Abstract:
The hexagonal kite has a generally central spar attach fitting having a series of receptacles therein, into which the six spars of the kite are installed. A peripheral tension member extends around the distal ends of the spars to define the hexagonal shape of the kite. The two upper or forwardmost spars are shortest, with the two lower or rearmost spars being longest and the two lateral spars being of intermediate length. This results in the kite surface behind the lateral spars having a larger area than the surface in front of the lateral spars, which results in greater stability and need for a smaller stabilizing tail. The bridle is generally centered on the somewhat forwardly placed spar attachment disc, resulting in the aerodynamic center being located behind the bridle for further stability.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/555,714, filed Mar. 24, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to tethered aerodynamic devices, and more particularly to various embodiments of a hexagonal kite. The structure of the present kite is provided by a somewhat forwardly disposed disc which secures the inboard ends of a series of six generally radially disposed spars, with the distal ends of the spars defining the corners of the hexagonal form. The angular spacing and lengths of the spars are adjusted to provide a shorter upper or leading edge for the kite, thereby placing the central spar connector with its central bridle line closer to the aerodynamic center and moving the aerodynamic center rearwardly or downwardly relative to the tether for greater stability.  
         [0004]     2. Description of the Related Art  
         [0005]     Kites tethered to some point on the ground, e.g., by a kite flyer holding the fixed end of the tether line, have been known for thousands of years. While innumerable different kite shapes have been developed over the centuries, perhaps the best known is the conventional rhomboid or diamond shaped kite, with its cruciform spar arrangement. Such kites have the advantage of being lightweight and simple to construct, but suffer various aerodynamic disadvantages.  
         [0006]     A problem with such rhomboid kites is that the widest portion of the kite is relatively far forward, thus resulting in the aerodynamic center of pressure being relatively far forward as well. The bridle conventionally extends from the tips of the four spars of such a kite, and while the center of the bridle is somewhat closer to the upper or forward end of the kite, this configuration still results in the aerodynamic center of pressure being higher or farther forward than the center of tensile force provided by the bridle. This is the reason such kites, and most other kite configurations, require a tail, i.e., to provide additional mass and aerodynamic area below and to the rear of the center of the bridle for stability.  
         [0007]     The present hexagonal kite provides at least a partial solution to the chronic problem of aerodynamic instability by means of a different kite planform. The present hexagonal kite provides a central, generally disc-shaped fitting to which the six spars are secured and from which the spars extend in a generally radial configuration. However, the six spars are of three different lengths, with the forwardmost or uppermost spars being shortest, the two lateral spars having intermediate lengths, and the two lowermost or rearmost spars having the greatest lengths. This places the spar attachment disc somewhat closer to the upper or leading edge of the kite, and results in a shorter lateral span between the distal ends of the two shorter leading spars. The result is relatively less forward area, which shifts the aerodynamic center somewhat rearwardly relative to the bridle and results in a need for a smaller tail for the kite.  
         [0008]     A discussion of the related art of which the present inventors are aware, and its differences and distinctions from the present invention, is provided below.  
         [0009]     U.S. Pat. No. 3,767,145 issued on Oct. 23, 1973 to Raymond P. Holland, Jr., titled “Kites,” describes a flexible kite structure having a pair of generally parallel longerons with a flexible span therebetween and flexible extensions to each side. Holland, Jr. teaches away from the present hexagonal kite due to the laterally flexible structure of his kite, the lack of any rigid central structure, provision for only two lateral attachments for the bridle, and lack of any form of structure (e.g., string or cord, etc.) to define the periphery of his kite.  
         [0010]     U.S. Pat. No. 6,062,510 issued on May 16, 2000 to Carlos De La Melena, titled “Kite,” describes a kite having an octagonal periphery and a complex, three-dimensional rigid frame to hold the tension lines providing the shape for the kite. The De La Melena kite frame does not provide a single, central fitting from which a series of radially disposed spars extend, as provided in the present hexagonal kite configuration. The surface of the De La Melena kite is porous, and provides for the removable placement of various non-porous shapes thereon to act as aerodynamic surfaces. De La Melena provides a multiple line tether to control his kite, and may optionally provide additional such tethers for the non-porous patterns placed on the porous surface of his kite. No multiple line bridle connecting to a single tether line is provided by De La Melena.  
         [0011]     U.S. Pat. No. 6,499,695 issued on Dec. 31, 2002 to Robert O. Talamo, titled “Balloon Kite,” describes a pair of embodiments of a pneumatically inflatable kite. One of the embodiments has a parasail configuration comprising a series of longitudinal tubes and a lateral leading edge tube. However, the closest embodiment to the present hexagonal kite invention is a kite having a conventional rhomboid configuration. The Talamo rhomboid kite includes only a two-line bridle with the lines attached at the laterally opposed corners, rather than having a multiple bridle line configuration as in the present hexagonal kite. Most critical is the fact that Talamo does not provide any form of rigid structure in his kites, due to their inflation.  
