US 3545756 A
Description (OCR text may contain errors)
United States Patent  Inventor Eugene W. Nash 5246 Peacock, Riverside, California [21 1 Appl. No'. 735,438  Filed June 7, 1968  Patented Dec. 8, 1970  TENNIS RACKET Wl'lll STRING SUPPORTS OF VARIABLE RESILIENCY 3 Claims, 9 Drawing Figs.
 US. 273/73  Int. A63h 51/12  Field of Search 273/73  7 References Cited UNITED STATES PATENTS 1,937,787 12/1933 Robinson 273/73 2,610,056 9/1952 Lovell 273/73 FORElGN PATENTS 106,248 12/1938 Australia 273/73(.3) 639,932 3/1928 France 273/73(4) 223,151 10/1924 Great Britain 273/73(4) 234,021 5/1925 Great Britain..... 273/73(4) 279,577 11/1927 Great Britain 273/73(4) Primary Examiner- Richard C. Pinkham Assistant Examiner-Richard .I. Apley Attorney-Dana E. Keech said openings and welded at their ends to said loops. At certain spaced intervals said oval subframes are joined together by welding to space said subframes threesixteenth of an inch apart. Arcuate attachment rods of flexible resilient plastic one-fourth inch in diameter rest in the external groove formed by said oval subframes, said rods being apertured to accommodate the conventional strings used in stringing said racket. Said rods are divided into two pairs of diametrically opposed sections symmetrical respectively with the major and minor axes of the racket frame and having a relatively high degree of resilient responsiveness, and two pairs of diametrically opposed sections alternately arranged with respect to said first two pairs of sections and having a relatively low degree of resilient responsiveness, this feature producing a sweet spot in the center of the racket frame.
TENNIS RACKET WITH STRING SUPPORTS F VARIABLE RESILIENCY This invention relates to rackets for tennis, badminton, squash and similar games using a stringed surface for striking a ball or other object.
Although such rackets have traditionally-been constructed using a wooden frame, recent years have seen several rackets developed using steel or aluminum frames. The use of metal frames has resulted in stringing problems. Several methods of securing the racket strings to metal frames have been developed and patented. For one reason or another all such stringing methods or deviceshave proven less than satisfacto- The invention described herein is designed to improve such metal racket by incorporation and use of a stringing device which eliminates the objections to the presently known rackets and their stringing. Inaddition, said stringing device provides certain other improvements and advantages not otherwise available. v
The within-described invention is based upon a racket frame composed of two parallel metal tubes, each having a diameter of approximately one-fourth inch, or other suitable size as necessary for strength, which are joined together together-at certain spaced intervals by welding or pinning, thereby separating the tubes approximately three-sixteenths of aninch. Said parallel tubes are shaped into an oval frame for the racket strings and then extended into the handle. By attaching a section of similar parallel tubing to the string area toward the .racket handle, certain other cross braces as needed, and a wooden, plastic or metal handle, the racket is complete except for the strings and their attachment device.
The strings themselves are attached to the frame by stringing back and forth across the string area of the racket through the separation between the tubes of the frame into and out of solid fit-inch rods, composed of nylon, hard rubber, plastic or other suitable material, herein called attachment rod, which lies in the groovebetween and adjacent to and on the outside of the parallel tubes surrounding the string area. The attachment rod is flexible, beveled at its ends and drilled, or slotted, to accommodate the stringing pattern desired.
The dimensions of the racket, and consequently of its attachment rod, will vary depending upon the type of racket desired and its stringing pattern. The detailed description which follows is of a tennis racket and its attachment rod. However, such description'is' for purpose of illustration only and should not be considered as a limitation.
FIG. 1 shows the total tennis racket consisting of parallel metal tubes 1, the parallel metal crossmember tubes 2, the handle 3, the strings 4, the main attachment rod 5, and the secondary attachment rod 6.- Y
' FIG. 2 is a partial perspective view of the racket frame which illustrates the tubular-frame members I and the crossmembers 2. The three-sixteenths inch separation between the parallel tubes is shown 7. v
FIG. 3 presents a cross-sectional view of the parallel metal tubes 1, the attachment rod and the strings 4.
