US20030181301A1

US20030181301A1 - Exercise loop hoop and toy

Info

Publication number: US20030181301A1
Application number: US10/102,713
Authority: US
Inventors: Roger Walsh
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-03-22
Filing date: 2002-03-22
Publication date: 2003-09-25

Abstract

An exercise/play loop is formed from a strap of predetermined length, cross-section, strength and extensibility, being selected from polyolefin and polyurethane elastomers and rubber, with a cross-section having a width to thickness ratio greater than five, and having the elastic extensibility of the loop limited to about 100%. A polyurethane elastomer is selected from the group consisting of polyester and polyether urethanes whch may be extruded and mechanically conditioned to provide a modified molecular structure of enhanced elasticity and reduced plasticity, having tensile strength of up to about 6,000 lbs per square inch. The polyolefin elastomers have a hardness number of at least about Shore 80. The ends of the plastic strap are thermally welded to each other, to form the loop. A method of mechanically enhancing the plastics is given.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO MICROFICHE APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

1. This invention is directed to an exercise belt and toy, and in particular to a simple oversize flexible loop, preferably of strong plastic for use both in exercising and as a play toy.

2. The modem combination of fast foods and extensive television watching, combined with the extreme professionalism of most sports has led to generations of children who are unused to playing physical games, and who have lost in some measure the fitness traditionally associated with the young.

The use of plastics in items for outdoor use has encountered problems associated with exposure to sunlight, the increasing concentration of ultraviolet (uv) rays leading to somewhat rapid out-door degradation of many of the plastics materials presently in use.

BRIEF SUMMARY OF THE INVENTION

I have found that a large flexible loop of high strength, preferably a urethane or a plastic elastomer can serve as an individual or a group exercise belt, and as a play toy, with a variety of uses. Such may include tug-of-war, both indoors and out of doors, use as a tree swing, and many other imaginative uses

The subject loops may be made from a suitable length of flexible elastomeric strapping, having the ends secured to form the loop.

In work carried out in developing high strength tie-down, load restraint plastic straps of linear form it was found that the undue plastic extension of a length of plastic, which in its “natural” extruded state might, under load, be as much as 300% of its original length, could be significantly modified. By mechanically treating an extruded strap, so as to plastically stretch it to about 250% of its original length, the resultant molecular alignment orientation produces a stiffer, stronger and more elastic belt, having the stretchability limited to about 100 percent when used within a predetermined load limit.

When formed into a loop large enough to contain a number of individuals such as three or four children or even adults, such a belt serves admirably as a cooperative toy or exercise medium, wherein the occupants can cooperatively manipulate the loop in mutual exercising relation.

A strap having a width of about one and a quarter to two inches (1¼″-2″) in a suitable length has the ends joined to form a loop. In the case of thermoplastics, a lap joint by hot-air welding is suitable in most instances. In the case of rubber, if used, it is necessary to first vulcanize the surface area being joined.

A ten foot length forms a loop suitable for two people to play in; a fifteen foot length forms a loop that can accommodate four people. A buckle may be used to form the loop, having the advantage of adjustability, and the disadvantage of potential impact, abrasion or entanglement.

In the case of thermoplastics, the loop thus formed may be of non-toxic, food-quality plastic such as a polyurethane, which does not discolour the skin or clothes of a user. The nature of many plastics is such that in a “raw” extruded state the extensibility is excessive, amounting to elongation by as much as six hundred percent. By reducing the extensibility of the product to about 100%, by means of a mechanical conditioning process, a high yield strength can be achieved, enabling an extremely light and strong strap to be made.

Securing the two ends of a selected length of the conditioned plastic, by welding or other secure attachment means readily forms a loop of desired size.

In one load strap embodiment, food-grade polyurethane, Dow 2123 90A “Pellethane” (T.M.) was extruded through a die, being drawn out by a drawing nip and then subjected to tensioning rolls running at a higher speed, to draw out the still-warm extruded strap by possibly as much as about 250% elongation. This resulted in a stiffer, stronger strap of reduced mass and cross-section, having a tensile strength in the order of about 6,000 pounds per square inch. In comparison, a rubber strap of equal strength is about five times heavier.

