Noma Lites Canada Ltd. v. Westinghouse Elec. Corp.

• Citation: 186 USPQ 485,399 F. Supp. 243
• Decision Date: 07 July 1975
• Docket Number: Civ. A. No. 2413-70.
• Parties: NOMA LITES CANADA LIMITED, Plaintiff, v. WESTINGHOUSE ELECTRIC CORP., et al., Defendants.
• Court: U.S. District Court — District of Columbia

399 F. Supp. 243

186 USPQ 485

NOMA LITES CANADA LIMITED, Plaintiff, v. WESTINGHOUSE ELECTRIC CORP., et al., Defendants.

Civ. A. No. 2413-70.

United States District Court, District of Columbia.

July 7, 1975.

COPYRIGHT MATERIAL OMITTED

Francis C. Browne, Washington, D. C., for plaintiff.

John F. Flannery, Julius Tabin, Chicago, Ill., Farrell R. Werbow, Arlington, Va., for defendants.

HART, Chief Judge.

FINDINGS OF FACT

Nature Of The Litigation And The Parties Thereto

1. This is a suit for patent infringement under 35 U.S.C. §§ 271, 281, with jurisdiction and venue pursuant to 28 U.S.C. §§ 1338(a) and 1400(b), respectively. Plaintiff also filed a counterclaim alleging a pendent claim for unfair competition under 28 U.S.C. § 1338(b).

2. Plaintiff, Noma Lites Canada Limited (Noma), is the owner of U.S. Letters Patent No. 3,395,244 ('244), which issued July 30, 1968, for a combination electric cord and strain relief device. Rudolph Koehler was designated the inventor of the patented combination.

3. The complaint generally alleges that defendants infringe the Koehler, '244 patent, and specifically, the plaintiff urges that Claims 1, 3, 4, 5 and 6 of the patent are infringed.

4. Defendant Belden Corporation is the manufacturer of the allegedly infringing devices which, in turn, have been incorporated into various consumer appliances made by defendant Westinghouse and then sold through assorted retail outlets including defendants, The Hecht Company and Valentine's Appliance Store. The Hecht Company is owned by the remaining defendant, The May Department Stores Company.

Defendants have denied validity and infringement of the asserted claims of the patent in suit.

The Patent in Suit

5. In electrical appliances, especially those designed for hand-held uses, such as domestic flat-irons, electric drills or electric hand mixers, the electrical conducting cord which usually extends from the appliance to a wall outlet is often subject to sharp bending or flexing at or near the point where the cord is attached to the appliance. Repeated flexing at this point causes fraying and wear and substantially reduces the life of the electric cord.

6. The appliance industry has long been aware of this problem, and since at least 1957, various strain relief devices have been used to minimize the strain on electric cords at the mechanical connection between the cord and the appliance.

7. The plaintiff's patent is for such a strain relief device in combination with an electric cord. Briefly, the plaintiff's patent describes a molded strain relief device which includes a tapered resilient sleeve having a wider end affixable to the appliance and a narrower "free" end displaced from the appliance. The electric cord extends axially through the sleeve which is molded about it. The sleeve is comprised of a series of spaced washer-like elements which circumscribe the cord and are movable as the cord is moved or flexed. In one embodiment, interconnecting pieces are secured to and between adjacent washer-like elements. In a second embodiment, the sleeve is formed of a series of interconnected spirals, which the Koehler patent states are washer-like elements.

8. Plaintiff specifically alleges that Claims 1, 3, 4, 5 and 6 are infringed by the defendants' strain relief device. Those claims are set out here as follows:

"1. The combination of an electric cord and a strain relief therefor comprising:

a series of washers assembled on said cord in closely spaced co-axial relation, said assembled washers together forming a sleeve disposed about said cord;

each said washer including a central aperture, said aperture of each washer in said series being tightly engaged upon said cord whereby each said washer constitutes a radial flange of said cord movable by and with it;

resilient interconnecting means between adjacent washers located radially outwardly of said cord for transmitting and distributing local stresses throughout the length of said sleeve upon flexing of said cord;

the radial widths of said washer flanges decreasing from one end of the sleeve to the other and each washer flange being deformable out of its radial plane upon said flexing of said cord;

the washer flanges of relatively small radial width being more resistant to such deformation than the washer flanges of relatively greater radial width."

