WO1983000635A1

WO1983000635A1 - Yo-yo with twist-resistant support

Info

Publication number: WO1983000635A1
Application number: PCT/US1981/001269
Authority: WO
Inventors: Patrick Maccarthy
Original assignee: Patrick Maccarthy
Priority date: 1981-08-18
Filing date: 1981-09-21
Publication date: 1983-03-03
Also published as: GB2125305B; AU8728882A; SE8204686D0; DE3152728T1; AU7721481A; SE441495B; GB2125305A; SE8204686L; EP0085677A1; AU561532B2

Abstract

A toy capable of combined rotational and translational motion. Two parallel discs (3) are connected through their centers by a single axle (2). The axle is suspended from a support (35) connected at a position between the two discs. Said support (35) is of a twist-resistant type, offering a greater torsional resistance to twisting about the axis of the string than conventional yo-yo strings. The support (35) may be anchored to the axle (2) in a non-sleeping mode, or it may be looped around the axle (2) allowing the yo-yo to sleep. In order to operate the toy, the end of the support (35) opposite that which is connected to the yo-yo axle (2) is held by the user, and an up-and-down gentle motion is imparted to the toy. The end of the support (35) may be connected to a swivel system (40) which is in turn connected to a ring (41) for holding the toy.

Description

YO-YO WITH TWIST-RESISTANT SUPPORT

RELATED APPLICATIONS This application is related to my co-pending United States applications: (1) "Tape-Supported Yo-Yo"₇ Serial No. 138,729 ^• filed April 9, 1980; (2) Yo-Yo With Twist-Resistant String", Serial No. 293,797, filed August 18, 1981 and (3) "Tape- Supported Sleeper Yo-Yo", Serial No. 298,720 filed September 2, 1981.

FIELD OF TEE INVENTION This invention relates to the field of rotating toys. More specifically, the invention relates to a yo-yo type toy wherein the axle of the yo-yo is sus¬ pended from a twist-resistant support, such as a twist-resistant string, chain, tape or other material offering a greater torsional resistance to twisting than the conventional yo-yo string.

BACKGROUND OF THE INVENTION A yo-yo consists of a single axle having two parallel position discs centrally connected to the axle. In one modification of a yo-yo, a string is tied at one of its ends to the axle between the discs and is held in the user's hand at the other end. The string is wrapped around the axle, and the body of the yo-yo is allowed to fall, thereby imparting a rota¬ tional momentum to the discs in association with their translational motion. This rotational momentum causes the yo-yo body to rise upward again, after it reaches the bottom of its swing. A gentle upward impulse applied to the yo-yo near the bottom of its swing compensates for the energy lost through friction.

In another variation of the yo-yo, the string is not actually tied to, or anchored to, the axle; rather, it is looped about the axle somewhat loosely, allowing the yo-yo body to spin freely in the looped string. Such rotational motion of a yo-yo body,

OMPI unaccompanied by translational motion along the string direction, is referred to as "sleeping". The "sleep¬ ing" yo-yo can be withdrawn from its "sleep" by jerk¬ ing the string, or alternatively, by relaxing the tension in the string.

A yo-yo is subject to a particular problem when used by children or inexperienced players. Generally the yo-yo leans over to one side and then undergoes a pronounced rotation about the axis of the string. At this point, the yo-yo is generally out of control. The inventor attributes this problem to precession, and considers it to be the most serious problem with yo-yo operation.

When a torque is applied to a rotating body tending to displace the original axis of rotation, the body reacts by rotating about an axis which is ortho¬ gonal to both the original axis of rotation and the axis of the applied torque. This phenomenon is called precession and has been studied extensively in con¬ junction with conventional gyroscopes and spinning tops, but not in conjunction with yo-yos. The direc¬ tion of the induced precessional rotation can be predicted from a knowledge of the original direction of spinning and of the direction of the applied torque. The inventor has checked these aspects out experimentally with yo-yos and confirmed that the basic difficulty with yo-yo operation is due to the phenomenon of precession. This precessional rotation generally occurs about an axis lying along the string direction.

Operation of a yo-yo would be simplified if the precessional problem were eliminated or minimized. One way for achieving this is to use a support mater¬ ial which offers a significant resistance to twisting about an axis lying along the length of the support, but which, at the same time, is sufficiently flexible

OMFI to wrap around the yo-yo axle. Such a support hinders precessional rotation about the support axis.

In the specification and claims of this applica¬ tion, the term "twist-resistant support" means that the support offers a significant barrier or opposition to twisting about the longitudinal axis of the support compared to conventional yo-yo strings which have been used on commercial yo-yos up to the present time. Of course, in order to be useful for a yo-yo, such a twist-resistant support must be flexible about axes transverse to the longitudinal axis of the support in order that the support may wind about the yo-yo axle.

As an indication of the increased versatility of the yo-yo presented herein, the user will find that the yo-yo can be handled quite roughly during its operation, and still, the user continues to retain control of its motion. The ability of the twist- resistant support to resist twisting about its longi¬ tudinal axis hinders the yo-yo from engaging in pre¬ cessional rotation and also facilitates the yo-yo in recovering from precessional motion when such does occur.

