PANDUIT CORPORATION v. Stahlin Bros. Fibre Works, Inc.

• Decision Date: 11 February 1972
• Docket Number: Civ. A. No. G-293-71.
• Parties: PANDUIT CORPORATION, Plaintiff, v. STAHLIN BROS. FIBRE WORKS, INC., Defendant.
• Court: U.S. District Court — Western District of Michigan

338 F. Supp. 1240

PANDUIT CORPORATION, Plaintiff, v. STAHLIN BROS. FIBRE WORKS, INC., Defendant.

Civ. A. No. G-293-71.

United States District Court, W. D. Michigan, S. D.

February 11, 1972.

Price & Heneveld, Grand Rapids, Mich., Randall G. Litton, and Lloyd Heneveld, Grand Rapids, Mich., of counsel. Petherbridge, O'Neill & Aubel, Chicago, Ill., Roy Petherbridge, Chicago, Ill., of counsel, for plaintiff

Hill, Sherman, Meroni, Gross & Simpson, Chicago, Ill., Donald J. Simpson, Chicago, Ill., of counsel, Schmidt, Smith & Howlett, Grand Rapids, Mich., Richard L. Spindle, Grand Rapids, Mich., of counsel, for defendant.

OPINION

FOX, Chief Judge.

The plaintiff, Panduit Corporation, brought this action asking the court to find the defendant in contempt of court for violation of the court's earlier injunction. The case involves a patent on electrical wiring duct owned by Panduit Corporation, U.S. Patent No. 3,024,301. The duct is used in channeling, arranging and orienting electrical circuits, usually in large electrical "control panels."

The patent in question was issued on March 6, 1962 to Kurt R. Walch. The Panduit Corporation later bought the patent from the General Electric Company. After the issuance of U.S. Patent No. 3,024,301, defendant Stahlin Bros. manufactured and sold, among others, two electrical wiring ducts called the Lok-Slot duct and the Web-Slot duct. The plaintiff filed suit claiming that the defendant's Lok-Slot and Web-Slot ducts infringed plaintiff's patent.

After a lengthy trial this court found U.S. Patent No. 3,024,301 valid and infringed by both devices. See D.C., 298 F.Supp. 435 (1969). The court's decision was appealed to the Sixth Circuit Court of Appeals and upheld as to both validity and infringement. See 430 F. 2d 221 (1971).

After the issuance of the court's injunction in May of 1969, defendant ceased the production and sale of the Lok-Slot and Web-Slot ducts. In their place the defendant now manufactures a "Tear-Drop" duct and a "Closed-Slot" duct. These two new ducts are the subject of the present contempt proceeding. The plaintiff contends that the new products are "infringing products" within the meaning of the court's injunction.

The standard applied in contempt proceedings following an adjudication of patent validity and infringement is abundantly clear. In such proceedings the question is whether the accused structure is equivalent to the original in relation to the patent in suit. Field Body Corporation v. Highland Body Mfg. Co., 13 F.2d 626 (6th Cir. 1926). Wadsworth Electric Mfg. Co. v. Westinghouse Electric & Mfg. Co., 71 F.2d 850 (6th Cir. 1934), certiorari denied Wadsworth Electric Mfg. Co. v. Sachs, 294 U.S. 724, 55 S.Ct. 552, 79 L. Ed. 1255. Thus, there are two focal points to the issue presently before the court: (1) the equivalency of the modified structures to the structures previously held infringing, and (2) the relationship of the new devices to the valid patent claim. Hirs v. Detroit Filter Corp., 424 F.2d 1040, 1041 (6th Cir. 1960).

Immediately before the hearing on the merits of plaintiff's allegations the defendant requested an in-chambers conference. The principal issue discussed was the proper role prior art should play in the upcoming proceedings. Plaintiff contended that prior art should play no role in contempt proceedings and that the sole issue before the court was the equivalency of the new devices to those already held infringing. Defendant, on the other hand, contended that the resolution of the issue required reference to the prior art to determine whether the new devices were more like prior art than the devices previously held infringing.

As early as 1926 the Sixth Circuit Court of Appeals resolved the question of prior art in contempt proceedings. In Field Body Corp. v. Highland Body Mfg. Co., supra, 13 F.2d at 627, the court said:

"We are not concerned with the prior art, nor with an original interpretation of the claims of the patent. It suffices here that in an action between the parties the patent was held infringed by appellant's original structure. The question, then, is whether the modified structure is the equivalent of the original in its relation to the patent in suit."