"3. A strain relief as set forth in Claim 1; wherein said interconnecting means comprises a plurality of narrow, circumferentially spaced, links interconnecting each said washer to each of its neighboring washings; said washers being formed of thin resilient material rendering them resiliently deformable between said links in response to stresses inclining said washers to each other."

"4. A strain relief as set forth in Claim 1 wherein:

said washers are formed of thin resilient material rendering them resilient deformable between their interconnections in response to stresses inclining said washers relative to each other."

"5. A strain relief as set forth in Claim 4 wherein:

said washers vary progressively in breadth from one end of the sleeve to the other producing tapering of said sleeve from a relatively broad end composed of wider washers to a narrow end composed of narrower washers;

the washers at the narrow end of the sleeve being more resistant to deformation between their interconnections than those at the broad end with a corresponding graduation in the flexibility of the sleeve."

"6. A strain relief as set forth in Claim 4, wherein the interconnecting means is constituted by a plurality of narrow, radially spaced links."

9. The file history of the Koehler patent '244 shows that it was issued on an application filed March 14, 1967, which was, in turn, a continuation-in-part of a parent application filed on February 1, 1965 and subsequently abandoned.

10. Pertinent parts of the file history of these applications disclose some important facts for consideration in this lawsuit. In the parent application, Serial No. 429,280, Koehler's invention was set forth and it was noted in the specification as originally filed that

"It is moreover desirable that the strain relief should be relatively stiff adjacent to the appliance and relatively flexible remote therefrom, the increase in flexibility being gradual to avoid the creation of well-defined angles in the strain relief about which the cord may be bent."

In an amendment filed before action by the Examiner the description was reversed to say that the strain relief sought to be patented was more flexible at the end adjacent the appliance than at the free end of the sleeve.

After final rejection of the "parent" application by the Examiner, an appeal to the Board of Appeals was filed. While the appeal was pending, a continuation-in-part application, which resulted in issuance of the present patent, was filed. Thereafter, the appeal was dismissed and the "parent" application was abandoned.

11. The applicant urged in the new specification, Column 5, lines 1-8, that,

"In sum, the sleeve S will therefore yield to bending or arching pressures relatively readily at its broad end. As the bending continues and the effects of the bending forces shift progressively towards the free end of sleeve S, they will encounter increasingly greater resistance and will generally react in the manner suggested by Fig. 10 wherein are shown the forms successively assumed by the sleeve S as it is being arched."

And this proposition of greater resistance to bending at the smaller, free end was emphasized and used to differentiate prior art in the applicant's amendment of November 13, 1967, and in the amendment of February 8, 1968.

12. As a further distinction over prior art cited by the Examiner, the applicant's solicitor, in the November 13, 1967 amendment, urged that the application called for "washers" and that "it will be appreciated that the axial cross-sectional dimension of a washer is very small in comparison with its radial cross-sectional dimension. . . ." This was redeclared in a latter part of the same amendment to be a basic difference between the application and prior art.

The Accused Device

13. The accused Belden strain relief device includes a sleeve which tapers from a wider end adjacent the appliance to a narrower end displaced therefrom.

14. However, in contrast to the device described in plaintiff's patent, the washer-like elements in the Belden device are equal or greater in axial length than in radial width. That is, the axial cross-sectional dimension is equal or larger in comparison with the radial cross-sectional dimension, and not "very small" in comparison with it as provided in the Koehler patent's file history.

15. Actual tests conducted in the courtroom did not prove conclusively that either the Belden device or the Koehler device is more resistant to bending forces at or near the narrow end of the strain relief sleeve than it is at the wider end. Both bent in similar fashion to prior art devices.

Prior Art

16. There is a great deal of prior art in the field of strain relief devices, and much of it is very close to the patent in suit. It was well known long before the application for the '244 Koehler patent that to be economically feasible, a strain relief device must be designed to be fairly simple, inexpensive to fabricate, and durable, but without imparting undesirable properties to the electrical cord such as extreme rigidity or inflexibility. See, e. g., the prior art U.S. Patent 3,051,774 issued August 28, 1962, upon an application by one Schelke. The Schelke, '774, patent discloses a tapered strain relief device molded from natural or synthetic rubber, plastic or like material. The illustrated embodiments of the '774 patent show pin-hole apertures extending through the molded sleeve giving it added flexibility. The specification discloses that flexibility increases in the direction of the narrow end and that additional flexibility may be obtained by increasing...