Amusement devices: toys – Tethered fixed-wing aircraft
Reexamination Certificate
2001-07-03
2002-08-20
Ackun, Jacob K. (Department: 3712)
Amusement devices: toys
Tethered fixed-wing aircraft
C446S031000, C446S034000, C446S056000, C446S061000
Reexamination Certificate
active
06435932
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a model space vehicle configured to possess suitable aerodynamic properties such that it is capable of gliding smoothly through the air for a substantial period of time relative to its size and weight.
2. Description of the Prior Art
Over the years conventional aircraft have taken shapes in many forms using fixed wings and tail plane of various platforms. The most commnon wing shapes are rectangular, swept back and delta with varying cross sectional and wing surface areas. Other more recent embodiments include aircraft which have wings which are movable to vary the angle of sweep while others have wings tilting on a horizontal axis to vary the angle of attack.
The aircraft wing is modified in a VTOL (vertical take off and landing) and a STOL (short take off and landing) and is generally a function of the propulsion unit used in conjunction with the aircraft.
There has been a suggestion that a rotating circular wing can be used effectively on an aircraft. Further, the thought is, that if the circular wing were fixed and not rotating, it would have such poor pitch stability that the circular wing could only be placed at the rear of the aircraft. This hypothesis is not accurate insofar as the instant application is concerned
In order for an object to fly through the air it must have some type of wing which constitutes an efficient airfoil. A typical cross section of a wing having an airfoil shape is depicted in FIG.
13
.
FIG. 13
shows that as the wing through the air, the air divides to pass around the wing. The airfoil is curved so that the air passing above the wing moves faster than the air passing beneath. Fast moving air creates a lower pressure than slow moving air. According to the principle of Bernoulli, the pressure of the air is therefore greater beneath the wing than above it. This difference in air pressure forces the wing upward. This force is called “lift.”
Besides lift, heavier than air machines (with and without engines) achieve flight by generating a force which overcomes their weight and supports them in air. For example, VTOL aircraft direct the power of their jet engines downward and heave themselves off of the ground by brute force.
The flying craft of the presence invention is a model space craft which does not contain an engine. The flying craft of the present invention functions as a glider, although its construction is unorthodox since it does not have the appearance of a typical glider.
External means of propulsion can optionally be used in conjunction with the model. For example, powered flight may be achieved in the craft of the present invention using jet turbine type engines in the form of ducted fan propulsion units for model aircraft. These may be placed on the craft in various positions.
A glider is the simplest type of winged aircraft. The typical glider has long straight wings that produce high lift at very low speed. It is pulled or thrust along the ground until it is moving fast enough that the lift generated by the “wings” exceeds its weight. When this occurs, the glider then rises into the air and flies. After release, from towing or thrusting means, the glider concurrently continues to move forward while it drops slowly pulled by a thrust force due to gravity. Friction with the air produces a forces called “drag” which acts to hold the glider back. These two pairs of opposing forces—lift and weight, thrust and drag- act on all aircraft. Aerodynamicists struggle with the opposing forces noted above in their efforts to improve aviation. The swept back wings referred to above in a jet engine aircraft are needed to minimize drag at high speeds. However lift is also reduced, requiring high take off and landing speeds.
The aforementioned forces were all considered in developing the craft of the present invention The predicate for the configuration of the flying craft of the present invention is a fictional space craft which has not been a flying craft and is in fact only a fictional means for space travel. The present invention has an appearance similar to the “U.S.S. STARSHIP ENTERPRISE.”
By substantially adopting the design and adhering to basic principles of aerodynamics and principles of flight, some of which are described above, it is possible to construct a glider model which is able to fly as well as any glider, conventional or otherwise, found in the prior art. However, in keeping with the aerodynamic principles mentioned above, one would expect that a cross-sectional view of the non-symmetrical airfoil of the aircraft would display a profile wherein the upper surface of the foil, as depicted in
FIG. 14
has an eccentricity (e) value (i.e., the extent of curvature of the surface, having a value between zero and 1, wherein zero is the extent of curvature found in a circle and 1 is a straight line) that is less than the eccentricity value of the lower surface of the airfoil. Contrary to the conventional principles of aerodynamic technology set forth above, the upper surface of the airfoil of the present invention, as shown in
FIG. 12
has an eccentricity value which is greater than the eccentricity value of, the lower surface of the airfoil. Thus the airfoil of the present invention has an upper surface that is shallower than the lower section thereof.
Other objects and features as well as additional details of the present invention will become apparent from the following detailed description and annexed drawings of the presently preferred embodiments thereof, when considered in conjunction with the associated drawings.
SUMMARY OF THE PRESENT INVENTION
The present invention embodies the criteria discussed above and result in a model space craft suitable for gliding having the following elements;
a fixed circular wing means for providing lift, having a topside and an underside and a thickness,
as shown in
FIG. 12
, the underside of the fixed circular wing is more convex than the topside of the circular wing;
the fixed circular wing having an approximate diameter 8 times that of its thickness;
a streamlined fuselage which extends fore and aft along a longitudinal axis about
which the model space craft can assume a roll attitude;
it has connecting means extending from said underside of said circular wing, protruding downward and rearward and attached to a fore section location on the streamlined fuselage;
the streamlined fuselage having a tapered profile toward the aft section thereof,
the streamlined fuselage being re-enforced using a lightweight stress bearing strut extending the length of the fuselage (as shown in FIG.
4
); that is, from the point of the fuselage where it meets the circular wing to the rear of the fuselage;
a pair of fins protruding from opposite sides of said streamlined fuselage and positioned and fixed at a first end to said aft section of said streamlined fuselage, and extending outward radially at an angle of approximately 40 degrees from the vertical axis and rearward at an angle of approximately 30 degrees to the vertical;
each fin is approximately 4 times wider than its thickness and having a streak profile to promote effective stability to the model space craft;
each fin at its upper end supports a boom at a height above the horizontal plane of said circular wing so as to avoid the booms being subjected to the turbulence which is produced by airflow over the airfoil which is a circular wing; the relative dimensions of the length, width and thickness of each boom is approximately 5 times as long as it is wide and approx 4 times wider than it is thick;
each boom comprises a flat underside and a domed topside with a rearward taper;
each boom lies on a horizontal plane parallel to the horizontal plane of said fixed circular wing with a slight tilt of 1.0 to 1.5 degrees clockwise (i.e., from the horizontal plane as depicted in FIG.
3
(
a
)) viewed from the left side of the model space ship;
the ballast is positioned in the foresection of the circular wing so as to achieve a center of gravity point which will be approximately t
Ackun Jacob K.
Baker & Rannells
Beck Thomas A.
Miller Bena B.
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