Dale C. Kramer, Dale Kramer
Detailed still photos of Lazair before conversion.
http://angelica14709.com/v-web/gallery/album121
For very detailed technical information.
http://www.rcgroups.com/forums/showthread.php?t=1412424 One of Dale's post
on this site.
Today I made a spreadsheet of all my flights and the mah each battery has
taken to charge after each flight. On my strictly duration flights with no
thermals I have been able to determine my effective flight time for the wheel
and amphib flight configurations before today's flight. So, although I had
flown 8.9 hrs on the JM1's I broke this down to effectively 3.5 hrs on wheels
and 2.5 on floats which means I have soared for about 2.9 hrs before todays
flight. Further, I can calculate that it takes 1.6 times more power to
maintain height in the amphib vs the wheels Lazair.
I also know that it took 11 gallons of gas to have the generators charge the
batteries for all this flying.
So, the amphib Lazair is using 2.3 gal/flight hr of fuel to charge it and the
wheels Lazair is only taking 1.5 gal/flight hr. I am amazed at these low
numbers but it is what it is. No hypothesizing here. I am using less fuel per
flight hr using generators to charge an electric Lazair than I did flying this
Lazair with two JPX gas engines.
I am currently 'greener' than before electrification and I will be even
'greener' when I get set up to charge with six 20 amp house circuits. Dale
http://blog.cafefoundation.org/?p=3475 Dean Sigler reports on Dale's electric explorations over the Lazair. Then related by Dean: http://blog.cafefoundation.org/?p=3460
Lazair, 1978 forward... partner Peter Corley. UltraflightLazairSeriesIIC-ICKY02.JPG Note.
Ultralight Flight,
2007 accident. "His
injuries were a simple fracture of the left upper arm, a simple fracture
of the upper left leg, a complicated fracture(s) of the area just above the
left ankle, and frostbite of both feet.
" Day and half in wilderness before rescue.
"Dale Kramer crashed into the ridge yesterday. He was on the mountain all night
with significant injuries" Dale recovered and got back soaring in
2008.
We met Dale at HAWP conference in 2009. He was showing his simulation notes concerning long-distance two-kite free-flight soaring; he mentioned that maybe two Lazair craft might be used in a trial.
inventions,
patent,
Canada,
BMapper,
http://www.bmapper.com/bmapper_005.htm
B4 quote
Hystar heavy lift airship at Expo '85 or 1986 ...[ ] verify "Hystar, a "flying saucer" being developed as a carrier for heavy cargo in remote areas, which was flown around the hall once every hour.
http://www.flickr.com/photos/expomuseum/136737107/ Hystar at Canada Pavilion, Expo 86, Vancouver, Canada
THOT, The THOHT Mine, llc "The THOHT Mine is a small US company dedicated to bringing to market the inventions of Dale Kramer."
AWE conference in 2009 in Chico, Calif.
CadyCart robotic golf cart
Kramer Concepts Inc.,
Canadian and USA soaring champion
Kramer Dale C: Remotely-controlled vehicle. July 1989: US 4844493 11 worldwide citation
A toy flying object consists of a single wing which is shaped
and weighted to provide aerodynamic capabilities. The single wing structure is
readily and simply manufactured.
Inventor: Dale C. Kramer
http://www.google.com/patents/about?id=57UzAAAAEBAJ&dq=4195439
System and method for wind-powered flight
SeePDFofApp
Also.
Dale Kramer is a soaring champion. He operates a special online business
regarding wind measuring.
United States Patent Application | 20010025900 |
Kind Code | A1 |
Kramer, Dale C. | October 4, 2001 |
System and method for wind-powered flight
Abstract
A system and method for wind-powered flight, comprising a low-speed, high-drag leading aircraft such as a kite, tethered to a low-speed, low-drag trailing aircraft, such as a glider. The leading aircraft is launched, and when the leading aircraft ascends into winds which are significantly greater than winds at the ground level and the takeoff velocity of the trailing aircraft, the leading aircraft begins to tow the trailing aircraft. The trailing aircraft becomes airborne and can be flown at a low air speed to maintain a constant drag on the leading aircraft, which in turn provides thrust to maintain the trailing aircraft aloft at the lower altitude.
