Abstract:
A toy in the form of a flying top. The toy has a flat body with at least an area nearby the center of gravity and at least one planar extension having a free end. The toy has a maximum distance r between a peripheral rim and the center of gravity, the mass m and/or the mass of inertia θ of the flat body being defined in such manner that the flat body can be laid with its area near the center of gravity onto a convex arched surface, especially onto a finger knuckle, where it can be given a fast rotatory motion ω (ω≧300 rpm) by flipping or jerking with a finger in a horizontal and tangential direction against the free end of an extension, while it receives only a slow translatory motion V T  (V T &lt;ω*r), so that its horizontal orientation is spin-stabilized and results in an air cushion carrying the flat body during its flight.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention refers to a toy in the form of a flying top comprising a flat body with at least an area nearby the center of gravity and at least one planar extension having a free end, and to a method for starting that peg.  
           [0003]    2. Description of the Related Art  
           [0004]    It is known that a body rotating at high speed around its own axis has a great positional stability. This principle is used e.g. to give the well-known “Frisbee” disk its stability in flight. However, this principle applies not only to rotationally symmetrical bodies, but also to the highly crooked boomerang used by the Australian aborigines e.g. for hunting. Such a boomerang has the additional advantage that its usually asymmetric shape causes it to change direction in flight, so that, ideally, one can catch the returning boomerang. The boomerang is therefore a very nice toy which, in contrast to the “Frisbee” disk, one can even throw and catch without a partner and constitutes an entertaining pastime. On the other hand, both “Frisbee” and boomerang require a vast open space, as their flight paths are very long. Particularly in large cities, such vast open space is hard to find, so that children growing up there often have no opportunity to play with these interesting flying objects. Even in the event that sufficient open space is available, “Frisbee” and boomerang require reasonably nice, not too windy weather, as they can only be thrown outdoors.  
           [0005]    On the other hand, rules for building small planes from paper are known, which do not destroy an obstacle in case of collision. The orientation of such flying objects is only stabilized by the airflow during flight so that they can stay airborne only if they have been started with a sufficiently high translatory velocity, too. Therefore, the pleasure in such flying objects is always of very short duration and interrupted by the necessity of fetching the flying object at a distant place of the room.  
           [0006]    From that circumstance results the problem of developing a flying toy that can be used indoors without danger for persons and objects and can fly at a slow velocity with stable behavior so that even in a narrow space a flight of long duration can be achieved.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    The invention refers to a toy in the form of a flying top comprising a flat body with at least an area nearby the center of gravity and at least one planar extension having a free end, whereby the maximum distance r between the peripheral edge and the center of gravity, the mass m and/or the mass of inertia ω of the flat body is defined in such manner that the following start method can be carried out:  
           [0008]    a) the flat body is laid with its area nearby the center of gravity onto a convex arched surface;  
           [0009]    b) the flat body is imparted a fast rotatory motion ω (ω≧300 rpm) by flipping or jerking with a finger in a horizontal and tangential direction against the free end of an extension, while the flat body receives only a slow translatory motion V T  (V T &lt;ω*r);  
           [0010]    c) thereby the horizontal orientation of the flat body is spin-stabilized and results in an air cushion carrying the flat body during its flight. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0011]    Further features, details, properties and advantages of the invention will become apparent from the following description of preferred embodiments of the invention with regard to the enclosed drawings, whereby:  
         [0012]    [0012]FIG. 1 is a top view of a first embodiment of the invention;  
         [0013]    [0013]FIG. 2 shows a second embodiment of the invention at the same view as FIG. 1;  
         [0014]    [0014]FIG. 3 shows another embodiment of the invention at the same view as FIG. 1;  
         [0015]    [0015]FIG. 4 shows a further modified embodiment of the invention at the same view as FIG. 1;  
         [0016]    [0016]FIG. 5 is a view on FIG. 2 in direction of arrow V. 
     
    
       [0017]    In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    The solution of this problem is possible with a toy according to claim  1 .  
