Roy Mueller, et al.
Rotary Arch Kite [ Skybow ]
extreme sport application of the Magnus Effect -- with apparent
potential for power-generation --
17 sec - Jan
25, 2010 - Uploaded by SkybowKite
200 foot Blue and Pink Skybows
wereTested in Winds ~10-12
MPH. Rotation speed is at ~5000 RPM's, giving them a minamal ...
2 min - Jan
26, 2010 - Uploaded by SkybowKite
Two Turbo-Jet Skybow
Airfoil Ribbons Flying in the Sky
Together in light winds 10-12 MPH. Arch is ~35 feet high. With higher ...
23 sec - Oct
25, 2010 - Uploaded by SkybowKite
The New Skybow
-PRO Electro Kite
WindMueller Aerology Lab. Boca Raton Florida. Capable of producing
1 min - Jan
25, 2010 - Uploaded by SkybowKite
(200 foot / 60 meter) Skybow
tested Dec. 2009 with Digital
Scale in 10-12 MPH Winds showed pulling up to 17.68 Lbs. on one end ...
What's a skybow?
It's a new kind of kite that acts sort of like an anti-gravity
rope---when you and a friend at the other end hold it across the wind
it pulls upward making a huge arch in the sky.
Who is flying
Kite enthusiasts worldwide are experimenting with skybows, improving
flying techniques, design and materials.
How does it work?
It's not really a rope at all. It's a
rapidly spinning ribbon.
ever noticed that a dropped card or ticket stub can start spinning and
glide away from you as it falls? A skybow's ribbon is attached to
swivels that allow it to spin the same way.
So why does
spinning make it go up?
That's a subtle question, but it's basically the same reason a spinning
ping-pong ball takes a curved flight. It's called the Magnus-Robins
Okay, so why up
instead of down?
With flat-ribbon skybows the fliers
may have to help the ribbon start
spinning in the correct direction---the top of the ribbon should spin
. Other skybows have
creased edges and always spin the same
direction, these skybows must be set up properly in relation to the
direction of the wind.
If started spinning in the wrong
skybow is just as happy to spin the otherway and fly into the ground!
Why does it make
that eerie sound?
The aerodynamic forces always act nearly at right angles to the ribbon
face, but the ribbon is constantly turning. This produces a rapidly
varying reaction against the air ---sound is the natural result. Since
the ribbon has two faces, the
frequency of the sound is twice the spin
A skybow flying well makes a howling sound reminiscent of the sound of
high wind in a pine woods, a skybow that is not entirely steady sounds
like a motorcyle race, with repeated accelerations and sudden
downshifts of pitch.
Loudness increases drastically with wind speed. At 20 mph (32 km/hr)
the curious have been drawn from a quarter-mile (400m) away. The sound
is very directional, with a quiet spot near the fliers and directly
Why are there
sometimes swivels in
the middle of the arch, not just at the ends?
A skybow needs to spin faster where
the wind is faster in order to fly
high. Multiple sections that spin idependently can accomodate
differences in windspeed along the skybow. Usually the fastest winds
hit the high center of the arch. Sometimes a single-section skybow is
tapered --- it's made wider in the center than at the ends so that the
high windspeeds at the center can be accomodated when the whole ribbon
is spinning at the same rpm.
How long can a
The record so far, 1000 ft (303 m) long is held by, Mr. Big, a six
section skybow 5/8" wide (1.6 cm). Tony Frame and Jim Mallos flew Mr.
Big over the Washington Monument Grounds, Washington, DC on November
The maximum length of a skybow is
proportional to the
strength-to-weight ratio of the ribbon material. There are fibers made
with ten times the strength-to-weight ratio of Mr. Big's ribbon, so
skybows two miles long (3 km) may be possible.
How wide can a
Tony Frame and I have flown skybows in widths
ranging from 10mm to
(Tell me about your experiments.)
How do you launch
Skybows are launched by pulling them
taut across the wind.
They can be
launched all at once, or in stages letting one section go up at a time.
Mr. Big was made from a sandwich of two outer layers of premium-grade
box sealing tape (3M #3750), with a narrow middle layer of heavy-duty
surveyor's flagging tape from blackburnflag.com . This design was prone
to snap where the edges were damaged.