Inventors: | Kramer, Dale C.; (Port Colborne, CA) |
Correspondence Name and Address: |
Dale Kramer 6 George Street Port Colborne ON L3K 3S1 CA |
Serial No.: | 761575 |
Series Code: | 09 |
Filed: | January 18, 2001 |
U.S. Current Class: | 244/2; 244/153R; 244/16 |
U.S. Class at Publication: | 244/2; 244/16; 244/153.00R |
Intern'l Class: | B64C 031/02; B64C 031/06 |
Foreign Application Data
Date | Code | Application Number |
---|---|---|
Jan 21, 2000 | CA | 2,296,935 |
Claims
I claim:
1. A system for wind-powered flight, comprising a tethered low-speed, high-drag
leading aircraft, adapted to remain aloft under a force of lift provided by a
high altitude wind acting against the aircraft in a flying direction, a force of
drag against the leading aircraft being opposed by a tether attached to the
leading aircraft, for wind-powered ascent to a first altitude, and a low-speed,
low-drag trailing aircraft tethered to the leading aircraft, and adapted to
remain aloft under a force of lift provided by one or more airfoils moving
through air at a second altitude which is lower than the first altitude, wherein
the leading aircraft extracts wind energy from the high altitude wind to tow the
trailing aircraft at a sufficient air speed to maintain the trailing aircraft
aloft.
2. The system of claim 1 in which the leading aircraft is a kite.
3. The system of claim 1 in which the trailing aircraft is a glider.
4. The system of claim 1 in which the leading aircraft is adapted to transport
one or more passengers or cargo.
5. The system of claim 1 in which the trailing aircraft is adapted to transport
one or more passengers or cargo.
6. A method of wind-powered flight utilizing a tethered low-speed, high-drag
leading aircraft adapted to remain aloft under a force of lift provided by a
high altitude wind acting against the aircraft in a flying direction, a force of
drag against the leading aircraft being opposed by a tether attached to the
leading aircraft, and a low-speed, low-drag trailing aircraft tethered to the
leading aircraft and adapted to remain aloft under a force of lift provided by
one or more airfoils moving through air in the flying direction, comprising the
steps of a. tethering the leading aircraft to the trailing aircraft, b.
stabilizing the leading aircraft so that it ascends to a higher altitude, and c.
towing the trailing aircraft in a flying direction, such that the trailing
aircraft ascends to a lower altitude, wherein a difference between a speed of a
high altitude wind in the flying direction at the higher altitude and a speed in
the flying direction of a wind at the lower altitude equals or exceeds a takeoff
velocity of the trailing aircraft plus a speed of wind across the leading
aircraft sufficient to generate a force of lift on the leading aircraft which
allows the leading aircraft to remain aloft.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] N/A
FEDERALLY SPONSORED RESEARCH DEVELOPMENT
[0002] N/A
BACKGROUND OF THE INVENTION
[0003] An aircraft requires lift in order to remain aloft. This vertical lift is
produced by air flowing past an aerodynamic structure such as a wing. In the
process of creating this lift a drag force perpendicular to the lift develops.
If a thrust force is applied opposite and equal to the drag, the aircraft will
remain aloft. If the thrust is greater than the drag, the aircraft could climb
or accelerate to a speed at which the drag equals the thrust.
[0004] The typical mode of providing this thrust to aircraft such as airplanes,
so-called "ultra-light" aircraft and helicopters, utilizes a motor-driven
propeller or a jet engine. These types of aircraft are capable of self-ascent
under the thrust provided by its propeller or jet engine, which generates
sufficient thrust to overcome the drag force. However, each of these types of
aircraft requires fuel to power the engine and is incapable of empowered flight.
