Note: Descriptions are shown in the official language in which they were submitted.
21166~5
FLYING TOY
This invention relates to a child's flying toy. The toy is designed to be thrown into
the air and to be caught, and to stay in flight for a sustained period of time in between
throwing and catching.
S Many other children's flying toys such as boomerangs and Frisbees (TM) are
designed to exhibit elements of flight. As well, many weighted flying toys exist for
throwing and catching. Of these however, few if any also exhibit true flight characteristics.
Tn~te~-1, they act more as projectiles than as true flying toys. By way of example only, U.S.
patent 4,293,134 provides a projectile device incorporating a wing element which is meant
to slow the toy somewhat in its descent. However, the toy still descends in the manner of
a projectile. C~ gh~n (U.S. Pat. No. Re. 34,032) also provides a weighted throwing toy
for catching, but it is incapable of true flight.
All of the existing toys provide either wings without weights which are more
difficult to catch, or weights without wings which are easier to catch but do not fly.
However, no toys exist to the inventor's knowledge which exhibit a rotary winged type of
flight incorporating a weight at one end of the single wing.
The present invention is slowed in its descent by means of a rotating wing whichacts to produce true lift to counter most of the downward motion of the toy. At the same
time, the toy has its weight located substantially at one end, making it more easily caught
by a child.
The invention provides a single-winged flying toy comprising a concentrated weight
means comprising at least half of the weight of the entire toy providing a centre of gravity
relatively close to the weight means. A single wing means is affixed at one of its ends to
the concentrated weight means, the wing means having a length between two and five times
2116635
its width, having a relatively straight forward edge and having a trailing edge, the centre
of balance between the leading edge and the trailing edge being located closer to the
leading edge. The wing means has a surface area between 200 and 600 square inches per
pound of total weight of the toy.
s
LIST OF DRAWINGS
Figure 1 is a plan view of the toy.
Figure 2 is a cross sectional view of the wing of the toy as seen along line 2-2 of
Figure 1 showing how an airfoil surface may be implemented in the wing.
Figure 3 is a front elevation view of the toy.
Figure 4 is an end view of the toy.
Figure 5 is a view showing the use of the toy.
Figure 6 is an alternative embodiment of the invention.
Figure 7 is a perspective view of the p~r~ ed embodiment of the invention.
Figure 8 is an end view of the preferred embodiment of the invention showing in
greater detail the spine or stiffener attached to the leading edge of the wing and the bevelled
edges of the wing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figure 1, the invention is comprised of a weight 10, such as a ball,
connected to or integral with one end of a single wing 20.
The weight 10, hereafter referred to as the ball, is preferably made of plastic or
rubber and has a relatively large weight with respect to the wing, so that the centre of
gravity of the toy is adjacent the ball, as shown for example by point 'A'.
21166:~5
-
The wing 20 should be made of a relatively stiff, relatively low weight material such
as foam, plastic or rubber. As seen in Figure 1, the wing has a forward edge 30 which is
more or less straight. As best seen in Figure 2, it is thicker in cross-section and therefore
heavier than the trailing edge 40, which in the plefe"ed embodiment has a curved edge or
contoured edge 90 as shown in Figure 1. What is important is that the centre of balance
between the leading and trailing edges of the wing be located closer to the leading edge of
the wing in order that the wing tend to tilt downwardly in the forward direction when in
flight. It is found that the optimum location of the centre of balance from front to back is
approximately 1/3 to 1/6 of the width of the wing from front to back, with the ideal being
between 1/4 to 1/5 of the width from front to back.
In practice, this may be achieved by making the leading edge thicker as shown, or
denser, as by means of an insert such as solid plastic or metal. Such an insert also serves
as a stiffener for the wing, permitting the rest of the wing to be made of still lighter, more
flexible material. Alternatively, the stiffener may be contoured onto the leading edge of the
wing as shown by reference numeral 50 in Figures 7 and 8 with the additional advantage
of providing scuff resistance. As an example, one model of the invention was made by
gluing a strip of 15 inch long by 0.5 inch wide by 1/16 inch thing curved polycarbonate to
the leading edge of a foamed polyethylene wing. The forward weighting of the wing was
thereby achieved with minimsll weight, resulting in the longest flight of any model tested.
By m~king the wing thicker in cross-section at the leading edge than the trailing
edge, the centre of balance of the wing from leading edge to trailing edge is located closer
to the forward edge. This causes the wing to tilt somewhat downwardly in use in the
forward direction, thereby making the wing function prop~ly as a wing. For optimal flight,
the wing should have an efficient air foil cross-section, or approximation thereto as shown
2116635
in the Figures.
