Mannesmann Demag Corp. v. Engineered Metal Products Co., Inc.

• Citation: 793 F.2d 1279,230 USPQ 45
• Decision Date: 12 June 1986
• Docket Number: 85-2409,Nos. 85-2381,s. 85-2381
• Parties: MANNESMANN DEMAG CORPORATION, Appellant, Cross-Appellee, v. ENGINEERED METAL PRODUCTS CO., INC., Appellee, Cross-Appellant. Appeal
• Court: United States Courts of Appeals. United States Court of Appeals for the Federal Circuit

Page 1279

793 F.2d 1279

230 U.S.P.Q. 45

MANNESMANN DEMAG CORPORATION, Appellant, Cross-Appellee, v. ENGINEERED METAL PRODUCTS CO., INC., Appellee, Cross-Appellant.

Appeal Nos. 85-2381, 85-2409.

United States Court of Appeals Federal Circuit.

June 12, 1986.

Michael A. Cornman, New York City, for appellant. With him on brief was Fritz L. Schweitzer, Jr. of Mandeville & Schweitzer, New York City, of counsel.

Francois N. Palmatier, Chicago, Ill., for appellee. With him on brief was Marshall A. Burmeister of Burmeister, York, Palmatier, Hamby & Jones, Chicago, Ill., of counsel.

Before BALDWIN, Circuit Judge, COWEN, Senior Circuit Judge, and NEWMAN, Circuit Judge.

PAULINE NEWMAN, Circuit Judge.

Mannesmann Demag Corporation (Mannesmann) appeals the final judgment of the United States District Court for the District of Delaware holding that claims 1, 2, 5-12, 14, 15, 18, and 19 of U.S. Patent No. 4,207,060 (the '060 patent), invented by Ludger Zangs and assigned to Mannesmann, were not infringed by Engineered Metal Products Co., Inc. (EMPCO). EMPCO cross-appeals from the district court's holding that the '060 patent is not invalid in terms of 35 U.S.C. Sec. 103. We affirm the district court's judgment in both respects.

Background

The background of this litigation and the issues at trial are well set out by the district court. Mannesmann Demag Corp. v. Engineered Metal Products Co., 605 F.Supp. 1362, 226 USPQ 466 (D.Del.1985). The '060 patent is directed to a vessel for a metal smelting furnace having an interior wall above the smelting zone consisting of at least one cooling pipe coil through which water is pumped, sections of said coil being in contact, thereby protecting the vessel from the corrosive action of hot slag. The claimed invention makes unnecessary the usual refractory lining above the smelting zone of the furnace, and is particularly useful to withstand the thermal and mechanical stress characteristics of electric arc furnaces. Claim 1, the broadest claim, is as follows:

1. A vessel for a metal smelting furnace having a smelting zone including a heat-resistant interior wall, and cooling means for protecting the interior of said vessel, characterized by

(a) at least a portion of the interior wall of said vessel above the smelting zone consisting of at least one cooling pipe coil;

(b) said coil including fluid passage-forming sections;

(c) said cooling pipe coil being exposed to the center of the vessel, and

(d) neighboring sections of said coil being arranged in a contacting relation.

The cooling pipe coil structure is illustrated in Figure 1 of Zangs '060 patent, which shows the pipe coil sections in a contacting relation:

NOTE: OPINION CONTAINS TABLE OR OTHER DATA THAT IS NOT VIEWABLE

EMPCO manufactures and sells cooling pipe coils for use in electric arc furnaces. As found by the district court, the accused coils comprise a plurality of pipe sections, separated from neighboring pipe sections by a bar of about 5/8 inch diameter called a "slag-stopping bar", which is welded to one side of a pipe section and separated from the neighboring section by a tolerance of 1/16 to 1/32 inch. The EMPCO pipe coils, described as having pipe sections about 2 1/2 inches in diameter, also have backbone bars welded to alternate pipe sections on the exterior side as a means of support. An EMPCO pipe coil was pictured in cross-section as follows, in exhibit PX-33:

NOTE: OPINION CONTAINS TABLE OR OTHER DATA THAT IS NOT VIEWABLE

EMPCO asserts that the spacing due to the bar between its pipes has the additional function of anchoring a protective layer of solidified slag, that the separation by 1/16 to 1/32 inch of the slag-stopping bar from the neighboring pipe section must be strictly construed in view of the prosecution history of the Zangs patent, and thus that the patent claims are not infringed by the EMPCO structure.

Mannesmann charged EMPCO with direct infringement, inducing infringement, and contributory infringement of the '060 patent, all either literally or by application of the doctrine of equivalents.