SUMMARY OF THE INVENTION

The presently claimed invention is comprised of a single axle which connects two parallel discs at their centers. A twist-resistant support is connected to the axle between the discs. In one modification of the invention, the twist-resistant support is tied to the axle, preventing the yo-yo from sleeping. In another modification, the twist-resistant support is looped about the axle, allowing the yo-yo to sleep.

In describing the association of the twist-resis¬ tant support with the yo-yo axle herein, the following terminology is adopted: "tied to" means that the twist-resistant support is tightly secured to, an¬ chored to, or embedded in, the axle, preventing the

OMPI yo-yo from sleeping; "looped about" means that the twist-resistant support loosely encircles or surrounds the axle in any manner which allows the yo-yo to sleep; "connected to" means that the twist-resistnat support is associated with the axle in either of the above two ways, that is, "connected to" embraces both "tied to" and "looped about".

In a particular embodiment of the present inven¬ tion, a system of one or more swivels is attached to the end of the twist-resistant support opposite the end of attachment to the axle. A holding ring is attached to the swivel system. In order to operate the preferred embodiment of the present invention, the user places his finger through the holding ring. After winding the support around the axle, the body of the yo-yo is allowed to fall. Therafter, gentle up and down oscillatory motion is maintained to keep the body of the yo-yo rotating, and thus sustaining its vertical up-and-down motion. The swivel system, if present, and including one or more swivels, allows relaxation of the rotational tension in the support resulting from twisting of the support about a verti¬ cal axis. This significantly facilitates operation of the toy.

In accordance with the above-presented descrip¬ tion of the invention, and a further description which will follow, it is the primary object of this inven¬ tion to provide a toy comprised of an axle; two discs supported at their center points on said axle; a twist-resistant support connected to said axle.

Another object of the present invention is to provide a yo-yo which is comprised of an axle; two discs supported at their center points on said axle; a twist-resistant support connected at one of its ends to said axle; a system of one or more swivels con¬ nected to the opposite end of said support; and a holding ring attached to said swivel system.

-g TREA

OMFI Another object of the present invention is to provide a yo-yo toy that is more smooth in operation than a conventional yo-yo toy.

Still another object of the present invention is to present a yo-yo toy with enchanced visual effects due to the presence of a tape which may include indi¬ cia.

Another object of the invention is to present a yo-yo toy which possesses greatly increased stability resulting in increased versatility of the function of the toy.

Another object of the present invention is to present a yo-yo toy of such design that difficulties due to precessional rotation can be readily rectified and proper yo-yo operation reinstated without having to stop the yo-yo and start all over again.

Another object of the present invention is to present a yo-yό toy containing a. twist-resistant support which offers considerable resistance to pre¬ cession of the yo-yo body about the axis of the support.

Another object of the invention is to present a yo-yo toy which experiences enhanced atmospheric resistance to precession due to the presence of a tape.

These and other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the details of con¬ struction and use as more fully set forth below, reference being made to the accompanying drawings forming a part hereof wherein like numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front view of a yo-yo illustrating the phenomenon of precession;

Figure 2 is a front view of an apparatus con¬ structed to measure and compare the torsional resistances of various support materials;

Figure 3 is a front view of one embodiment of the present invention incorporating a twist-resistant string;

Figure 4 is a front view of an embodiment of the present invention incorporating a tape;

Figure 5 is a front view of another embodiment of the present invention incorporating a tape-cum-string combination; and

Figure 6 is a front view of an embodiment of the tape-cum-string combination where the string pene¬ trates the length of the tape segment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present "yo-yo with twist-resistant support" is described in detail in terms of its pre¬ ferred embodiments, it is to be understood that this invention is not limited to the particular arrangement of parts shown, as such devices may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

Referring now to the drawings, Figure 1 illus¬ trates the phenomenon of precession as it relates to a spinning yo-yo. The body of the yo-yo is referred to generally by the number 1. The body contains a single axle 2. The axle 2 has a pair of identical discs 3 positioned at their center points on the axle 2. Imagine the yo-yo body 1 to be spinning about the axis 5-5 such that the "+" symbols on discs 3 indicate that those portions of the discs are rising from the plane of the page; the "-" symbols indicate that those portions of the discs 3 are descending into the plane of the page. The string 4 is being pulled to the side, tending to topple the yo-yo body 1 in a clock¬ wise manner as viewed facing Figure 1, and as indi¬ cated by the arrows 6. It is a well-known principle

- lύrϊ

OMFI of physics that, when a torque is applied to a rotat¬ ing object, which tends to displace the original axis of rotation, the rotating object will rotate about an axis which is mutually perpendicular to both the original axis of rotation and to the axis of the applied torque. This induced rotation is referred to as precession. In the case of a yo-yo spinning as illustrated in Figure 1 and subjected to a torque as indicated in Figure 1, the yo-yo body 1 will spin or precess about an axis lying along the line 7-7 and the direction of precession is indicated by the curved arrow 8. If either the direction of rotation about the axis 5-5, or the direction of the applied torque as indicated by arrows 6 is reversed, the direction of precessional rotation will be reversed, and will occur in the opposite direction to that indicated by the curved arrow 8.