As seen in plan view in Figure 1, the wing is narrower at the end 25 adjacent the
ball 10, and wider towards the opposite end 26, and may be given a contoured trailing edge
90. The speed of end 26 during rotation is higher that the speed of end 25, and therefore
5 more lift is generated at any given speed by placing more lifting area towards the high
speed end 26. The region adjacent end 25 provides less lift and hence less surface area is
placed in that region. In effect, the material is placed where it will do the most good,
resulting in more efficient flight. Also, having less wing surface near the weight makes it
easier to catch the weight. For example, if the weight is in the shape of a ball, the spherical
10 - surface will be exposed and easy to catch in the hand.
The weight of the wing portion 20 may be significantly less than that of the ball.
In experiments, the ball may be anywhere from 1.5 to 3 or more times the weight of the
wing. What is important is that the assembled toy have a centre of gravity approximately
one/fifth or less of the length of the toy, as seen in Figure 1.
The wing portion must be stiff enough to act as an airfoil when in use, as well as
withstand the wear and tear of use and the stresses induced when the toy is thrown.
Moreover, for reasons of safety to the user, it is obviously preferable to make the toy, and
in particular at least the leading edge of the wing if not the entire wing, out of a material
which will not cause injury if it strikes a person. For this reason, in the preferred
embodiment of the invention, the wing is formed largely of foam, plastic or rubber.
In use, the toy is grasped by the end of the wing 26 and thrown high into the air.
Because the majority of the weight of the toy is concentrated in the ball which is located
at a distance from the point where the user grasps the wing, a large amount of centripetal
force may be developed allowing the ball to be thrown high into the air. The toy, and in
211663~
particular the ball portion of the toy, has sufficient weight and heft that it is capable of
being thrown straight up, with the ball leading and the wing 'following behind' - ie pointing
straight down - thereby permitting the toy to ascend upwardly without the wing causing
appreciable drag or lift. In effect, the toy is able to ascend straight upwardly like a dart.
When the toy reaches the top of its trajectory, its vertical and horizontal speed is
sufficiently slow that the ball starts to fall and pull the wing down behind it. As it does so,
the leading edge of the air foil will tend to tilt down below the trailing edge because of its
greater weight. The wing will then begin to experience aerodynamic forces including lift
and thrust so that the wing accelerates like a aircraft wing in a dive. This causes the wing
and thus the toy to rotate about its centre of gravity much like a helicopter wing. As the
rotation speeds up, the centripetal forces caused will cause the orientation of the toy to
become more horizontal from end to end or 'flatten out'. The rotation of the wing and the
aerodynamic forces thereby engendered slow the descent of the toy in the same way as a
helicopter's rotors.
The net result is that the toy may be thrown upwardly, and it will start to
'helicopter' shortly after it reaches the peak of its trajectory and begins to descend, as
shown in Figure 5.
By locating the centre of gravity adjacent the ball, the toy will rotate about its centre
of gravity when thrown into the air. In effect, the wing will approximate rotation about a
relatively fixed point, namely the ball. This makes the toy easier to catch by a child as it
provides a central relatively slow moving mass to grasp.
The weight of the ball is limited practically by the necessity that it have enough
weight relative to its air resistance to enable the user to throw the combined ball and wing
sufficiently high into the air to be a useful toy. For this reason, a light styrofoam ball for
2116635
example would not be particularly useful. However, the ball may not be so heavy that a
wing of the required weight and dimensions relative to the ball would be so massive that
it would not be able to achieve the desired rotation during descent. In practice, it has been
found that the weight of the ball should be of the order of 15 to 150 grams (.03 to 0.33
S pounds) and that the weight of the wing should be roughly half or less that of the ball used.
If the ball is made too heavy relative to the lift capability of the wing, the ball will tend to
'pull' the toy dowllw~d faster than desired. In effect the toy will spiral to earth, rather
than achieve the helicopter-like rotation and true flight desired.
It has been found through experiment that the length of the wing should be
approximately two to five times the maximum width W of the wing, with the optimum
value being approximately three times the maximum width of the wing.
The length of the wing has been found to be ideally approximately 19 inches, as this
permits a child to hold the end of the wing at his side without the ball touching the ground,
in order to throw the toy. The maximum width of the wing is therefore ideally about 7
1 5 inches.
The overall surface area of the wing should ideally be of the order to 200 to 600
square inches per pound of overall weight of the toy to provide the right amount of lift and
the weight of the ball should be between approximately .03 and .3 pounds. In the l)refelled
embodiment shown in Figure 7, the ball has a weight of . l S pounds, the wing has a weight
of .08 pounds, with a length of 18 inches and a maximum width 'W' of 6 inches. The
preferred embodiment has a wing with a surface area of approximately 80 square inches,
giving a surface area to ball weight ratio of 80/.lS = 533 square inches/pound. The total
device surface area to weight is therefore 80/(.15+.08) = 348 square inches/pound.