Mr. Big's 5/8" wide
Polypropylene gift-wrapping ribbon is very strong and colorful, but it
is difficult to attach centerweighting in a really permanent way.
The best design so far is an unsymmetrical sandwich of 3M's #863 tape
(a transparent monofilament-reinforced polypropylene strapping tape),
which is very strong for its weight and lets the color of the bottom
layer show through, with a narrow middle layer of polyethylene adhesive
tape as the centerweighting, and a bottom layer of 50-micron (2-mil)
thick colored polyethylene bag plastic from bearclaw.net.
There are apparently no retail sources for the 3M #863 tape---you have
to order a carton of 36 from a tape wholesaler.
To fly, a skybow needs a strip of stretchy material (centerweighting)
running along the center of the ribbon. The centerweighting, needs to
be stretchier than the rest of the ribbon so that it shares little of
the ribbon's tension. Inelastic materials will not have a stabilizing
Roughly speaking, the centerweighting should increase the weight of the
ribbon by 50% and be narrower than 75% the ribbon width.
An adhesive vinyl tape, such as electrician's tape, can be simply stuck
on one or both sides of a ribbon, or a non-adhesive vinyl tape, such as
surveyor's flagging tape, can be used in a sandwich construction.
Polyethylene adhesive tape, such as "Frost King Weatherseal Tape,"
which is used to install plastic-film storm windows, is better than
vinyl because it is less prone to delaminate.
It seems that the function of the centerweighting is to make tranverse
waves move along the skybow more slowly than the torsional (twist)
waves. There two other ways to accomplish this same end:
1) carry all the tension at the very edges of the ribbon by placing
low-stretch fibers there, or
2) give the a ribbon a tube-like cross section so it can act a like a
These should be fruitful areas for research.
Skybows rely on damping from aerodynamic forces to spin smoothly, so
the skybow must be rather light. A rule of thumb is that the skybow
should not weigh more than 15 times the weight of the air in the
cylinder that circumscribes it. For example a 17mm wide skybow can spin
smoothly if its weight is 4 g/m---and even lighter is better.
A skybow does need a certain stiffness across its width so that when
twisted under tension it will not buckle and twist up like twine.
The ends of a skybow segment must be held by very low friction swivels.
Only high quality (e.g. SAMPO) ball-bearing fishing swivels will work.
Use the largest size you can find, as the small ones will wear out in a
few minutes even though the tension is moderate. For some reason the
black swivels last longer than the nickel plated ones. Lubricate each
swivel with a drop of sewing machine oil. Do everything you can to keep
the swivels out of the dirt.
For long-life swivels you have to take the trouble to make your own,
using quality ball bearings with rubber seals. I am using MR115-2RS
bearings from bocabearings.com.
A skybow needs to be long enough to power the spinning of its bearings.
This minimum length depends on the width of the ribbon. We've had
success with 30m lengths at 19mm width, and 50m lengths at 15mm width.
When multiple segments are used in a bow (as in Mr. Big), the segments
can be shorter since in general one segment only needs to power one
swivel instead of two. Most recently I have been making 17mm-wide
skybows with multiple segments just 24m long. In the eastern U.S. the
flying fields are never big enough, so short segments are more
The longest single section we've flown was about 114m, but really long
single sections are in danger of twisting up like twine if the
windspeed varies greatly along the length of the bow
Finally!! After 16 Years of Research, 7 Miles of Ribbon, 100's of
Variations of Materials and Swivel Systems, we have sorted out All The
Best... To bring to you the Ultimate in Skybow Design and
Introducing The Original WindMueller Turbo-Jet Skybow!!!
The complete system was developed and is manufactured at the
WindMueller Aerology Laboratory
(Based in Boca Raton Florida since
1991). The NEW Basic Skybow Unit is NOW comprised of 1 Continuous
200' Section of Rip-Stop Airfoil Ribbon, which translates into a Top
Arch Height of ~24Meters/77 Feet. Available soon from our site,
we will have add-on, connectable sections that come in 30M/100' &
60M/200' lengths, to build an arch as high as you want to go.
There is no known limit. The longest we have gone is 1000',
creating an arch approximately 350-400 feet high in the center.
