US 3581353 A
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Description (OCR text may contain errors)
une 1,1971 R. I. SONNTAG TIP FOR SHOELACES Filed March a. 1970 INVENTOR RALPH I. SONNTAG ATTORNEY United States Patent O US. Cl. 24143 9 Claims ABSTRACT OF THE DISCLOSURE A tip attachable to a shoelace merely by heating with a match, the tip being made of heat shrinkable plastic tubing bearing normally dry, heat reactivated adhesive on the inner surface thereof. Alternatively, the adhesive can be pre-applied to the shoelace material,
SPECIFICATION This application is a continuation-in-part of patent application Ser. No. 843,963, filed July 23, 1969 and now abandoned.
BACKGROUND OF THE INVENTION (1) Field of the invention The present invention relates generally to shoelace tips, and in particular to a tip that can be easily and permanently attached to a shoelace or the like merely by heating the same in place on the lace.
(2) Description of the prior art Shoelaces are most commonly factory made in specific lengths, and the ends of each lace are tipped at the factory with metal or a plastic material so that they will not fray and can be easily threaded through shoe eyelets. The style of a shoe usually determines the length of shoelace required, and the shoelace color normally matches that of the pair of shoes with which the laces are to be used. Since many people own several pairs of shoes of differing styles and colors, several different colors and lengths of shoelaces may be used by the average person.
Probably everyone has experienced having a shoelace break. When this occurs, the search in the average home or oflice for a replacement of the right size and color frequently proves fruitless. Therefore, it would be convenient at such times if a kit were available whereby the person could himself make a replacement shoelace.
There are also instances where odd size shoelaces not readily available commercially are required. For exam ple, athletic personnel sometimes have a problem finding shoelaces of the desired length and color. It thus would be a convenience if a kit were available whereby persons with such difiiculties could make shoelaces to their own specifications,
Woven fabric shoelace material can be easily obtained in bulk, and it is an easy matter to cut a length of lace from a reel of such material. The problem has been how to place tips on the cut length, or more precisely how to provide tips that an unskilled person can easily and quickly permanently attach to the lace. While sug gestions for at home or in the office installed tips have been advanced, to date none has enjoyed general acceptance and commercial success. Usually, this is either because the available tips are too hard to install, or because they produce an unsightly and generally unsatisfactory shoelace.
A novel approach to the problem of easily installed shoelace tips was suggested by US. Pat. 3,330,011, which proposes using modern heat shrinkable plastic tubing for ice making shoelace tips. The patent lists several heat shrinkable plastics that can be utilized, but for reasons of practicality, polyvinylchloride would in most instances be utilized, since it sells for less than one-half the price of the other heat shrinkable plastics listed. While the concept of the patent in theory has merit, in actual practice the present inventor has found that when polyvinylchloride heat shrinkable plastic tubing alone is used for shoelace tips, the tips frequently are not sufiiciently fastened to the shoelace. In fact, when used with a shoelace made of resiliently crushable, bulky cotton or synthetic woven fabric such tips can be easily removed merely by a gentle pull.
Fabric shoelaces of the resiliently crushable type are the most common in use today. Thus, since tips are needed on a shoelace to easily pass the ends thereof through the eyelets of a shoe, a tip which can be easily removed from the lace is simply unsatisfactory,
The applicant herein believes that the reason why polyvinylchloride plastic tips such as are described by U.S. Pat. 3,330,011 are not better secured to resiliently crushable shoelaces is the nature of the conflicting forces involved. As is clearly set out in said patent, heat shrinkable plastics are made by first expanding them, and then subjecting them to radiation to temporarily fix them in an expanded state. When they are subsequently heated, they return toward their original dimensions because of internal forces.
When heat shrinkable plastic tubing is placed about a wire or other relatively rigid member of adequate dimension, upon heating the tubing shrinks against the surface of such member. The rigid member sets up no opposing forces that act on the shrinking tubing. The applicant believes this is not the case when working with resiliently crushable fabric shoelaces.
