WO1996020769A1

WO1996020769A1 - Gyroscopic flying device

Info

Publication number: WO1996020769A1
Application number: PCT/US1995/000197
Authority: WO
Inventors: William Bell Forti
Original assignee: Forti, William, Mark
Priority date: 1992-01-21
Filing date: 1995-01-06
Publication date: 1996-07-11
Also published as: WO1993013841A1

Abstract

A free spinning annular cylinder like hollow body (12), having a leading (34) and trailing (36) end which are open at the ends, and having a side wall with an inner and outer surface. The leading end contains a balanced, uniformly and heavily weighted rim (14) for generating gyroscopic forces. When the device is lofted forward with a spinning motion (22) about an axis (24) in substantially the direction of flight, the body is gyroscopically stabilized, in reference to direction, attitude and orientation. The weighted rim (14) also shifts the body's center of gravity (42) toward the center of pressure, near the leading edge, which enables creation of lift.

Description

GYROSCOPIC FLYING DEVICE

FIELD OF THE INVENTION

This invention relates to gyroscopic flying mechanisms having an annular hollow body of cylindrical-like shape which can be manually or mechanically propelled.

DESCRIPTION OF THE PRIOR ART

The prior art discloses various tubular devices to be thrown through the air with a spinning motion in the direction of an axis through the device.

An early example was disclosed in U.S. Patent No. 3,264,776 to Morrow, in which a straight, hollow tube, with unbalanced weighting toward the leading end, is propelled with a rotational motion about its longitudinal axis. A slight taper extended from the trailing end to the leading end on both the interior and external surfaces of the tube. The tube was provided with a forward annular weighted area, such that its center of gravity was located within the leading one-half to one-third of the tube. Best stability was noted with length to diameter ratios (IJD) of around 1 :1 to 1 :2. Moving the center of gravity toward the leading part of the tube, along with tapered surfaces and proper diameter ratios was believed to produce aerodynamic characteristics which enhance flight in a direction along its longitudinal axis.

Kahn et al, in U.S. Patent No. 4,151,674, claims improved aerodynamic performance by incorporating a ledge along the forward edge of the cylindrical body. The rearwardly directed ledge is claimed to reduce drag and move the center of gravity to the forward quarter of the total tubular length. Best performance was reported with the center of gravity placed at about 25% of the distance from the leading edge.

Bowers, in U.S. Patent 4,246,721, teaches the use of an annular recess on the outer surface of the hollow body adjacent the leading edge, together with an annular ridge formed on the adjacent inner wall. In addition, a weighted annular ring is adjustably positioned within the cylinder so as to change the station location of the forward center of gravity. Selection of the center of gravity is said to change the aerodynamic characteristics so as to produce several curvilinear flight paths.

Hill, in U.S. Patent 4,790,788, states that the above cited devices have not had much commercial impact because aerodynamic characteristics are easily lost. He notes that said devices have erratic, unpredictable, and inconsistent flight characteristics. He allegedly achieves consistent flight by improving aerodynamic characteristics in a dimensionally constrained design by placing a relatively thick peripheral ring at the leading edge of a short tube body. The ring leading edge is chamfered while the trailing edge fairs smoothly into the tube body thickness. It is stated that the LJD ratio must be held between .8 and .74, and the ratio of leading end to trailing end weight must be around 2.2 to 1 to place the center of gravity at substantially the intersection of the forward and rearward body sections.

Etheridge, in U.S. Patent 4,850,923 also notes limitations and shortcomings of prior art devices. He claims to improve flight through employment of a number of aerodynamics specific point designs. The outer surface inclines radically outwardly and rearwardly at a 16-degree angle in order to increase lift. The ratio of leading area weight to trailing area weight is substantially between 2.2:1 to 2.5:1 with an LTD design of about .86.

It may be noted that all of the above devices are designed based upon aerodynamic considerations, i.e., center of gravity positioning, tubular shapes, leading and trailing edge angles, side tapering, surface characteristics, length to diameter ratios, etc. While all of the devices spin and have some degree of front weighting, none provide very satisfactory flight results and none appear to have been commercially successful. Thus, a need still exists for a device of this general type that provides greatly enhanced flight characteristics in terms of duration and distance, spin momentum and smoothness, as well as predictability and consistency.

