US2324022A - Aerial device - Google Patents

Description

July 13, 1943. PRAUSE, JR 2,324,022

AERIAL DEVICE Filed Oct. 9, 1940 Patented July 13, 1943 UNITED STATES PATENT OFFICE AERIAL DEVICE Robert H. Praus, Jr., Astoria, Oreg.

Application October 9, 1940, Serial No. 360,496

5 Claims.

This invention relates to boomerangs or like terial devices, and more particularly to a boom-- erang comprising several arms, which I term a polyrang.

Prior boomerangs have usually consisted of a plurality of blades radiating from the center of the assembly, some of the blades being of the so-called leading type, and others being of the so-called trailing type. In the primitive type of ooomerang, only two such blades have been used, the boomerang being made in L-shape, with one leading blade and one trailing blade. Such prior boomerangs have been di'fiicult to handle to produce satisfactory performance, and a great deal of practice and some innate skill have been required to attain any degree of proficency.

In overcoming the disadvantages of the prior structures, it is a major object of my invention to provide a boomerang or polyrang of relatively simple construction, and with the use of which a considerable degree of proficiency can be readily attained.

A further object of my invention is to provide a novel type of boomerang or polyrang, the blades of which are entirely offset from the center of the assembly throughout their entire axes.

Still a further object of my invention is the provision of a novel type of boomerang or polyrang, all the blades thereof being formed either as blades of the leading type, or blades of the trailing type.

Still a further object of my invention is the provision of a novel type of boomerang having means associated therewith to provide a sound effect when the boomerang is in flight.

Still further objects and advantages of my invention will appear from the following de scription and appended claims, wherein Figure 1 is a plan of one embodiment of my invention showing the general structure of the boomerang and a sound effect device that can be mounted thereon, this embodiment being formed of one piece of material.

Fig. 2 is a plan of a second embodiment of my invention, wherein the blades are formed as individual elements and three of them secured together to form what I term a trirang.

Fig. 3 is a section of a blade taken on the line 3-3 of Figure 1.

Fig. 4 is a section of a blade taken on the line 44 of Figure 1.

Fig. 5 is a side elevation in section of the'end of the blades of the boomerang of my invention, illustrating the preferred manner of shaping the end of the blade.

Fig. 6 is a section of a blade taken on the line 6-6 of Fig. 2.

Fig. 7 is a section of a preferred modification of arm l2 taken along a point generally designated at line 6-6, such modification being particularly adapted for trap-shooting and preferably made of clay or plastic material.

Referring to Figure 1, the boomerang or trirang I l shown therein is preferably formed from one piece of material such as cardboard, plywood, metal, plastic compositions, or the like. In the case of some materials such as plastic compositions, it is preferred to use a metal reinforcement, as might be made of wire, sheet metal, or the equivalent.

As shown in Figure l, the polyrang comprises a plurality of blades l2, preferably three in number, the inner end I3 of each blade merging with another blade at a section I4 intermediate the ends of the latter blade. By reason of this construction, the axis of each of the blades is entirely offset from the center of the assembly throughout the length of the blade. In a 16" polyrang, an ofiset of about 5 has been found preferable, this offset varying with the material used and the type of construction employed.

The offset of the blades is of material advantage in that each blade exerts the maximum effect in turning, the construction is stronger because the unsupported or free length of each blade is held to a minimum, and a hollow center is provided which reduces the weight of the assembly and provides means in which sound effect devices may be mounted and used with a minimum of resistance to the flight of the polyrang.

Each blade I2 is curved as indicated at [5. When the direction of curvature is in the direction of rotation of the polyrang when in flight, blades [2 are of the so-called leading type. When the blades are curved opposite to the direction of rotation of the polyrang, they are known as the trailing type. As distinguished from a primitive type boomerang which consists of one leading blade and one trailing blade, the polyrang of the present invention has all the blades of one type, whether it be the leading or the trailing type. The leading type blade is preferred, because it gives the polyrang a much better' turning performance. It is also of advantage, especially with frail constructions, in that upon striking the ground, or any object, the leading type blade strikes at a much more favorable angle than the trailing type blade. Thus the shock is less and there is less danger of the device being damaged.

The curvature of blades I2 is also of advantage in that the appearance of the assembly more closely approaches the appearance of the primitive boomerang, which is desirable as a sales aid.