[0005] Examples of aircraft which do not use any external power source are
gliders, hang-gliders and para-gliders. However, these types of aircraft still
require some external means of ascending to a height at which the aircraft can
be flown. A glider, for example, is typically towed to the required altitude by
a propeller-driven airplane, while hang-gliders and para-sails may be
transported to the required altitude on land, for example up a mountain or to
the edge of a precipice. Since there is no source of thrust, none of these
aircraft is capable of self-ascent without the assistance of an external source
of power, either human or mechanical, to elevate the aircraft to a flying
altitude. To stay aloft these aircraft must rely on finding air that rises
vertically at a greater speed than the aircraft is descending through the air.
[0006] Of conventional aircraft, only hot air balloons and dirigibles are
capable of ascending without external assistance or the use of motor or jet
engine. A hot air balloon relies on a furnace which heats air beneath an opening
in the balloon to render it buoyant, while a dirigible is filled with an
inherently buoyant gas such as helium. However, buoyant aircraft such as hot air
balloons, which rely on wind currents to move horizontally, are difficult to
control and notoriously subject to the vicissitudes of ambient weather and wind
conditions, and as such dirigibles typically utilize a motor-driven propeller
for thrust.
[0007] The present invention overcomes these disadvantages by providing a system
and method for wind-powered flight, which requires no external power source or
assistance. The system, involving a pair of wind-powered aircraft operating in
tandem, is self-ascending and relies solely on wind differentials at various
altitudes to both ascend and maintain a desired altitude. The system and method
of the invention thus provides the advantage of virtually unlimited flight
duration. As system of the invention does not consume or combust fuel, it is
inexpensive to use and environmentally friendly.
[0008] The invention may be used to transport persons and/or cargo in the
general direction of prevailing wind currents. The invention may also be enjoyed
as a solo or team sport, involving considerable skill in the utilization of
differential wind currents to maximize speed and distance.
[0009] The invention accomplishes this by providing a system and method for
wind-powered flight, comprising a low-speed, high-drag leading aircraft, such as
a kite, adapted to remain aloft under a force of lift provided by a high
altitude wind acting against the aircraft in a flying direction. The leading
aircraft is thus adapted for wind-powered ascent on a tether which provides the
thrust force, to climb to a higher altitude. The invention further comprises a
low-speed, low-drag trailing aircraft, such as a glider, tethered to the leading
aircraft and adapted to remain aloft under a force of lift provided by the
airfoils of the trailing aircraft moving through the air at a lower altitude.
[0010] The leading aircraft is launched, and when the leading aircraft ascends
into winds which are significantly greater than winds at the ground level and
the takeoff velocity of the trailing aircraft, the leading aircraft begins to
tow the trailing aircraft. Because the wind speed at the higher altitude of the
leading aircraft is significantly greater than the ground winds and the takeoff
velocity of the trailing aircraft, the trailing aircraft becomes airborne. As
the trailing aircraft ascends, the leading aircraft ascends with it, constantly
maintaining an altitude difference to take advantage of the higher wind speeds
at higher altitudes. The trailing aircraft is flown at a low airspeed, such that
its ground speed is less than the ground speed of the higher altitude wind, to
maintain a constant drag on the leading aircraft. The leading aircraft in turn
provides thrust to the trailing aircraft, to provide the lift necessary for the
trailing aircraft to remain aloft. In effect, the leading aircraft extracts wind
energy from the higher altitude wind to tow the trailing aircraft at a
sufficient wind speed as to maintain the trailing aircraft aloft at the lower
altitude.
[0011] The present invention thus provides a system for wind-powered flight,
comprising a tethered low-speed, high-drag leading aircraft, adapted to remain
aloft under a force of lift provided by a high altitude wind acting against the
leading aircraft in a flying direction, a force of drag against the leading
aircraft being opposed by a tether attached to the leading aircraft, for
wind-powered ascent to a first altitude, and a low-speed, low-drag trailing
aircraft tethered to the leading aircraft, and adapted to remain aloft under a
force of lift provided by one or more airfoils moving through air at a second
altitude which is lower than the first altitude, wherein the leading aircraft
extracts wind energy from the high altitude wind to tow the trailing aircraft at
a sufficient air speed to maintain the trailing aircraft aloft.
