Esnault-Pelterie v. United States

81 Ct. Cl. 785, 1935 U.S. Ct. Cl. LEXIS 190, 1935 WL 2196
CourtUnited States Court of Claims
DecidedNovember 4, 1935
DocketNo. D-388
StatusPublished
Cited by1 cases

This text of 81 Ct. Cl. 785 (Esnault-Pelterie 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
Esnault-Pelterie v. United States, 81 Ct. Cl. 785, 1935 U.S. Ct. Cl. LEXIS 190, 1935 WL 2196 (cc 1935).

Opinion

Booth, Chief Justice,

delivered the opinion of the court:

The plaintiff, Bobert Esnault-Pelterie, is a citizen and resident of France. At a comparatively early age he became a student and experimenter in the science of aeronautics, attaining high rank as an inventor and practitioner in the art of aviation. The United States Patent Office on November 3, 1914, granted to plaintiff Letters Patent #1115795 under circumstances to be referred to in detail later in this opinion.

Plaintiff in the petition charges the defendant with having infringed his patent rights, and specifically relies upon the validity of claims 2, 5, 6, 7, 8, and 9 of the letters patent to sustain the charge. The suit is brought under the act of June 25, 1910 (36 Stat. 851), as amended by the act of July 1, 1918 (40 Stat. 705), and section 155 of the Judicial Code.

In the first brief of defendant the jurisdiction of the court was challenged and a repetition of the defense was included in defendant’s second brief. The defense was not pressed in oral argument and, as we understand it, was finally abandoned. At any rate, finding II with respect to this issue is amply supported by the record, and Ave have no doubt as to our jurisdiction under section 155 of the Judicial Code.

The defense to the suit is predicated upon three grounds: First, the invalidity of the patent because anticipated by the prior art and lack of novelty; second, the claims are not supported by the disclosure; and, third, the claims should be restricted to the precise devices described, and defendant did not use or cause to be manufactured any airplanes embodying this precise mechanism.

Plaintiff’s patent is for what is known in the art as the “ joy stick ”, a single vertical lever so connected with the equilibrium controlling organs of an airplane as to enable the pilot thereof to cause the same to' assume any required attitude in flight. The novelty of the invention and detail of its construction, as well as operativeness, we will discuss later in this opinion.

The solution of the present controversy, despite familiarity with same, involves a repetition of the principles of flight, and at this point it is essential to state and keep in [829]*829mind that we are dealing with an art at a time when it was in an initiatory, formative state. The possibility of flying a heavier-than-air machine had but recently been demonstrated, i. e., a plane propelled by motive power and carrying a passenger or passengers when the plaintiff’s inventions were applied for, and the various devices and mechanisms developed to control the stabilizing organs of the plane in flight, indisputably demonstate that the necessity therefor was imperative, and existing ones, to say the least, not satisfactory.

It is a scientific fact that it is the reaction of the air upon the wing surfaces of a plane that supports the same in the air through which it travels. To secure this reaction in the type of machine involved, a propeller and a motor are employed. A minimum of maintained speed is indispensable to flights. Two types of control are involved m the piloting of a plane, i. e., directional and equilibrium control. Directional control is effected by the functioning of a vertically hinged control surface located generally in the rear of the fuselage, a control surface which corresponds to a rudder on a ship and is operated by the pilot to direct the course of the plane and correct yawing if the same should occur. The steering of an airplane in normal flight is not usually a critical control. “It is”, as finding X states, “immaterial whether the machine flies toward one point of the compass or another so far as its safety is concerned.”

Equilibrium or attitude control, on the other hand, involves two vital and important factors, i. e., longitudinal equilibrium control and lateral equilibrium control. Longitudinal equilibrium control is effected by the functioning of what is known in the art as an “elevator”, which is in fact a horizontally hinged rudder located at the rear of the fuselage, capable of being moved upward or downward by the pilot, thus varying the angle of attack of its surface, thus lowering or raising the rear of the aeroplane, and enabling the pilot to either ascend or descend as his flying course exacts.

Lateral equilibrium control is effected by what may be fundamentally termed “wing distortion.” Originally, in [830]*830order to accomplish this, a portion of the outer end of each wing surface was constructed to yield to a warping force whereby one such surface was inclined upward and the opposite downward, producing a resultant decreased lift on one surface and an increased lift on the opposite one, thus causing the plane to roll about its longitudinal axis.

Maintenance of lateral equilibrium is a factor of extremely vital importance to safety in flight. Unequal air currents, air pockets, and tumultuous atmosphere, all invisible to the pilot and constantly to be anticipated, very frequently disturb the lateral equilibrium of an airplane, and it is of very great importance that this temporary loss of equilibrium bo immediately regained.

The original process of wing warping has been generally if not universally superseded by ailerons, which are conced-edly direct mechanical equivalents for wing warping. (See Wright Co. v. Herring-Curtiss Co., 204 Fed. 597, 607, 608, later sustained by the Circuit Court of Appeals, second circuit. See 211 Fed. 654.) Ailerons are standardized portions of the outer rear wing surfaces, hinged in place and capable of movement so as to distort or alter the contour or form of a portion of the wing surfaces and thus obtain precisely the same air reactions obtained by wing warping. Their presence neither increases nor diminishes the total wing surface, and they are operated by the poilot for lateral equilibrium control.

A rolling movement or change of attitude from horizontal flight is incidental whenever the pilot wishes to turn the plane to the right or left. The turning of a plane is effected by means of its rudder, and to avoid sharp turns calculated to produce skidding, or, as stated in evidence, “ side-slips ”, banking is resorted to, i. e., a more or less gradual inclination of the plane designed to overcome any centrifugal force brought into play by the turning movement, and the so-called “ banking movement ” is effected by the pilot operating the organs of lateral equilibrium control, the ailerons. The differential drag of the wings of a plane, manifest when the plane is banked or subjected to the rolling movement, develops a deviation from its directional course, i. e., “ a [831]*831yaw ”, the degree of which is dependent upon the angle of the roll and “ upon the character of structure employed for altering the wing surfaces.”

The uncertainty of atmospheric conditions and their contrariety of movement in a majority of the time during flight induce simultaneously a disturbance of both longitudinal and lateral equilibrium, and to correct the same “ it is necessary that the airplane shall be tilted in an oblique vertical plane lying between the longitudinal and transverse planes of equilibrium or attitude control.” In other words, the pilot may not resort to á sole banking movement as in effecting a turn but must simultaneously incline or tilt the plane at such an oblique angle as will restore the same to normal equilibrium.

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81 Ct. Cl. 785, 1935 U.S. Ct. Cl. LEXIS 190, 1935 WL 2196, Counsel Stack Legal Research, https://law.counselstack.com/opinion/esnault-pelterie-v-united-states-cc-1935.