The topic of precession has been discussed and studied extensively in the past. In particular, the precession of spinning tops has been discussed at length in the literature, for example, in "Spinning Tops and Gyroscopic Motion" by J. Perry (1850-1920) republished Dover, New York (1957); "An elementary Treatment of the Theory of Spinning Tops and gyro¬ scopic Motion" by H. Crabtree, Longmans, Green and Co., London (1923); and "A Treatise on Gyrostatics and Rotational Motion" by A. Gray 1918, republished in 1959 by Dover, New York. In addition, this topic has been treated in numerous journal articles. In con¬ trast, the inventor is not aware of any discussion in the literature relating to the precession of yo-yos. When a yo-yo goes out of control, it generally rotates about the axis of the string. Curiously, it appears that this rotational motion had not been attributed to precession until so explained by my co-pending U. S. patent applications, Serial No. 138,729, Serial

OMP No. 178,628, Serial No. 293,797 and Serial No. 298,720. Precession of a yo-yo about the axis of the string had not been discussed in any prior U. S. patents. Isaacson, U. S. Patent 3,175,326, mentions the rotation of a yo-yo "about the axis of the sus¬ pending string" but does not attribute it to preces¬ sion. Isaacson discusses the use of inertial rings in the yo-yo. However, it is worth pointing out here, that, regardless of the actual moment of inertia of the yo-yo body, precession will still occur, as illu¬ strated in Figure 1, when a torque is applied to the yo-yo body 1 which tends to reorientate its original axis of rotation. A number of commercial yo-yos possess these "inertial rings" or flywheels in their designs; this cannot solve, and may actually aggra¬ vate, the precessional problem in yo-yos.

The inventor is not aware of any other patent, or other literature, which addresses the precession of a yo-yo, as discussed in connection with Figure 1 above. The specific information including directions, pro¬ vided in Figure 1 has been checked experimentally with yo-yos by the inventor and is totally consistent with predictions based on physical principles (see, for example, Figure 9.20 in "University Physics" by Sears and Zemansky, 4th edition, Addison-Wesley Publishing Co., (1970); or Figure XXII (page 10) or Figure 19 (page 37) in "An Elementary Treatment of the Theory of Spinning Tops and Gyroscopic Motion" by H. Crabtree, Longmans, Green and Co., 1923 (originally printed 1909). This confirms that the effect is due to pre¬ cession and not due to some other cause.

The precession of the yo-yo indicated by the curved arrow 8 of Figure 1 could be counteracted by applying a torque in the opposite direction to the curved arrow 8 of Figure 1. Such a torque can be supplied by means of the string 4, if the string is capable of offering a torsional resistance to twist¬ ing. Conventional yo-yo strings offer very little resistance to twisting and contribute very little to hindering precession of the yo-yo body. The essence of this invention is the introduction of. supports which display a significant torsional resistance to twisting and are thus capable of counteracting the tendency toward precession by the yo-yo body. The inventor is not aware of any teachings on these spe¬ cific concepts other than that within my co-pending U.S. patent applications. Specifically, the inventor is not aware of any use of, or teachings relating to the use of, twist-resistant supports in association with yo-yos. My co-pending U.S. patent application Serial No. 178,628, entitled: "Precession-Resistant Yo-Yo Device" describes an alternative method for combatting the precessional problem in yo-yo type devices.

The inventor has discovered that substitution of a twist-resistant support for the conventional yo-yo string successfully counteracts the precessional problem in yo-yos and leads to a dramatic improvement in their operability. The inventor has further estab¬ lished that a swivel system, consisting of one or more swivels attached to the support material opposite the end of attachment to the axle, further improves the operability of the yo-yo. This invention results in a yo-yo type toy which is easier to operate than a conventional yo-yo and which can be readily operated by very young children and by inexperienced adults. These improvements result from the torsional resis¬ tance to twisting of the support materials, which, in association with the yo-yo body consitutes the present invention. An example of a twist-resistant support material which is particularly effective in associa¬ tion with the present invention is a type of twist- resistant string called metallic cord. Metallic cord

"_&URE consists of strands of fibers around which thin or flat metal thread, or simulated metal thread, is woven. This material is available commercially at a rather inexpensive cost. One type of such material is produced by KNITRIMS-of Miami (2431 N.W. 2nd Avenue, Miami, Florida, 33127). One type of metallic cord consists of LUREX woven about multiple strands of RAYON fibers. Another class of twist-resistant mater¬ ial consists of fine chains, such as those found in jewelry stores. Such chains offer a considerable resistance to twisting, but nevertheless, can readily wrap around a yo-yo axle. The inventor has discovered that a tape or ribbon is also particularly effective for use with the present invention. In the case of a tape, other effects in addition to its torsional resistance to twisting, contribute to the improved performance of the yo-yo; these aspects will be dis¬ cussed later in this specification.^' The attachment of a swivel means, or a swivel means connected to a holding ring, leads to a significant improvement in the performance and handleability of the new yo-yo. It should be pointed out that the above specific twist-resistant supports are quoted simply as particu¬ lar examples, and that the invention is not limited to the specific items and products named above, but embraces the generalized concept of a twist-resistant support in association with a yo-yo type toy.

Conventional yo-yo strings offer very little torsional resistance to twisting. The essence of the present invention is the introduction of a twist- resistant support alone or in combination with a swivel. The pronounced improvement in the performance of the yo-yo of the present invention compared to the conventional yo-yo is readily apparent to a person using the toy. However, it is desirable to measure the torsional resistance to twisting of the supports used in the present invention in order to show quanti¬ tatively that they differ significantly from conven¬ tional yo-yo strings.