[0012] The present invention further provides a method of wind-powered flight
utilizing a tethered low-speed, high-drag leading aircraft adapted to remain
aloft under a force of lift provided by a high altitude wind acting against the
aircraft in a flying direction, a force of drag against the leading aircraft
being opposed by a tether attached to the leading aircraft, and a low-speed,
low-drag trailing aircraft tethered to the leading aircraft and adapted to
remain aloft under a force of lift provided by one or more airfoils moving
through air in the flying direction, comprising the steps of: a. tethering the
leading aircraft to the trailing aircraft, b. stabilizing the leading aircraft
so that it ascends to a higher altitude, and c. towing the trailing aircraft in
a flying direction, such that the trailing aircraft ascends to a lower altitude,
wherein a difference between a speed of a high altitude wind in the flying
direction at the higher altitude and a speed in the flying direction of a wind
at the lower altitude equals or exceeds a takeoff velocity of the trailing
aircraft plus a speed of wind across the leading aircraft sufficient to generate
a force of lift on the leading aircraft which allows the leading aircraft to
remain aloft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In drawings which illustrate by way of example only a preferred
embodiment of the invention,
[0014] FIG. 1 is a schematic side view of the system of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 illustrates a system for wind-powered flight according to the
invention. A tethered low-speed, high-drag leading aircraft, such as a kite 10,
is adapted to remain aloft under a force of lift provided by a wind acting
against the aircraft in a flying direction. The leading aircraft 10 preferably
has a relatively low lift-to-drag ratio, for example in the range of 1:1 to
10:1. In the preferred embodiment illustrated, the lift-to-drag ratio of the
kite 10 is in the order of 1:1. The leading aircraft 10 may be a kite, a para-glider,
or any like low-speed, high-drag tethered aircraft, and may optionally carry a
pilot.
[0016] The leading aircraft 10 is stabilized by a tether 12, which maintains the
leading aircraft 10 at an orientation, relative to the direction of the wind,
and provides the thrust necessary to keep the leading aircraft 10 aloft. The
tether 12 is in turn attached to a low-speed, low-drag trailing aircraft, such
as a glider 20, which in the preferred embodiment shown has a lift-to-drag ratio
in the order of 30:1. The glider 20, controlled by a pilot, has wings 22 with
airfoils, and thus remains aloft as it moves through air in the flying
direction. This generates lift sufficient to overcome the force of gravity, as
is well known to those skilled in the art.
[0017] In order to maintain a constant altitude the glider 20 requires
sufficient thrust to generate lift equal to its weight. This thrust is provided
by the leading aircraft 10. The invention relies on the difference between the
wind speeds at a higher altitudes and the wind speeds at a lower altitudes. A
significant wind speed differential is typical in regions with prevailing air
currents such as the jet stream, where on most days the wind speed at a higher
altitude is significantly greater than the wind speed at a lower altitude.
[0018] According to the system, the leading aircraft 10, which in the example
shown is a kite, is launched downwind in a conventional fashion. The tether 12
is unwound from a reel or other suitable payoff device (not shown), to allow the
kite 10 to ascend to an altitude at which the wind speed in the flying direction
exceeds the wind speed at ground level plus the takeoff velocity of the trailing
aircraft 20 plus the wind speed across the leading aircraft 10, in the example
shown a glider which has a takeoff velocity of approximately 30 m.p.h.
[0019] When the kite 10 has ascended into winds which are significantly greater
than the wind speed at ground level plus the takeoff velocity of the glider 20
plus the wind speed across the kite 10, the glider brake is released and the
kite 10 begins to tow the glider 20 in the flying direction. The glider 20
becomes airborne and the kite 10 and glider 20 ascend, in tandem, to the desired
altitude. According to the example illustrated in FIG. 1, the glider 20 ascends
to 5,000 feet where the wind speed in the flying direction is 30 m.p.h., while
the kite 10 ascends to 20,000 feet, where the wind speed in the flying direction
is 90 m.p.h. The length of the tether 12 must accommodate the vertical distance
between the leading aircraft 10 and the trailing aircraft 20, the horizontal
distance between the leading aircraft 10 and the trailing aircraft 20, and the
`droop` caused by the weight of the tether 12 over such a large distance. The
tether 12 can be shortened or lengthened by the pilot in the glider 20 as needed
during the flight, to accommodate disparate wind differentials at different
altitudes.