FIG. 4 shows a partial perspective view of the racket when strung showing the parallel metal tubes 1, the space between the tubes 7, the attachment rod 5, the string holes 8, the string slots between the holes 9 and the strings 4.
FIG. 5 is a cross-sectional-view on a plane similar to the plane of projection in FIG. l'which shows the metal frame I, the attachment rod 5, the strings in the impact area4, the strings passing between the parallel tubes 4a, and the strings passing into and along the attachment rod 4b.
FIG. 6 is a partial view of the outside circumference of the racket showing the parallel tubes 1, the space between the tubes 7, the attachment rod 5, the string holes 8 and a continuous string slot 9. v 7
FIG. '7 is a view similar to that in FIG. 6, but which illustrates a drilling pattern of the attachment rod 5 which consists of U-shaped routed string beds 11 which leave an anchor knob around which the rackets strings can be looped, thereby speeding up the stringing process by eliminating the necessity of pulling the entire string length back and forth between drill holes 8.
FIG. 8 is a cross-sectional view of the attachment rod 5 having the same drilling pattern as that illustrated in FIG. 7. The anchor knob 10 is outlined by its U-shaped routed string bed 11. The next anchor knob 10 is outlined by its U-shaped routed string bed 11a. These successive anchor knobs 10 are offset so as to equalize the string pressures.
FIG. 9 shows a view of said racket similar to that shown in FIG. I but which illustrates the use of attachment rod sections 12 and 13 which are opposite each other in the stringing pattern and which by varying the resiliency of said attachment rod sections 12 and 13 a sweet spot" 14 can be designed into said racket impact'area, according to the user's preference. The term sweet spot" in tennis parlance means soft spot" and this is attained in my racket by using a softer, more resilient plastic material-for the rod sections 12 than for the rod sections 13.
The advantages of using such attachment rods include the following:
a. STRING PROTECTION 1. By eliminating the previously developed wire or spring steel string attachment devices, a critical metal to string contact is avoided and thereby the durability of the rackets strings is enhanced.
. The within described attachment rods provide a widened contact area at the point where the strings are attached, thereby widening the point of potential wear and extending the life of the racket strings.
3. By providing slots between the string holes or routed beds in said attachment rod, the racket strings are protected from accidental wear and damage similar to that afforded by the traditional drilled and slotted wooden racket.
b. Use of the attachment rods make the entire area within the racket frame available as an impact or playing surface.
0. The attachment rods eliminate all wires or other metal devices designed for string attachment and thereby eliminates the bending or breaking associated with such devices.
d. By contrast to the presently available wire or spring steel devices for string attachment, the attachment rods are simple in concept, easy to manufacture and handle, and do not require extensive storage and shipment protection.
e. The metal racket using the attachment rods is capable of being strung and restrung by use of traditional stringing machines and methods.
f. The attachment rods, when strung in place will not shift in location and will not permit shifting of the rackets strings.
g. The attachment rods, because of their installed location surrounding and extending beyond the metal frame of the racket, provide a measure of added protection for the frame itself. A worn or unsightly attachment rod can be replaced at least as often as new strings are installed, whereas a bent or damaged metal racket frame means a new racket.
h. The same metal racket can be strung or restrung in either traditional or unorthodox string patterns merely by use of different attachment rods which are drilled or slotted to accommodate such pattern. a
i. By use of attachment rod material having different resiliency characteristics, the users of such rackets can vary the playing characteristics of their rackets. Neither the traditional wooden rackets nor the metal rackets using wire or spring attachment devices can offer this particular individual playing advantage.
j. These attachment rods can be manufactured and offered in solid colors or any combination thereof. Such possibility adds a worthwhile aesthetic value to the otherwise tremendous practical advantages of the rackets and string attachment devices detailed herein.
I. A racket comprising:
an approximately oval frame having external peripheral groove means from which ample string accommodating aperture means lying in the plane of said frame communicates with the area confined by said frame;
means for mounting said frame on said handle; and
resilient string attachment rod means resting in said peripheral groove and having holes communicating with said aperture means of said frame at suitable intervals for stringing said racket; said rod means being divided into a plurality of pairs of diametrically opposed sections, the sections of each pair having a like degree of resiliency While the sections of alternate pairs differ in resiliency from that of the others, to modify the performance of the racket in play.