In order to quantify the torsion-resistance of various types of yo-yo supports, an apparatus of the type illustrated in Figure 2 was designed and con¬ structed. This apparatus can be applied to strings, tapes and other materials. Its application to strings will be described first, followed by a discussion of its application to tapes. The members 9 and 10 are vertical supports joined by an upper connector 11 and a lower connector 12. The members 13 and 14 are vertical bars which are connected to supports 9 and 10, respectively. Pulleys 15 and 16 are slidably connected to bars 13 and 14 by means of clamps 17 and 18, respectively. Hook 19 in upper connector 11 supports the string 20. The string 20 has a split ring 21 attached at its lower end. The string 20 is connected, through the split ring 21, to a cylindrical rod 22 of known diameter by means of a hook 23 which is screwed into rod 22. A weight 24 is attached to the lower end of rod 22. A light thread 25 is con¬ nected to cylindrical rod 22. The thread 25 lies in the groove of the pulley 15, and there is a known mass 26 suspended from the thread 25. A thread 27 is attached to rod 22 on the opposite side of attachment as thread 25. Thread 25 and thread 27 are attached to rod 22 at slightly different vertical levels, as indicated in Figure 2. Thread 27 lies in the groove of pulley 16 and has a known mass 28 suspended from it. Weights 26 and 28 are identical. Two series of parallel holes 29 and 30, are arranged in a vertical sequence along support members 9 and 10. The plane containing these sets of holes lies slightly in front of the plane containing the bars 13 and 14. A remova¬ ble pin 31 can be supported at opposite ends in a cor¬ responding pair of these holes.

0-v.PI The apparatus is operated as follows: the string under study is supported from the hook 19 as indicated above. While disconnected from the string, the rod 22 is manually twisted a specified number of revolutions in a chosen direction, let's say, clockwise as one looks down on the rod 22 from the top. This causes the threads 25 and 27 to wrap around the rod 22 in the same direction, thereby forcing the two weights 26 and 28 to rise. These weights exert a torque or mo¬ ment on the rod 22 tending to rotate it in the oppo¬ site direction to the imposed rotation. After the rod 22 has been rotated a specified number of times, it is connected to the string 20 through the split ring 21 and hook 23. The torque applied by the two weights 26 and 28 causes the rod 22 to rotate in an anticlockwise direction as viewed from above, thus causing the string to be twisted in this direction also. The rod 22 and attached weight 24 will continue to rotate until the opposing torque offered by the twisted string is exactly equal in magnitude to the torque due to the supported weights 26 and 28, at which point equilibrium is reached. If the threads 25 and 27 become completely unwrapped from the rod 22 during this process, the same step is repeated again, by disconnecting the rod 22 from the string 20 and again rotating the rod 22 manually in a clockwise di¬ rection, as viewed from the top. During this rewind¬ ing, the twisted string is prevented from untwisting by insertion of the pin 31 into the split ring 21, while the pin 31 is supported in the holes 29 and 30.

The total weight suspended from the string 20 is given by the sum of the weights of the split ring 21, the hook 23, the rod 22 and the weight 24, thereby providing a tension in the string.

The torque or moment applied to the rod 22 by the weight 26 is given by the product of the weight 26 and the radius of the rod 22. A similar torque is applied by the weight 28. Since both weights are equal, and since both torques act in the same direction, the total torque is given by the product of one of the weights by the diameter of the rod. The weight of the threads and the radius of the threads are ignored in these calculations due to their very small contribu¬ tions to the overall measurments. The end-to-end distance of strings generally becomes smaller during twisting; accordingly, clamps 17 and 18 allow the positions of the pulleys 15 and 16 to be adjusted so that the segment of thread 25 between rod 22 and pulley 15, and also the segment of thread 27 between rod 22 and pulley 16, are horizontal prior to taking final measurements.

The torsional resistances of various strings were compared by counting the number of rotations induced in a given length of string by a specified torque. The greater the number of rotations induced in a particular string by a given torque, the smaller the torsional resistance offered by that string. In all of these measurements, a rod 22 of 0.25 inch diameter was used, and the two suspended masses 26 and 28, had weights of either 1 gram or weights of 2 grams each. Thus all experiments were carried out under a total torque of 0.25 gram inch or a torque of 0.50 gram inch. The measured data for a number of string mater¬ ials, are summarized in Table I. All results are the average of at least six separate measurements. Equi¬ librium was approached from both directions in all experiments in order to compensate for frictional effects within the apparatus. Typically, all indivi¬ dual readings fell within 5% of the average value, indicating good reproducibility and precision for the measurements. Some strings, in particular the conven¬ tional looped or double-stranded yo-yo strings offer a

OMPI different torsional resistance to twisting in the clockwise and anticlockwise directions; in those cases, the number of revolutions reported in Table 1 refers to the average for the clockwise and anticlock¬ wise directions.

TABLE I

Length Weight Suspended Torque No. of

Type of String r (Inches) From String (Grams) (Gram Inch) Revolu¬ tions

Duncan Yo-Yc ,® 41.75 29.63 0.5 90 String

Festival Yo- ^■Ϊ® 40.50 29.63 0.5 90 String

Duracraft 38.25 29.63 0.5 66 Yo-Yo String

Metallic Cord 40.25 29.33 0.50 0.8

Metallic Cord 41.00 29.33 0.50 0.4

Duncan Yo-Yc ,® 44.00 52.15 0.25 56 String

Metallic Cord 44.00 51.85 0.25 0.13

Metallic Cord 43.50 51.85 0.25 0.40

Braided Nylon 43.00 52.15 0.25 30 (25 Lbs.)

