GB2386329A

GB2386329A - Toy flying disk

Info

Publication number: GB2386329A
Application number: GB0202054A
Authority: GB
Inventors: Robert John Collins
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-01-30
Filing date: 2002-01-30
Publication date: 2003-09-17
Anticipated expiration: 2022-01-30
Also published as: GB0202054D0; GB2386329B

Abstract

A toy flying disk generally similar to a Frisbee (RTM) is provided with air acceleration means whereby air surrounding the top of the disk is drawn into and accelerated over the curved upper surface of the disk. The air acceleration means is preferably in the form of a radial disk fan 2. The disk may be circular or polygonal in plan.

Description

1 2386329

AERIAL DEVICE

This invention relates to an aerial device or toy.

There are many examples of aerial device but most fall into one of several categories, Kites for example take many forms but may be categorised as tethered. Tethering ensures that the kite is controlled and thereby flight is sustained. Kites rely on a tether to sustain a controlled attitude to a prevailing wind and the energy to sustain the flight is drawn from the wind, Aerial balloons are another category which may or may not be tethered but rely on the natural buoyancy of certain gases. Controllable and steerable balloons are of course well known.

Gliders form a category of many types and are well known. Gliders are generally distinguished from kites by virtue of their non-reliance on tethering to sustain controlled flight but rather rely on aerodynamic characteristics and possibly employ moveable or adjustable control surfaces. Energy to sustain flight is drawn from either exploiting the natural movement of the air or by the use of a tether to a power source, which may be a winch or perhaps a powered aircraft for example.

Another category of aerial device use the parachute principal which ensure a minimal rate of descent by means of a canopy presenting the maximum cross sectional area and hence air resistance to the descent path. A payload situated some distance beneath the canopy and thus ensuring a low center of gravity ensures stability.

Generally, parachutes only descend and do not normally ascend unless some control mechanism such as a tether or tow is employed or they are launched in an upward direction. The "Frisbee", some times referred to as a disk wing, falls into the later category but with slight modification. Spin is imparted at its launch and so it is not dependent on a payload for stability. Its rate of descent is retarded as its spin ensures that it presents the maximum air resistance to the descent path.

Model or toy aero planes, darts and helicopters employing conventional "tear drop" aerofoils are of course well known although very simple toys may rely just on angled propulsion and control surfaces such as may be used in a wound rubber powered model or a folded paper dart for example.

Flapping wing or hornithopters is yet another class of flying device which attempt to emulate the wing action of birds, flying reptiles or flying insects. Hornithopters are a well known novelty.

Rocket or thruster propelled flying devices might be regarded as yet another category particularly if they are equipped with aerodynamic control surfaces or other control means A note worthy feature of many flying devices is the employment of the "tear drop" or conventional aerofoil, that is bulbous at the leading edge and trailing to a thin section Such aerofoils are widely used in many types of Dying devices and whilst this is known to be an important development, it has one significant shortcoming

The conventional aerofoil generates lift and deflection forces by virtue of the imbalance of forces caused by air flowing over both its surfaces.

In a horizontal aerofoil for aircraft, the upward force resulting from air flowing over its upper surface is greater than the downward force resulting from air flowing over its lower surface. This is achieved by such means as making the aerofoil asymmetric about its chord line and adjusting the angle that the chord line makes with the air stream.

The conventional aerofoil is a highly developed means of generating aerodynamic forces but the aerofoil would be much more effective in providing lift if there where no lower surface but this is not possible in a conventional aerofoil.

The present invention differs significantly from all of these categories so far described and in deed differs in many respects from other flying vehicles in so far as it does not depend on conventional aerofoils to generate lift nor suffer from the disadvantage that such aerofoils present from their dependence on a lower surface. Neither does it depend on flapping wings or thrusters to effect lift.

According to the present invention there is provided a vertical ascending and descending aerial device comprising a body, a means of axially drawing in surrounding air and accelerating it across the upper surface of the body and which may be fixed to the body or rotatable on the vertical axis of the body.

