Dugan v. Lear Avia, Inc.

55 F. Supp. 223, 61 U.S.P.Q. (BNA) 404, 1944 U.S. Dist. LEXIS 2404
CourtDistrict Court, S.D. New York
DecidedApril 28, 1944
StatusPublished
Cited by9 cases

This text of 55 F. Supp. 223 (Dugan v. Lear Avia, Inc.) is published on Counsel Stack Legal Research, covering District Court, S.D. New York primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Dugan v. Lear Avia, Inc., 55 F. Supp. 223, 61 U.S.P.Q. (BNA) 404, 1944 U.S. Dist. LEXIS 2404 (S.D.N.Y. 1944).

Opinion

RIFKIND, District Judge.

By his complaint, plaintiff alleged infringement by defendant of plaintiff’s patent No. 1,959,264 issued May 13, 1934, and sought an injunction and an accounting. At the trial plaintiff abandoned his prayer for an injunction and limited the claims in issue to numbers 1, 2, 3, 4 and 6. The answer denied infringement and alleged invalidity of the patent for want of invention, inoperativeness and insufficiency of the disclosure.

The patent in suit is for a direction-finding and position-indicating system. The principal subject of the claimed invention, in its most elaborated form, relates to a system whereby aircraft and other vehicles may be automatically directed in straight line, drift-corrected movement toward or away from a radio beacon or on a line joining two beacons defining the proposed course of travel. The system consists of one or more pairs of radio loop antennae installed upon a craft in such a manner that each pair of loops is free to rotate about a vertical axis, the number of pairs corresponding to the number of radio beacons in relation to which the craft is to be directed. The two loops of each pair are angularly disposed towards each other; and, being free to rotate, can be so oriented toward the beacon that the radio signals impinging upon each of the two loops are either equal or unequal in intensity. When the signals entering each of the loops are unequal in strength, the loop more strongly energized will cause an electric impulse, amplified by a radio receiver, to move a galvanometer needle, over a dial, to the right or left, depending upon which of the loops is the more strongly energized. Contact of the needle with commutator strips upon the dial brings a follow up motor into play, correspondingly to the right or left, depending on which side of the dial has been contacted. The follow up motor is arranged to turn the shaft upon which the loop antennae rotate until the pair of loops reach a point of equilibrium in the strength of the radio signals received, at which time it is directed toward the radio beacon. The rotation of the shaft upon which the radio loops are mounted is transmitted, by means of pulleys, to an indicator so disposed as to be visible to the pilot, and adjusted to point in the same direction as the line bisecting the angle of the two loop antennae.

When two such indicators, operated by two individual units such as described, are brought together upon concentric axes, the angle of deviation between the two indicators reveals the angle between the lines joining the craft and the two beacons, and enables the pilot to steer the craft into alignment with the proposed course of travel in straight line, drift-corrected direction.

Claim 3 reads: “In a direction finding system, a vehicle, two direction determining devices, each rotatable about a normally vertical axis on said vehicle, a pilot director including two indicators rotatable on said vehicle, means for transmitting the rota- • tion of one of said devices to one of said indicators, means for transmitting the rotation of the other device to the other indicator, said indicators being mounted on said vehicle to align substantially with each other only when the lines of direction of said devices lie in substantially the same plane.”

Claim 6 reads: “A radio transmitter; a vehicle; a radio receiver responsive to said transmitter and including a directional antenna rotatable about a normally vertical axis on said vehicle; a pilot director separate from said receiver and including an indicator rotatable on said vehicle; mechanism for rotating said antenna and indicator in synchronism; said mechanism including a follow-up motor and independent means for energizing said motor; and a circuit closer operable by energy derived from said transmitter through said receiver to control application of said means to said motor”.

Plaintiff does not contend that there is novelty in any of the elements of his system. He relies upon the claim of novelty for his combination. While there is evidence of some licenses issued by the plaintiff, no concrete exemplification of any device or devices manufactured under the patent in suit has been exhibited.

The accused devices are shown in three patents (Plaintiff’s Exhibits 7, 8 and 9) and in an advertisement published by defendant (Plaintiff’s Exhibit 10). These devices are admittedly manufactured and sold by the defendant except for one which, the defendant claims, has been made experimentally only (Plaintiff’s Exhibit 9).

Insofar as the patent and the accused devices relate to an automatic direction-finder *225 they all require and possess these three elements: 1, a sighting device to identify a landmark or target sufficiently distant to be suitable for the mode of travel employed; 2, a mechanism or means to cause the sighting device to remain trained upon the target regardless of the movement of the vehicle; 3, a mechanism which automatically and constantly transmits to the pilot visual intelligence of the direction of the target.

Plaintiff claims that he has a pioneer patent entitled to broad and liberal reading. Defendant concedes that if the patent in issue were entitled to a broad interpretation the accused devices which it manufactures and sells would constitute infringements ; but it asserts that if the patent is so interpreted, it is clearly anticipated by the prior art; whereas, if the patent in suit is limited to a narrow scope, it is not infringed. Because the issue is so presented it has seemed to me preferable to reverse the usual order and to consider first the issue of validity.

Validity

The real issue developed between the parties is this: plaintiff claims that he has invented the first automatic system for directing an aircraft in drift-corrected movement in relation to a radio beacon. Defendant claims that plaintiff’s teaching is old in the art; that his patent is a paper patent; that the delay in the practical utilization of the principles underlying plaintiff’s combination was not caused by ignorance of those skilled in the art but by the difficulty of solving a number of practical problems in connection with their utilization, such as weight, balance, effect of temperature changes, bi-directional ambiguity, problems which had to be solved before practical use could be made of the well known principles in the navigation of an aircraft; that defendant did solve those problems whereas plaintiff did not.

Plaintiff’s own testimony as to the development of his invention is instructive. In January, 1930, he said, he read that an aeroplane flying in a fog from San Diego to Los Angeles had crashed into a mountainside. Many lives were lost. He considered that if that plane had been able to fly in a straight line between San Diego and Los Angeles the disaster would not have occurred. At that time he had already procured British patent No. 161,784 issued in 1921 for “improved drift-correction and indicating apparatus” and had already filed his application which later matured into U. S. patent No. 1,800,931 for a synchronous bomb-sight. He knew, therefore, that it was possible to maintain a moving craft in alignment with two landmarks by sighting two telescopes, one addressed to each of the landmarks, and transmitting the direction of each of the telescopes, by any one of many repeater systems, to an indicator or pointer visible to the pilot.

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Bluebook (online)
55 F. Supp. 223, 61 U.S.P.Q. (BNA) 404, 1944 U.S. Dist. LEXIS 2404, Counsel Stack Legal Research, https://law.counselstack.com/opinion/dugan-v-lear-avia-inc-nysd-1944.