US1097973A - Tennis or like ball. - Google Patents

Description

' J. GORDON.

TENNIS 0B. LIKE BALL.

APPLICATION FILED JAN. 30, 1914.

1,097,973 Ptented May 26, 19m

Wz'Znesses: v In venior:

Jbkanrz fiard'an,

JOHANN GORDON, OF DRESDEN, GERMANY.

TENNIS OR LIKE BALL.

Specification of Letters Patent.

Patented May 26, 1914:.

Application filed January 30, 1914. Serial No. 815,373.

To all whom it may concern Be it known that I, J OHANN GORDON, manager, a subject of the Emperor of Germany, residing at Scheffelstrasse 29, Dresden-Au, Germany, have invented certain new and useful Improvements in Tennis or like Balls, of which the following is a specification.

The covering of tennis balls with fabric is generally effected by cutting from the fabric two double tongue-shaped pieces which, when placed together, form a spherical surface. These pieces of material or fabric have been secured to the surface of the rubber ball hitherto, by means of a seam with which the two pieces are sewn together in the overcast manner at their curve of contact, glue being used sometimes in addition. This overcast or whip stitch has the drawback however that, owing to the edges of the fabric being drawn toward each other by the thread, a bead is produced at the curve of contact, which slightly projects above the surface of the finished ball. The existence of such a bead has many drawbacks. First of all, the ball rebounds from the ground or from the racket at an angle that cannot be anticipated. Moreover the friction at the bead is greatly increased, and thus the seam is easily torn, more particularly as the overcast sewing thread, even when made of elastic material (gut), cannot yield or give properly. Finally, the fabric is easily frayed at the joint. In any case, experience shows that known tennis balls always first become defective at the seam. This drawback is obviated according to this invention by the-two double-tongue-shaped portions forming the spherical surface, being joined not along a smooth edge, but in a zig-zag or sinuous line. In such a case it is no longer necessary to use an overcast stitch, but it is possible to sew with one or threads which are drawn through continuously in the direction of the joint through the points or tongues formed by the zigzag lines. Thus, the formation of the bead above referred to is avoided, and the surface remains perfectly smooth. The threads are held with not too much friction in the fabric, so that in the event of a strain at one point, due to the striking of the ball, they can yield in a somewhat elastic manner and do not break so easily. Finally the points or teeth produced can be glued on to the rubber ball in a much more reliable manner,

two

so that in certain conditions it is possible to do without a thread at all.

A construction according to this invention is illustrated in the accompanying drawing in which;

Figures 1-3 show the old method of cov ering tennis balls with fabric, while; Figs. f and 5 illustrate the new method of manufacture. Fig. 1 shows one of the doubletongue shaped pieces of fabric, two of which, placed together, are placed 011 the surface of the rubber ball and then form .a spherical surface. Fig. 2 shows a tennis ball in the course of manufacture, in which one piece of fabric is sewn on completely, and the other only partly. Fig. 3 shows such a finished tennis ball. Fig. 4 shows the tennis ball'co'vered by the new. process, in a half finished state, while Fig. 5 shows the same tennis ball finished.

As already stated, hitherto in the process of covering tennis balls with fabric, two double-tongue shaped pieces of fabric 1 (Fig. 1) are placed together around a rubber ball 2 (Fig. 2) in the manner shown in Figs. 2 and 8, and the joint 3 is sewn by a thread f in the overcast manner. Thus there is produced the above mentioned bead 5 indicated by cross-hatching, which has the drawbacks referred to.

According to this invention, the edges of the fabric are provided with teeth points or tongues 6, fitting into each other when they are put together, in the manner indicated in Figs. 4c and 5. Thus very considerable advantages are obtained. First of all the solid surfaces of the pieces of fabric are smaller, so that they automatically fit better the surface of the rubber ball without forming creases. The engagement of the teeth with each other takes place without forcing and also without the formation of creases. In gluing on to the rubber ball, there is therefore much less risk of the fabric be coming detached from the surface, as there are no internal strains. It is possible therefore in certain circumstances to do without any sewing. It is however advisable to sew the fabric as well as glue it, for the sake of greater security. The sewing is effected by means of one or two threads which, as shown in Figs. 4 and 5, are drawn straight through the teeth, but not sewn on in an overcast stitch. The threads meet in the teeth with only a slight friction, so that when shape of the ball changes when it is struck, they yield easily and can expand if they be of elastic material, which of course is not the case when the sewing is done in an overcast stitch. The threads therefore do not easily break. h/Ioreover, any reason for forming the bead referred to, disappears, and thus it is possible to aim in a much more accurate manner, and the balls do not wear out more quickly at the seam than at other points.

lVhat I claim is 1. In a tennis or like ball the combination of a core and pieces of fabric for covering provided with toothed edges which are adapted to fit each other.

2. I11 a tennis or like ball, the combination of a core and pieces of fabric for covering provided with toothed edges which are adapted to fit each other, and a thread stitched through all the teeth of the toothed edge in a direction parallel to their tips.

8. In a tennis or like ball, the combination of a core and pieces of fabric for covering provided with toothed edges which are adapted to fit each other, and threads stitched through all the teeth of the toothed edge in a direction parallel to their tips.

4. In a tennis or like ball, the combina tion of acore and pieces of fabric for covering provided with toothed edges which are adapted to fit each other, the said cover ing being glued upon the core.

5. In a tennis or like ball, the combina tion of a core and pieces of fabric for covering provided with toothed edges which are adapted to fit each other, the said covering being glued upon the core and stitched thereon by stitches passing through the teeth of the toothed edge of the fabric in a direction parallel to the tips of the teeth.

In witness whereof I have hereunto signed 4 my name this eighth day of January 1914.

JOHANN GORDON.

Witnesses L. A. BERGHoLz, H. C. T. NESBET.

M Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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