A specific embodiment of the invention, suitable for use as a toy or for amusement purposes, will be described below by way of example only with reference to figures 1 to 10 of the accompanying drawings, wherein:

Figure 1 is a is an isometric view of the invention from above showing the body 1' the convex upper surface la, the lower rim lb of the body, a disk fan 2 and the direction of rotation is as indicated by the curved arrows.

Figure 2 is a sectional view of the body 1 and disk fan 2 attached and indicates the upper surface la, the lower rim lb and the lower surface lo.

Figure 3 is an isometric view of the disk fan 2 from above and the direction of rotation is as indicated by the curved arrows.

Figure 4 is an isometric view of the invention from above illustrating by means of downwardly pointed arrows how ambient air is drawn coaxially into the disk fan 2.

Figure 5 is an isometric view of the invention from above illustrating by means of outwardly radial pointed arrows how air is accelerated by the disk fan 2 and downwardly deflected over the upper surface 1 a of the body 1.

Figure 6 is an isometric view of the invention from above illustrating by means of downwardly pointed arrows how ambient air is induced to enter the airstream accelerated by and leaving the periphery of the disk fan 2 over the upper surface la of the body 1.

Figure 7 is an isometric view of the invention from above illustrating by means of arrows how ambient air is drawn coaxially into the disk fan 2 and accelerated radially and downwardly deflected over the upper surface 1 a of the body 1 and how ambient air is induced to enter the accelerated air stream over the upper surface 1 a of the body 1 and detach from the upper surface at the lower rim lb.

s Figure 8 is a side elevation of the invention illustrating by means of arrows how ambient air is drawn coaxially into the disk fan 2 and accelerated radially and downwardly deflected over the upper surface la of the body 1 and how ambient air is induced to emer the accelerated air stream over the upper surface la Of the body 1 and detach from the upper surface at the lower rim lb as in figure 7.

Figure 9 is a side elevation of the invention as in figure 8 but with all arrows illustrating airflow removed for clarity.

Figure 10 is a sectional view of the body 1 but with the disk fan 2 attached by an axel 3 and bearing 4 such that the disk fan 2 may rotate with respect to the body 1.

Referring to figure 1 isometric view and figure 2 sectional view, the invention has a disk or polygonal plan form body 1 and is essentially a thin shell type structure with convex upper surface la and a lower rim lb with a disk fan 2 situated at the top.

In one embodiment of the invention, situated at the centre of the upper surface la of the body 1 and mounted rigidly thereto is a radial air accelerator or disk fan 2 In another embodiment of the invention, the disk fan 2 is mounted rotatably to the body 1.

Referring to figure 2 sectional view, the upper surface 1 a of the body 1 is curved in a particular convex profile and is of such a surface texture as to enhance the boundary layer adhesion of air caused to flow over the upper surface 1 a radially by virtue of the disk fan 2.

The upper surface la ofthe body 1 curves downward toward a lower rim lb and is of such a design that air flowing over the upper surface la radially from its centre at the top by virtue of the disk fan 2 attaches to the upper surface by boundary layer effects and readily detaches from the upper surface at its lower rim 1 D moving in a downward or substantially downward direction.

Thus when sufficient angular momentum is imparted to the disk fan 2 in the direction, indicated by curved arrows in figure 1, ambient air is drawn into the top of the disk fan 2 and is caused to be accelerated radially outwards thereby across the upper surface 1 a of the body l.

In the first embodiment of the invention, the body 1 and disk fan 2 rotate at high speed in the direction indicated and the disk fan is so designed that ambient air is caused to be drawn into it coaxially until it is forced to leave at the periphery of the disk fan by virtue of the radial acceleration imparted to it thereby.

The disk fan 2, whilst it may be free to rotate about its axis relative to the body 1 as will be described in a further embodiment, is firmly coupled to the body in this embodiment. Referring to figure 4, the air drawn coaxially into the disk fan 2 is illustrated by downwardly pointed arrows.

Refemng to figures 1 and 2, in this embodiment of the invention it is caused to ascend by imparting rotational spin to the body 1 and disk fan 2 about the vertical axis in the direction indicated and the angular momentum so imparted is sufficient to sustain the ascent until the kinetic energy is dissipated at which time the invention commences to

descend but the rate of descent is limited by the curvature of the under surface 1 c of the body 1 as in the manner of a parachute.

