Torsional twist airfoil control means

A control system for aircraft airfoils, which is an improvement over existing aileron, flap, spoiler and deicing technologies, in providing increased roll control and aerodynamic lifting and braking functions; with greatly reduced drag increased airspeed and precise control performance at all airspeeds, due to clean uninterrupted airfoil surfaces and directional conformance of wing to the intended flight path. This is accomplished by use of a torque tube mounted internally in the aeroelastic airfoil structure, and firmly attached to the airfoil tip structure. In operation the inboard end of the torque tube when rotated differentially on its pivot axis, imposes a helicoidal twist on the aeroelastic airfoil structure, with maximum angle of incidence at the outboard wing tip, providing near perfect lateral roll control or cooperating to provide increased lift and braking or maneuverability, also the foregoing operations provide automatic deicing. The torque tube can be operated by conventional control systems, e.g. cable/pulley, electric/hydraulic servo etc.

FIELD OF INVENTION 
The present invention relates to the construction of airfoils, more 
particularly to wing construction using an arrangement for providing 
lateral roll control, lift, manuerability and automatic deicing control. 
BACKGROUND OF INVENTION 
The present aircraft wing technologies utilize trailing edge ailerons and 
spoilers for roll control and flaps, both leading and trailing edge to 
increase aerodynamic lift for decreasing runway lengths for take offs and 
drag for reducing approach speeds for landings; also for maneuverability 
at high and low airspeeds. These control devices are used universally on 
all current aircraft, and are all similar in concept and function. 
Transonic and supersonic flight have always posed control problems for 
aircraft in making the transition from subsonic flight. Conventional 
aileron control reversal has long been a problem, being caused by the 
interaction of the aileron control surfaces and elastic deformation of the 
wing. At transonic speeds, a torsionally elastic wing, common on high 
performance aircraft, with a downward deflection of the aileron produces a 
twist that diminishes the angle of attack at the wing tip and thereby 
reduces the lift acting on the tip section and the rolling moment. Thus 
the actual roll moment may be smaller than the same aileron deflection 
would provide on a rigid wing. The effect increases with airspeed and at 
higher airspeed, approaching supersonic airspeeds, the function of the 
aileron will be neutralized and then reversed. 
In view of the forgoing, it is an object of the present invention to 
provide an airfoil control means and method of using the same in aircraft 
lateral roll control, aerodynamic lifting and braking devices and 
automatic deicing of airfoil surfaces. 
FIELD OF SEARCH 
Patent classification: 244/2/45A/51/75R/89/90R/123/134A/152/184/198/211/232 
DESCRIPTION OF PRIOR ART 
Adequate lateral roll control and lift control functions with minimum drag 
have plagued aircraft designers since the inception of aviation. In the 
early days of aviation, wing warping, controlled by wires, was used by the 
Wright brothers and others to provide a means of roll control for 
aeroplanes. 
Roll control and lift control devices which in function superficially 
resemble the novel roll and lift control devices invented by the applicant 
are disclosed in the following U.S. patents. 
______________________________________ 
U.S. Pat. No. 
Patentee(s) Issue Date 
______________________________________ 
821393 O. & W. Wright May 22,1906 
983697 Igo Etrich Feb. 7,1911 
1054484 John Anderson Feb. 25,1913 
1132686 James Rooney Mar. 23,1915 
1145013 Edson Gallaudet 
Jul. 6,1915 
3734432 George Low May, 22,1973 
4729528 Angelo Borzachillo 
Mar. 8,1988 
______________________________________ 
U.S. Pat No. 821,393 FLYING MACHINE (O. & W. Wright) One of the objects of 
this patent was lateral control of the two superimposed aeroplanes by 
helicoidal warp or twist actuated by the pilot laterally shifting his body 
while lying on a cradle, connected by ropes to the aeroplanes. 
U.S. Pat. No. 983,697 SUPPORTING-SURFACE FOR FLYING MACHINE (Igo Etrich) 
Discloses a bird like monoplane design utilizing a complex system of wires 
or ropes to provide independent warping of the wing tip sections to 
produce lateral stability. 
U.S. Pat. No. 1,054,484 AEROPLANE (John Anderson) Discloses a high wing 
monoplane with a tilting wing capability: also there is a warping section 
positioned at each end of the wing controlled by a cable that lifts the 
warping section from the top of the main plane to vary the relative angle 
of the carrying plane and car body. Thereby resulting in depressing that 
side of the carrying plane. 
U.S. Pat. No. 1,132,686 AEROPLANE CONSTRUCTION (James Rooney) discloses a 
cable controlled wing warping aeroplane, depicted as a biplane. It uses a 
tubular longitudinal frame members and multiple tension wires. 
