US2023673A - Tennis ball cover - Google Patents

Description

Deco 1Q, 1935. [3 w 2,023,673

TENNI 5 BALL COVER Filed March 22, 1954 INVENTOR [Ma/4r W. ELL/5 ATTORNEYS necessary to render the composite fabric as a heavily felted woolen fabric having both sides with a thick napped surface. 7

The hard spun yarn 5 in the felted fabric retains its form with much less spreading of fiber over the felted portion than the soft spun yarn 4.

And this is desirable because the yarn 5 with its hard twist is designed not only to give a' roughened surface to the ball (except as the surface is smoothed up by a heavy nap) but also to make such roughened surface a long wearing surface V;

which hard spun yarn will do. The arrangement is also desirable with respect to yarn 4, because the body fabric of this yarn is on the'side cemented to the ball. What there is left of the tightly woven body fabric (after fulling and spreading its fibers to make the felted component) is held down against the ball by the ocment which, in addition to the tight weave, givessheets with my preferred arrangement of yarns and felted fibers all positioned to work together in resisting the wear on the ball.

The composite fabricpreferably made as described is formed and attached to the ball to give it the improved cover construction. The body sheet of yarn 4 is on the bottom next to the ball, see Fig. 6 inwhich the rubber ball component is R and the cement S. The wearing sheet of yarn 5 is on top of the body sheet and anchored into the body by the tie-ins I (see Fig. 8) of the composite weave, by the felted fiber F (Fig. 8)fillingall the interstices of the composite weave, and by the fact that all these components have been through a big shrinkage operation to lock them in their relative positions (as indicated generally by the detail of .the surface shown in Fig. 1; the same surface, of course, extends all over the ball). 7

After this has been done and the tennis ball is ready for play, I have found by actual practice that the wear on the ball normally proceeds as follows: The original nap is worn off. The peaks of. the crosses C are uncovered and provide wearing pimples all over the face of the ball. These pimples are gradually worn down and while they are wearing down nap is gradually supplied for the surface of the ball from the concavities or valleys between the pimples, as can be readily appreciated from enlarged view Fig. 8. The top bar of each cross wears out. This makes broken ends of yarn 5. Such ends are opposite ends of the small lengths of yarn 5 originally divided to make the top bar of the crosses. These short lengths are tied tightly at 1 into the body fabric. When broken through at the centers (which are highand take the wear first) such short lengths are up-ended and present little tufts over the surface of the ball. Such tufts are still anchored into the body fabric and the broken ends are not long enough (see proportions of Fig. 1) to give an unraveled or loose end appearance to the'ball surface. The tufts are distributed with enough frequency all over the surface of the ball thatthey do not give a w ornout appearance to the ball. On the contrary the surface of the ball is given a good nap condition and appearance, with assurance of continued life in the ball. The under bars of the crosses are worn through and their tufts are presented with the same result of continued good nap condition and appearance. While this is going on the felted fibers in the valleys between ridges of yarn 5 yield additional nap. Finally all the yarn 5 is worn off the ball. The only thing left to wear is the body fabric in the sheet of yarn 4. I have discovered a surprising wearing quality in this sheet of yarn 4 after the yarn 5 has been entirely worn off its top face. And this feature of my invention needs a little special consideration.

If the tennis ball cover were made of easily felted yarn 4 tightly woven and without the sheet of yarn 5, it would be an ordinary tennis ball cover of the prior art. Such covers have been used for many years. 4 With such a prior art cover the life of the tennis ball under hard play is very short. The difficulty has been that when the nap wears down to the tightly woven yarn, the latter is worn smooth and there is then no nap on the ball. This takes place either in spots or all over the ball. In either case there is the tendency for the ball to float when its surface is too smooth to grip theair for proper travel and spin. Considered academically, one would suppose that the same kind of tightly woven body fabric would act the same way when a superimposed sheet of wearing fabric was worn ofi the body fabric. But I have discovered in the experiments leading to and the actual practice of my invention that the body fabric of yarn 4, when that is all that is left on the ball (after my other components have worn off), will act quite differently than if such body fabric were the original and sole component of the cover. Fig. 2 indicates the difference. There is a sufficiently roughened surface on the worn ball for continued play when only the body fabric is left. This results from the great number of uniformly distributed small recesses or pits 8 all overthe ball. They are not large but they are larger than the interstices of the body fabric and large enough to prevent the smoothness that has been objectionable.

This roughness in the tightly woven body fabric comes, I believe, from the fact that such fabric is a component part of a composite fabric that has had a sheet of wearing fabric (like yarn 5 presents) combined with it and worn off its surface. After that has been done the body fabric takes a different top surface than if it had been used alone for the tennis ball cover, as it has been in the past. Specifically, I believe that such roughened surface is caused by the slight displacement of threads in even a very tightly woven fabric due to the presence of the second sheet of threads making up the composite weave. This slight displacement for example of yarns 4 in its tight body fabric weave takes place in line with and due to the presence of yarn 5 tied in on the top surface of the body fabric. As the yarn 5 is higher than the body fabric, and as it Wears away, it is pressed into the body fabric to accentuate any possible depressions in the top surface of the body fabric. And when yarn 5 is worn off the top surface of the cover then has the pits or depressions 8 I have pointed out. Whatever the cause is, the body fabric is in fact rendered with a suitable playing surface due to its slight roughness. And it cannot be worn smooth until it is worn sufficiently in depth to obliterate the pits or depressions in it. I have found that these are sufficiently deep to materially prolong the life of the tennis ball.