The yo-yo strings listed in Table I were taken from commercial yo-yos. The data in Table I indicate that typical yo-yo strings having lengths of about 40 inches and under a tension of about 30 grams will undergo significantly more than 40 revolutions when subjected to a torque of 0.5 gram inch, and undergo significantly more than 25 revolutions when subjected to a torque of 0.25 gram inch under a tension of about 50 grams, as measured in the manner described above. The twist-resistant strings which are the subject of this application rotate less than 40 complete revolu¬ tions under a torque of 0.5 gram inch and a tension of 29.63 grams; and rotate less than 20. complete

revolutions under a torque of 0.25 gram inch and a tension of 52.15 grams.

Figure 3 illustrates one embodiment of a yo-yo with twist-resistant string. In this embodiment, the twist-resistant string 32 is looped 33 about the axle 2, allowing the yo-yo to sleep. Alternatively, the twist-resistant string 32 may be tied to the axle 2 in a non-sleeping mode.

The apparatus illustrated in Figure 2 was also used to measure the torsional resistances to twisting of various tape materials.

When a tape is twisted slightly, it produces a "spiral staircase" type of configuration. However, if it is twisted excessively, this configuration col¬ lapses and the tape folds over in a pronounced manner along its width. Tapes differ considerably in their resistance to this type of collapse, that is, in their inherent torsional resistance to twisting. When this type of structural collapse occurs, the tape loses a significant portion of its torsional resistance to twisting. When there is a weight supported from the lower end of the tape, that is, if the tape is under tension, its total torsional resistance increases; in other words, this collapse does not occur until a greater torque is applied to the system. However, this is not due to the inherent twist-resistance residing in the tape material itself, but is due in large part to the imposed tension. Accordingly, in these experiments, it is desirable to have the tension on the tape as small as possible by having the total suspended weight from the tape as small as practica¬ ble; thus, the weight 24 (Figure 2) was not employed in the experiments involving tapes.

The torsional resistances of various tapes were compared by gradually increasing the two weights 26 and 28, that is, by gradually increasing the torque applied to a fixed length of tape and noting:

OMFI (i) How many rotations are induced in the tape by each applied torque, and

(ii) What magnitude of torque first causes struc¬ tural collapse of the tape.

The weights 26 and 28 can be varied conveniently by tying small plastic bags to the ends of the strings 25 and 27; known masses can then the added to, and removed from these bags.

In all of these experiments, a rod 22 of 0.25 inch diameter was used; the plastic bags weighed 0.19 gram each. The support 21 in these experiments was flat rather than round in order to accommodate the tape, and weighed 0.37 gram; the rod 22 plus attached hook 23 had a weight of 2.08 grams. Thus, the tension in the tape, due to the suspended weight of sup¬ port 21, rod 22 and hook 23, had a value of 2.45 grams. The tape was supported at its upper end by an elongated flat support connected to hook 19.

The measured data for a number of tape materials are presented in Table II. The third column in Table II gives the number of rotations induced in each tape by a specified torque, for example 1.2/0.3 means that the tape displayed a total of 1.2 twists from top to bottom when it was subjected to a torque of 0.3 gram inch. Column 4 specifies the minimum torque which causes the "spiral staircase" configuration of the twisted tape to collapse.

All results are the average of at least three separate measurements. Equilibrium was approached from both directions in all experiments in order to compensate for frictional effects within the measuring apparatus. All individual readings fell very close to the average value, indicating good reproducibility and precision for the measurements.

The commercially available tapes of different types had slightly different widths. However, it was possible to choose combinations which had reasonably close dimensions for comparison purposes, for example, the first four tapes listed in Table II have approxi¬ mately the same width; and the 5th, 6th and 7th tapes listed in Table II are also close to each other in width, allowing valid comparisons to be made.

TABLE II

TWISTS/TORQUE COLLAPSE POINT

TAPE WIDTH (INCH) (1/GRAM INCH) (GRAM INCH)

Satin 15/16 1.2/0.3 0.43

Satin 7/8 1.6/0.3; 2.4/0.55 0.8

Taffeta Plaid 31/32 1.7/0.3; 2.7/0.55 0.6

Grosgrain 15/16 0.9/0.3; 2.05/0.8; 2.92/1.30; 3.93/2. 04; 4.6/2.54 3.0

Twill Tape 3/4 2.0/0.3 0.35

Grosgrain 11/16 1.6/0.3; 3.1/0.8;

4.4/1.30; 5.3/1.8 2.2

All tapes for these measurements were 42 inches in length from top to bottom.