SUMMARY OF THE INVENTION

The present invention is directed to a free-spinning annular cylinder-like hollow body flying apparatus, open at both ends, having a leading and a trailing end and having a side wall with an inner and outer surface. The body contains a weighted, dense and balanced annular rim along its leading edge, which acts as a gyroscope when spinning. The rim must be sufficiently dense and weighted to produce substantial gyroscopic effects when the body is propelled through the air with a spinning motion. Significant and adequate gyroscopic effects cannot be achieved without proper weighting, density and balance. The free-spinning gyroscopic rim allows the body to maintain its reference direction, attitude and orientation while in flight. The weighted rim also shifts the body's center of gravity forward toward the leading edge, which enables the creation of lift. It is the balanced interaction between substantial gyroscopic forces and aerodynamic lift forces which creates superb flight performance.

The annular hollow body can be of various sizes utilizing different materials such as light plastics, metal or composite materials. However, the leading edge rim must be sufficiently dense and weighted in order to create the needed angular momentum to maintain substantial gyroscopic stability. The high density of the rim also allows the front end of the cyclinder to remain relatively thin, which reduces air resistance and enhances performance.

Gyroscopic principles are well-known. In the case of this device, a dense and weighted gyroscopic rim is located toward the leading edge of the body. When propelled forward at launch with a spinning motion, the dense and weighted spinning rim allows the body to maintain its projected direction and attitudinal orientation. In other words, the rim's angular momentum prevents it from nosing down as a response to the force of gravity. Angular momentum H is defined as H = MR2W, where M is the mass, R the radius of the rim about the spin axis and W is the spin velocity.

This orientational stability allows the top and bottom cylindrical segments of the spinning body to act as dual wings. Therefore, lift is created in much the same way as the fixed airfoils of a bi-winged airplane. As long as the angular momentum of the device, as described in the above formula, is adequate to offset disturbing torques, such as gravity, the cylinder will hold its orientation and fly in the direction of launch. However, as the device loses its angular momentum, gravity will prevail and the rim will tend to nose down about its horizontal axis. Further, as the nose begins to turn downwardly, the resulting forces of gyroscopic precession causes the device to precess from right to left (if its spinning direction is clockwise) and the flight path will follow the direction of precession. A gyroscope's precession rate is expressed as P= T/H, where P is the rate of precession, T is the applied torque and H is the angular momentum.

In the case of a cylindrical body, with a thin uniform side wall, it has been determined from experimental results that the weight of the rim portion should be between 75% and 85% of the device's total weight, and that it should constitute less than the leading 31% of the device's axial length. The rim must also be of a material that has a specific gravity exceeding 5.7 g/cm3. The rim can consist of a weighted ring embedded in a cylinder body, or evenly distributed weights along the leading edge.

It will be noted that the simple design of this invention operates well without aerodynamic modifications. This is because stability of this design depends more upon gyroscopic effects than aerodynamic variations required by prior art. However, nothing in the fundamental design, taught herein, precludes aerodynamic variations which could alter flying characteristics including leading edge angles, side thickness and tapering, the addition of ribs, grooves, notches or fins to the body, length-to- diameter ratios, etc. It is understood that aerodynamic variations will be detrimental to flight performance if they materially interfere with the maximum gyroscopic performance of the rim. It is an object of the present invention to obtain superb flight performance of a spinning hollow body utilizing balanced interaction between substantial gyroscopic forces and aerodynamic lift forces.

Yet another object of this invention is to provide a rotating flight vehicle which can be easily propelled, either manually or mechanically.

Yet another object of the invention is to provide a rotating flight vehicle with a reduced sensitivity to aerodynamic characteristics of the body shape.

Still another object of the invention is to provide a flight vehicle which can be inexpensively manufactured.

Still another object of the invention is to provide a flight vehicle that is relatively safe to use.