When a piece of heat shrinkable plastic tubing is placed about the end of a fabric shoelace of the resiliently crushable type and heated, it seeks to return toward its original unexpanded size. However, in the process of shrinking it begins to crush the shoelace, which being somewhat resilient causes the setting up of forces opposing the shrinking tubing. The forces generated by the shoelace become progressively greater as the tubing progressively shrinks and crushes the resilient shoelace material, and finally a balance of forces occurs that stops further constrictive movement of the tubing. The result is that the tip does not obtain a firm grip on the shoelace, and the tip can thus later be pulled off.
The present invention utilizes heat shrinkable plastic tubing for making a shoelace tip, but resolves the problem of having such a tip become firmly and permanently attached to the lace during the shrinking process.
SUMMARY OF THE INVENTION In the present invention a length of heat shrinkable plastic tubing is utilized to make a shoelace tip, but not alone as in the above cited patent. Rather, in a first embodiment of the invention the interior surface of the length of tubing bears a normally dry, heat reactivated adhesive. The length of tubing is threaded onto a length of shoelace material, and when installation thereof to form a tip is desired, the length of tubing is merely heated gently with a common match.
The heat from a match will cause the plastic tubing material to begin shrinking, and at the same time will reactivate the normally dry heat sensitive adhesive, rendering it tacky. The tubing continues to shrink, crushing the resilient material of the shoelace and engaging the tacky adhesive therewith, until a balance of forces between the compressed shoelace material and the shrinking tubing has been reached. Shrinking then ceases and the tubing is allowed to cool, which stabilizes the tubing and causes the adhesive to again set up.
The result is a plastic shoelace tip that is very neat in appearance, and which cannot be removed from the sho..- lace. The degree to which the tubing shrinks, and hence the final diameter of the tip, is of course dependent upon the resilience and body of the shoelace material. But so long as enough shrinkage occurs to engage the tacky adhesive with the shoelace material, a permanently attached tip is produced. Obviously, little or no skill is required to make a tip with the invention, and heating can be achieved by other means than a match.
In another embodiment of the invention the heat reactivated adhesive is pre-applied to the lace material, and allowed to dry. The plastic tips are thereafter positioned on the lace and heated, with results substantially the same as when the adhesive is placed within the tubing.
It is the principal object of the present invention to provide a shoelace tip that can be quickly and permanently installed on a shoelace by anyone, utilizing a minimum of skill.
A further object is to provide a shoelace tip utilizing heat shrinkable plastic, and which becomes permanently attached to the shoelace.
Another object is to provide a shoelace kit that can be utilized by anyone to easily make shoelaces of any desired length.
Other objects and many of the attendant advantages of the invention will become readily apparent from the following description of the preferred embodiments, when taken in conjunction with the accompanying drawings.
7 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of the shoelace kit of the invention, showing a length of shoelace material with a plurality of expanded tips thereon, and showing how the material is laid out against a broken shoelace in the process of making a replacement lace;
FIG. 2 shows one of the expanded tips of FIG. 1 in place on a shoelace, and being heated with a match;
FIG. 3 shows the lace and tip of FIG. 2, after the tip has completed shrinking and cooled;
FIG. 4 is a greatly enlarged cross-sectional view of the lace and tip of FIG. 3, taken on the line 4-4; and
FIG. 5 is an elevational view showing how the tip of the invention can be utilized to make a decorative tip on a shoelace.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, the shoelace kit of the invention is indicated generally at 10 and includes a spool of shoelace material 12 having a plurality of short tubing lengths or sleeves 14 slidably received thereon, each sleeve 14 comprising an expanded shoelace tip. While the shoelace material 12 can be of nearly any suitable material, commonly it will comprise woven cotton or synthetic fabric, and as such will be resiliently crushable. Commonly, the shoelace material 12 will be woven in a tubular form, which is then flattened.
A shoelace can be made with the kit 10 by first measuring out the desired length of material 12. When a replacement lace is being made, the two halves of the old lace can be used for this purpose. In FIG. 1 such an old lace is shown at 16, the lace being broken at 18. Obviously, a ruler or the like can be used to measure a precise length of lace material 12, if desired.
After laying out the length of lace material 12 desired in FIG. 1, a pair of sleeves 14 is slid onto the selected lace portion. The selected length of lace material is then severed from the spool, say at 22, after which the sleeves 14 are slid into the desired position at the ends of the lace length 12.