Referring to figure 1 O7 in a further embodiment of the invention, situated at the centre of the upper surface 1 a of the body 1, as in the first embodiment, but mounted rotationally thereto is a radial air accelerator or disk fan 2.

In this embodiment of the invention the dislc fan 2 may rotate relative to the body 1 coaxially but in all other respects the two embodiments of the invention are the same This embodiment of the invention allows for the rotational energy imparted to generate lift to be confined to the disk fan 2 and thus facilitate the inclusion of a payload mass within the body 1 which may not be evenly distributed and thus could not be uniformly rotated as would be necessary to sustain ascent.

Referring to figure 4, in both embodiments of the invention so far described the reaction to ambient air being drawn into the disk fan 2 at its top, as illustrated by the downward pointed arrows, results in a component of lift force being imparted to the invention by virtue of the coupling between the disk fan 2 and the body 1.

Referring to figure 5, the accelerated air being forced to flow radially over the upper surface la of the body 1 and downwardly deflected over the upper surface la of the body 1, by the action of the disk fan 2 as illustrated by means of outwardly radially pointed arrows, forms a laminar boundary layer which adheres to the upper surface 1 a of the body 1, by virtue of boundary layer effects, as it flows outwards across the upper surface la.

The boundary layer tends to exhibit larninar flow at its interface with the upper surface la of the body 1 but is inclined to become turbulent at the upper regions of the accelerated air stream This turbulence in the upper regions of the accelerated air stream is an important factor to a process CVI1.1.'-Ulllg LO lit as.11 be cxplai,e.

Due to the attachment effect of the accelerated air stream through its boundary layer caused to flow over the upper surface la of the body 1, it is compelled to follow the curvature of the upper surface 1 a of the body 1 such that when it reaches the lower rim lb of the upper surface it is already deflected in a downward or substantially downward direction and thus contributes to the lift imparted to the body due to the upwardly directed reaction as it detaches from the upper surface la at its lower rim lb. An additional component of lift results by a process of air induction. As the accelerated air stream compelled to flow over and attached to the upper surface la of the body 1 by the action of the disk fan 2, a degree of turbulence occurs in the upper region of the accelerated air stream as already stated. The consequence of this is that ambient air above the upper surface 1 a of the body 1 but which does not pass through the disk fan 2 is induced to enter the accelerated air stream and flow over the upper surface J a as if it were so to do if it had passed through the disk fan 2.

The consequence of this is that a greater air mass is caused to flow over the upper surface 1 a of the body 1 in a downward direction than is drawn into the disk fan 2 thus adding to the air mass leaving the lower run lb of the body 1 resulting in an additional component of lift.

The ambient air thus drawn into the accelerated air stream caused to flow over the upper surface 1 a of the body 1 by the disk fan 2 results in a reduction in ambient air pressure above the body 1 and to some degree this reduction in ambient air pressure extends to an area g.ea,er than the p'all area ofthe body 1 and results in an additional component of lift acting over at least the total plan area of the invention.

The overall result is that when a sufficient mass of air is drawn into the top of the disk fan 2, the force of the accelerated air stream flowing over the upper surface 1 a of the body 1 and leaving the upper surface la at its lower rim lb assisted by the resulting air pressure reduction effect above the upper surface 1 a of the body 1 caused by turbulence in the upper regions of the accelerated air stream flowing over the upper surface la of the body 1 and inducing ambient air into the air steam, combined with the reaction to the suction force resulting when ambient air is drawn into the top of the disk fan 2 is greater than the total weight of the invention then the invention will ascend vertically due to these forces and this ascent will be sustained while these forces prevail. Referring to figure I and 2, in the embodiments of the invention so far described it is caused to ascend by imparting rotational spin to the disk fan 2 about the vertical axis in the direction indicated and the angular momentum so imparted is sufficient to sustain the ascent until the kinetic energy is dissipated at which time the invention commences to descend but the rate of descent is limited by the curvature of the under surface 1 c of the body 1 in the manner of a parachute.