The above and other objects, features and advantages of the present invention will become more apparent when making reference to the following detailed description and to the accompanying sheets of drawings in which preferred structural embodiments incorporating the principals of this invention are shown.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a rear perspective view illustrating the operation of a gyroscopic flying device in accordance with the present invention as an aerial sports toy which is manually propelled.

Figure 2 is a side elevation view of the device of Figure 1 depicting the x axis and showing the forward leading edge.

Figure 3 is an end view of the device of Figure 1 as seen from the leading edge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to Figure 1 , there is shown the general operation of a gyroscopic flying cylinder body 10 in accordance with the present invention when thrown by a hand 16 as an aerial sports toy. The body 10 includes a hollow cylindrical body 12 with a leading end 34 and a trailing end 36. A dense and weighted rim 14 is shown attached to the interior of the cylinder 12 at the leading end 34. The body 10 is shown being manually held by a hand 16 just prior to launch. When the body 10 is thrown by hand 16, gripping fingers 18 work in cooperation with wrist 20 to impart axial spin to the device in the direction illustrated by arrow 22. At the same time, the hand 16 provides an initial forward velocity along spin axis 24. It is anticipated that manual usage will include games of catch or competition events in which throwers aim for maximum flight times, distance, or accuracy.

The body 10 is designed for durability. The forward rim 14 is preferably made of a high-density metal such as spring steel that allows for resiliency when gripped by hand 16 while maintaining product durability. The rim 14 may be heavily coated with any number of plastic coatings to avoid exposure of sharp edges and provide for safety. The cylinder 12 of the body 10 can be constructed by adhering a thin (.009 to .030 inches thick), durable and shock resistant plastic strip around either the outside or the inside leading edge of the dense rim 14. Attachment to the outside of the rim 14 may be preferred since the strip material will protect the rim from damage. A durable plastic such as polyester, polycarbonate, polyethylene or polypropylene works well since it does not crack or shatter if subjected to a hard impact. This design provides for a very durable, light and safe product.

The body 10 is also designed for manufacturability. Spring steel and plastic sheets are commodity products that are readily available at reasonable costs. The rim 14 can be fashioned from either a steel strap, wire coil or spring by using traditional rolling, welding, coiling or spring-making equipment. The plastic which makes up the cylinder 12 can simply be wrapped around the rim 14 by hand or by utilizing machines typically used in the product labeling industry. Adhesion of the plastic to the rim 14 can be achieved by utilizing either glue or transfer tapes. The use of tape has the advantage of enabling the product to be sold in a disassembled kit form, if so desired. A rim with a section of transfer tape wrapped around the rim may be sold in ring form. A protective layer on the tape may than be removed, and a strip of stiff but Tollable plastic is wrapped around the rim, and held by the adhesive. Injection molding and extrusion manufacturing processes also can be readily utilized.

In a preferred embodiment of the present invention, the cylinder 12 has a diameter of 3.75 inches, a length of 2,125 inches, and a wall thickness of .010 inches, while the rim portion 14 ahs a wall thickness of .050 inches. The length of the rim 14 is .5 inches, which accounts for 25% of the body's 10 total length. The ctlinder 12 and the rim 14 combination weighs approsimately 26 grams. These dimensions provide optimal characteristics for a game of catch because of the following results: a straight and stable flight can be achieved for both long and short distances; the cylinder fits comfortably within the grip of an average sized man; the diameter of the cylinder is large enough to reduce the possibility of someone being inadvertently struck in the eye; and the cylinder's lightweight construction prevents serious harm if someone is accidently struck.

It will be recognized that body 10 can be launched by various known mechanical or powered mechanism means which can aim and impart the initial velocity and spin conditions. Such means may be carried aboard a spinning device or may be externally separate. Included in these means are springs, catapults and other leverage mechanisms, explosive or burning propellant systems, as well as normal powered devices running on electricity or various fuel systems.