The sleeves 14 are made of a heat shrinkable plastic, preferably polyvinylchloride because of its economy and easy availability. However, any of the plastics listed in said US. Pat. 3,330,011 can be utilized, if desired. Polyvinylchloride can be commercially obtained as a heat shrinkable in several colors or clear. Typically, a piece of such tubing with an expanded internal diameter of about 0.125 inch will, when heated and shrunk in such a manner that it may fully shrink to its unexpanded or recovered dimensions, have an internal diameter of about 0.062 inch.
The sleeves 14 are cut to the desired length from a long length of tubing. For ease of handling and installation on the lace material 12, if desired the sleeves 14 can be only partially severed from each other until the time of final installation, when final severing can be done. The interior surface of each sleeve 14 bears a normally dry, heat reactivated adhesive, which can simply comprise a coating 26 of the adhesive applied to the inner surface of the sleeves 14 and allowed to dry prior to assembly of said sections on the lace material 12. The manner in which the heat sensitive adhesive is applied to the sleeves 14 is immaterial, except that the adhesive material must be normally dry for slidability of the sleeves 14 on the lace material 12.
A choice is available as to the heat reactivated adhesive 26 to be used. However, the applicant has found that one such adhesive perfectly suitable for use with heat shrinkable polyvinylchloride tubing in practicing the invention is the product known commercially as Cascobond SA5461, a synthetic resin solution having a ketone odor when wet and a normal viscosity of 4,000-6,000 cps., Brookfield, manufactured by Borden, Inc/Chemical Division, New York, NY. This synthetic resin drys readily and remains dry under normal conditions, but will become tacky and reactivated when submitted to the heat of a match. Moreover, it is especially designed to bond fabric to plastic. The invention is not to be limited to this adhesive material, however, for others of the commercially available, normally dry, heat reactivated adhesives will also give satisfactory results.
After the heat shrinkable sleeves 14, bearing the heat reactivated adhesive on their interior surface, are in place on the lace material 12, a match 24 is struck and held therebelow as in FIG. 2, the material 12 and the sleeve 14 being held a distance above the lit match 24 and being slowly rolled between the fingers to provide for gentle, even heating of the sleeve 14. Obviously, another heating method, such as immersion, could be used if desired.
As the expanded sleeve 14 and the adhesive coating 26 approach design temperature, the heat shrinkable plastic begins to shrink and the adhesive is reactivated and turns tacky. The sleeve or tip 14 proceeds to shrink and thereby compresses the resilient material of the lace 12, engaging the tacky adhesive therewith and producing a tip 14 of reduced diameter (FIG. 3). When the contractive forces of the sleeve or tip 14 are balanced by the forces generated Within the resiliently compressible material 12, shrinking of the tip 14 ceases and heating thereof is stopped. The tip 14 is then allowed to cool, producing the completed structure shown in FIGS. 3 and 4.
As is best shown in FIG. 4, when cooling of the tip 14 is completed the result is a substantially rigid plastic tip of reduced diameter which reduces the diameter of the end of the lace material 12, and which is permanently secured to the lace material 12 by the now reset adhesive 26. The tip as shown in FIGS. 3 and 4 has been repeatedly found to be permanently attached, regardless of the particular type or dimensions of the lace material 12 employed. Thus, an easily usable shoelace tip that completely fulfills the objects of the invention has been provided.
It must be specifically pointed out that the coating 26 actually bonds or adheres the tip 14 to the lace 12. This is totally different from the results obtained with the plastic sleeves 14 without the coating 26. In the latter case the inner surface of a tip is, of course, softened by the heat, and in this state can become embedded in the fabric fibers, where it then hardens upon cooling. However, the plastic does not actually adhere to the fabric lace, and because the latter is not tightly compressed, the tip can be pulled off. In the present invention, the tip 14 is actually bonded to the lace 12, by the adhesive 26, whereby it is permanently attached and cannot be removed.
In another embodiment of the invention the heat sensitive adhesive is placed on the lace material rather than within the heat shrinkable tubing. T 0 practice this embodiment the adhesive is thinned, and is then sprayed on or otherwise applied to the total length or selected portions of the lace material. The adhesive is then allowed to dry, after which short lengths of uncoated heat shrinkable tubing are threaded thereon.
