US2616214A - Toy ground-controlled landing gear - Google Patents

Description

Nov. 4, 1952 D. J. HYDRICK 2,

TOY GROUND-CONTROLLED LANDING GEAR Filed March '7, 1947 2 SHEETSSHEET l Nov. 4, 1952 D. J. HYDRICK 2,515,214

TOY GROUND-CONTROLLED LANDING GEAR Filed March 7, 1947 2 SHEETSSHEET 2 Patented Nov. 4, 1952 UNITED STATES PATENT OFFICE TOY GROUND-CONTROLLED LANDING GEAR 1 Claim. 1

a The present invention relates to toy airplanes and particularly to toy airplanes of th selfpropelled type adapted to fly in circular paths while restrained by a tethering cord or cable.

The self -propelled toy airplane has now become widely known. Airplanes of this class fly at rather high speeds and are adapted to land, after flights, upon landing 'gear carried by the plane and which resembles in large part the landing gear of passenger carrying planes. While the passenger carrying plane, however, normally includes means for retracting its landing gear while the plane is in mid-flight, no satisfactory method of or apparatus for effecting the retraction of the landing gear of a self-propelled toy airplane has so far been provided. The purpose of the present invention is to provide a landing gear control mechanism for toy self-propelled airplanes which will operate without failure and in an entirely satisfactory manner, while at th same time is of simple nature, light weight and low cost.

The improved landing gear operating mechanism which comprises the subject matter of the invention is of automatically operating character, functionin to automatically retract the ground engaging wheels when the airplane is in full flight, thus reducing the air resistance and permitting the airplane to progress more rapidly, and automatically preparing the plane for. landing, when its speed decreases, by extending its landing gear to ground engaging position. Advantage is taken of the fact that, as the airplane circles around the. point at which the tethering cable i held during flight, itdevelops a very substantial centrifugal force which. would, were it not for the tethering cable, cause the airplane to depart from its circular and assume a rectilineal path of movement. During all the time that the plane is in flight the tethering cable is subjected to a considerable amount of tension but the amount of tension will vary, being relatively small, in the first instance or until the plane reaches full flying speed, and again falling toward the end of the flight, as the plane decreases in speed due to the fact that its engine is running out of gas, or for any other reason. During the initial and final periods of flight the landing gear should be extended but during the major portion of the flight it should be retracted and, by taking advantage of the variations in centrifugal forc developed during the flight, automatic extension and retraction of the landing gear may be effected. The invention is not limited to an automatically operating mechanism for extending or retracting landing gear but may be utilized to operate the Wing flaps of the 2 airplane, or to automatically operate landinglights or other instrumentalities associated with the plane.

By way of example one embodiment of the invention, in which the landing gear and wing flaps are automatically actuated, is disclosed but it will be understood that the mechanism may be considerably modified insofar as details and arrangement of its component elements are concerned, in adapting the same to toy airplanes of different. types and for the automatic operation of different instrumentalities.

In the drawings:

Figure 1 is a perspective view of a toy airplane of the self-propelled type, being illustrated diagrammatically and largely'by dotted lines in order that the various elements of the automatic landing gear operating mechanism may be more clearly perceived;

' Figure 2 is a transverse section through the forward end of the fuselage of the airplane;

Figure 3 is a top plan view, showing the operating elements of the mechanisms in different positions from, those which the same elements occupy in Figures 1 and 2; and

' Figure 4 is a longitudinal vertical section through the fuselage of the airplane, with landing gear extended, the plane being in flight.

The invention contemplates the utilization of any known type of landing gear and the combination with that gear of the novel means for automatically operating it. The mechanism which has been illustrated, rather diagrammatically, has been found to be suitable for use in the fabrication of toy self-propelled airplanes, being inexpensive, very simple and of durable nature. It-includes landing wheels I 9, II and I2, Wheels I0 and II being the forward wheels and, in the embodiment shown, being hingedly connected to the undersurfaces of the wings I3 and I4, or otherwise to the structure of said wings, in any suitable manner. Wheels I0 and II are mounted upon stub axles which extend transversely from the foldable wheel carrying arms I5 and I5, these arms being connected, respectively, to the wings by hinge devices I! and I8 for-swinging movements about aXes ab and cd, respectively, which are inclined to the longitudinal axis of the airplane so that, when the landing gear is retracted, the wheels II! and II respectively will not only be swung upwardly and inwardly but also slightly rearwardly, to occupy the ultimate positions in which they are shown in Figure 3.