In another thermoplastic embodiment a Dow polyolefin elastomer Engage (T.M.) 8480 Grade # 8003, provides a strap having a developed tensile strength of about 7,000 psi (pound per square inch of cross section), having a hardness of Shore 86 and density of 0.885 gms/cu. cm.

In contrast to the plastics, a rubber strap of corresponding strength is characterized by significantly greater tensile stiffness, and is more likely to soil the hands and clothes of the users.

The polyurethane material of such a loop hoop has a most desirable quality, a natural resistance to ultraviolet degradation. Thus, unlike the case of many plastic toys when left lying around out of doors, the structural strength of the polyurethane loop is not significantly adversely affected by sunlight, thus suiting it for outdoor use.

Straps having sections such as two inches width by fifty five mil (0.055 inches); one and one half inches width by seventy mil (0.070 inches), or three quarters of an inch by one hundred and forty mil are readily made of polyurethane.

These straps have a load capacity in the order of about six hundred pounds.

In the case of polyolefin straps, or non-oriented urethane straps, greater cross-sectional mass is required in order to provide the desired tensile strength for the play/exercise loop.

The universality of the flexible loop, as a play/exercise loop for all ages is cause for providing a wide range of loops, wherein smaller loops for smaller users such as young children have correspondingly reduced tensile stiffness, such that the elastic stretching of the loop is somewhat proportional to the weight and strength of the user.

Thus the present invention provides a closed, elastically extensible exercise/play loop of substantially uniform cross section, of material selected from the group consisting of polyurethanes, polyolefins and rubbers.

In the case of polyurethanes, the thermosetting polyester and polyether urethanes have particular value in that they are FDA-approved as being of food-grade utility, i.e. nontoxic, and are susceptible to mechanical conditioning for enhanced elastic strength and diminished plastic extensibility, with tensile strength of up to about 6,000 1b/sq. inch.

For the polyolefin thermosetting elastomers, which are also extrudable, these have extensibility of up to about one hundred percent, and tensile strength in the range of about six thousand to seven thousand pounds per square inch. This portion of the group of elastomers have a Shore hardness of about eighty and greater.

The invention also provides a process for manufacturing a high strength elastic strap of controlled extensibility, comprising the steps of extruding a selected thermoplastic through a die; drawing the extruded plastic through a draw-off nip running at a first speed; passing the extruded strap through a tensioning nip running at a speed significantly higher than the first speed, whereby the strap is significantly elongated, and the elastic stiffness is increased.

The selection of the plastic material has a further advantage that it is initially clear, so that colour can be readily added at an initial milling stage, prior to extrusion. Thus hoop straps may be clear, semi-clear or coloured, and in colour finishes that are fast, and not subject to rub-off.

The adoption of food-grade plastic has a major advantage where young children are concerned, where the introduction of such a strap into the mouth of a child poses no problem in terms of toxicity.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Certain embodiments of the invention are described by way of illustration, without limitation thereto other than as set forth in the accompanying claims, reference being made to the accompanying drawings, wherein: [0029]
FIG. 1 is a side view of an extrusion and tension-drawing conditioning process for the subject product; [0030]
FIG. 2 is a perspective view of a loop belt in accordance with the present invention; [0031]
FIG. 3 is a schematic perspective view illustrating use of a subject loop belt by a group of individuals; and, [0032]
FIG. 4 is a table listing a range of characteristics of thermoplastic belts and users.[0033]