U.S. Pat. No. 1,145,013 AEROPLANE (Edson Gallaudet) An improved wing 
construction and control mechanisms; one to vary the wing angle of 
incidence, the other to provide wing warping by use of cables, pulleys and 
pinion gears to vary the angular position of the outer with respect to the 
inner portion to maintain lateral balance. 
U.S. Pat. No. 3,734,432 SUPPRESSION OF FLUTTER (George Low) Discloses an 
active aerodynamic control system to control flutter over a large range of 
oscillatory frequencies. Torsion and bending motions or deflections of the 
fluttering member are automatically controlled by leading and trailing 
edge control surface deflections which produce lift forces and pitching 
moments to suppress flutter. 
U.S. Pat. No. 4,729,528 AEROELASTIC CONTROL FLAP (Angelo Borzachillo) An 
aeroelastic control system induces torsional or bending motions on fighter 
aircraft wings to enhance the roll capability of the aircraft rather than 
oppose such notions. 
It is significant, however, that none of the prior art patents identified 
above are concerned with the specific problems solved by applicant. 
Conventional ailerons provide more than adequate roll control at high air 
speeds, but are lacking in providing roll control at low airspeeds. Due to 
these conditions, ailerons are sized for the low airspeed roll control 
requirements, therefore ailerons and flaps always have large surface areas 
and large angular motion of operation, and the associated drag weight, 
construction complexity and high related costs. 
SUMMARY OF INVENTION 
A control means for aircraft airfoils, which is a significant improvement 
over the prior art of existing aileron, flap, spoiler and deicing 
technologies. Said means provides increased lateral roll control and 
aerodynamic lifting and braking functions; with greatly reduced drag, 
increased airspeed and precise control performance at all airspeeds, due 
to clean uninterrupted airfoil surfaces and directional conformance of 
wing to the intended flight path, lacking prior art's conventional 
ailerons, spoilers and flaps. This is accomplished by use of a torque tube 
mounted internally within the airfoil structure, substantially aligned 
with and ahead of the airfoil linear axis, positioned for aerodynamic 
balance and firmly attached to the airfoil tip structure. The inboard end 
of said airfoil structure is firmly attached to the fusalage. 
In operation the inboard end of the torque tube is rotated on its pivot 
axis by a control system. It imposes a helicoidal twist on the airfoil 
structure, with maximum angular displacement or angle of incidence at the 
outboard tip and progressively lower angles of incidence as measured 
closer to the inboard end of the airfoil. The torque tube can be operated 
by conventional control systems e.g. cable/pulley, electric/hydraulic 
servo etc. 
Advanced fighter aircraft frequently fly at transonic and supersonic 
airspeed. With today's control technology, they are continuously exposed 
to wing surface wrinkling, due to large twisting roll control moments 
applied by high aerodynamic pressures caused by operation of ailerons 
and/or flaps. This invention solves the subject problem by providing an 
aeroelastic wing structure, comprising an upper aeroelastic skin covering, 
a lower aeroelastic skin covering both attached to a flexible continuous 
leading edge structure, a flexible continuous trailing edge structure, a 
set of rotatable flexible rib structures, a wing tip structure, and 
operated by a rotatable torque tube that is mounted on a set of anti 
friction bearings, which are mounted on said rotatable flexible rib 
structures and firmly attached to said wing tip structure. 
To accomodate the aeroelastic distortion of the wing airfoil skin during 
the normal operation of the above helicoidal twist of the aeroelastic wing 
structure. I have invented the following aeroelastic surface skin covering 
for aircraft wings and other airfoil control surfaces as follows. 
This aeroelastic wing structure that is flexible and compliant, while being 
made of rigid sheet material, formed aluminum or titanium; or composite 
fabrication, urethane/fabric epoxy/kevlar/fiberglass/carbon fiber or any 
combination of available engineering polymers, elastomers, and/or 
reinforcement fabrics or prepegs; all structural components of the 
aeroelastic wing structure can be fabricated using these materials. 
The aeroelastic surface skin covering is formed of continueous low 
amplitude linear wave forms, aligned in a chordwise direction, whose 
amplitude and pitch, along with thickness of all components can vary to 
suite individual applications. The linear wave forms ends make a smooth 
transition from the wave form to areas that are relatively straight in a 
spanwise direction and blend smoothly with the flexible leading edge 
structure and the flexible trailing edge structure. The aeroelastic skin 
covering can be applied to wing structures using conventional methods. The 
wave forms absorb alternating tension and compressive skin forces, usually 
up to 1% of the diagonal span of a low aspect ratio wing and 
proportionally less on a high aspect ratio wing, encountered during 
aeroelastic deformation, while increasing stiffness in a chordwise 
direction. 
