Louis C. Stukenborg, Harold v. Utterback and Associated Aircraft Industries, Inc. v. The United States

372 F.2d 498, 178 Ct. Cl. 738
CourtUnited States Court of Claims
DecidedFebruary 17, 1967
Docket298-61
StatusPublished
Cited by10 cases

This text of 372 F.2d 498 (Louis C. Stukenborg, Harold v. Utterback and Associated Aircraft Industries, Inc. v. The United States) is published on Counsel Stack Legal Research, covering United States Court of Claims primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Louis C. Stukenborg, Harold v. Utterback and Associated Aircraft Industries, Inc. v. The United States, 372 F.2d 498, 178 Ct. Cl. 738 (cc 1967).

Opinion

OPINION

PER CURIAM:

This case was referred to Trial Commissioner Donald E. Lane with directions to make findings of fact and recommendation for conclusions of law. The commissioner has done so in an opinion and report filed on May 5, 1966. Plaintiff has filed no exceptions to the commissioner’s findings or opinion and the defendant excepts only to some of the commissioner’s findings and conclusions. The case has been submitted to the court on oral argument of counsel and the briefs of the parties. Since the court is in agreement with the opinion,, findings and recommendation of the commissioner, with one slight additional modification, it hereby adopts the same, as modified, as the basis for its judgment in this case, as hereinafter set forth. Therefore it is concluded that claims 3 and 5 of patent 2,580,482 are invalid, that claims 1, 2, 4, 6, 8, 9, 14, 15 and 16 of patent 2,580,482 are valid but have not been infringed by the defendant, that claims 5, 6 and 7 of patent 2,843,408 are valid and have been used by defendant without license from the patent owner, and that plaintiffs are entitled to recover for such use. Judgment is entered to that effect with the amount of recovery to be determined pursuant to Rule 47(c) (2).

Opinion of Commissioner **

LANE, Commissioner:

This is a patent suit under Title 28 U.S.C. § 1498, in which plaintiffs seek to recover reasonable and entire compensation for the unauthorized use or manufacture by or for the defendant of patented inventions. Plaintiffs alleged infringement of claims 1-6, 8, 9, and 14'-16 of U.S. Letters Patent No. 2,580,482 entitled “Turnbuckle Lock” which issued to the plaintiffs Louis C. Stukenborg and Harold V. Utterback January 1, 1952, on an application filed July 12, 1945. Plaintiffs further allege infringement of claims 5, 6, and 7, of U. S. Letters Patent No. 2,843,408 entitled “Lock for Turnbuckle” issued to Stukenborg July 15, 1958, on an application filed June 27, 1956. Plaintiffs Stukenborg and Utter-back are the owners of said patents. Plaintiff, Associated Aircraft Industries, Inc., is the exclusive licensee with the right to grant sub-licenses under said patents. The parties have agreed to defer trial of any accounting issues until the issues of patent infringement and patent validity are decided.

It is found that claims 3 and 5 of the '482 patent are invalid and that claims 1, 2, 4, 6, 8, 9, and 14-16 of the ’482 patent are valid but not infringed. It is further found that claims 5, 6, and 7 of the ’408 patent are valid and infringed.

Both patents in suit describe and claim improve turnbuckle assemblies. A turn *500 buckle assembly is an adjustable connector generally used to interconnect cables, wires, or rods so that the length and tension of the cables, wires, or rods may be readily adjusted. A turnbuckle assembly of the type involved in this suit is illustrated in the accompanying drawing. A conventional turnbuckle assembly is comprised of a cylindrical barrel or sleeve having terminal rods threaded in each end. Since World War I, turnbuckle assemblies have been used extensively in aircraft primary and secondary flight control systems for interconnecting and, adjusting the length and tension of control cables. For example, the B-52 airplane has over 100 turnbuckle assemblies mounted therein. One of the principal objections to the use of turnbuckle assemblies in flight control systems has been that the barrel or sleeve portion of the assembly has a natural tendency to unscrew, causing the cables to become loose or disconnected. To prevent the unscrewing of the barrel once the turnbuckle was properly adjusted, the aircraft industry adopted a somewhat elaborate method of wrapping the conventional turnbuckle assembly with locking wire. At least one airplane crash *501 has been attributed to the breaking of the locking wire and the subsequent unscrewing of the turnbuckle barrel. After a period of use, a control cable becomes stretched and requires periodic retension-ing. Many of the turnbuckle assemblies are located in remote locations in an airplane, requiring a skilled mechanic, sometimes using only one hand, to unwrap locking wire on the turnbuckle assembly, adjust the cable tension, and then to re-wrap the assembly. The average time required to adjust the tension of a control cable by this method is from 10 to 30 minutes. The aircraft industry has been continuously seeking a turnbuckle assembly that was more reliable and less expensive to maintain. During the 1940’s the industry evaluated over 21 proposed devices. None of these was found to be sufficiently better to warrant a change.

*500 TURNBUCKLE ASSEMBLY

*501 In 1944 Stukenborg, while working in a machine shop that made conventional turnbuckle assembly parts, developed several turnbuckle assemblies which eliminated the need to wrap the turnbuckle assemblies with locking wire. In 1945 a patent application was filed by Stuken-borg and Utterback that issued in 1952 as the '482 patent here in suit.

Fig. 1 of the '482 patent shows a turnbuckle assembly in which the turnbuckle rods have longitudinal grooves cut therein at a depth greater than the depth of the threads, and the barrel has radial notches formed in its ends. A somewhat U-shaped locking member or clip is positioned with one leg of the member in the rod groove and the base of the locking member engaging the barrel in a radial notch. In this embodiment the base of the locking clip is the primary locking member preventing the barrel from rotating relative to the rods. In Fig. 6A, however, the longitudinal grooves in the rods are grooved to the depth of the threads only, and a longitudinal groove is cut in the threads of the barrel so that when the rod and barrel longitudinal grooves are alined they form a longitudinal aperture in which is positioned one leg of the locking clip. In this embodiment the leg of the locking clip is the primary locking member preventing the rotation of the barrel in relation to the rods. After the patent issued, an exclusive license was granted by the patentees to the plaintiff, Associated Aircraft Industries, Inc. At first personnel of Associated attempted without success to sell turnbuckle assemblies that were similar to the assembly shown in Fig. 1 of the '482 patent. In 1953, Associated had limited success in selling turnbuckle assemblies similar to that shown in Fig. 6A of the '482 patent. Even though many of the engineers in the aircraft industry were enthusiastic about the new turnbuckle assembly, its safety and reliability were questioned because it was thought that the locking clip could possibly vibrate from engagement with the other turnbuckle parts and that the clip could be pulled from the assembly by a pull of less than 15 pounds. Associated contracted with an independent testing laboratory to test the new turnbuckle assembly. At the completion of the favorable tests, the test reports were sent to the aircraft manufacturers. The Glen L. Martin Company conducted an analysis to compare what was by then generally referred to as the “Stukelock” turnbuckle assembly with the conventional assembly.

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372 F.2d 498, 178 Ct. Cl. 738, Counsel Stack Legal Research, https://law.counselstack.com/opinion/louis-c-stukenborg-harold-v-utterback-and-associated-aircraft-cc-1967.