The wing should ideally be made straight as seen in front view (Figure 3) (ie the
2116635
-
wing should be as flat as possible from end 25 to end 26) in order to permit the toy to be
thrown upwardly as far as possible. Any curvature or warping of the wing tends to reduce
the height of throw obtainable.
In the preferred embodiment, the trailing edges 51, 52 of the contoured wing surface
5 are bevelled as shown to assist in approxim~tin~ an air foil cross-section to increase
aerodynamic lift and to reduce aerodynamic drag.
It will be noted that the contoured surface 60 in Figure 8 for example becomes the
top surface of the toy and flat surface 70 the bottom surface when the toy is in flight.
When the toy attempts to go into rotary flight, it will normally assume this orientation
10 automatically because of the design characteristics of the wing. Where it fails to do so and
attempts to fly in an upside down orientation, the toy will simply spiral downwardly until
it rights itself or strikes the ground. In most cases, the toy will go into flight directly in the
correct orientation.
In this and other respects, the toy differs significantly from nature. In nature, maple
15 seeds and the like are not evolved to be thrown upwards, but rather to be dropped and to
start rotating as quickly as possible. This is contrary to the design of the present toy, where
rotation is desired only when the toy has been thrown up to its maximum height. As well,
in nature, seed wings usually have warps in them which induce them to start spinning
almost immediately when thrown upwards. Seeds are made of a close cellular structure
20 which would not scale up to a size large enough to throw because the resulting embodiment
would be too heavy. This is because weight goes up as a cubic function of size. Air
ell~laillll,ent such as foam is needed to reduce the weight so that flight is possible.
Moveover, seeds in nature are rigid, whereas a flexible embodiment is required. The back
of a seed wing is a cellulose membrane with thicker veins protruding across the width for
2116635
stiffness. This arrangement further results in the seed in nature being brittle and not
suitable for throwing. The present embodiment uses flexible foam which is good for
throwing.
In addition, as seen in cross-section in Figure 2, although not strictly necessary, the
5 wing may optionally be given an airfoil cross-section or an approximation thereof to
improve somewhat its flight characteristics.
Notwith~t~n(ling the desirability of making the wing straight as outlined above, in
the preferred embodiment, the wing may be given a slight curve upward near its end in the
region shown by 'R' in Figure 7 in order to introduce enough turbulence to start the
10 process of rotation. If the wing is fabricated perfectly flat, the toy may not always rotate
as desired but instead go straight up and straight down in the manner of a dart. By
providing a curved tip, the wing is induced to start rotating in all cases near the top of its
trajectory.
By moulding the curved tip into the wing with a substance such as a memory metal
15 or deformable plastic, the degree of curvature of the wing can be controlled by the user, to
control the toy's flight characteristics, ie a flat tip causes to toy to go much higher before
rotation begins. Alternatively, the curved tip may be achieved by means of an additional
flap made of sufficiently light flexible material that will lie essentially flat when thrown
rapidly upwards, curling or popping out somewhat at lower velocity to induce the wing to
20 swing outwardly and assist in initiating rotation. In fact, even if the wing is made solely
of foamed polyethylene, the foamed polyethylene will allow the user to bend it to a
sufficient degree to achieve the desired effect and to m~int~in that bend for a period of
time.
Figure 6 illustrates an alternative embodiment of the invention. In this embodiment,
2116635
-
the lifting area of the wing is concentrated exclusively at the high velocity end 26 of the
wing, and the wing is connected by means of either a string or a relatively stiff supporting
member 35 to the weight at some distance from the lifting area. It has been found that
even with only a string connecting the ball to the wing, a workable (ie flying) embodiment
5 is achieved. When the connecting member 35 is flexible, the lifting section may still rotate
around the weight and keep the embodiment flying. Having a flexible member such as a
string 35 does result in suboptimal throwing upward however. The device does not go as
high due to flapping and spinning of the loosely connected trailing wing. When the
connecting portion 35 is stiff, it tends to reduce undue flapping and spinning of the lifting
10 section during the upward tossing of the device. This allows the device to reach maximal
and desirable height.
The toy may be manufactured simply and cheaply by using foamed polyethylene cut
and glued to the correct shape. Alternatively, it may be made by means of an injection
moulding process whereby the ball and leading edge spine is formed first of high weight
15 density polyethylene and then low weight density foamed polyethylene introduced to form
the wing. The toy would then be ejected from the mould in one piece (ball, wing and
forward edge spine).
Alternatively, the wing section can be extruded through a die having the desired
airfoil cross-section. The leading edge spine could be extruded at the same time, and the
20 resulting combination extrusion can be stamped into wings of the desired shape for
attachment to the balls.