         [0012]     U.S. Patent Publication No. 2002/20,784, published on Feb. 21, 2002, titled “Flexible Kite,” describes a flexible parasail type kite, with no rigid structure. The only structural members which are not completely flexible are semi-rigid, somewhat flexible fiberglass rods used as the leading and lateral edge members, to which the bridle lines are attached. This configuration teaches away from the present hexagonal kite, with its flexible peripheral members and rigid, or at least semi-rigid, radially disposed spar structure extending from a generally central fitting.  
         [0013]     U.S. Design Pat. No. 246,807 issued on Dec. 27, 1977 to Aaron C. Moore, titled “Kite,” illustrates a design having a polygonal shape with diagonal cross bracing. However, no central fitting is apparent in the Moore design, and no bridle configuration is disclosed.  
         [0014]     U.S. Des. Pat. Nos. 428,069 and 428,070, both issued on Jul. 11, 2000 to Chen Nan Cheng and titled “Kite,” illustrate designs having configurations resembling that of a hot air balloon. The balloon portions of the Cheng kite designs are generally flat and planar with a conventional rigid crossmember(s), but the outer edges are shaped to provide overall outlines similar to that of a hot air balloon. The tails of the Cheng kites are open cylindrical structures, made to resemble the gondola of the balloon. The primary differences between the &#39;069 and &#39;070 designs of Cheng are that (1) the &#39;070 design does not include a lateral brace spar, and (2) the &#39;070 design includes a larger, spiral tail extending below the gondola tail structure. The Cheng kite design configuration teaches away from the present kite, in that among other points of difference, Cheng provides the greatest aerodynamic area at the forward or upper portion of his kite, hence the need for the relatively large tail portion.  
         [0015]     Japanese Patent Publication No. 10-165,660 published on Jun. 23, 1998, titled “Foldable Kite,” describes (according to the drawings and English abstract) a kite folded of a single sheet of material, with the center of the sheet folded to form a vertical surface and the outer portions extending outwardly therefrom to form flying surfaces. A single lateral spar passes across the vertical surface and attaches to the two flying surfaces to provide rigidity for the assembly. No generally central spar fitting with a series of spars radiating outwardly therefrom, is disclosed in the &#39;660 Japanese Patent Publication.  
         [0016]     Finally, Japanese Patent Publication No. 10-305,177 published on Nov. 17, 1988, titled “Kite And Manufacture Therefor,” describes (according to the drawings and English abstract) a method of cutting, folding, and gluing a plain sheet of material, such as a sheet formed from opening a shopping bag and folding it flat, into a kite. The completed kite configuration appears to closely resemble kite of the &#39;145 U.S. patent to Holland, Jr., discussed further above. The same points of difference noted between the Holland, Jr. kite and the present hexagonal kite, are seen to apply here as well.  
         [0017]     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a hexagonal kite solving the aforementioned problems is desired.  
       SUMMARY OF THE INVENTION  
       [0018]     The hexagonal kite incorporates various structural and aerodynamic improvements over earlier kites of the related art. The hexagonal configuration is provided by a central disc having a series of six sockets disposed therearound, with six rigid, or semi-rigid, spars extending outwardly therefrom. A tension member (string, etc.) extends around the distal ends of the spars to define the periphery of the kite, and to serve as an attachment edge for the aerodynamic surface or cover for the present kite. A bridle attaches to the distal ends of the six spars and to the central disc, with a tether line (kite string, etc.) attaching to the bridle.  
         [0019]     The hexagonal kite has a novel planform, in that the hexagonal shape is not regular. The upper or forwardmost two spars are relatively short, with the lower or rearmost two spars being the longest of the spars. The two lateral spars have lengths intermediate between the forward and rearward spars. This results in the portion of the kite forward of the lateral spars having a smaller area than the portion rearward of the lateral spars, with the uppermost or leading edge of the kite surface being shorter than the lowermost or trailing edge of the surface. This results in the aerodynamic area forward of the lateral spars being considerably less than the area rearward of the lateral spars. As the bridle is generally centered from the spar attachment disc, it will be seen that the bridle is ahead of the aerodynamic center of the present kite. This provides much greater stability for the present kite in comparison to other conventional kite configurations, and greatly reduces the need for a stabilizing tail.  
         [0020]     These and other features of the present invention will become apparent upon consideration and review of the following specification and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a perspective view of a hexagon shaped kite according to the present invention, as it would be deployed in flight.  
         [0022]      FIG. 2  is a rear elevation view of the present hexagonal kite, showing the configuration of its spars and lateral bow string.  