[0020] Once the trailing aircraft 20 has reached the selected cruising altitude
(5,000 feet in the embodiment shown), the thrust provided by the drag on the
leading aircraft 10 maintains the trailing aircraft 20 aloft. The glider 20 must
maintain a wind speed of approximately 40 m.p.h. in the flying direction, which
requires approximately 50 lbs. of thrust, i.e. 50 lbs. of tension on the tether
12.
[0021] With a 30 m.p.h. tail wind at the lower altitude, the trailing aircraft
20 must maintain a ground speed of approximately 70 m.p.h. (with a flying speed
of 40 m.p.h.) in order to maintain a constant altitude. This sets the ground
speed of the kite 10 to 70 m.p.h. in the 90 m.p.h. wind at the higher altitude.
Thus, the kite 10 experiences a constant wind of 20 m.p.h., the difference
between its ground speed and the ground speed of the higher altitude wind, which
maintains tension in the tether 12 and thus provides thrust to the glider 20.
[0022] In effect, the leading aircraft 10 extracts wind energy from the higher
altitude wind to tow the trailing aircraft at a sufficient air speed to maintain
the trailing aircraft aloft.
[0023] Preferably the glider 20 is flown at speed which results in the minimum
drag on the glider 20, i.e. maximizing the lift-to-drag ratio. The glider pilot
controls the air speed of the kite 10 by controlling the air speed of the glider
20 and, if necessary, adjusting the length of the tether 12 to alter the
altitude differential between the kite 10 and the glider 20 to accommodate wind
speed changes. It will be appreciated that with a sufficient wind speed
differential there is virtually no limit to the length or duration of flight
according to the system of the invention, while the system of the invention
affords a skilled pilot considerably more control than a balloonist.
[0024] It will also be appreciated that the flying direction does not have to be
the same as the wind direction, so long as the components of the higher and
lower altitude winds in the flying direction provide the necessary wind speed
differential to meet the minimum air speed of the trailing aircraft 20.
[0025] To land the system of the invention, the pilot reels in the tether 12 to
reduce the altitude differential between the leading aircraft 10 and the
trailing aircraft 20. This commensurately reduces the wind speed differential,
and thus the thrust exerted on the trailing aircraft 20. As the trailing
aircraft 20 descends its speed increases, while the higher altitude wind speed
acting on the leading aircraft 10 decreases, to the point where the leading
aircraft 10 has a positive air speed and experiences drag in the direction
opposite to the flying direction. As the trailing aircraft 20 lands the leading
aircraft 10 is maintained at a low altitude (e.g. 100 feet) by the forward speed
of the trailing aircraft 20, and actually assists in braking the trailing
aircraft 20.
[0026] It is possible to supplement the lift on the leading aircraft by using a
buoyant gas such as helium, however this would ordinarily be unnecessary in the
preferred embodiment because of the low speed, high drag and low speed, low drag
characteristics of the leading aircraft 10 and trailing aircraft 20,
respectively.
[0027] Also, although the invention has been described in relation to a flight
path which generally follows the direction of the wind, it may be possible to
design a system according to the invention which can fly across the wind, and
possibly even into the wind at a small angle.
[0028] As a sport, the system of the invention could be flown solo by the glider
pilot, or as a team by providing a pilot for the leading aircraft. In the latter
situation either the leading aircraft 10 or the trailing aircraft 20 can control
the flight path (although the ground speed remains controlled by the trailing
aircraft 20), so that one pilot can sleep while the other pilots the system.
Launching of the trailing aircraft 20 can be facilitated by a motor- or
human-powered device such as a bicycle forming part of the frame for carrying
the pilot of the trailing aircraft 20.
[0029] A preferred embodiment of the invention having been thus described by way
of example only, it will be apparent to those skilled in the art that certain
modifications and adaptations will be apparent to those skilled in the art. The
invention is intended to include all such modifications and adaptations as fall
within the scope of the appended claims.