Referring again to Figure 1 , it has been found that when properly thrown, the device will initially follow a more or less linear flight path from the initial direction 24. Gyroscopic effects tend to stabilize the flight path against the gravitational forces acting to rotate the heavy gyroscopic rim 14 downward about a horizontal axis 32. Toward the end of flight, when the spinning and forward velocity diminish, the device will precess from right to left about a vertical axis 26. The flight then will veer to the left along path 30. The end of flight is characterized by the rim nosing down accompanied by gyroscopic coning motions.

Figure 2 shows a side view of the body 10 with the weighted, dense and balanced rim 14 oriented with its x axis along the direction of launch arrow 24. The rim portion 14 is comprised of a thin annular metal band attached to the leading edge of the internal wall of the cylinder 12. The body's center of gravity is shown at point 42.

Figure 3 shows the front view of body 10 corresponding to the line 3-3 of Figure 2, with the y and x axes exposed. Leading edge 44, comprised of the rim 14 and the cylinder 12 , has a thickness on the order of .254 cm. The effects of head-on drag from the thin, flat leading edge 44 are negligible.

The performance of the body 10 is heavily dependent on both the weight and density of the rim 14. The weight of the rim 14 is preferably between 75% and 85% of the total weight of the body 10, while the density should exceed 5.7 g/cm3. Two experiments have been performed to obtain these results. With respect to the effects of varying weight, comparative performance tests have been made which show the importance of appropriate up-front weighting to obtain significant gyroscopic effects and enhanced flight performance. Plastic models were used having body lengths of 5.08 cm and diameters of 9.56 cm. Various weighted metal rims of 1.27 cm have been added to the forward region along the leading edge. Table 1 below presents "normal throw" averages of approximate flight ranges of devices with different rim weight percentages (but with densities held constant) obtained under wind-still conditions and an observation appraisal of flight characteristics.

Table I

% of Rim Weight to Average Normal Throw Flight the Total Device (Yards. Characteristics

51% 14 m Very wobbly spin, poor lift, does not soar, no precession.

64% 18 m Wobbly spin, poor lift, does not soar, no precession.

73% 46 m Rough spin, exhibits lift and soars somewhat, some precession,

81% 60 m Smooth spin, exhibits good lift and soars well, precession.

86% 60 m Very smooth spin, exhibits good lift and soars well, much precession

Not only is rim weight important to performance, but density is also a key factor. To demonstrate this point, comparative performance tests have been made, which show the importance of rim density to obtain significant gyroscopic effects and enhanced flight performance. As with the previously described tests, plastic models were used, each having body lengths of 2 inches and diameters of 3.75 inches. In this case, the weight of the rims were held constant at 17 grams but the materials used had different densities. The table below presents "normal throw " averages of approximate flight ranges of devices with different rim densities obtained under wind- still conditions and observation appraisals of flight characteristics.

Table II

Material Density of Rim Average Normal Throw Flight .α/crτ.3. (yards) Characteristics

Polycabonate 1.2 g/cm3 23 M wobbly spin, poor lift, unstable flight 2.7 g/cm3 33 M Rough spin, some lift, unstable flight

tin 5.75 g/cm3 51 M smoother spin, exhibits lift, more stable steel 7.84 g/cm3 60 M Smooth spin, lifts very well, very stable flight

lead 11.34 g/cm3 68 M Smooth spin, very strong lift, very stable flight

It should be noted that this data confirms the expectation of improved distances and flight characteristics at the larger forward rim weight distributions. In addition, greater precession is exhibited at the end of flight as relative rim weight increases.

Weight distributions of the present invention are determined without regard to aerodynamic modifications of the cylinder. In contrast, prior art weight distributions are sited in conjunction with a variety of specific aerodynamic modifications. Nevertheless, weight distributions of previous designs are well below the criteria of having the rim account for 75% of the total weight, as indicated above. Futhermore, there appears to be nothing in the prior art which reveals the importance of having high density material for making the rim. Therefore, previous designs cannot achieve sufficient gyroscopic stabilization to reach the greater ranges or smoother flight characteristics exhibited by the present invention. Maximum ranges for "hard throws" of a typical man can exceed 100 meters.

