Wright Co. v. Paulhan

• Citation: 177 F. 261
• Parties: WRIGHT CO. v. PAULHAN.
• Decision Date: 17 February 1910
• Court: U.S. District Court — Southern District of New York

177 F. 261

WRIGHT CO. v. PAULHAN.

United States Circuit Court, S.D. New York.

February 17, 1910

Mr Toulmin and P. W. Williamson, for complainant.

Clarence J. Shearn, for defendant.

HAND District Judge.

There is very little that I should wish to add to Judge Hazel's opinion in the case of Wright Co. v. Herring-Curtiss Co., 177 F. 257, were it not for the ardor of the defendant's counsel and their insistence that a different showing has been made here. In view of the seriousness of the contest, I feel obliged to give my own reasons for this decision.

The defendant says that he does not infringe the patent because he does not use a device which automatically always presents to the wind that side of the rudder nearer the angle of lesser incidence; and that if the patent be construed as merely a combination of a vertical rudder with a device for creating a differential in the angle of incidence of the rear marginal edges of the plane, it is not a novel discovery, but was anticipated in the art. Therefore, the first consideration must be the proper construction of the contested claims of the patent in suit.

Claim 7 is the main reliance of the complainants, and that is as follows:

'(7) In a flying-machine, the combination, with an aeroplane and means for simultaneously moving the lateral portions thereof into different angular relations to the normal plane of the body of the aeroplane and to each other, so as to present to the atmosphere different angles of incidence of a vertical rudder, and means whereby said rudder is caused to present to the wind that side thereof nearest the side of the aeroplane having the smaller angle of incidence and offering the least resistance to the atmosphere, substantially as described.'

The specifications and diagrams upon which this claim was allowed after a pendency of three years in the Patent Office, showed the tiller ropes of the vertical rudder attached to the rope which ran along the rear of the lower plane, in such wise that, when the marginal parts of the two planes were warped as indicated, the rudder was turned towards the margin which had the lesser angle of incidence.

Moreover, there was a constant proportion between the degree of deflection of the rudder and that of warping of the plane.

The Bleriot and Farman planes, which the defendant uses, do not have the combination described, and the complainants have in fact at times abandoned it. It is therefore a very sound contention that if the connection between the tiller ropes and the warping device in a constant proportion, be an essential element in the combination patented, the planes which the defendant uses are in no sense infringements, and the case need not go into the question of the validity of the complainant's patent at all.

To an intelligent understanding of the invention and the question of how essential is the attachment of the tiller ropes to the warping rope, the method of maintaining equilibrium under the patented combination must first be set forth. Assume an aeroplane with or without dihedral sustaining surfaces, to be propelled through the air, having the combination specified, and also suppose the left wing has been accidentally depressed. That in itself will result, as all agree, in starting a revolution towards the left. This is the resultant of two motions: First, the forward motion of the plane; and, second, the motion at right angles caused by the sliding of the machine laterally in its own plane and over the successive columns of air. The resultant is precisely analogous to any planetary motion. This resultant is accentuated by the movement of the center of pressure towards the depressed lateral margin, giving a greater leverage to the propeller nearer the elevated wing. Also, the vertical rudder becomes transverse in its reaction to the lateral motion of the aeroplane, and consequently the rudder is pushed up, and by its leverage further turns the direction of the plane to the left. Thus the machine will begin to revolve to the left. Moreover, this very motion will cause the right wing to be further elevated, because of the increased drift, or head-resistance caused by its increasing speed, and the decreased drift against the left wing, caused by its diminished speed. Thus, in turn, the initial depression creates a revolution, and that, in turn, an increased depression with its corresponding acceleration of revolution, so on co-operating till the machine will swoop downwards to the left to its entire destruction.

The first part of the patented combination for correcting the depression of the left wing is to increase the angle of incidence upon the left side, so increasing that component of the drift which is opposite to the action of gravity. However, contrary to the assumptions of earlier speculators, this alone has a precisely contrary effect to what might be expected, because although the lifting component of the drift is increased, the head-resistance is much increased, and this decreases the velocity of the left wing in greater proportion than the increase in the angle of incidence tends to raise it. That revolution, already initiated by the very tilt itself, is therefore increased by the differential in the angle of incidence between the two margins. The right wing, which has thus an added velocity relatively to the left wing, will, in spite of its lesser angle of incidence, rise more rapidly than the left wing. Unless the revolution be corrected the increased angle of incidence will therefore remain ineffectual to restore the balance, but will rather further disturb it, and it is therefore necessary that the rudder should be put over towards the right wing, thus counteracting the revolution. When this is done, the increased angle of the incidence on the left wing becomes effectual and the left wing rises, so restoring the equilibrium of the plane. It is the combination of a differential in the angle of incidence with a rudder which operates against the side of lesser angle which produces this result.

Now, to come back to the connection of the tiller ropes to the warping mechanism. This is, of course, one 'means whereby said rudder is caused to present to the wind that side thereof nearest the side of the aeroplane having the smaller angle of incidence, and offering the least resistance to the atmosphere. ' Literally considered, tiller ropes under the independent control of the operator are equally such a means. But the invention is not of a machine, it is not an invention of this means of so turning the rudder, but it is an invention of a combination of which this action of the rudder is a part. The statute authorizes such an invention, and if the combination be not a mere aggregation of old elements, as I shall try to show hereafter, then the precise means is of no consequence. In the patent in suit any skilled operator, who may serve pro hac vice for a 'skilled mechanic,' finding the automatic connection unsatisfactory, would at once disconnect it and attach the tiller ropes to a lever or to a foot pedal which he could directly control. As the examiner said in his letter of July 14, 1903, it is merely a matter of taste to attach the tiller ropes to the warping rope. The machine would be changed, but the combination would remain, because there would remain the means of causing the rudder to operate upon the side of lesser incidence. The defendant urges very vehemently that the means must be the means specified. All that the specifications need contain is so clear a description that any skilled mechanic may use the invention. Where the change is only an obvious modification of the means specified, and a modification which retains each element of the combination contributing the same effect as before, the claim is not too broad which includes the modification. Of course, were the invention an advance over a prior art which had progressed already to the combination without any automatic movement of the rudder, then the claim must have been limited to the precise specifications. This would be because only when so limited would the patent be an invention at all and the construction would be necessary ut res valeat quam pereat. The defendant insists that this is the case with the patent in suit, and I shall consider that contention later. Assuming for the present, however, that the patent need not be so limited to be saved, then it becomes a pioneer, and as such under the well-known rules is entitled to a broad construction. Therefore, viewed first as a combination, not a machine, and second, as a pioneer patent which advances by more than just the degree of an automatic connection, I cannot agree that it was not a fair equivalent to operate the tiller ropes independently by a mechanism under the direct control of the aviator. That connection was not essential to the three rudder system of control.

The question next arises whether the fact, which I must assume from the affidavits, that the rudder under some circumstances of aviation is turned towards that side of the drift nearer the angle of greater incidence relieves the defendant of infringement. In this connection, the distinction must be carefully observed between turning the rudder towards that side of the main longitudinal axis which is nearer the angle of lesser incidence, and presenting to the wind that side of it which is nearer that angle; the latter being the essential specified. While the two might be readily identified, a moment's consideration discloses that they will be quite different whenever the plane is itself turning in either direction. For example, if the plane is turning to the left in a circle whose radius is 'r,' and has itself a total length of longitudinal axis, a, then the rudder, if free, would stream at...