Many of the common tapes, such as twill tape, Mylar, satin or taffeta plaid, with the dimensions and texture usually found commercially, do not exhibit a pronounced degree of torsional resistance to twisting; accordingly, these materials are not particularly effective for use in conjunction with a yo-yo. As shown by the data in Table II, a 42 inch segment of typical cloth tapes (satin; taffeta plaid) of widths between 28/32 inch and 31/32 inch cannot withstand a torque of 1.0 gram inch under a tension of 2.45 grams; whereas it requires a torque of 3 gram inch to cause collapse of grosgrain tape of similar dimensions (42 inches long; 15/16 inches wide). Similarly, a 42 inch length of twill tape or Mylar, each of 3/4 inch width, cannot withstand a torque of 0.70 gram inch when supporting a weight of 2.45 grams but a similar grosgrain tape (42 inches in length and 11/16 inches in width) can withstand a torque of 2.2 gram inch before its "spiral staircase" configuration collapses. Although all torsional resistance to twisting is important in connection with this inven¬ tion, it is most important that the tape not collapse since collapse of the tape during operation makes it nearly impossible to continue smooth yo-yo operation.

An embodiment of the present invention comprising a yo-yo body connected to a tape or ribbon support is illustrated in Figure 4. In this embodiment, discs 3 are positioned further apart from each other, leaving a wider groove 34 between the discs. A flat ribbon or tape 35, of width 36 is connected at one of its ends to the axle 2. The tape 35 is connected to the axle 2 in such a manner that when tape 35 is fully extended, the edges 37 of the tape 35 are perpendicular to the axle 2.

A fold 38 is placed at the other end of the tape 35 by folding the tape 35 over upon itself. This fold is maintained by sewing; weaving; stapling; gluing; etc. A loop 39 passes within the fold 38. A swivel system 40, containing one or more swivel mem¬ bers, is connected to the loop 39. The swivel sys¬ tem 40 allows for rotational motion of the support 39 and the attached tape 35 and yo-yo body 1. The swivel system 40 also facilitates the removal of twists from the tape 35, when the tape 35 becomes twisted about a vertical axis.

A ring 41, for holding the yo-yo is connected to the swivel system 40. The entire device may be held by the user by placing a finger through the ring 41.

The tape 35 may be comprised of a wide variety of flat elongated material, natural or synthetic. Among the materials of which the tape 35 may be constituted are leather, suede, felt, jute, hair, various types of skin, fiber glass, various cloth materials, such as wool, silk, cotton, linen, satin, velvet, carbon cloth, and/or synthetic plastics or polymers, such as polyester, polyethylene, polypropylene, polyolefins, nylon, acrylic, rayon, acetate, or various blends of the above-listed materials. The tape 35 may have parallel sides as shown within Figures 4, 5 and 6, or the sides of the tape 35 may be nonparallel. The tape 35 may have a woven texture or it may consist of a non-woven material. However, the inventor has dis¬ covered that grosgrain tape or ribbon is particularly well adapted for use in connection with the present invention. The essential feature is that the material can provide a tape of sufficient torsional resistance. Grosgrain tape is characterized by having a corrugated pattern with ridges and grooves normal to the sides 37 of the tape 35. This type of tape exhibits a signifi¬ cant resistance to twisting about its longitudinal axis, compared to most cloth tapes. Consequently, when the grosgrain tape is forcibly twisted, it has a strong tendency to become untwisted again. If, during operation of the yo-yo it is swung to the side, along a direction parallel to its axis 5-5, it will undergo a severe gyroscopic precession about the vertical axis. The twisting which is induced in the tape as a result of this precessional rotation is readily and rapidly undone by the propensity of the grosgrain tape to exist in an untwisted configuration. This untwist¬ ing is partially effected through the induced rotation of the yo-yo body 1 in the opposite direction to the twisting originally caused by the precession. More importantly, the swivel system 40 is very effective in relieving these twists, as a result of the torque caused by the twisted grosgrain tape. Another advan¬ tage of the grosgrain tape is its ability to remain straight along its width 36, and to resist wrinkling or warping along this dimension. Furthermore, if the tape is forced to become twisted about a vertical axis, resulting in the tape adopting a 'spiral stair¬ case' type of configuration, the corrugated lines still remain in horizontal alignment, thus maintaining the axle 2 of the yo-yo in a horizontal orientation.

Grosgrain tape is particularly effective for use with yo-yos. Of course, the other materials such as twill tape, Mylar, satin, plaid, etc., may become torsional resistant by increasing their thickness above the conventional values or through other modifi¬ cations of their structure or by treatment. The desirable feature of a tape for use in conjunction with a yo-yo is that it possess a significant degree of torsional resistance to twisting. Based on the data in Table II, a ribbon-type material suitable for use as a yo-yo tape should have the following charac¬ teristic torsional resistance to twisting: a 42 inch segment of material of width 15/16 inches, and under a tension of 2.45 grams, should withstand a torque of 1.0 gram inch or more without collapse of its "spiral staircase" configuration. A 42 inch segment of the material of width 11/16 inches, and under a tension of 2.45 grams, should withstand a torque of 0.70 gram inch or more without causing collapse of the "spiral staircase" configuration of the twisted tape. How¬ ever, the inventor has also established that when a swivel system is used in association with the toy, tapes of substantially lesser torsional resistance than those mentioned above may be employed.