         [0019]    Both boomerangs and “Frisbees” are held at their periphery with one hand and then thrown away forcefully with a movement of the arm. This momentum sends them in a fast rotation, which is essential for their stability in flight. Inevitably, the flying object also receives a great impulse, so that it flies away at high speed and, in the event that it hits an obstacle, can seriously damage that object or even be destroyed itself. As these characteristics, which are a disadvantage for playing narrow space, result from the impulse energy incurred when starting, the invention described here uses a different principle: The center of gravity of the flying object is supported on a resting body and then pushed in tangential direction in at least one peripheral point, so that a high torque will send the light-weight body in a fast rotary movement without a too great flying impulse. To achieve this, the inertia of masses of the invented flying object is relatively large compared to its moment of inertia, so that the greater part of the starting energy is translated into a rotary movement and only a relatively small part into the forward movement. This results from the geometry of the flying top with its wing-like extension, as this ends in a peripheral tip, which supplies a relatively low moment of inertia, but still contributes to the inertia of masses of the whole object. It is of key importance for this invention that the mass of the invented toy lies close to its center of gravity, while the mass in the periphery is significantly lower. This results from the free end of the wing-like extension, whereas e.g. a Frisbee disk has a rim all round. While other flying objects are stabilized by a peripheral ring connecting several wing-like extensions, the invention described here has no such ring in order to reduce the moment of inertia as far as possible. Moreover, the free end of the wing-like extension is of key importance for starting the invented flying object. In case of a ring shape, it would be almost impossible to induce a tangential torque.  
         [0020]    A peripheral stabilization element is not needed because the base of the flat body, including all extensions, is limited by a smooth curve. As the wing-like extension(s) verge(s) into the flat body without any notch, the invented flying object is comparatively stable, particularly around the wing(s), so that no peripheral rings or the like are needed to stabilize it (them). Another measure helping to stabilize the invented flying object is that the cross-section of the wing-like extension tapers barely or not at all around its center of gravity compared with the peripheral area.  
         [0021]    The inherent stability of the invented structure can be further improved if the flat body has a diameter of between 2 cm and 10 cm. With such a small diameter, the forces acting upon the wing-like extension during the flight are relatively small, so that a peripheral stabilization can be omitted.  
         [0022]    Furthermore, the invention provides for a thickness of the flat body of 0.1 mm to 3 mm, preferably 0.2 mm to 1 mm, ideally 0.3 mm to 0.7 mm. The required thickness results primarily from the stability requirements to the invented flying object and possibly from factors related to the production.  
         [0023]    A light, stable material, particularly plastic, should be the material of choice for the invented flying object. Moreover, such a plastic material is already corrosion-proof without any further treatment, so that is production costs are reduced to a minimum. As the desired color can already be achieved by adding pigments to the e.g. granulated raw material, the object will not need to be colored afterwards. Selecting a suitable material will also make sure that it contains no toxic substances and thus poses no risk for playing children, even if they should try to take such a toy into their mouths. Furthermore, the invented object was deliberately dimensioned with a diameter that makes it impossible to swallow the toy.  
         [0024]    In addition, the invention makes it possible to punch out the flat body, including the wing-like extensions, in one piece from a rigid film. This production method proceeds from a film-like intermediate product, so that the further production steps can be done with simple tools, which permits a production at particularly low cost.  
         [0025]    The further concept of this invention, that the wing-like extension(s) diverge about radially from the center of gravity of the flat body, make use of the fact that the shortest connection between two points is a straight line. The radial arrangement of the wing-like extensions creates a connection between the wing&#39;s peripherals and the centroidal area of the flying object with the least possible material requirement and thus with a low moment of inertia.  
         [0026]    The invention can be further developed in that the wing-shaped extension(s) has (have) a base with a curved perimeter. By bending the wing-like extensions e.g. in their peripheral area, the lift generated there can be increased, as the bent wing areas result in a greater wing cross section in that area. If there are several wings, they should all be bent in the same direction, against the preferred rotation direction, in order to improve flying properties, especially flight stability.  
         [0027]    As the surface of the wing-like extension(s) is slightly inclined in relation to the base of the flat body, similar to a propeller, the invented toy can draw on its rotational energy throughout the entire flight to accelerate the molecules of the surrounding air downwards and thus generate an ascending force according to Newton&#39;s law of reaction—an ascending force that balances the weight of the invented toy, so that it can stay in the air even at minimal translation speed. Similar to a helicopter, this results in optimal properties when flying at low speed, which is of particular importance for use indoors. The inclination of an extension in relation to the base of the flat body may be between 5° and  30 °, preferably between 10° and 20°.  
         [0028]    The inclination of the wing-like extension(s) in relation to the base of the flat body can be achieved by shaping the plastic film. For this purpose, the punched-out body can be heated (at least partially) and thus temporarily transformed in a plastic state. When cooling down, it can be forced into the desired shape.  
         [0029]    The flying properties of the invented toy depend on a number of fringe conditions. Particularly fluidic factors must be taken into account. Therefore, not all feasible shapes of the flat body are fit to fly. On the basis of further studies, the inventor designed various categories of flying objects that have particularly favorable flying qualities due to their shape.  
         [0030]    The first variant has a second planar extension offset by about 10° to 90°, preferably by 30° to 60°, opposite to the preferred direction of rotation. This extension serves to stabilize the position of the actual lifting wing, which should ideally be longer, and thus ensures stable flight. The advantage of this variant is that only one lifting wing plus a stabilizing wing are necessary, which further reduces the moment of inertia. A high torque can apply on the comparatively long lifting wing, so that this structure can be sent in a particularly strong rotary movement, take up a high quantum of rotational energy at the start and thus can stay in the air for a particularly long time.  