An Incredible 33 Pounds of Pull on each end of the 1000' Skybow was
recorded. The Turbo-Jet Skybow now also comes with our Latest
High Performance MEGA-Velocity Ground Swivel's, rated at 85
Pounds/85,000 RPM's. In a Light Wind, the Skybow Ribbon can spin
at an incredible 4000 rpm's. With Higher Dead-Smooth Winds (16-22
MPH), 7000-10,000 rpm's are now possible... A hum will begin to
sound once the Skybow Pops Up Into the Air, which is the loudest from
beneath the Center of the arch. Like the sweeping motion of a
(Rotary Wing Aircraft) Helicopter Blade, the Skybow Airfoil Ribbon has
a Sweeping Lateral Rotation. This creates an Incredible Low
Pressure towards the direction of the oncoming wind, which magically
lifts the Skybow high into the air, based on the Magnus Effect
Principle. (Named after the German Physicist and Chemist Heinrich
Gustav Magnus (Photo below)). Although Heinrich Magnus Published
his papers of this Discovered Effect in the Mid 1800's, there has never
been an apparatus to Demonstrate this Effect and Principle until Now.
The Turbo-Jet Skybow is the perfect tool for High School and College
Mathematic & Science Projects. You can now move a Class of Students
Momentarily Outdoors to an open area and demonstrate in real time, the
Mathematical and Scientific Concepts of Angular Momentum, Angular
Velocity and Witness first hand, just how powerful The Aerodynamic
Principle of the Magnus Effect is. The Basic Skybow Unit Now
includes... A Pair MEGA-Velocity Ground Swivel's, A 60M/200'
Skybow Airfoil Ribbon, and A 10" Yo-Yo Winder... which all fit into 2
special drawstring pouches to keep everything together in, with the
instructions. It is possible to obtain an arch past 90
degrees perpendicular tilted into the direction of the wind Using Micro
Aerial Swivels. With longer bows, a horseshoe type arch, shaped
like the St. Louis Arch in Missouri is possible. Find a friend or
two, to help you hold the ends so you can hear the noise it makes from
underneath the center. With a good wind it can sound like A Thundering
Waterfall or an Oscillating Turbo-Jet Engine
Chart Based on using 85,000 rpm rated
swivels with a 17 mm/200' Rip-Stop Skybow Airfoil Ribbon.
The Highest Velocity ever Recorded was 10,625 rpm's, July of 2009.
Wind Speed -- ~ RPM Range : SkyBow
8 MPH --3000 : Parallel to Ground
10 MPH -- 4000 : Low Wavy Arch
12 MPH/10 Knots -- 5000 : Minimal Arch
14 MPH -- 6000 : Good Arch
16 MPH -- 7000 : Great Arch
18 MPH -- 8000 : Strong Arch
20 MPH -- 9000 : Very Strong Arch
22 Mph -- 10,000 : Super Strong Arch
24 MPH/20 Knots -- 11,000 : Maximum Lifting Arch
26 MPH & Above -- Above 12,000 : Instability Range
ROTARY ARCH KITE AND SWIVEL SYSTEM
Inventor: MUELLER ROY
IPC: B64C31/06; F16B7/00
-- A rotary arch kite
kit may include a rotary arch kite and a system for connecting various
segments of the kite. The connecting system may include ground swivels,
aerial swivel connectors and static connectors. The ground swivels may
be single independent swivels for attaching a handle to the rotary arch
kite. The aerial swivel connectors may be double independent swivels
for, for example, attaching two lengths of rotary arch kite together.
The static connectors may also be used for joining two lengths of
rotary arch kite together. The rotary arch kite of the present may
include a unique folding and stitching design to permit enhanced
rotation and lift.
BACKGROUND OF THE INVENTION
 The present invention relates to kites and, more particularly,
to a rotary arch kite and swivel systems for operating rotary arch
 Rotary arch kites may produce a pulling force in excess of 50-60
pounds. These kites may also rotate at high velocities, often upwards
of 20,000 revolutions per minute (rpm) or greater. Current swivel
systems may not be able to work with these pulling forces and
 As can be seen, there is a need for a rotary arch kite and
swivel system that may allow operation of the rotary arch kite at
typical pulling forces and high rotational velocities.