Application of the helicoidal twist also provides automatic deicing of the 
wing each time the tortional twist is activated. Thin ice accumulation, 
due to freezing rain and sleet weather conditions, can't conform to the to 
the movement of the aeroelastic wing skin covering. Ice being a rigid 
structure, will crack seperate, and fall off with sufficient forward 
speed. 
Present invention is unlimited in its use in the control of airfoils, 
ranging from hang gliders and ultra lights (these can be covered with 
fabric or polymer sheets, such as polyester) to small, medium and large 
transports and commercial aircraft, including high speed high performance 
aircraft. 
Further applications are controllable wings for racing cars and boats, 
ground effect vehicles, sails, rudders and keels for sailboats, helicopter 
lift and tail rotors, propellers for aircraft and boats, and turbine 
blades.

PREFERRED EMBODIMENT 
Referring now to the drawing, FIG. 1 depicts an aircraft left wing 20, 
equiped that extends from a fuselage 31, with a flexible leading edge 
structure 22, and a flexible trailing edge structure 26, attached to the 
flexible wing tip structure 23, equipped with a torsional twist rotatable 
torque tube 21, arranged within the wing 20, and firmly attached to the 
flexible wing tip structure 23, positioned for in the aerodynamic center 
aerodynamic balance and mounted on a plurality of anti-friction support 
bearings 24, each of which are attached to a set of flexible rib 
structures 25. The torque tube 21, is mounted on said bearings 24, and is 
actuated by a rotational control drive means 29, a fuel tank 32, is 
mounted on the wing tip structure. The right wing 30 (not shown) contains 
all of the features of the left wing. The aeroelastic covering skins 27 
and 28 absorb the alternating tension and compression forces that occur 
during the normal operation of the aeroelastic wing structure 20. The 
drawing, FIG. 2 is an end view of the wing 20, of FIG. 1, showing the wing 
tip structure 23, in its normal static position, without fuel tank 32. The 
drawing FIG. 3, is an end view of the wing 20, of FIG. 2, showing the 
helicoidal twist of wing 20, wing tip structure 23, differentially 
operated with right wing 30, (not shown) for a lateral roll to the right; 
or cooperated with right wing 30, (not shown) to provide increased lift 
for slow flight, landings take offs and maneuverability. The rotatable 
torque tube when differentially rotated clockwise, in mm rotates the wing 
tip structure, also in a clockwise direction, which imposes a helicoidal 
twist on the wing structure, resulting in a lateral right roll (see FIG. 
3). The torque tube when differentially rotated counter clockwise, in turn 
rotates the wing tip structure, also in a counterclockwise direction, 
which imposes a helicoidal twist on the aeroelastic wing structure, 
resulting in a lateral left roll (FIG. 4). The twist surface profile when 
twisted changes from a normal airfoil surface profile to a warped airfoil 
surface profile. 
The drawing of FIG. 4 is an end view of the wing 20 of FIG. 2, showing the 
helicoidal twist of the wing 20, wing tip structure 23, differentially 
operated with right wing 30, (not shown) for a lateral roll to the left; 
or cooperated with right wing 30,(not shown) to providing decreased lift 
for maneuverability, cooperated with elevators or canards. The drawing of 
FIG. 5 is an enlarged sectional view 2--2 showing the flexible leading 
edge structure 22, bonded to the upper aeroelastic skin covering 27, and 
also bonded to the lower aeroelastic skin covering 28, both showing the 
wave form sectional profiles with a transition blend to a relatively 
straight area prior to the flexible leading edge structure 22, and the 
leading edge of the flexible rib structure 25. The drawing of FIG. 6 is an 
enlarged sectional view 3--3 of FIG. 1, showing the flexible trailing edge 
structure 26, bonded to the upper aeroelastic skin covering 27, and also 
bonded to the lower aeroelastic skin covering 28, both showing the wave 
form sectional profiles with a transition blend to a relatively straight 
area prior to the flexible trailing edge structure 26, and the flexible 
rib structure 25. The drawing of FIG. 7 shows an enlarged sectional view 
4--4 of the drawing of FIG. 1 showing the profile of the continuous low 
amplitude linear wave forms. 
While the TORSIONAL TWIST AIRFOIL CONTROL MEANS has been described with 
reference to particular embodiments, it should be understood that such 
embodiments are merely illustrative as there are numerous variations and 
modifications which may be made by those skilled in the art. Thus, the 
invention is to be construed as being limited only by the spirit and scope 
of the appended claims.