Although the present invention has been described in considerable detail with reference to certain preferred cylindrical aerial toy versions thereof, other versions and applications are possible. The present invention can be utilized in the defense industry as a bullet, projectile, mortar, target practice device, self-propelled aircraft, etc. Also, it may be used in the medium of water as a torpedo or submarine. Furthermore, various hollow body shapes and known aerodynamic modifications may also be spun and flown. Therefore, the spirit and scope of the appended claims should not necessarily be limited to the description of the preferred versions and applications contained herein.

Claims

CLAIMSWhat is claimed is:

1. A free spinning gyroscopic flying device which is capable of flight due to interacting gyroscopic forces and lift forces and comprised of:

a cylindrical hollow body positioned about an axis and having a leading and a trailing open end, said hollow body having an inner surface and an outer surface;

a uniform, balanced annular rim attached to said hollow body at said leading end and disposed concentrically about said axis for generating gyroscopic forces when spun about said axis;

the weight of said rim being more than 75% of the weight of said flying device, and said rim has a density greater than 5.7 grams per cubic centimeter to gyroscopically stabilize said cylinder in reference to direction, attitude, and orientation during forward flight motion.

2. The gyroscopic flying device of Claim 1 wherein the axial length of said rim end is less than the axial length of said trailing end.

3. The gyroscopic flying device of Claim 1 , wherein the axial length of said rim is less than 31% of the total length of said device.

4. The gyroscopic flying device of Claim 1 , wherein the diameter of an outer surface of said rim is about equal to the diameter of said inner surface of said body.

5. The gyroscopic flying device of Claim 1 , wherein the diameter of said rim is a little less than ten centimeters and the axial length of the rim is about 1.25 centimeters.

6. The device of claim 1 , wherein the axial length of said trailing end is about 60% of the diameter of the device.

7. A free spinning gyroscopic flying device which is capable of flight due to interacting gyroscopic forces and lift forces comprises: a hollow cylinder defining a forward opening and rear opening and having side portion, said side portion having a cylindrical leading end section terminating at said forward opening and a cylindrical trailing end section terminating at said rear opening, wherein said leading end section and said trailing end section have a combined length equal to the length of said cylinder;

an anular rim having a density greater than 5.7 g/cm3 attached to said side portion of said cylinder at said leading end section, said rim being sufficiently weighted with respect to said cylinder to create gyroscopic stabilization effects for said flying device while said device is spinning about its longitudinal axis and propelled forward with said leading end section forwardly oriented;

8. The gyroscopic flying device of Claim 7, wherein said flying device has a ratio of rim weight to total flying device weight greater than 3 to 1 for gyroscopically stabilizing said flying device in reference to direction, attitude and orientation during forward flight motion.

9. The gyroscopic flying device of Claim 7, wherein the axial length of said leading end section is less than 31% of the total length of said cylinder.

10. The gyroscopic flying device of Claim 9, wherein said annular rim is disposed entirely within said leading end section of said device.

11. The gyroscopic flying device of Claim 7, wherein said rim has an inner and outer surtace and said side portion has an inner and outer surface, the diameter of said outer surface of said rim is equal to the diameter of said inner surface of said side portion.

12. The gyroscopic flying device of Claim 7, wherein said rim has an inner and outer surface and said side portion has an inner and outer surface, the diameter of said inner surface of said rim is equal to the diameter of said outer surface of said side portion.

13. The gyroscopic flying device of Claim 1, wherein said rim has an inner and outer surface and said side portion has an inner and outer surface, the diameter of said inner surface of said rim is equal to the diameter of said inner surface of said side portion and the diameter of said outer surface of said rim is equal to the diameter of said outer surface of said side portion.

14. A method of making the flying device comprising: forming a thin flat stiff but flexible dense band into a ring; wrapping a length of tape around the band to hold the band in its ring shape; removing a protective layer from said tape to expose an adhesive surface; wrapping a strip of stiff but flexible plastic about the ring to secure the strip by means of said adhesive surface, the strip having an axial length greater than said ring so that a cylindrical body is created having a trailing end extending away from said ring; and attaching abutting edges of said strip to complete said cylinder.