SUMMARY OF THE INVENTION
 In one aspect of the present invention, a rotary arch kite kit
comprises a rotary arch kite; a ground swivel adapted to provide a
handle for the kite; and an aerial swivel connector optionally
connecting the rotary arch kite to a second rotary arch kite.
 In another aspect of the present invention, a ground swivel
comprises a strap having a tube rotationally attached to the strap; a
monofilament extending from a body of the ground swivel, the tube
attaching to one end of the monofilament; an end casing permitting
another end of the monofilament to pass through into the body of the
ground swivel a spacer ring within the end casing, the monofilament
passing through the spacer ring; and a bearing, wherein the
monofilament fits into an inner bore hole of the bearing.
 In a further aspect of the present invention, a rotary arch kite
comprises a strip of material, wherein the strip of material is from 1
to 4 inches wide and from 100 to 300 feet long, wherein the kite is
formed by folding the strip of material in thirds and stitching the
folded material along its length at one side of the strip; and an end
of the folded material being folded and stitched to itself to form a
loop in one end of the kite; and a slit cut in the end of the kite.
 These and other features, aspects and advantages of the present
invention will become better understood with reference to the following
drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
is a perspective view of
an aerial swivel connector according to an embodiment of the present
is a side view of the
aerial swivel connector of FIG. 1;
is a top view of the
aerial swivel connector of FIG. 1;
is an exploded
perspective view of the aerial swivel connector of FIG. 1;
is a perspective view of
a ground swivel according to an embodiment of the present invention;
is an exploded
perspective view of the ground swivel of FIG. 5;
is a perspective view of
a handle being inserted into the ground swivel of FIG. 5;
is a perspective view of
a static connector according to an embodiment of the present invention;
is a perspective
partially taken-apart view of a rotary arch kite according to an
embodiment of the present invention;
is a perspective view
of an end of the kite of FIG. 9; and
is a top view of an end
seam of the kite of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
 The following detailed description is of the best currently
contemplated modes of carrying out exemplary embodiments of the
invention. The description is not to be taken in a limiting sense, but
is made merely for the purpose of illustrating the general principles
of the invention, since the scope of the invention is best defined by
the appended claims.
 Various inventive features are described below that can each be
used independently of one another or in combination with other features.
 Broadly, an embodiment of the present invention provides a
rotary arch kite and system for connecting various segments of the
kite. The connecting system may include ground swivels, aerial swivel
connectors and static connectors. The ground swivels may be single
independent swivels (that is, a first end may rotate relative to a
fixed second end) for attaching a handle to the rotary arch kite. The
aerial swivel connectors may be double independent swivels (that is,
each end may independently rotate) for, for example, attaching multiple
lengths of rotary arch kite together. The static connectors may also be
used for joining two lengths of rotary arch kite together. The rotary
arch kite of the present may include a unique folding and stitching
design to permit enhanced rotation and lift.
 Referring to FIGS. 1 through 4, an aerial swivel connector 10
may include tube casing 12 having end casings 28 attached to each end
thereof. A monofilament 20 may extend from each end casing 28. The
extending end of the monofilament 20 may attach to a tube 22. The tube
22 may attach a first rotary arch kite 24 with a second rotary arch
kite 26. Typically, two aerial swivel connectors 10 may attach to each
end of a central rotary arch kite, with two additional rotary arch
kites attached to each of these aerial swivel connectors 10. In an
alternate embodiment, the tube from one end casing 28 may attach to a
strap handle and the tube from the other end casing 28 may attach to
the rotary arch kite. Within the tube casing 12, each monofilament 20
may pass through a bushing 14 and fit into an inner bore hole of a
bearing 16. Each monofilament 20 may have different diameters, as shown
in FIG. 4. Alternatively, each monofilament 20 may have the same
diameter. A bushing 18 may fit between adjacent bearings 16. The tube
casing 12, end casings 28, and bushings 14, 18 may be made of any
suitable material, such as PVC, CPVC, ABS, carbon composite, metal, and
the like. The bearing 16 may be a high RPM rated bearing, such as a
bearing rated at 10,000-500,000 RPMs.