When it is desired to form a shoelace tip, the same steps as outlined hereinabove are followed. The tip is slid to the proper place on the lace, which'is coated with the dry adhesive, and heat is applied. The heat shrinks the plastic and re-activates the dry adhesive, and after cooling a tip is obtained that is comparable in structure to that produced by placing the adhesive within the tubing sections. The Cascobond SA-5461 adhesive identified earlier is ideally suited for use with this embodiment of the in- \vention, the presence thereof on the lace material being substantially undetectable by the naked eye, and the coated lace retaining essentially the same physical characteristics as before being coated.
The invention can also be utilized to produce ornamental laces, as in FIG. 5, wherein the tip 14 is secured to the lace material 12 at a distance from the end thereof. The material 28 beyond the tip 14 is then unravelled, to provide a decorative lace end.
Utilizing the shoelace kit of the invention, with the novel tip 14, anyone can make shoelaces to his own description. For home use lengths of brown and black lace material with several tips slidably mounted thereon can be sold, which will enable the purchaser to make his own replacement laces. For those who want variety, lace material and tips in several varying colors can be made available. Athletic departments can buy spools of lace material and prepared tips 14, and make their own laces.
For use by athletic departments, and others, a special method of packaging the invention can be m st useful. In this concept a reel or spool of shoelace material several hundred feet in length is provided with pairs of tips, spaced every three feet or so, the shoelace material with the spaced tips thereon then being wound on the spool. An athletic coach or manager can then carry such a spool directly to the playing field or gymnasium, where replacement of laces in any size can be easily made. The lace material is merely unwound from the spool, the length needed severed, and the pairs of tips slid into position and installed.
Obviously, many modifications and variations of the invention are possible.
1. A tip for use on a shoelace to prevent fraying and to ease threading of the shoelace through eyelets, comprising: a heat shrinkable plastic sleeve adapted to fit about Said shoelace, the interior surface of said sleeve incorporating a normally dry, heat reactivated adhesive.
2. A tip as recited in claim 1, wherein said sleeve is made of heat shrinkable polyvinylchloride.
3. A tip as recited in claim 1,. wherein the interior surface of said sleeve is coated with said adhesive.
4. In combination, a shoelace made of resiliently crushable woven fabric; and a tip for said shoelace, comprising: a heat shrinkable plastic sleeve received on said shoelace, one of the interior surface of said sleeve or the surface of said shoelace carrying a normally dry, heat reactivated adhesive, said sleeve in its expanded state having an internal diameter such that it can be easily slid along said shoelace.
5. The combination as recited in claim 4, wherein the interior of said sleeve is coated with said adhesive.
6. The combination as recited in claim 4, wherein the surface of said shoelace is coated with said adhesive.
7. In combination, a shoelace made of resiliently crushable woven fabric; and a tip for said! shoelace, comprising: a sleeve made of heat shrinkable plastic, said sleeve being shrunk about and somewhat compressing said shoelace, the interior of said sleeve bearing a heat reactivated adhesive bonding said sleeve to said fabric shoelace.
8. In combination, a shoelace made of resiliently crushable woven fabric; and a tip for said shoelace, comprising: a sleeve made of heat shrinkable plastic, said sleeve being shrunk about and somewhat compressing said shoelace, there being a coating of heat reactivated adhesive on said fabric shoelace bonding said sleeve to said shoelace.
9. In combination, a spool; a shoelace several feet in length wound on said spool, and made of resiliently crushable woven fabric; and a plurality of tips arranged in spaced pairs on said shoelace, each of said tips comprising: a heat shrinkable plastic sleeve slidably received on said shoelace, one of the interior surface of said sleeve or the surface of said shoelace carrying a normally dry, heat reactivated adhesive, said sleeve in its expanded state having an internal diameter such that it can be easily slid along said shoelace.
References Cited UNITED STATES PATENTS 761,963 6/1904 Hiller 24143 2,145,476 l/l939 Dennis 24143 3,330,011 7/1967 Michael 24143 DONALD A. GRIFFIN, Primary Examiner