The tail wheel I2 is mounted upon the lower end of a lever 20 pivctally attached to the frame of the airplane and is adapted to be rocked from the position in which it is shown in full lines in Figures 1 and 4 to the position in which it is indicated in dotted lines in Figure 4. The landing wheels may thus all be retracted and the means for eifecting such retraction, and effecting extension to operative position, automatically, will now be described.

This means includes an element 25 disposed in a horizontal plane and mounted upon a supporting member 26 for rotation about a vertical axis. Movement in one direction, i. e. in the clockwise direction, as element 25 is seen in Figures 1 and 3, is limited by means of a stop aflixed to the frame of the airplane, such a stop being diagrammatic-ally indicated at 21 and normally member 25 is held against stop 21 by the action of a resilient element 23, which may be a helical spring or a strong rubber band, one end of element 28 being connected'to member 25 laterally of the pivotal axis of that member, as clearly shown in Figures 1 and 3, and its opposite end being connected to a rigid portion of the frame of the airplane. Movement of member 25 in a counterclockwise direction (Figures 1 and 3) may be effected by the tethering cable 30, one end of the tethering cable being connected to the forward end of member 25 and its opposite end being adapted to be held by the operator of the airplane.

It is clear from the description which has so far been made that, when the airplane is in flight, the position of member 25 will be dependent upon the 'relative magnitudes of the forces exerted upon that member by the tethering cable, which tends to rotate it in a counterclockwise direction, and the pull of the spring member 28, which tends to rotate it in the opposite direction. The action of the spring member 28 is relatively constant, whereas the tension in the tethering cable 30 will vary widely, being great when the speed of the airplane is high and decreasing as the airplane loses speed. The arrangement is such that, when the airplane has attained relatively high speed the tension in the tethering cable is sufficient to pull member 25 into the position-in which it is shown in full lines in Figure 3 and, when the tension in cable 30 falls below a predetermined amount, depending upon the strength of the spring 28, member 25 is pulled by the springin a clockwise direction until it comes to rest against stop 27.

The landing gear and wing flaps are operatively connected to member 25 in such manner that the airplane is automatically prepared for landing as the tension in tethering cable 30 falls, links 32 and 33 communicating the rotary movements of member 25 to the arms l and I6 and links 34 and 35 operatively connecting member 25 to file of this patent:

the rocking lever 29. It will be observed that the adjacent ends of links 34 and are connected to the end of a lever 36 which is fixed upon a rotary shaft 31 extending transversely of the airplane, the ends of this shaft extending into and being secured to the Wing flaps 38 and 39 respectively. Hence the landing gear is not only actuated when member 25 revol'ves upon its vertical axis but the wing flaps, 38 and 39 will likewise be actuated and, when the landing gear is extended or rendered operative, the wing flaps will be lowered and the airplane prepared for contact with the ground in the usual manner.

It will be appreciated by those familiar with the construction and operation of toy airplanes that the drawings are rather diagrammatic and that the mechanism provided for automatically operating the landing gear and Wing flaps may be widely varied in adapting the invention to toy airplanes of diiferent types, the mechanism illustrated and descri-bed'being set forth by way -of example only. I Also that other instrumentalities may be connected to, and operated by, the rotatable member 25. i

Having thus described the invention, what is claimed as new and desired to be secured by-Letters Patent is:

In a toy airplane, in combination, a frame, wings rigidly secured to said frame, a member movably mounted on said frame, resilient means normally maintaining said member in a predetermined position with respect to said frame and resisting movement away from said position, a control cable connected to said member in such manner as to move said member against the action of said resilientmeans when the tension in the cable reaches a predetermined amount, a

stop limiting the movement of said member under REFERENCES CITED 'The following references are of record in the v UNITED STATES PATENTS Number I Name Date 2,061,953 Sampson -1 Nov. 24, 1936 2,182,913 Brubaker jl." Dec. 12, 1939 2,384,193 Platt Sept. 4, 1945 2,404,922 Padgett July 30, 1946 2,454,598 Doyle Nov. 23, 1948

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