         [0023]      FIG. 3A  is a detail perspective view of a first embodiment of the spar attachment disc, showing the fitting of spars having round or cylindrical cross sections thereto.  
         [0024]      FIG. 3B  is a detail perspective view of another embodiment of the spar attachment disc, configured for the installation of spars having square or rectangular cross sections therewith.  
         [0025]      FIG. 4A  is a detail perspective view of one of the spar tip fittings configured for use with a spar having a round or cylindrical cross section.  
         [0026]      FIG. 4B  is a detail perspective view of an alternative embodiment spar tip fitting, configured for use with a spar having a square or rectangular cross section. 
     
    
       [0027]     Similar reference characters denote corresponding features consistently throughout the attached drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]     The present invention comprises various embodiments of a hexagonal kite that provides various improvements in structural and aerodynamic efficiency in comparison to conventional kites.  FIGS. 1 and 2  respectively provide front perspective and rear elevation views of the present kite, designated by the reference character  10 . The present kite  10  has a hexagonal planform, defined by the ends of the six radially disposed spars as shown in  FIG. 2 . The relative lengths of these spars and their interconnection provide certain structural and particularly aerodynamic advantages, as discussed in detail further below.  
         [0029]      FIG. 2  provides a view of the spar structure of the present hexagonal kite  10 . The kite  10  shape is defined by a series of six elongate spars, comprising two forwardly disposed spars  12  and  14 , two mutually opposed lateral spars  16  and  18 , and two rearwardly disposed or aft spars  20  and  22 . The spars  12  through  22  may be formed of wood, solid or hollow Nylon® or other plastic rod, or other material as desired. Each spar  12  through  22  has a fitting installation end  24 , which installs either removably or permanently in one of the six radially disposed, coplanar sockets or receptacles  26  of the generally centrally disposed spar attachment fitting or disc  28 . Details of this fitting  28  are shown in  FIG. 3A , for spars having round or cylindrical cross sections, with corresponding fitting  28   b  being shown in  FIG. 3B  having square or rectangular sockets  26   b  for spars with fitting installation ends  24   b  with corresponding cross sections.  
         [0030]     Each of the spars  12  through  22  has a distal end  30 , with a peripheral tensile member  32  (e.g., cord, string, etc.) extending about the distal tips  30  of the spars  12  through  22  to define the hexagonal periphery of the present kite  10 . The kite  10  is covered by a flight surface  34  of paper, Nylon® or other plastic sheet, or other material as desired. The flight surface  34  includes a windward side  36  ( FIG. 1 ) and an opposite back side  38  ( FIG. 2 ) and extends across all of the radially disposed spars  12  through  22 , attaching to the peripheral tensile member  32 . A tensile bow string  40  extends across the span of the two lateral spars  16  and  18 , and across the back side  38  of the flight surface  34 , bowing the two lateral spars  16  and  18  rearwardly.  
         [0031]      FIGS. 4A and 4B  illustrate different embodiments of the spar end caps which are provided with the present hexagonal kite  10 . In  FIG. 4A , a spar end cap  42  is shown, with the end cap  42  having a spar attachment socket  44  into which the distal end  30  of one of the spars  12  through  22  is installed. The distal end of the cap  42  opposite the spar attachment socket  44  includes a slot  46  for the installation of the peripheral tensile member  32  therein.  FIG. 4B  illustrates a spar end cap  42   b  which is functionally like the end cap  42  of  FIG. 4A , but which includes a square or rectangular socket  44   b  for a spar having a square or rectangular cross section and distal end  30   b . It will be understood that the cross sectional shapes of the various spars, spar attachment fitting sockets, and end cap sockets are not critical, so long as they are compatible with one another in any given kite construction.  
         [0032]     Returning to  FIG. 2 , it will be noted that the various spars  12  through  22  are not equal in length to one another. This is a critical feature of the present hexagonal kite  10 , and provides much of the aerodynamic advantage of the kite  10 . It will be noted in  FIG. 2  that the two forward or front spars  12  and  14  are relatively short in comparison to the other spars, with the two opposed lateral spars  16  and  18  being somewhat longer than the two front spars  12  and  14 . The two rearward or aft spars  20  and  22  are the longest of any of the spars  12  through  22 . The specific ratios of the lengths of the front, lateral, and aft spars, as well as the overall size of the kite  10 , may be adjusted as desired to provide the desired aerodynamic effects.  
         [0033]     While it is not a requirement that the opposite spars, e.g.,  12  and  22 , or  14  and  20 , be in alignment with one another, preferably the alignment of the spar attachment receptacles  26  in the spar attachment fitting  28  provides for such alignment. When the opposite spar members are aligned with one another, the included angle between the two front spars  12  and  14  will be identical to the included angle between the two rear spars  20  and  22 . As the two front spars  12  and  14  are shorter than the two rear spars  20  and  22 , the span across the distal ends  30  of the two front spars  12  and  14 , which defines the leading edge  48  of the kite  10 , will be shorter than the span across the distal ends  30  of the two aft spars  20  and  22  defining the trailing edge  50  of the kite  10 .  