The under surface 1 c of the body 1 may follow the profile of the upper surface 1 a but may be otherwise profiled to afford the minimum descent rate for the purpose of prolonging the descent duration.

During the descent phase, stability may be maintained by continued rotational spin or by positioning the centre of gravity below the under surface 1 c to ensure the under surface presents the maximum air resistance in the descent path.

The second embodiment ofthe invention described and illustrated in figure 10 allows for the rotational energy imparted to generate lift to be confined to the disk fan 2 and thus facilitate the inclusion of a payload mass within the body 1 which may not be evenly distributed and thus would not be uniformly rotated as would be necessary to sustain ascent.

Claims

Claims:

1 An aerial device with a body of circular or polyagonal plan form with a special convex curve to its upper surface able to ascend in a controlled manner by means of the surrounding air at the top being drawn into and accelerated over fine curved upper surface and which attaches to the downwardly curved upper surface by aerodynamic effects and provides an upwardly directed reaction as it leaves the lower rim of the invention.

2 An aerial device as claimed in Claim 1, wherein the means of accelerating the air is a radial disk fan which axially draws in the surrounding air from above and thereby provides an upwardly directed reaction to the invention.

3 An aerial device as claimed in Claim 1 and Claim 2 wherein the air accelerated over the upper surface exhibited laminar flow at its interface with the upper surface and becomes turbulent at its interface with the surrounding air above and thereby induces air from above to enter the accelerated airstream and add the the mass of air leaving the upper surface at its lower rim and hence adding to the upwardly directed reaction.

4 An aerial device as claimed in Claim 1 and 2 in which the disk fan means of accelerating the air over its upper surface is free to rotate relative to the upper surface such that the body may accommodate an unbalanced payload.

An aerial device as claimed in Claim 1, 2, 3 and 4 in which the concave under surface of the body (nay act as a parachute and hence retard the descent rate of the invention. 6 An aerial device as claimed in any preceding claim, which is not dependent on the conventional teardrop aerofoil to generate aerodynamic lift forces.

4 An aerial device as claimed in Claim 1, or 3 wherein the air accelerated over the upper surface and which induces air above to enter the airstream by the induction process causes the air pressure above to be reduced thereby over the plan area of the body and thereby adding to the upwardly directed reaction.

5 An aerial device as claimed in Claim 1, 2, 3 or 4 in which the means of accelerating the air over its upper surface forms part of the upper surface such that greater angular momentum can be imparted by the combined rotation of both the body and the disk fan air accelerating means.

Jib 6 An aerial device as claimed in Claim 1, 2, 3 or 4 in which the disk fan means of accelerating the air over its upper surface is free to rotate relative to the upper surface such that the body may accommodate an unbalanced payload.

7 An aerial device as claimed in Claim 1, 2, 3' 4, 5 or 6 in which the concave under surface ofthe body may act as a parachute and hence retard the descent rate ofthe invention. 8 An aerial device as claimed in any preceding claim which is not dependent on the conventional tear drop aerofoil to generate aerodynamic lift forces.

Amendments to the claims have been filed as follows Claims: 1 An aerial device with a body of circular or polygonal plan form with a special convex curve to its upper surface able to ascend in a controlled manner by means of the surrounding air at the top being drawn into air accelerating means, thereby causing; an upward reaction, and being accelerated radially over the specially downwardly curved upper surface and which is caused to attach to the surface by aerodynamic effects by the air flow's laminar characteristics and which exhibits turbulence at its interface with the surrounding air above and thereby entrains or induces additional mass of air from above the surface, resulting in additional upward reaction and partial pressure reduction in the air above the surface which results in additional upward reaction, and which subsequently provides additional upward reaction to the device as the combined air mass is expelled from the upper surface at its lower rim in a downward or substantially downward direction.

2 An aerial device as claimed in Claim 1, wherein the means of accelerating the air is a radial disk fan, which axially draws in the surrounding air from above and thereby provides an upwardly directed reaction to the invention.

3 An aerial device as claimed in Claim 1 and 2 in which the means of accelerating the air over its upper surface forms part of the upper surface such that greater angular momentum can be imparted by the combined rotation of both the body and the disk fan air accelerating means.