US 3068611 A
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Description (OCR text may contain errors)
Dec. 18, 1962 J. D. LAUDERDALE TOY AIRCRAFT Filed sept. 1, 1959 1N VEN TOR.
United States Patent C 3,068,611 TOY AIRCRAFT Jack D. Lauderdale, Norman, Okla., assigner of twenty percent to Harold R. Shoemake, Muskogee, Okla. Filed Sept. 1, 1959, Ser. No. 837,378 6 Claims. (Cl. 46-75) This invention relates to amusement devices and more particularly to toy aircraft, especially toy simulating helicopters.
An object of the invention is to provide a simple and inexpensive toy aircraft capable of being whirled around and around while tethered at the end of a string, during which the rotor of the aircraft spins and causes a sound which simulates and represents the sound of an engine in a conventional, full scale helicopter and causing the craft to assume a flight position giving the appearance of controlled directed ight.
A toy aircraft in accordance with the invention is iiown by twirling it in a horizontal plane and in a counterclockwise direction. With the pitch of the rotor blades arranged as subsequently disclosed, the rotor will spin, and the toy aircraft is capable of directed flight pursuant to the previously mentioned obiective. Therefore, with practice perfect landings can be made and acrobatic maneuvers consisting of loops, figure eights and inverted flight may be achieved ordinarily impossible with toy aircraft heretofore used because of uncontrolled tumbling that would result. y
A feature of the invention is the device for simulating the sound of an engine. The rotor hub and support for the rotor have short leaves connected respectively therewith which pass over each other causing a clicking sound. r[he frequency of the sound increases in response to the increase in speed of the rotor and correspondingly decreases as the rotor speed decreases. This creates a realistic sound which is variable in accordance with rotor speed.
There are a number of structural features of the toy aircraft which cooperate to provide a superior toy. For instance, the landing gear is connected with the fuselage by tting into a slot in the bottom of the fuselage, preventing the landing gear from turning or twisting during landings. In general this stabilizes the landing gear and holds it in a fixed position.
A further structural feature of importance is found in the actual construction of the hub. rThe rotor hub can be produced very inexpensively and serves the intended purpose effectively, providing a wide support area for the root ends of the blades.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawing forming a part hereof, wherein like numerals refer to like parts throughout, and 1n which:
FIGURE 1 is a top view of a toy in accordance with the invention;
FIGURE 2 is a side view of the toy in FGURE l;
FGURE 3 is an irregular sectional view taken approximately on the line 3--3 of FlGURE 2; and
FlGURE 4 is an exploded perspective view of a portion of the hub structure of the toy aircraft.
In the accompanying drawing there is illustrated a toy aircraft l exemplifying the invention. The aircraft has an air frame or fuselage 12 made of a thin wooden strip provided with an upstanding fairing 14 at approximately the 20% station of the fuselage. Post 16 having a bifurcated lower end 1 8 straddles fairing 14 and is held firmly in place, for instance by being glued. The post may be made of a wooden dowel, and the longitudinal axis thereof is angled upwardly and rearwardly when the heilcopter is in a rest position on a horizontal supporting surface (FIG. 2). Post 16 is mounted on fairing i4 and tilted rearwardly at an angle of 15 from the vertical axis, the vertical aXis being 96 to the bottom edge of the fuselage 12. When in flight however it will be apparent that angular displacement of the fuselage and post 16 will necessarily occur to bring the fuselage to a horizontal position, in order to achieve the appearance of directed flight heretofore mentioned and to enable the craft to perform the aforementioned landings and stunt maneuvers.
Empennage 29 is at the rear end of fuselage l2, and there is a landing gear 22 at the forward end of the fuselage. The landing gear is composed of two wheels 2d and 25 mounted for rotation on laterally outwardly extending spindles 28 and Si) formed at the forward eX- tremities of spring wires 32 and 34. These wires are directed rearwardly and upwardly (FIGS. l and 2) and are connected together by an integral loop 36 at the innerrnost position of each. A fastener, for instance screw 3S, is passed through loop 36 and engaged in the undersurface of the fuselage 12 thereby holding the entire landing gear secure on the fuselage. The landing wheels project forwardly of the nose of the fuselage (FIG. 2). Downwardly opening groove 40 is formed in the bottom part of the fuselage l2 and accommodates loop 36 together with a short part of each of the wires 32 and 34. The longitudinal aXis of groove 4d is Afrom front to rear of the fuselage, and the purpose of the slot is to lock the wires of the landing gear to the fuselage and prevent the landing gear from twisting or turning during landings.
Laterally projecting rigid connecting arm 44 is fixed to the `fuselage slightly in advance of post i6. The projecting arm has means by which to hold cord or string 46 fixed thereto. It will therefore be apparent that in order to achieve the aforementioned directed flight, landing `and stunt maneuvers, the location of the arm i4 on the fuselage is selected in relation to the center of gravity of the fuselage, location of the rotor and the magnitude of the aircraft weight and drag force imposed on the rotor during flight. These means consist of an `aperture near the outer end of arm d4 in which swivel 48 is engaged. Cord 46 is attached to the swivel and provides means by which to tether the aircraft. The arm 4d may ybe held in place in a number of ways, one of which is to pass it through an aperture transversely through fuselage l2 and glue -it in place. A head 50 at ythe inner end of the arm 44 will assure that the arm will not pull out of the aperture in the fuselage.