 Referring now to FIGS. 5 through 7, a ground swivel 30 may
include a strap 32 having a tube 34 rotationally attached to the strap
32 to allow the tube 34 to spin freely at high velocities. A
monofilament 36 may extend from a body 38 of the ground swivel 30. The
tube 34 may attach to one end of the monofilament 36. The other end of
the monofilament 36 may pass through an end casing 40, a spacer ring 42
and fit into an inner bore hole of a bearing 44. A first spacer 46 may
attach to the end casing 40. A tube 48 may fit over and attach to the
first spacer 46. A second spacer 50 may fit into and attach to the tube
48. As discussed below, the strap 32 may attach within the second
spacer 50. A heat shrink tubing 52 may be used to cover and protect the
components of the body 38 of the ground swivel 30. The end casing 40,
tube 48, and spacers 46, 50 may be made of any suitable material, such
as PVC, CPVC, ABS, carbon composite, metal, and the like. The bearing
44 may be a shielded high RPM rated bearing, such as a bearing rated
for at least about 85,000 RPMs, however other bearing ratings may be
 According to one embodiment of the present invention, the strap
32 may be folded in as shown in FIG. 7. The resulting four layers of
strap 32 may be inserted into the second spacer 50. A hole (not shown)
may be drilled in either the second spacer 50 and/or the tube 48. The
hole may also pass through the four layers of strap 32. A pin (not
shown) may be inserted into the hole to hold the strap 32. Optionally,
a monofilament may be inserted through the pin to reinforce the strap
32 onto the body 38 of the ground swivel 30. Other means, as may be
known in the art, for connecting the strap 32 to the body 38 of the
ground swivel 30 may be used.
 The tube 34 of the ground swivel 30 may attach to one end of a
rotary arch kite. The ground swivel 30 of the present invention may
allow the rotary arch kite to rotate at high velocities, even while a
pulling force is applied from the ground swivel 30. The spacers 46, 50
may be, for example [1/2] inch pipe and the tube 48 may be a [1/2] inch
coupling and the end casing 40 may be a [1/2] inch cap.
 The ground swivel 30 may have other uses where a swivel handle
may be desirable. For example, the ground swivel 30 may be used to
connect a dog collar to a leash, thereby preventing twisting of the
 Referring to FIG. 8, a static connector 80 may be used join ends
of a rotary arch kite. The static connector 80 may be used, for
example, in place of the aerial swivel connector 10, described above.
The static connector 80 may have first and second tubes 82 attached by
a monofilament 84. In one embodiment, three rotary arch kites may be
part of a kite package, wherein the ends of the middle rotary arch kite
connect with the other two rotary arch kites with two aerial swivel
connectors. In another embodiment, a first and a second rotary arch
kite may be joined with the static connector 80. A fourth and fifth
rotary arch kite may also be joined with the static connector 80. A
third rotary arch kite may have the aerial swivel connector at each end
to connect to the first/second rotary arch kites at one end, and to the
fourth/fifth rotary arch kites at the other end. The ground swivel 30
may be used as a handle for the first rotary arch kite. Such a package
may incorporate several features of the present invention into a single
rotary arch kite package or kit.
 Referring now to FIGS. 9 through 11, a rotary arch kite 90 may
be an airfoil ribbon formed from, for example, ripstop nylon that is
folded in thirds, as shown in FIG. 9. An exterior third 92 may be
attached with stitching 100 for the length of the kite 90. The length
of the kite 90 may be from about 100 to about 300 feet, typically about
200 feet. The unfolded kite 90 may have a width from about 1 to about 4
inches, typically about 2 inches. Each kite end 94 may have a slit 96
cut therein. The slit 96 may be use to retain a tube of, for example,
the ground swivel 30, the aerial swivel connector 10 or the static
connector 80. The kite end 94 of the kite may be formed by folding
about 6 inches of a material end 98 of the kite onto itself. This
material end 98 is then folded under itself (back toward the kite end
94) for about two inches to create a fold 106, resulting in a
three-layer thickness 102. This three layer thickness may be joined
with stitching 104 as an interior, elongated X, as shown in FIG. 11.
The stitching 104 may not extend across the width of the kite 90, as
such stitching may provide a perforation in the kite capable of
tearing. The stitching 104 may extend beyond the fold 106, as shown in