In cross-section, the inner portion of each blade I2 is of the shape shown in Fig. 4, the cross-section of the outer ends being of the shape shown in Fig. 3. In Fig. 4, it will be noted that the leading edge I! of the blades is of substantially the same shape as the trailing edge It, edge I! being only slightly less in thickness. As the outer end of the blade is approached as in Fig. 3, the difference between the edges become much more marked, and the leading edge I! is much thinner than the trailing edge Hi.

In Fig. 2, I have shown a further embodiment of my invention wherein the blades are made as individual elements 19, assembled to form a polyrang 2| similar in shape to that of Fig. 1, and secured together at 22 by suitable fastening means, such as screws, rivets, or the like. This method of construction is of advantage in that if one blade is damaged, it can be readily replaced and the remaining good blades need not be discarded. Furthermore, the manner of securing the blades by one blade overlapping another provides a generally concave face on one side of the assembly which aids the boomerang action.

In this embodiment, the blades are preferably curved, as in the embodiment shown in Fig. 1. In section, blades l9 may be formed as shown in Fig. 6, the leading edge 23 being relatively blunt as compared to the trailing edge 24.

In my invention, it is preferred to rack the blades as shown in Fig. at 25, that is, curve them in the plane of the assembly, so that the edges thereof are above the plane of the central portion of the assembly. By reason of such curvature, one side of the polyrang is of generally concave shape, and the opposite side of generally convex shape. This racking is secured to some degree by the overlapping blade construction of Fig. 2.

To obtain interesting sound effects from the polyrang while traveling through the air, rubber bands, catgut, or similar flexible material capable of being vibrated by the air, may be mounted in the different ways shown in Fig. 1. 26 may be mounted in harp style by providing a series of notches 21 at the end of one of the arms, and a series of notches 28 on the outside of the opposite arm. Rubber bands 26 under tension may then be secured in the notches, and

will remain in position during the flight of the polyrang. This arrangement is particularly desirable as the bands pass over the central opening 21 of the assembly and may be better vibrated.

Rubber bands or the like may also be mounted as shown at 29, by providing spaced holes 3] in one or more of the blades l2 and securing the bands therein, holes 3| being positioned so that the bands extend across the space dividing two adjacent blades.

At 33, I show a further method of mounting by spaced holes 32, the holes being so arranged that the band lies wholly within the area of one blade, and adjacent the outer end thereof.

Interesting effects can also be secured by mounting the rubber bands upon the leading or trailing edges of the blades. For the former, it is preferred to provide a pin 34 in the leading edge of the blade near the outer end thereof, and a hole 35 toward the center of the assembly with Bands a rubber band 36 stretched therebetween. To secure a rubber band 31 to a trailing edge of a wing, it is preferred to employ spaced pins 38 and 39 in the edge of the blade, the band being stretched therebetween.

With the use of rubber bands or the equivalent, the polyrang, in sailing through the air, makes a noise resembling the motor of an airplane in flight.

Referring to Fig. 2, the embodiment there illustrated employs a tubular sound effect device as, for instance, a whistle 4|. The center of the polyrang is preferably formed with notches 42 and 43 with which the whistle makes a flt sufficiently tight to retain it in position during flight. By reason of the combined forward and rotary movement of the polyrang in its flight, the flow of air relative to the whistle produces a very pleasing note.

If desired, the whistle or similar device can be mounted in the center of the polyrang with its axis normal to the plane of the latter.

Obviously there are many other ways of mounting sound producing devices on the polyrang.

The use of such sound effect devices on the polyrang has been found to change its performance to only a very minor degree. Whatever change is made affects the radius of turn by slightly cutting it down. However, the polyrang still returns to the position of the thrower when thrown properly.

The polyrang of my invention has been found to work equally well in windy weather as in calm weather, providing the polyrang is thrown in a direction to buck the wind on its outward flight and return with the wind on its return flight.

The polyrangs herein illustrated are righthanded, that is, they are designed to be used by right-handed throwers and to rotate counterclockwise, as viewed in Figs. 1 and 2. For lefthanded throwers, the construction is reversed in that the rack and the bevel on the leading edge of the blades are reversed, the direction of rotation being clockwise, as viewed in Figs. 1 and 2.