If the Weave of yarn were used as a single sheet, it would not serve my purpose. If the skeleton for a felt-ed cover surface is merely roughened by disposing of its felted fabric in a single sheet, it soon wears out. The skeleton fabric yarn arrangement in any open or fancy fabric of single sheet character is necessarily weak and sleazy. This is true of my particular arrangement of yarn 5 as a single sheet form without the sheet of yarn 5. And it is true of other arrangements of yarn 5 which could be referred to as fancy weaves or fabrics in single sheet form.

As I have intended to point out, my invention is not to be found in a single sheet form of fabric but in a two-sheet fabric of composite form in which each ply or sheet combines to make the other one function differently in the tennis ball use than either one can function alone. It is true, however, that of I desired to have a tennis ball with a single layer of closely woven felted fabric and of improved form, I could arrive at that result by making the tennis ball with my composite cover, putting it in a machine to take off the top sheet (of yarn 5) by machine wear and leave only the body fabric sheet on the ball. The ball to be sold would then have a cover of improved form derived from the composite sheet, as indicated in Figs. 2 and 7. And it would embody a distinct feature of my invention which is novel and useful in the cover. But my invention is primarily found in the characteristics of a tennis ball made with the composite sheets combined for prolonged wear while maintaining the playing quality of the ball.

By consolidating the two sheets of yarn, locked together by the composite weave and by the heavy felting and big shrinkage due to fulling of the yarns in their composite form and constructing the rubber ball portion with this form for covering, 'I make a tennis ball that will outwear any prior art tennis ball of which I am aware. And except for its superior wearing qualities and continued good appearance the new ball will have the standard qualities of the best tennis balls. The thickness and weight per unit area of cover can be substantially the same in the new ball as under prior art standards, which is a help in manufacture and in the introduction of the ball on the market.

In the drawing it is not possible to show the exact relative arrangement of all the yarn and felted fiber making up the improved cover. The yarns become so heavily covered with felted fiber that they are submerged in the mass. The showing is necessarily skeletonized to a considerable degree. The general nature of a heavily felted woolen cloth is, however, well understood and it should be understood that in this respect my drawing necessarily omits much of the felting fiber that would hide the yarn arrangement shown. With this explanation one skilled in the art will fuliy understand the nature of the invention and be able to put it in practice with such variations as come within the scope of its construction principles.

Having disclosed my invention, what I claim is:

l. A tennis ball constructed with a woolen cover, said cover consisting of two sheets of yarn woven together one on top of the other each sheet having warp and weft threads, the inner sheet being closely woven and the outer sheet being loosely Woven with its threads spaced apart a plurality of times as far as the threads of the inner sheet and the whole felted and tied together in tightly locked composite form, said two sheets of yarn being tied together in the weaving at points spaced closely enough together to prevent loose ends of any substantial length as the sheet on the outer side of the ball wears through.

2. A tennis ball constructed with a center por- 5 tion of rubber and a woolen cover portion, the latter comprising a composite weave of a heavily felted and tightly woven body fabric and an open woven wearing fabric on top of and tightly tied in at spaced points to the body fabric, said wearing fabric being arranged with its threads spaced apart a plurality of times as far as the threads of the inner sheet and submerged in felted fiber of the woolen cover and forming a supporting and wearing skeleton for retarding the wearing away of the said felted fiber.

3. A tennis ball comprising an inflated center portion and a cloth cover portion to take the wear and control the flight, said cover portion constructed of a tightly woven body fabric made of heavily felted yarn and a wearing fabric made of larger and harder twisted yarn loosely woven in open mesh form, said wearing fabric being tightly tied into the body fabric at spaced points located midway between the crossing points of the heavier yarn weave, the cloth cover being heavily felted with the larger yarn submerged in the cloth by the felted fibers.

4. In a tennis ball of the type having an inflated rubber center with a cover made of felted plain square woven cloth, the combination in the cover portion of two sheets of woven yarn, one sheet made of soft spun single yarns tightly woven together and very heavily felted, the other sheet made of heavier hard twisted two-ply yarns loosely woven and lying on top of the first sheet to roughen the cover, said second sheet having its yarns tied down tightly into the first sheet at points midway between the crossing points of the heavier yarn, one with another, so as to leave heavy yarn bulges at said crossing points, said two sheets being submerged in felted fiber of the composite'form of cover.

5. In a tennis ball of the type having an inflated rubber ball portion, the combination with'45 the ball portion of a cover portion including a tightly woven woolen cloth with a smooth back portion cemented to the ball, a loosely woven woolen cloth lying on the face of the other cloth to roughen the ball surface for frictional engagement with the air, said loosely woven cloth being consolidated with the tightly woven cloth by weaving tie-ins at spaced points located between the crossing points of the loosely woven cloth, both cloths being shrunk together and submerged in heavily felted fibers filling up the mesh of the loosely woven cloth and acting with said tie-ins to consolidate the components of the cover for interaction during the wearing action of tennis play upon the ball. 6O

6. A tennis ball cover construction comprising a tightly woven cloth with a smooth back side for cementing to the ball, a large number of yarn crosses uniformly distributed over the top side of the woven cloth, the points of the crosses being tied down into the tightly woven cloth so as to make the crosses generally convex in form with their high points at their centers, a body of felted fiber submerging said crosses and further tying the crosses and woven cloth together by mutual 7 O felting of the fibers, the crosses being sufficient in number to give a long wearing pimply surface to the ball as it wears in play so as to maintain frictional resistance for racket and air.

DWIGHT W. ELLIS.

Images