Guided kite with stable yet adjustable curve profile

The curve profile of the front edge of an air-filled wing or sports kite of a type which is guided from the ground is maintained without the use of any bracing system. This curve profile, which is very important in determining the flight characteristic of the wing, is controlled exclusively by adjusting the various lengths of balance lines. Two symmetrical line bundles or connecting balances radiate from end points of at least two steering lines and are fastened to various points on the wing base. If so desired, central balance lines can be connected to the wing base without intermediate fastenings. The fastening points on the wing base are located chiefly at the front portion of the wing base. The lengths of the various balance lines preferably increase from the side edges to the middle. However, the rate at which the balance line length becomes greater can increase, decrease, or remain constant, at least in certain areas.

BACKGROUND OF THE INVENTION 
The invention relates to a sport kite, i.e., an air foil or wing, which can 
be guided from the ground according to a known guidance principle 
utilizing at least two steering lines and air-filled, parafoil wings, 
typically made of rip-stop nylon. Such sport kites, which are guided from 
the ground by two lines simultaneously serving as attachment and steering 
lines, are known as "flexifoils". In sport kites such as that of the 
present invention, the particular curve profile of the wing, and 
especially of the front edge of the wing, is very important in determining 
flight capability and maneuverability. The desired curve profile is 
typically provided in known guided kites by a multi-part, rigid rod system 
with a shape corresponding to the desired curve profile. The rigid rod 
system is inserted into a pocket positioned in the front edge of the kite 
or wing and retained there. The system includes a middle portion that is 
cylindrical in shape, and outer parts which taper conically outward. 
It is also known from the prior art to give a wing its needed stability and 
shape by means of a bracing housed in a pocket of the front edge of the 
kite or wing. The bracing is composed of a material lighter and softer 
than metal, e.g., an expanded rigid polystyrene plastic such as Styrofoam. 
The present invention relates to a sports kite or wing which is completely 
free of any kind of bracing. This results in a reduction in weight as 
compared to other constructions as well as better transportability, 
improved flight characteristics, such as making the kite capable of flying 
in narrower, i.e., smaller, curves, and reduced production costs. These 
advantages are made possible by the elimination of the pocket which 
previously has been necessary to house the rigid rod system or bracing. 
The invention instead uses additional balance lines to provide the kite 
with the desired curve profile. 
SUMMARY OF THE INVENTION 
This technical advance is made possible by application of a novel line 
guidance principle to the sports kite of the present invention. This 
principle, which is adapted in modified form from its use in connection 
with glide parachutes, consists of establishing and stabilizing the curve 
profile of the wing through the use of lines connected to the wing rather 
than by means of material type bracing. The wing is symmetrically filled 
with air relative to its longitudinal axis. The curve profile of the wing 
is established exclusively by means of coordinating the largely differing 
lengths of various balance lines. Two symmetrical line bundles are 
provided. The balance lines are attached at various points on the wing 
base, either directly or by means of intermediate fastenings. 
In known glide parachutes the balance lines used for steering are operated 
separately from the balance lines serving to the carry the load (e.g., the 
parachute jumper). The balance lines used for steering are separated from 
the load carrying balance lines and are attached at the back part of the 
wing base. By way of contrast, the balance lines in the inventive sports 
kite, which does not carry a load, are designed to radiate outwards as 
bundles from the end of each steering line. The bundles serve both to 
steer the kite and to stabilize the curve profile of the wing. 
According to a preferred embodiment of the invention, the attachment points 
of the balance lines are not uniformly distributed over the base of the 
wing. The balance lines are preferably distributed only in the forward 
area of the wing base, and ideally on the front edge or in the immediate 
vicinity of the front edge of the wing base. In the rear area, and 
particularly in the rear 50% to 60%, and more advantageously 75% to 80% of 
the rear wing surface, fewer balance lines are fastened. It is preferable 
to have no balance lines at all fastened to this portion of the wing. 