Rotor 54 is made of a hub 56 and two blades 58 and 60 connected with the hub. These blades have approximately 5 pitch, although the angularity may be varied, it being apparent that because of the angle, the air resistance will cause rotation of the blades and impose aV tilting drag lforce on the fuselage about a fulcrum defined by the projecting arm i4 during flight. The blades may be made of balsa wood or some other lightweight substance and need not be longitudinally twisted to maintain production costs low. Hub 56' is made of block 62 having two ramps 6dand 66 affording angular surfaces 63 and 7d at opposite edges thereof. The surfaces face upwardly and are divided from the center portion 72 of the hub by means of vertical walls forming abutments 74 and 76 against which the inner edges of the root parts of blades dil and S8 abut. The blade roots are wide thereby providing a substantial gluing surface for engaging and holding the blades secure on surfaces 68 and 7d. The surfaces 68 and 7l) are oppositely inclined with respect to each other so that the blades 5S and ed, when glued in place, automatically assume the proper pitch accenti angle with one blade having a negative angle of attack and the other blade having a positive angle of attack. Accordingly, the rolling moment produced in flight about the longitudinal airis through the fuselage must be balanced by the proper selection of weight and extent of tl e projecting arm 44, to achieve the directed balance flight.
Spindle 30 is used to mount the hub for rotation on the upper end of post 16. 'The spindle is preferably a screw having a smooth part Si on its shank and a threaded lower part to be th-readed into the post 16 preferably on the longitudinal aXis thereof. Washer '52 is interposed 'between the head of the spindle forming screw and washer 83 mounted on the top surface of block 62. Lower washer 34 is disposed between the bottom surface of block 62 and the upper end of post 16.
There is a device for producing a sound in response to rotation of rotor 54. The device consists of a pair of small plates S6 and S8 secured to the bottom surface of block 62 and spaced angularly 180 from each other. They straddle post 16 when the hub is mounted thereon and are contacted by a short projection, for instance plate 90 which is secured to post 16 and which projects laterally therefrom. As the rotor is set into operation a click- "ing sound results from plates 36 and S3 successively striking and flexing over plate 90.
In use the toy aircraft is tethered at the end of cord 46 and swung around and around. As previously mentioned, practice will enable the user to fly the toy helicopter in numerous Ways including the making of laudings, takeols, acrobaties, etc.
While the aircraft is in night, the pitch of the rotor blades causes the rotor to rotate and produce directed ight as well as Vto produce a sound emanating from the sound device. It will also be apparent to those skilled in the art from the fo-regoing description, that while the aircraft simulates a helicopter, aero-dynamically an autogyro action is involved inasmuch as no powered rotation of the rotor blades is involved, the blades automatically rotating in response to forward movement of the aircraft through the air. Thus, the string merely imposes forward motion to the toy to directionaily control the flight pattern as aforementioned by virtue of the novel relationship of the rotor, fuselage and projecting arm as hereinbefore described.
The foregoing is considered as illustrative only of the principles of the invention.V Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired -to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.
What is claimed as new is as follows:
1. A toy aircraft adapted to be operated while tethered at the end of a cord, said toy aircraft comprising a fuselage, a laterally projecting fulcrum arm secured to said fuselage intermediate opposite ends thereof and to which a tethering cord is adapted to be connected, a rotor connected with said fuselage and located thereabove, a rotor post secured to said fuselage and with which said rotor is operatively connected, said rotor including a hub, means mounting said Yhub for free rotation on said rotor post, said hub having oppositely angled surfaces to which blades of the rotor are Xed thereby retaining the blades at different angles of attack whereby a directed Hight pattern is achieved.
2. The combination of claim 1 wherein there is a sound producing device operatively connected between said hub and said post and rendered operative in response to rotation of said hub.
3. The combination of claim 1 wherein there is a landing gear secured to said fuselage and including spring arms with ground engaging members at the outer end thereof projecting forwardly in front'of the fuselage, and means in addition to the securing meansr for holding the spring wires to the fuselage for preventing the landing gear from shifting during'landings.
4. A toy aircraft comprising, airframe means, freewheeling rotor means rotatably mounted on the airframe means about a rotor axis, blade means mounted on said rotor means for rotation about said rotor axis in a plane disposed at an acute rear angle with respect to a longitudinal rolling axis through the airframe means in response to forward movement of the airframe means to thereby produce a directed Hight positioning force on the airframe means and a rolling torque about the rolling axis, rigid laterally projecting means mounted. on said airframe means on one side thereof to balance said rolling torque and provide a fulcrum point with respect to which the positioning lforce and weight of the airframe means react to maintain directed flight and means connected to said rigid laterally projecting means for Vimparting forward movement to the airframe means.
5. The toy aircraft as defined in claim 4 wherein said blade means comprises a hub fixed to said rotor means vertically spaced above the airframe means and having oppositely inclined surfaces on opposite sides of the rotor axis and flat blades mounted on said inclined surfaces presenting positive and negative angle of attack surfaces to induce rotor rotation and balanced controlled iight in response to forward movement of the airframe means.
6. A toy aircraft comprising, an airframe having a loaded weight distribution so as to assume a rearwardly inclined position when at rest, tethering means operatively connected to the airframe for imparting forward movement thereto, connecting means rigidly mounted on the airframe and projecting laterally `therefrom for securing the tethering means to the airframe in fixed laterally spaced relation thereto, non-powered rotor means freely rotatably mounted by the airframe about a vertical axis in flight and rearwardly spaced from the connecting means, blade means operatively mounted in a rearwardly inclinedV rotational plane by -the rotor means when at rest with oppositely directed attack angles operative in response to forward movement of the airframe to produce directed flight in a horizontal plane.
References Cited in the tile of this patent UNITED STATES PATENTS OTHER REFERENCES German application No.1,036,733, Aug. 14, 1958, KL 77f 28.