Pratt v. United States

43 F. Supp. 461, 95 Ct. Cl. 608, 52 U.S.P.Q. (BNA) 542, 1942 U.S. Ct. Cl. LEXIS 127
CourtUnited States Court of Claims
DecidedMarch 2, 1942
DocketNo. H-328
StatusPublished
Cited by4 cases

This text of 43 F. Supp. 461 (Pratt v. 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
Pratt v. United States, 43 F. Supp. 461, 95 Ct. Cl. 608, 52 U.S.P.Q. (BNA) 542, 1942 U.S. Ct. Cl. LEXIS 127 (cc 1942).

Opinion

MaddeN, Judge,

delivered the opinion of the Court:

This is a patent case in which plaintiff charges the defendant with the infringement of all the claims, except claims 6 and 10, of United States Patent No. 1499472, issued to plaintiff, Hazen C. Pratt, July 1,1924, for “Airplane Landing Mechanism.” On February 8, 1937, this court rendered its decision sustaining claims 1, 2, 3, 9, 12, 13, 14, 15, and 16 as valid and infringed. Hazen C. Pratt v. The United States, 85 C. Cls. 1. The case is' now before the court under the order of December 4, 1939, granting the defendant’s motion for a new trial under Section 175 of the Judicial Code.1 The order authorized the defendant to present evidence regarding the patents, publications, and uses listed in its motion and their effect on the claims previously held valid and infringed, and to present additional evidence as to the method or methods of landing and apparatus employed by the United States within a period of six years prior to the filing of the petition. The prior record was made available on the new trial.

Pursuant to the order, the defendant on ■ the new trial introduced the newly discovered prior patent to Whiteway (see finding 32) and prior British patent to Le Mesurier (see finding 30) and presented testimony of Captain Richardson, former head of the Design Branch of the Bureau of Aeronautics of the Navy Department, as to the apparatus and technique employed by the defendant during the period in question.

[636]*636The various claims in plaintiff’s patent involve an airplane landing mechanism, consisting of a rod attached to the body of the plane by a universal joint at a point in the rear of and below the center of gravity of the plane, with a hook on the end of the rod for the purpose of engaging a retarding device such as a cable stretched on the deck of the ship or other limited area where the plane is to be landed. The rod, withdrawn to lie against the body of the plane while in flight, serves when its hook end is let down by the pilot, to strike on the cable when the plane passes over the cable, and by sliding across the cable to bring the hook into engagement with it. When the cable is caught by the hook, it is stretched, whereupon braking devices such as. drums or springs or pneumatic pistons at the ends of the cable bring the plane to a gradual stop. Instead of the hook being on the end of the rod, the hook might, under the claims, be attached to the end of, for example, a wire or cable connected with the plane, with a rod serving only the purpose of guiding the hook into engagement with the cable on the ground or deck. Under that arrangement, the pull would not be upon the rod, but upon the wire or cable attached to the plane. No patent is claimed upon the mechanism on the ground or deck, intended to be engaged by the mechanism on the plane.

Plaintiff stressed in his claims the merit of arresting the speed of the plane while in flight, and thus letting it descend to the landing surface after its forward motion had been decelerated. In order to carry out this purpose without danger that the plane would nose over forward or yaw sidewise as a result of the pull, plaintiff specified that the pull of the hook and rod should be exerted upon the plane to the rear of the center of gravity of the plane and approximately in fore and aft horizontal alinement with the center of gravity of the plane.

The defendant claims that the mechanism covered by plaintiff’s claims was anticipated by earlier patents, publications, and practices, and that in any event the defendant did not, within the period of the statute of limitations before the bringing of this suit, infringe plaintiff’s alleged patent.

[637]*637As to anticipation, the device of the rod attached to the plane by a hinge or pivot, with a hook at the end of the rod to engage a retarding device on the landing surface was shown by Le Mesurier’s United States Patent, issued September 9, 1919. (See findings 30 and 31.) Figure 2 of Le Mesurier’s patent is reproduced in finding 31. British, Austrian, and French patents to Von Keissler in 1912 (see finding 21) had disclosed various types of drag brakes such as rakes or plows, vertically movable under the pilot’s control and intended to be let down to tear into the earth and stop the progress of the plane after its landing gear had touched the ground. These devices did not contemplate engagement with any retarding mechanism located on the landing field.

Plaintiff claims originality in the attachment of the rod or cable to the body of the plane at a point which would permit the retarding force to be transmitted to the plane in the rear of and in approximate fore and aft horizontal alinement with the center of gravity of the plane. However, the British patent to Whiteway of 1918, referred to in finding 32, Figure 8 of which patent is reproduced in that finding, shows a catch on a plane adapted to engage a stationary retarder, the catch being so located that the retarding force may be applied to the plane in the rear of and approximately in fore and aft horizontal alinement with the center of gravity of the plane.

If, then, the rod and hook were anticipated, and their location on the plane was anticipated, was their being so designed as to operate to retard the movement of the plane while still in flight, and thus cause it to land, rather than merely to retard the movement of the plane and stop its roll on the landing surface after it had reached that surface, original % We think not. The catch on the Whiteway patent as pictured in Figure 8 would operate that way if the plane were flown across the landing cable in a tail down attitude, or, whether or not the plane was in that attitude, if it descended across the cable in such a position that the front part of the landing gear passed over the cable but the catch engaged it. And the likelihood of such an engagement would be increased by lengthening the catch, or the member connecting it with the body of the plane, or by putting the catch at the end of a [638]*638binged and movable rod, as Whiteway suggested and as Le Mesurier did. Whiteway’s patent may not be limited to the exact construction and proportionate dimensions shown on his drawing when his specifications provided in terms for hinging the support, or arm of the catch, and arranging it “in such a way as to allow the clips to be raised or lowered by the aviator as desired.”

The Le Mesurier United States patent device could also operate to retard a plane while in flight. Whether it was intended to do so or not is not clear. A portion of the specifications is as follows:

Thus when an aeroplane E is about to alight as it comes down on the landing surface A it will pass as shown in Fig. 2 in succession over these loops and a hook F suitably disposed on the under part of the aeroplane will engage with certainty one or other of the loops.

Figure 2 of the Le Mesurier patent, reproduced in connection with finding 31, cannot be taken as limiting the possible descent of the hook to a point just above the horizontal plane passing through the bottom of the wheels, even taking into consideration the statement in the spcifications “as shown in Fig. 2.” (See finding 31.) In the British patent to Le Mesurier of 1918, referred to in finding 30, there is the same Figure 2 and the same written matter as in his American patent, except that the language “as shown in Fig. 2,” quoted above, is not present.

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43 F. Supp. 461, 95 Ct. Cl. 608, 52 U.S.P.Q. (BNA) 542, 1942 U.S. Ct. Cl. LEXIS 127, Counsel Stack Legal Research, https://law.counselstack.com/opinion/pratt-v-united-states-cc-1942.