Preferably, at least the outermost balance lines are not directly fastened 
to the wing base, but rather are attached to the wing base by means of 
intermediate fastenings formed by pieces of fabric, preferably triangular 
in shape. Intermediate fastenings of this type are known as "keels". It is 
also known to replace these fabric triangles with triangularly positioned 
lines. According to the preferred embodiment of the invention, the keels 
in their entirety rather than only a portion of these keels are replaced 
by triangularly positioned lines, without fabric covering.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the drawing figures, reference numeral 1 denotes the base and reference 
numeral 2 the cover of an inventive kite or wing according to the present 
invention. Positioned just above the front edge 7 of the wing base are air 
intake openings 8. Air flows into compartments 9, into which the interior 
of the wing is divided, through these air intake openings during operation 
or use of the wing. The spatial contour of the wing itself is established 
by the varied height of each of a plurality of compartment walls 10, which 
divide the interior of the wing into compartments 9. To equalize the 
pressure between the individual compartments 9, openings 16 in compartment 
walls 10 may be provided. Openings 16 are shown in FIG. 4, but for the 
sake of simplification are not shown in FIG. 3. The relative dimensions of 
compartment walls 10 are indicated for further clarification in FIG. 3. 
As can be seen from the drawing figures, and in particular, from FIGS. 1, 
4, 5, and 8, balance lines 4a-4j radiate, in two symmetrical bundles, from 
end points 5 of steering lines 6. Referring to FIGS. 1 and 4, intermediate 
fastenings 14a-14j are attached to the respective end points 13a -13j of 
balance lines 4a-4j, respectively. According to the present invention, 
intermediate fastenings 14a-14j are formed by connecting balances, or line 
systems, consisting of at least two lines which radiate from a single 
point to least two attachment points. For example, referring to FIG. 4, 
the intermediate fastening 14b is formed by three lines, 14b.sub.1, 
14b.sub.2 and 14b.sub.3, which are secured in any known manner so as to 
attach with corresponding points 15b.sub.1, 15b.sub.2 and 15b.sub.3 on the 
base 1. Keels may be used in place of intermediate fastenings 14a-14j. 
The embodiments illustrated in FIGS. 1-4 and in FIGS. 5-9 differ in several 
ways. In the second embodiment illustrated in FIGS. 5-9, third lines 
14a.sub.3 to 14j.sub.3, which are present in the intermediate fastenings 
of the first embodiment in FIGS. 1-4, have been eliminated. Also, as is 
apparent from FIG. 5, in the second embodiment, the two innermost balance 
lines 4e and 4f are jointly attached to a single point 13e, f on the front 
edge of base 1 without the use of an intermediate fastening. By contrast, 
in the first embodiment of the wing illustrated in FIGS. 1-4, the two 
innermost balance lines 4e and 4f are connected to base 1 at two different 
places and through respective intermediate fastenings 14e and 14f. 
Further, in the second embodiment, balance lines 4d and 4g, i.e., those 
balance lines which, moving outward from the central longitudinal axis L 
of the wing, are adjacent the innermost balance lines 4e and 4f, are also 
directly attached to the front edge of the base 1 without intermediate 
fastenings. By contrast, balance lines 4d and 4g of the first embodiment 
are attached to base 1 through respective intermediate fastenings 14d and 
14g, respectively. The number of compartments is different in the first 
and second embodiments. Compartment walls 10 divide the interior of the 
wing illustrated in FIGS. 1-4 into 18 separate compartments 9. By 
contrast, walls 10 divide the interior of the wing shown in FIGS. 5-8 into 
only 16 separate compartments. Moreover, the connecting holes 16, which 
are present in walls 10 of the first embodiment to provide communication 
between compartments 9, have been omitted from the compartment walls 10 of 
the second embodiment. Additionally, as can be seen by a comparison of 
FIGS. 3 and 7, the cross-sectional wing contours of the two embodiments 
differ. Finally, bends in the front edge of the wings also are slightly 
different. 
The flight performance and maneuverability of the inventive kite can be 
optimized by providing the correct curve to the front edge 7 of base 1 and 
thus to the entire guided kite. According to the present invention, such a 
correct curve is defined and maintained by the appropriate manual 
adjustment of the various lengths of the balance lines 4a-4j between end 
points 5 and 13a-13j. Any known manner can be used to adjust the lengths 
of balance lines 4a-4j In the illustrated embodiments, the varying 
relative lengths are indicated in brackets in FIGS. 1 and 5. For the best 
performance, the varying lengths of the balance lines should increase from 
the lateral edges of the wing toward the central longitudinal axis 
thereof. At the same time, the rate at which the lengths of the balance 
lines increase, in the same direction, can increase, decrease or remain 
the same.