         [0031]    Another category of flying toys is characterized by several wing-like extensions in rotationally symmetric positions to the center of gravity of the flat body or laterally inversed to an axis running through that center of gravity. In this case, the flying object owes its stable flying qualities to a symmetric geometry. At the same time, the center of gravity is positioned favorably approximately in the middle of the flat body.  
         [0032]    The flying qualities of the rotationally symmetric variant can be further perfected if the wing-like extensions, offset against each other in identical angles, lead away from the center of gravity of the flat body. This results in an approximately star-shaped structure, while the individual beams can follow a curved line.  
         [0033]    In this variant, the center of the object generates no ascending force, so that there can be a centric recess surrounded by the closed ring of the flat body. As this ring takes over the connection and stabilization of the wing-like extensions, the center of the object can be omitted as largely neutral, which further reduces the moment of inertia of this structure. Moreover, this ring-shaped structure makes it possible to decouple the wings to a very large extent, so that the inclination of a wing can be achieved with the simplest means.  
         [0034]    It can be achieved e.g. if the closed ring of the flat body is undulated in tangential direction. Due to this undulation, the protruding wings will have an incidence, which provides an ascending force during flight.  
         [0035]    The inclination angle of the wing-like extensions can be determined as the number of undulations of the closed ring is equivalent to the number of extensions, and the phases of the points from which the wings diverge are shifted against the undulations. Thus, the wing-like elements themselves need not be deformed, so that a highly symmetrical structure can be achieved even with the simplest tools.  
         [0036]    To start the invented flying top, the centroidal area of the flat body is placed on a convex surface, e.g. a knuckle. Then one extension of the flat body is flicked with a finger in roughly horizontal direction, so that the body is sent in a fast rotation. A gyro force then stabilizes the orientation of the object, and a propeller-like effect of the extensions may exert a supporting vertical force, so that the object flies away in a stable manner with a relatively slow translatory velocity and remains airborne for a long duration.  
         [0037]    This method is suitable for operating the flying top indoors. As a particularly slow translation movement is desired, the invented flying top is chipped only at one peripheral end. The large torque applying in this case results in a fast rotary movement, while the horizontal accelerating force, which results in a translation movement, is relatively low. This is achieved by the shape of the extension generating the ascending force, especially by a rearward rim of such extension, especially of a distal part thereof, having a section with a tangent extending towards the center of gravity or even in front of this point, seen in direction of movement of that jerked extension. This gives a maximum resulting torque at a definite jerk, allowing an optimum ratio v R /v T  between rotational speed V R =ω* r and translatory speed V T .  
         [0038]    [0038]FIG. 1 shows the flying top  1  in original size. It is made from 0.2 mm plastic film and therefore extremely lightweight; it weighs only about 0.5 g. It has a ring-shaped body  2  with three preferably wing-like extensions  3  positioned at intervals of 120° around the center of the ring. Like the ring  2 , the wing-like extensions  3  are about 0.6 cm to 1.0 cm wide. At the junction  4 , the wing-like extensions  3  at first diverge radially, before gradually bending by about 90°. At their ends, they are approximately coaxial to the ring  2 . They end in wing tips  5  limited by a roughly semi-circular curve. The flying top  1  has a preferred rotation direction  7  which goes approximately from the free end  5  of a wing  3  to its junction  4  with the ring.  
         [0039]    The entire borderline  6  of the flying object  1  is extremely smooth and strongly rounded particularly around the junctions  4 , so that there are no notches that might impair stability. The ring  2  is undulated along its perimeter with an approximately sinusoidal amplitude. One undulation period is equivalent to one-third of the ring perimeter, so that a total of three undulations occur along this perimeter. The undulation of the ring  2  is dephased against the wings  3  in such a way that there is a maximum of the wave amplitude  9  on the front side  8  of each wing-like extension  3 , while the following minimum  11  is located on the back side of the wing  10 . For this reason, the ring  2  is inclined downward at the junctions  4  between a front side  8  and a backside  10  of a wing. This inclination affects the otherwise planar wings  3  into their tips  5 . Consequently, all wings  3  are inclined against the turning direction  7 , i.e. downwards from their junctions  4  on the ring  2  to their free ends  5 . If the flying top  1  rotates at high speed in direction of the arrow  7 , the wing-like extensions  3  displace the air downwards, which results in an opposite ascending force for the flying top  1 . Due to the extremely low weight of the flying top  1 , it can stay in the air for a very long time and even gain height continuously over a long period of time.  