And again in 1934, in Wadsworth Electric Mfg. Co. v. Westinghouse Electric & Mfg. Co., supra, 71 F.2d at 852, the Sixth Circuit Court of Appeals said:

"We think it clear that the only issue presented by this appeal is whether the defendant's modified structures infringe the patent claims, and whether their manufacture violates the writ of injunction, and upon that issue neither the court below nor this court need consider the prior art."

The policy behind the Sixth Circuit decisions is clear. When an original suit is brought for patent infringement the parties are given the opportunity to test the validity of the patent claim, and if the claim is found valid to test whether the claim has been infringed by defendant's product. In an original patent proceeding the court examines the prior art in great detail. See, for example, the court's opinion in the principal case, found at 298 F.Supp. 435 (1969). Such prior art is relevant to the validity and scope of the patent claim.¹

Once the parties have had their day in court and a final determination is made on the merits, however, judicial policy calls for a definite end to a litigated question. The parties may, of course, appeal the court's decision, but if upheld, the parties are bound by the determination of the principle litigated.²

Advancement over prior art is critical to patent validity and a valid patent claim can only be read in terms of its advancement over prior art. Prior art is central to proceedings for patent infringement. This court conformed to the teachings of the Sixth Circuit Court of Appeals when at 298 F.Supp. 435 it exhaustively evaluated the status of prior art.

The Sixth Circuit Court of Appeals has said that in contempt proceedings the question is whether the modified structure is equivalent to the original in relation to the patent in suit. Supra. And, in resolving this question, the court need not consider prior art. Wadsworth Electric Mfg. Co. v. Westinghouse Electric & Mfg. Co., supra. Field Body Corp. v. Highland Body Mfg. Co., supra. The relationship of the patent claim to the prior art has been completely considered.

In testing the equivalency of the structures in relation to the patent in suit, the court must necessarily read the claim in the light of its original decision. It considers the modified structure in the light of the patent claim as determined earlier — including the court's examination of prior art. The court will not, however, reopen the question of how the claim should be read at a later contempt proceeding. Thus, the proper place to bring in evidence of prior art is in the original infringement proceeding.

THE TEAR-DROP DUCT

The Walch patent, U.S. Patent No. 3,024,301, was designed to achieve the following functions or results:

A. easy insertion of wires in the duct;

B. prevention of accidental removal of wires from the duct;

C. provision of maximum useful space for bringing wires from the duct; and

D. facilitation of intentional removal of wires from the duct.

Additionally, Claim 5 of the Walch patent reads:

A wall for supporting and orienting wires comprising

A. a side wall

B. having longitudinally spaced substantially parallel slits

C. open at one edge of said wall

D. and defining substantially parallel edges on longitudinally spaced fingers

E. the free ends of said fingers being enlarged

F. to narrow the outer ends of the slits and provide restricted passages for the wires between the finger ends and thereby prevent accidental removal of the wires from between the fingers,

G. said fingers being flexible to permit their deflection and provide wider fingerspring at their free ends to facilitate positioning and removal of wires between said fingers.

As stated in the original opinion, "There is no dispute in this case that the words of the claim read literally on defendant's Lok-Slot duct." 298 F.Supp. 435, 448 (1969). See the original opinion, supra, for drawings of both the Lok-Slot and Panduit ducts.

Plaintiff herein asserts that Claim 5 likewise reads literally on the Tear-Drop duct and is the equivalent of the Walch patent. Obviously, the defendant contests this assertion. The evidence produced at trial focused on two points of contention concerning the Tear-Drop duct.

First, the defendant, both through its expert and its cross-examination of plaintiff's expert, sought to show that that part of Claim 5, which reads, "and defining substantially parallel edges on longitudinally spaced fingers," does not read on the Tear-Drop duct. There is no dispute that except for this language, Claim 5 does read on the Tear-Drop duct.

This court holds that the finger edges of the Tear-Drop duct are substantially parallel within the meaning of Claim 5 of the Walch Patent. The finger edges are not mathematically parallel. Claim 5, however, requires only substantial parallelism. Much testimony was heard on the nature of substantial parallelism; the defendant's argument being that although curved lines as shown in Figure 1 might be considered substantially parallel, curved lines as depicted in Figure 2 surely are not.

The word substantial is derived from the word substance and means, "consisting of, relating to, sharing the nature of, or constituting substance: existing as or in substance." Webster's Third New International Dictionary (1963). In substance, the finger edges of the Tear-Drop duct are parallel. They are certainly parallel enough to define "longitudinally spaced substantially parallel slits." The edges clearly define "fingers," which achieve the functional results of the Walch patent, and therefore are substantially parallel.

In the words of Claim 5, the fingers of the Tear-Drop duct are narrow at "the outer ends of the slits and provide...