Panduit Corporation v. Stahlin Bros. Fibre Works, Inc., 19786.

• Decision Date: 07 August 1970
• Docket Number: No. 19786.,19786.
• Citation: 430 F.2d 221
• Parties: PANDUIT CORPORATION, Plaintiff-Appellee, v. STAHLIN BROS. FIBRE WORKS, INC., Defendant-Appellant.
• Court: U.S. Court of Appeals — Sixth Circuit

430 F.2d 221 (1970)

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

No. 19786.

United States Court of Appeals, Sixth Circuit.

August 7, 1970.

John D. Simpson and A. James Valliere, Chicago, Ill., Robert A. Stenzel, Donald J. Simpson, Hill, Sherman, Meroni, Gross and Simpson, Chicago, Ill., on the brief, for appellant.

Roy E. Petherbridge and John M. O'Neill, Chicago, Ill., Petherbridge, O'Neill & Lindgren, Chicago, Ill., on the brief, for appellee.

Before WEICK, EDWARDS, and CELEBREZZE, Circuit Judges.

CELEBREZZE, Circuit Judge.

This is an appeal from an order of the United States District Court for the Western District of Michigan, Southern Division, holding a patent on an electrical wiring duct owned by the Panduit Corporation, U. S. Patent No. 3,024,301, issued on March 6, 1962 to K. R. Walch hereinafter the "Walch" patent, valid and infringed by two devices manufactured by Stahlin Bros. Fibre Works, Inc. 35 U.S.C. §§ 101, 102, 103 (1964). Stahlin Bros. appeals, asserting various errors of fact, procedure, and law.

The patent in suit is on a rack for supporting, orienting and arranging wires in electrical circuits. Similar devices are reasonably familiar: they are commonly used to support and arrange wires in radios, phonographs, televisions, and other electrical circuits. The patent was awarded to Walch, an employee of the General Electric Company, after an interference proceeding in the patent office between Walch and Mr. Jack E. Caveney, president of the Panduit Corporation, whose application on a similar rack, the "Panduit Duct," was filed shortly after the Walch application. Claim 5 of the Walch patent, the only claim in issue in the instant proceedings, was the claim in interference on which Walch was awarded priority of invention. Subsequent to the issuance of the patent to Walch, Panduit Corporation purchased the Walch patent from General Electric.

Claim 5 provides:

"5. A wall for supporting and orienting wires comprising a side wall having longitudinally spaced substantially parallel slits open at one edge of said wall and defining substantially parallel edges on longitudinally spaced fingers, the free ends of said fingers being enlarged 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, said fingers being flexible to permit their deflection and provide wider spacing at their free ends to facilitate positioning and removal of wires between said fingers."

Restated, claim 5 described a wiring duct composed of a strip of material (plastic, wood, metal, etc.) with one or two rows of flexible, perpendicular, finger-like projections (the "side walls") attached to its edge or edges. The fingers are spaced evenly apart, the distance between two adjacent fingers on the same side of the strip being roughly equal to the diameter of wires being carried through the duct. Wires being carried through the duct enter and leave through these "substantially parallel slits" between the fingers. To prevent slippage or accidental removal of wires passing between adjacent fingers, the free ends of the fingers are enlarged into knobs; consequently, the distance between adjacent fingers at their free ends may be somewhat less than the diameter of wires passing between them. Being flexible, the fingers may be bent toward or away from the backing strip to provide wider spacing at the free ends of the fingers, and facilitate placement, positioning, and removal of wires.

Prior to 1955, the year Walch filed his patent application, several techniques and devices were used to order and arrange wires in electrical circuits, or electrical control panels. The "flat wiring" method, for example, did not require the use of ducts: wires were simply laid flat against the back wall of the control panel. The "tied" or "laced" cable method, similarly, did not require the use of special ducts: wires between electrical components were installed loosely in the electrical control panel and then laced together with ties. Although both these methods, "flat wiring" and "laced" cable, were in common use in the late 1920's, each had drawbacks that were well recognized by industry people. Consequently, between 1930 and 1955, a spate of patents were acquired on various types of wiring ducts. One acquired by General Electric in the 1930's, for example, was a three-sided metal duct with perforated round holes in its side walls. Wires carried through the duct entered and left through these holes, through which they had to be threaded. U. S. Patent No. 2,006,150. This duct, as all others with holes in their side walls, had the disadvantage that wires could not be removed from the duct, or repositioned within it, unless they were first disconnected from the components they connected, and threaded back through the holes. The District Court found, from substantially undisputed testimony, that a wire near the bottom of such a duct could often not be removed from it unless the wires above it were also removed. Round hole ducts had the added disadvantage that, being inaccessible, wires could not be traced to their origin or rearranged in the control panel without dis-assembling it.

At trial, Stahlin Bros. tested the validity of the Walch patent against two such prior art devices which had not been before the patent office, notwithstanding its seven searches: the Taylor duct and the Franz patent, U. S. Pat. No. 2,712,916.

The Taylor duct is a three-sided duct made of a "rigid thermo-plastic" material, according to the Taylor Electric Company brochures describing it. The Taylor duct has rows of holes in its side walls, the number of rows varying depending upon whether the customer selects a one-inch or four-inch high duct, or some intermediate size. The higher the side wall, the greater the number of holes. Slits from the top of the side wall to the top row of holes form apertures. The side wall between these apertures may be deflected in much the same way as the fingers of the Walch device to increase the size of the aperture and allow for easier placement of wires into the top row of holes. In all but the one-inch high duct, there are more than one row of holes, and the holes in the bottom row, or rows (there may be as many as three rows), are closed. The only way wire can be placed in these lower holes is to thread it...