When a 16" right-handed polyrang is thrown by a right-handed person at an angle of 45 to 75 with the horizontal, it goes out in a substantially straight path for a distance of 50 yards or more, spinning in a counter-clockwise direction. The spin is so great that the pull, due to the vacuum on the curved surface, is unable to cause this free gyro to precess. As the polyrang slows down, the vacuum is eventually able to cause the free gyro to precess, the precession being in a counter-clockwise direction.

As slower speeds are reached, the vacuum is able to move the plane of the polyrang to the horizontal. At this time, the gyro effect has also decreased so that the polyrang, which has had its velocity changed glides back to the thrower.

Obviously the size. weight, degree of curvature of the blades, and the manner of throwing, effeet the turning radius of the assembly.

If desired, a hand cord 44 may be secured to the polyrang through an aperture 45, and the assembly Whirled about by hand to produce an entertaining sound effect, either the whistle, or the rubber bands, or both, being used.

For cheap construction, cardboard has been found ideal for making the polyrang of my invention. It is sufficiently resilient to withstand shock, and can be easily cut or stamped out. For still greater strength, spring steel reinforcements can be pressed into the cardboard. Rubber,

molded or otherwise formed around such a framework, makes an ideal construction for children, as it will stand rough treatment and. yet not cause injury on contact.

For uses such as hunting, where rough treat ment will be experienced, a polyrang of sheet metal is preferable, the assembly being stamped or cut from a sheet of metal in one piece. In a sheet metal construction, the desired shape is imparted to the sections of the blades by bending them.

Plywood is preferred in a construction when the blades are first individually formed and then secured together, as shown in Fig. 2. The plywood is preferably cut in a direction whereby the grain of the outer layers is as closely parallel to the axis of the blades as possible. To prevent such materials as plywood and cardboard from coming apart by reason of the laminations thereon separating, it is preferred to apply tape or similar means adjacent the ends of the arms, and at other points likely to separate. Any material other than metal as, for instance, cardboard and plywood should be coated with shellac, varnish, dope, or other protective covering material, to protect against wetting and softening of the material.

The polyrang of my invention is also suitable for use as a flying target, as for trap-shooting and like purposes. When so used, it is preferred to form the center of the assembly as a solid of the general configuration shown in dotted line 30 in Fig. 1, the arms I2 coming off therefrom tangentially. Generally the same outline of the polyrang is retained except for the open center.

As such targets are usuall made of clay or plastic material, it is preferred to give them a cross-section as shown in Fig. 7 to make them lighter and make the central portion concave on the inside and convex on the outside, or the facing side, as viewed in Fig. 1. The center will be likewise concave and convex, and more or less dome-shaped and more circular, the arms retaining the same offset from the center.

In operation, polyrangs of this type go forwardly and then turn almost 180 and return part Way. Thus they are ideal for trap-shooting, giving the rifleman a turning target, and a target which crosses his line of fire.

It is to be understood that the invention may be embodied in specific forms other than that illustrated without departing from the principle or essential characteristics thereof. The embodiments shown are therefore to be considered as illustrative and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description and drawing. All modifications and changes which come within the meaning and range of equivalency of the claims are therefore intended to be included therein.

I claim:

1. A boomerang comprising at least three blades secured together, each of said blades having one end secured to another of said blades at a point intermediate the ends of the latter,

2. A boomerang comprising at least three blades secured together, each of said blades having one end secured to another of said blades at a point intermediate the ends of the latter, the unsecured end of each of said blades being curved forwardly in the direction of rotation of said boomerang when in flight.

3. A boomerang comprising at least three blades secured together in a manner to form a central assembly having a hollow center in said boomerang, the axis of each of said blades being offset from the center of said assembly, each of said blades being of sufficient length to have at least one end extend beyond said central assembly, the outer ends of each of said blades being bent toward one face of the assembly.

4. A boomerang comprising at least three blades secured together, each of said blades having one end secured to another of said blades at a point intermediate the ends of the latter, the outer ends of each of the blades being bent toward one face of the assembly.

5. A boomerang comprising at least three blades secured together in a manner whereby one edge of each blade with one edge of each of the remaining blades defines a closed hollow center, each of said blades being of sufiicient length to have at least one end extend a material distance beyond said hollow center, the adjacent edges of adjacent blades being spaced one from the other.

ROBERT H. PRAUsE, JR.

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