The inventor has found that two features of the invention contribute to improved operational ability. The features are: (1) twist resistance of the yo-yo tape and (2) a swivel which releases any twisting which does occur. By testing various embodiments of the invention, the inventor has found that the best results are obtained using twist resistant tape in combination with a swivel. However, good results can also be obtained by using a twist resistant tape alone or by using a swivel in combination with a tape having no particular ability to resist twisting. More parti¬ cularly, the best results are obtained using a swivel in combination with a tape having a twist resistance such that a 42 inch segment with a width of 15/16 inches, and under a tension of 2.45 grams, can with¬ stand a torque of 1.0 gram inch or more without col¬ lapse. However, good results are obtained using such a tape without a swivel or by using a swivel in com¬ bination with a tape having a twist resistance such that a 42 inch segment with a width of 15/16 inches cannot withstand a torque of 1.0 gram inch without collapse. A swivel as referred to herein means any means which will allow for release of the twisting of the tape such as a conventional yo-yo string having very little torsional resistance itself.

The tape 35 may be anchored to the axle 2 by splitting the axle 2 in two along its length and inserting the tape 35 between the two halves of the axle. The tape 35 may be held in this position by gluing, wedging etc. Alternatively, the tape 35 may be looped about axle 2 in a sleeping mode. Figure 5 illustrates another sleeping modification of the invention. In this modification, a string segment 42, which is connected to tape 35, is looped about axle 2. The axle 2 contains a groove 43 in order to maintain the string segment 42 centrally located along the axle 2.

The string 42 (not used in place of swivel 40) may be comprised of any of a wide variety of string materials, natural or synthetic. The type of string most conventionally used in conjunction with yo-yos is

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OMPI laid; i.e., it consists of twisted strands. Laid string is particularly suitable for the situation where it must be doubled over to form a loop as in the axle of a sleeper yo-yo; the laid string twists about itself in two strands very effectively, to form a loop. This type of string is also very effective in connection with the present invention. However, other types of string, such as braided nylon or twine, hemp, cord, etc., may also be used in association with the present invention.

It should be pointed out that twist-resistant string such as metallic cord is particularly effective in connection with the present invention to connect the tape 35 to the axle 2, as illustrated in Figure 5, but not in place of swivel 40.

Another embodiment of the tape-cum-string combi¬ nation is illustrated in Figure 6, wherein the string 44 is looped about the axle 2; the string 44 enters one end 45 of tape 35 and exits at the opposite end 46. In this case, the tightness of the loop 33 about the axle 2 may be controlled as in the case of the conventional sleeper yo-yo.

In the case of a tape-supported yo-yo as illus¬ trated in Figure 4, the suspension of the axle 2 from the width 36 of the tape 35 further adds to the ease of operation of the toy. In addition, the wrapping of the tape 35 upon itself during operation of the toy leads to a smoother motion than in the case of the conventional string yo-yo, where the string piles on top of itself in a rather irregular manner, and which frequently collapses during the winding operation.

A further feature of the tape is that, during precession of the yo-yo body, the tape acts as a barrier or "sail" encountering significant atmospheric resistance and thereby serving to dissipate the pre¬ cessional rotational energy in the precessing yo-yo. A tape which resists collapse is desirable in this context also.

The use of a ribbon or tape 35 provides scope for introducing decorative and visual effects not possible with the conventional string yo-yo. For- example, writing, pictures or other colored designs and indicia may be imprinted on the tape; or the tape may be comprised of luminous or fluorescent material to further add to its attractiveness as a plaything. The tape-supported yo-yo of the present invention provides a dramatically different visual impact during opera¬ tion compared to the conventional string yo-yo.

The yo-yo of the present invention is operated in essentially the same manner as a conventional yo-yo. The string 32 (Fig. 3) or tape 35 (Fig. 4), or tape- cum-string 35 + 42 (Fig. 5) may be wound around the axle 2 of the yo-yo simply wrapping it by hand. In the case of a sleeper, the loop 33 must be suffi¬ ciently tight to "catch" on the axle 2 during winding. To initiate operation of the yo-yo, the body 1 of the yo-yo may be held in one hand and the end of the string 32 or the tape 35 or the holding ring 41 may be held in the other hand. The body 1 of the yo-yo is allowed to fall free while still holding one end of the string 32 or of the tape 35 or ring 41. As the body 1 of the yo-yo falls under the influence of gravity, the body 1 is forced to rotate about its axle 2, with consequent unwrapping of the twist- resistant support from around the axle 2. When the twist-resistant support has become completely unwound, the body 1 of the yo-yo has acquired considerable angular momentum. In the case where the support is anchored to the axle, this angular momentum forces the body 1 of the yo-yo to continue rotating, thus winding the support about the axle 2 in the opposite sense to the manner in which it was wrapped around the axle

PI during the previous downward swing. Consequently, the body 1 of the yo-yo is forced to rise upward again. A gentle upward impulse applied to the support just prior to the yo-yo body 1 reaching the bottom-most part of its swing, allows the up-down oscillation of the yo-yo body 1 to continue indefinitely. This applied impulse compensates for both frictional loss of energy and dissipation of the translational compo¬ nent of the energy which occurs as the bottom of the yo-yo swing, when the body 1 of the yo-yo is forced to change the direction of its translational motion.

In the case of a sleeper, where the axle 2 lies in the loop 33 of the string or tape, the rotational momentum of the yo-yo body 1 at the bottom of its swing allows the yo-yo to continue rotating in this position, i.e., sleep, until its rotational kinetic energy is dissipated by friction. However, if the rotating yo-yo is brought out of its sleep, the yo-yo body 1 will again travel up along the support, the distance of rise depending on the amount of rotational kinetic energy remaining in the yo-yo. The rotating yo-yo may be brought out of its sleep by jerking the support, or alternatively, by relaxing the tension in the support.