         [0040]    In the variant shown, the central recess  12  inside the ring  2  has a diameter of about 22 mm, so that the center of gravity in the middle of this recess  12  is only 11 mm away from the nearest border line  13 . Thus the ring  2  of the flying top  1  can be placed on a knuckle or a crooked finger, where it is additionally centered. Then the one of the free ends  5  of the wing-like extensions  3  is chipped with a finger of the other hand and the flying top  1  is thus sent in a fast rotational movement.  
         [0041]    If the flying top  1  is placed on a flat surface for starting, some of the energy absorbed from chipping is converted into a translation movement, so that the flying top  1 , barely slowed down due to the low air resistance, flies away. If, however, the flying top  1  is placed over a crooked finger, it cannot fly away when it is chipped, but only gets a fast rotational movement and rises vertically, similar to a helicopter.  
         [0042]    Embodiment  21  of a flying peg, which is shown in FIG. 2, differs from embodiment  1  mainly in that the central body does not have the shape of a ring, but roughly that of a disk. Again, three wings  23 , offset by 120° each, diverge from this central area  22 . Again, these wings  23 , which diverge in the shape of a star, are bent from their longitudinal axes, which are approximately radial at the junctions  24 , in an approximately tangential axis direction close to their peripheral ends  25 . Here, too, the rim or edge  26  is completely rounded, so that no notches impair the stability of the flying top  21 . The preferred direction of rotation  27  also runs from the wing tips  25  to the preceding junctions  24 .  
         [0043]    As can be seen from the lateral view in FIG. 5, the wings  23  are also inclined against the base  28  of the flying top  21 . This is achieved by an undulation of the center part  22  particularly at the junctions  24 . The undulation is such that the wings  23  are inclined downwards from their front edge  29  in turning direction  27  to their rear edge  30 . When the flying top  21  is turning fast  27 , the air molecules are accelerated and the flying top  21  receives an ascending force which provides it with optimal flying qualities. In contrast to embodiment  1 , as shown in FIG. 1, however, this flying top  21  cannot be centered e.g. on a knuckle, so that it receives a translation movement in addition to the rotational movement when it is chipped.  
         [0044]    While the flying objects described above  1 ,  21  have a rotationally symmetric base, the third flying top  31  instead has a basic shape that is symmetric to a central axis  32 , as three different wings  35 ,  36 ,  37  are joined to a disk-shaped central body  34  close to the center of gravity  33 . While two wings  35 ,  36  have an approximately angled shape and are joined to the central body  34  around one of their sides, the third wing  37  has the shape of a triangle, one side of which is joined to the central part  34 . Cross-section, diameter and weight are roughly equivalent to versions  1  and  21 . All wings  35 ,  36 ,  37  are surrounded by a rounded edge or border line  38 . The preferred turning direction  39  of this flying top  31  is clockwise. Accordingly, the wings  35 ,  36 ,  37  are inclined downwards opposite to this turning direction  39  in order to generate the ascending force needed for a long flight. Like in the previously described variants  1 ,  21 , the inclination of the wings  35 ,  36 ,  37  is relatively flat and lies approximately between 5° and 15°. Also with this embodiment  31 , it is not possible to start vertically, but owing to its differently shaped wings  35 ,  36 ,  37 , it can be chipped in different spots  40 ,  41 ,  42  which have different distances to the center of gravity  33 . With the same start impulse, the start energy is thus divided into different rotary and translation movements for each wing, so that one can achieve a slow and rising flight as well as a fast and, due to the low rotary speed, slowly descending flight.  
         [0045]    Finally, embodiment  51  of the flying top, as shown in FIG. 4, is completely unsymmetrical. Roughly speaking, this embodiment consists of a central part  52  in the shape of a ring segment comprising a central angle of 60°, with a main wing  54  in front in the rotating direction  53  protruding roughly perpendicularly, an auxiliary wing  55  offset by around 30° and a third steering or stabilization wing  56 . While the surface of the auxiliary wing  55  is about 80% to 90% of that of the main wing  54 , the steering wing  57  is relatively small with a surface of only about 10% to 20%. In this variant, the main wing  54  can be designed for maximum rise, the steering wing  56  ensures a stable flight, similar to the horizontal tail unit of an aircraft, and the auxiliary wing  55  has been optimized to be used preferably for starting. The preferred flying speed of this flying top  51  can be adjusted by the ratio of the lengths of main wing  54  and auxiliary wing  55 . It has turned out that optimal long-distance flying qualities can be achieved with a wing length ratio of 5:4.  
         [0046]    While certain preferred embodiments of the present invention have been disclosed in detail, it is to be understood that various modifications may be adopted without departing from the spirit of the invention or scope of the following claims.