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows [0034] apparatus 10 for carrying out the process. A cross-head feeder 12 connects with a die nozzle 14, by which an extruded strapping 15 of thermoplastic is passed.
A pair of [0035] nip rolls 16 assist in drawing the continuous strapping 15 from the nozzle 14.
A second pair of [0036] rolls 18, operating at higher peripheral speed than the rolls 16 further tensions and elongates the strapping 15, which is stored on roll 20.
A [0037] loop belt 22 is shown (not to scale) in FIG. 2, being illustrated with a weld zone 23.
FIG. 3 shows a circle of young individuals having a [0038] loop belt 22 in encompassing tensioned relation about them.
The subject process, as carried out by the [0039] apparatus 10, comprises extruding thermoplastic by way of feeder 12 and extrusion nozzle 14.
A typical extrusion melt temperature is in the range 350-550 F. degrees (175-290 C.) [0040]
Passage of the [0041] extruded section 15 is assisted by nip rolls 16, the peripheral speed of which slightly exceeds the rate of extrusion of the nozzle 14, to thereby draw down and tension the section 15.
This results in moderate elongation of the extrudate, and a corresponding diminution in its cross-section. [0042]
The second pair of tensioning rolls [0043] 18 operate at a significantly higher peripheral speed than the rolls 16, thereby further drawing-down the profile of the extrudate 15, while tensioning it further and elongating it correspondingly, while forming a stronger belting.
The [0044] storage roll 20 operates at a speed sufficient to receive and store the linear, drawn-down belting under a slight tension.
In FIG. 2, a cut length of belting [0045] 15 has its ends welded to form a loop hoop 22.
FIG. 3 shows a ring of five individuals having a [0046] loop hoop 22 around them, serving to enclose them. In the disclosed embodimant, having a breaking strength of about 600 pounds, the loop hoop 22 stretches readily under their load to as much as twice its length, while affording effective support against which the users can lean, and with which they can manoever one another.
FIG. 4 displays the approximate physical characteristics of a family of belts, with belt widths; belt thickness in {fraction (1/1000)}ths of an inch (mils); the length of belting from which the loop is made; the number of intended users; the range in weight for the individual users; the material selection, polyurethane or polyolefin; and the weight of the belt. [0047]
It will be understood that in order to convey an appropriate feeling of “give”, longer belts may be made stiffer, by way of a thicker section, to avoid an impression of undue extension under normal play conditions. [0048]
Owing to the extreme extensibilty of the plastic material when stretched beyond the elastic regime, such that plastic extension takes place, determination of the ultimate breaking load for the respective belts was not readily determined. Such plastic extension being frequently in excess of 300% generally serves as adequate warning that a belt is being overstressed, and that failure is to be expected. [0049]

Claims

1. An exercise/play loop formed from a strap of predetermined length, cross-section, strength and extensibility, of material selected from the group consisting of polyolefin and polyurethane elastomers and rubber, said predetermined cross-section having a width to thickness ratio greater than five, and having the elastic extensibility of the loop limited to about 100%.

2. The loop as set forth in claim 1, wherein said polyurethane elastomer is selected from the group consisting of polyester and polyether urethanes.

3. The loop as set forth in claim 2, wherein said elastomer is extruded and mechanically conditioned to provide a modified molecular structure of enhanced elasticity and reduced plasticity, having tensile strength of up to about 6,000 lbs per square inch.

4. The loop as set forth in claim 1, wherein said material consists of polyolefin elastomer having a hardness number of at least about Shore 80.

5. The loop as set forth in claim 1, wherein said material consists of rubber.

6. The loop as set forth in claim 5, wherein said rubber consists of synthetic rubber.

7. The loop as set forth in claim 5, wherein said rubber consists of natural rubber.

8. The loop as set forth in claim 1, wherein the ends of said strap are thermally welded to each other, to form said loop.

9. The loop as set forth in claim 5, wherein the ends of said strap are vulcanized, prior to being secured to each other.

10. A large flexible, high strength exercise/play loop of thermoplastic selected from the group consisting of polyolefins and polyurethanes, having a thickness in the range of 40 to 70 mils, a width of one to two inches, and a strap length of from 72 to 96 inches.

11. The method of reducing the extensibility of a thermoplastic strap, consisting of the steps of extruding the strap at a predetermined first rate, drawing-off the extruded strap at a second rate slightly in excess of the first rate, tensioning the strap through a tensioning nip operating at a third rate in excess of 100% higher than said second rate, whereby the tensile strength of said strap is significantly increased, and its propensity for plastic yield extensibility is substantially reduced.

12. The method as set forth in claim 11, wherein said third rate is as high as about 250% of said second rate

13. The method as set forth in claim 12, including winding said strap on a drum, under a light tension.