         [0034]     The above-described geometry also results in the placement of the two opposed lateral spar members  16  and  18  and the spar attachment fitting  28 , closer to the leading edge  48  than to the trailing edge  50 . The greater distance between the maximum span of the kite  10 , as defined by the span of the two lateral spar members  16  and  18 , and the trailing edge  50 , in comparison to the distance between the lateral spar members  16  and  18  and the leading edge  48 , along with the wider span of the trailing edge  50  in comparison to the leading edge  48 , results in considerably greater flight surface area for the rearward portion  52  of the kite  10  between the lateral spars  16  and  18  and the trailing edge  50 , than for the forward portion  54  of the kite  10  between the lateral spars  16  and  18  and the leading edge  48 .  
         [0035]     This relatively larger rearward surface area  52  results in the aerodynamic center of pressure being located somewhat rearwardly of its location in a conventional kite, with the aerodynamic center of the present kite  10  perhaps being located behind or to the rear of the spar attachment fitting  28 . This greatly assists the stability of the present kite  10 , as the central line for the bridle extends from the spar attachment fitting  28 .  
         [0036]      FIG. 1  of the drawings illustrates the bridle configuration for the present hexagonal kite  10 . The bridle assembly comprises a series of six peripheral bridle lines  56  which extend from the distal ends  30  of the six spars  12  through  22 , and a central bridle line  58  which extends from the spar attachment fitting  28 . The bridle assembly extends from the windward surface  34  of the kite  10 , with the central bridle line penetrating through the flight surface  34 . Each of the peripheral bridle lines  56  attaches to the kite  10  at an eye  60  extending from the spar end cap  42  ( FIG. 4A ) or  42   b  ( FIG. 4B ), with the central bridle line  58  attaching to a similar eye  62  extending from the spar attachment fitting  28  ( FIG. 3A ) or  28   b  ( FIG. 3B ). The various bridle lines  56  and  58  join one another in front of the kite  10  at their mutual kite line connector ends  64 , where they connect to a conventional kite line or string (not shown). The placement of the tensile center of the bridle assembly at the relatively forwardly positioned spar attachment fitting  28 , along with the larger rearward surface area  52 , greatly enhance the aerodynamic stability of the present hexagonal kite  10 .  
         [0037]     In the event that even greater aerodynamic stability is required, a tail assembly may be added to the kite  10 , as shown in  FIG. 1 . The tail assembly comprises a tail attachment bridle  64  which extends across the span of the trailing edge  50 , between the distal ends  30  of the two aft spars  20  and  22 . The ends of the bridle  64  may be secured to the kite  10  by means of the eyes  60  of the spar end caps  42  affixed to the distal ends  30  of the two rearward spars  20  and  22 . A tail  66  is then attached to the tail attachment bridle  64 , preferably generally medially therealong. The tail  66  may be formed of conventional materials known to be of use for such purposes, e.g., a strip or strips of fabric or other material secured to the bridle  64  with string or cord, etc. The size and length of the tail  66  may be adjusted as required, depending upon the aerodynamic stability of the kite  10  with its different forward and rearward areas  54  and  52 , the materials used in the construction of the present kite  10  and its tail  66 , and the amount of wind and turbulence anticipated for any given kite flying session.  
         [0038]     In conclusion, the hexagonal kite provides various improvements in aerodynamics and structure for kites. The irregular hexagon shape, with its leading edge smaller than the trailing edge, results in greater aerodynamic area rearward of the central bridle attachment, thereby shifting the center of pressure rearwardly relative to the bridle attachment to provide greater stability. Thus, the present kite requires a smaller tail to provide the required stability, particularly in consideration of the seven-point bridle attachment system.  
         [0039]     The kite may be constructed of any suitable materials and to any practicable size, as desired. The three diagonally opposed spar pairs, i.e., the two lateral spars, the left forward and right rear spars, and the right forward and left rear spars, have the same total length. Thus, a diagonal measurement across any two opposed spar tips, will be equal to the diagonal measurement across any other two opposed spar tips. This results in a decrease in the area of the forward portion of the kite as the rearward area is increased, as the forward spars are shortened and the rearward spars are lengthened to place the central attachment fitting or disc closer to the leading edge of the kite. Accordingly, the aerodynamic stability is improved, as explained further above. The hexagonal kite, with its improved aerodynamic stability, ease of construction, and durability provided by the central spar attachment fitting and distal spar tip fittings, will prove to be widely accepted by those who enjoy the hobby of kite flying.  
         [0040]     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.