Literal Infringement

Literal infringement requires that the accused device embody every element of the patent claim. Stewart-Warner Corp. v. City of Pontiac, 767 F.2d 1563, 1570, 226 UPSQ 676, 681 (Fed.Cir.1985); Builders Concrete, Inc. v. Bremerton Concrete Products Co., 757 F.2d 255, 257, 225 USPQ 240, 241 (Fed.Cir.1985). The burden of proving infringement by a preponderance of the evidence was upon Mannesmann at trial. Hughes Aircraft Co. v. United States, 717 F.2d 1351, 1361, 219 USPQ 473, 480 (Fed.Cir.1983).

Analysis of patent infringement involves two inquiries: determination of the scope of the claims, if there is a dispute as to claim interpretation or construction; followed by determination of whether properly interpreted claims encompass the accused structure. The threshold question of claim interpretation is, on appeal, reviewed for legal correctness. The application of the claim to the accused structure is a matter of fact, reviewed for clear error. See Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 866, 228 USPQ 90, 93 (Fed.Cir.1985). In resolving a dispute as to the interpretation of a claim, reference may be had to the specification, the prosecution history, and the other claims in the patent. Id. at 867, 228 USPQ at 93.

At the trial EMPCO denied literal infringement on two grounds. First, EMPCO argued that the phrase "consisting of" in clause (a) of claim 1 is an exclusionary term that prevents infringement by EMPCO's coils because they contain additional structures not set forth in claim 1, namely the slag-stopping and backbone bars. The district court correctly observed that the phrase "consisting of" appears in clause (a), not the preamble of the claim, and thus limits only the element set forth in clause (a). The court correctly declined to read this usage of "consisting of" as excluding all other elements from the claim as a whole.

Referring to the patent's prosecution history, the district court observed that "consisting of" was added to clause (a) by Mannesmann during prosecution in order to distinguish the claims from cited references disclosing composite wall structures partly containing cooling pipes, and that the phrase was limiting only to the extent that it required "at least one cooling pipe coil" forming a wall structure. Accordingly the court correctly rejected EMPCO's argument that literal infringement was avoided merely by the addition of the slag-stopping and backbone bars to the cooling pipe coil. The court held that these bars did not detract from the coil's structural integrity as a wall. Mannesmann, 605 F.Supp. at 1380, 226 USPQ at 480. The presence of additional elements is irrelevant if all the claimed elements are present in the accused structure. A.B. Dick Co. v. Burroughs Corp., 713 F.2d 700, 703, 218 USPQ 965, 967 (Fed.Cir.1983), cert. denied, 464 U.S. 1042, 104 S.Ct. 707, 79 L.Ed.2d 171 (1984).

Turning to clause (d) of claim 1, Mannesmann contends that the court clearly erred in holding that the clause "neighboring sections of said coil being arranged in a contacting relation" requires that the sections actually touch. Mannesmann argues that EMPCO's neighboring coil sections are in substantial if not actual contact, because they are sufficiently close to prevent the flow of slag through the coil to the exterior wall. Mannesmann also argues that EMPCO's interposition of the 5/8 inch slag-stopping bar between the pipes is no more than a reshaping of the pipe sections, and can not avoid the plain reading and intent of the claims. Mannesmann asserts that the 1/16 to 1/36 inch gap places the sections "in a contacting relation" as stated in clause (d), and that this gap is within manufacturing tolerances. EMPCO argues that Zangs gave up the opportunity so to interpret the claims when he changed "closely adjacent" to "in a contacting relation".

The district court reviewed the prosecution history, and determined that Zangs had originally employed the term "closely adjacent" to describe the spacing between pipe sections. Upon the examiner's objection to "closely adjacent" on the two-fold ground of indefiniteness and not distinguishing from certain cited references, Zangs substituted the words "in a contacting relation". The district court also observed that the dictionary defines "contacting" as meaning physical touching.

The district court also declined to construe the phrase "sections of said coil" in clause (d) literally to include the combination of a slag-stopping bar welded to a pipe, the court stating that its construction of the term "sections of said coil" to mean only pipes was the more reasonable, in light of the specification.

The district court also observed that even the combination of the pipe and slag-stopping bar in the EMPCO system, did not touch the neighboring pipe but was separated by a 1/16 to 1/32 inch gap. Mannesmann disputes both the existence and the significance of this gap. The district court referred favorably to the testimony of Mr. Wunsche, the President of EMPCO, to the effect that EMPCO "intentionally welded the [slag-stopping] bar to only one adjacent pipe to ensure flexibility and thereby avoid cracking of the panel structure". Mannesmann, 605 F.Supp. at 1379, 226 USPQ at 479. The court said that Mr. Wunsche testified that "the slag stopping bars were purposefully spaced from one of the adjoining pipes by the use of a 1/32 of an inch feeler gauge and that it was acceptable for the resulting space to be as large as 1/16 of an inch." Id. Although Mannesmann maintains that one of ordinary skill in this art would not view such a tolerance as a "space", the district court found as fact that a small gap existed, and that the pipe sections were not "contacting".

The district court concluded that the words in clause (d), "in a contacting relation", require strict construction in view of the prosecution history and...