of a patented item may be copied if the consumable parts are not patented separately.³ Leco explains that, by also describing a sequential valve, the preamble to claims one through four of the reexamined '512 patent ("Preamble") limits the '512 patent's coverage to a valve/gate combination.⁴ The relevant portion of the Preamble provides as follows:

A gate operative in valve apparatus in which apertured gates are conveyed sequentially along a longitudinally extending guide structure into and out of flow controlling relation with the pour opening of a teeming vessel and wherein, in order to adjustably position said gates with respect to said pour opening for flow throttling purposes, said guide structure is movable transversely of the direction of movement of said gates along said guide structure, said gate comprising....

As interpreted by Leco, that language renders the valve an essential element of claims one through four such that they cover only devices that include all components of both the described valve and the gate.

Although not entirely clear from its presentation, Leco apparently gives considerable weight to the fact that the preamble to claims one through four of the Original '512 patent included the phrase "of the type" such that it read as follows: "A gate operative in valve apparatus of the type in which apertured gates are conveyed sequentially...." (emphasis supplied). Again reading its arguments broadly, Leco's position seems to offer that the phrase "of the type" was deleted during reexamination of the '512 patent to make the sequential valve an essential element of that patent and thereby avoid reciprocal valve prior art.

The '512 patent's reexamination history, however, suggests Flo-Con probably will be able to show the allegedly limiting language simply describes the type valves in which '512 gates are used. One of the principal questions before the Patent and Trade-mark Office ("PTO") during reexamination of the '512 patent was whether offset holes in reciprocal valve slide gates qualified as prior art that warranted rejection of the '512 patent's first four claims. After reexamining the '512 patent against the cited reciprocal valve prior art and after a post-rejection interview with counsel for the patentee, the PTO examiner stated:

The Examiner's position is that, while allowable matter may be disclosed, the presence in the claims of the words "of the type" creates a possible ambiguity that prevents distinct claiming of the invention. Deletion of these words from the claims would remove the possible indefiniteness and resultant ambiguity to enable the preamble to give life and meaning to the body of the claims and thus render them allowable. The Examiner's does not sic consider such a change would alter the effective scope of the claims 1 to 4, as granted, but does correct a drafting error and thus, renders the claims more precise.

Examiner Interview Record, Serial No. 90/002359 (June 6, 1991) ('512 patent reexamination file history) (emphasis supplied). Contrary to Leco's allegations, these comments suggest that the impact of deleting the words "of the type" was only minor and did not change the entire scope of the relevant claim's coverage. Furthermore, as noted by Flo-Con, throughout the three hundred seventy-four pages of reexamination documents Flo-Con consistently referred to the '512 patent as covering the '512 gate only and not the valve/gate combination. In short, while Leco's interpretation is plausible, Flo-Con's interpretation is more consistent with the PTO examiner's and Flo-Con's pre-litigation treatment of the Preamble.

Like its non-infringement arguments, Leco's claims concerning invalidity and unenforceability are unpersuasive. Under 35 U.S.C. § 282, patents are presumed valid, and parties challenging a patent's validity have the burden of proving invalidity by clear and convincing evidence. Jones v. Hardy, 727 F.2d 1524, 1528 (Fed.Cir.1984). Significantly,...