The most advantageous feature of the present yo-yo compared to the conventional yo-yos and prior modifications thereof, is its facility to recover, even after experiencing gyroscopic precession. For example, if during operation of the yo-yo it is swung sideways, that is, in a direction parallel to the yo-yo axis 5-5, it experiences a gyroscopic precession about a vertical axis; this behavior is common to all yo-yos and generally results in total loss of control over the yo-yo motion. However, in the case of the yo-yo of the present invention, the twist-resistant support, in conjunction with the swivel system, coun¬ teracts the precessional rotation and the problem is rapidly and automatically eliminated.

It is possible to fabricate the body 1 of the yo-yo from a variety of materials, such as wood; plastic, metal; rubber composite, etc. The body 1 of the yo-yo could be molded or turned as one complete unit, or the disc 4 and axle 2 portions could be made separately and then fastened together, by various means, including but not limited to gluing; screwing; wedging; soldering; welding; etc. The axle 2 may or may not contain the groove 43.

One of the modifications incorporating a twist- resistant string which the inventor found to work effectively employs two discs, each of 57 millimeters diameter and separated from each other by 2.5 milli¬ meters by means of an axle of 6 millimeter diameter. The string consists of a 102 centimeters length of metallic cord, manufactured by KNITRIMS of Miami (2431 N.W. 2nd Avenue, Miami, Florida 33127), and is an¬ chored to the axle by wedging one end of it between the axle and one of the discs during assembly of the yo-yo. These yo-yos also work effectively when sus¬ pended from a swivel system (consisting of fisherman's swivels) and a holding ring.

In the case of a tape-supported yo-yo, the inven¬ tor has found that a tape width of 16 millimeters works particularly well when the tape is composed of grosgrain polyester, and connected to an axle having a diameter of 6 millimeters, which is in turn connected to discs having diameters of 52 millimeters. A swivel system is connected to the other end of the tape and a holding ring is attached to the swivel system.

When the yo-yo is assembled by inserting the tape between two axle halves, the circumference of the axle may be slightly elliptical rather than circular; this effect is desirable as it tends to compensate for the bulge occurring where the tape exits from the axle, thereby leading to a smoother operation of the yo-yo. The instant invention is shown and described in what is considered to be the most practical and pre¬ ferred embodiment. It is recognized, however, that departures may be made therefrom, which are within the scope of the invention, and that obvious modifications will occur to one skilled in the art upon reading this disclosure.

Claims

1. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, comprising: an axle; a first disc connected at a center point to said axle; a second disc connected at a center point to said axle; a twist-resistant support connected at one end to said axle at a position between said first disc and said second disc.

2. A toy capable of combined rotational motion about a horiziontal axis and translational motion in a vertical direction, as claimed in claim 1, wherein said support is connected to said axle by looping said support about said axle.

3. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 1, wherein said support is connected to said axle by firmly anchoring said one end of said support to said axle.

4. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 1, wherein said support is connected to said axle by means of a string connected to said one end of said support with said string looped about said axle.

5. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in any of claims 1, 2, 3 or 4, wherein said support is comprised of a twist- resistant string.

6. A toy capable of combined rotational motion about a horizontal axis and translational motion in a

OMPf vertical direction, as claimed in any of claims 1, 2, 3 or 4 wherein said support is comprised of a twist- resistant chain.

7. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in any of claims 1, 2, 3 or 4 wherein said support is comprised of a metallic cord.

8. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in any of claims 1, 2, 3 or 4, wherein said support is comprised of a tape.

9. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 8, wherein said tape is a grosgrain tape.

10. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in any of claims 1, 2, 3 or 4 further comprising: a swivel means connected to the other end of said support.

11. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 10 further comprising: a ring for holding the toy attached to said swivel means.

12. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 5, wherein said twist-resistant string has a twist-resistance such that a length of said twist-resistant string of about 40 inches, supporting a weight of about 30 grams, will undergo 40 revolutions of twisting or less when subjected to a torque of 0.5 gram inch.

13. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 5, wherein said twist-resistant string has a twist-resistance such that a length of said twist-resistant-string of about 40 inches, supporting a weight of about 50 grams, will undergo 25 revolutions of twisting or less when subjected to a torque of about 0.25 gram inch.

14. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 13, wherein said twist-resistant string will undergo 10 revolu¬ tions or less when subjected to a torque of 0.25 gram inch.

15. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 12, wherein said twist-resistant string will undergo 15 revolu¬ tions of twisting or less.,when subjected to a torque of 0.5 gram inch.

16. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction as claimed in claim 8, wherein said tape has a twist-resistance such that about a 42 inch segment with a width of about 15/16 inches, and sus¬ taining a suspended weight of about 2.5 grams, can withstand a torque of 1.0 gram inch or more without collapse.

17. A toy as claimed in claim 16 further com¬ prising a swivel connected to the other end of said tape.

18. A toy capable of combined rotational motion about a horizontal axis and translational motion in a vertical direction, as claimed in claim 4, wherein said string enters one end of said tape and exits another end of said tape.

19. A toy capable of combined rotational and translational motion substantially as shown and des¬ cribed herein.