US3843121A

US3843121A - Racket with replaceable string frame

Info

Publication number: US3843121A
Application number: US00298999*A
Authority: US
Inventors: T Edlefsen
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-03-29
Filing date: 1972-03-06
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22

Abstract

A racket for use in playing tennis or similar games, the racket having a removable playing surface. The racket-frame is provided with an opening, and a removable string-frame is provided to carry the playing surface. The string-frame can be easily removed from the racket-frame, and another string-frame with a new playing surface can be inserted into the racket-frame and secured by fastening means.

Description

United States Patent 1191 I Edlefsen Oct. 22, 1974 [54] RACKET WITH REPLACEABLE STRING 2,369,145 2/1945 Kent 273/73 L FRAME 2,969,984 l/l96l Presnick... 273/73 L [76] inventor: Thomas B. Edlefsen, 1315 N. June FOREIGN PATENTS 0R APPLICATIONS St., Hollywood, Calif. 99028 582,861 10/1924 France 273 73 J 151,916 6/1953 Australia 273/73 L [22] 1972 2,000,606 9/1969 273/7311 [2]] Appl. No.: 298,999

Primary ExaminerAnton O. Oechsle .Remed Apphcamn Data Assistant Examiner-Richard J. Apley gmsmn of Ser. No. 129,059, March 29, l97l, Pat. Attorney, Agent or Firm JOne-S Thomas & Askew [52] US. Cl;..-. 273/73 L [57] ABSTRACT [51] Int. Cl A63b 51/00 A racket for use in 1 p aymg tenms or s1m1lar games, the [58] held of Search 273/73 73 73 73 racket having a removable playing surface. The rack- 273/73 73 73 L et-frame is provided with an opening, and a removable string-frame is provided to carry the playing surface. [56] Rem'ences and The string-frame can be easily removed from the rack- UNITED STATES PATENTS et-frame, and another string-frame with a new playing 240,183 4/1881 Richardson 273/73 1. ur ace can be e ted into the racket-frame and sel,558,507 l0/l925 Ryder 273/73 L cured by fastening means. 2,004,609 6/l935 Johnston 273/73 L 2,171,223 8/1939 Robinson 273/73 11 4 Clalms, 10 Drawing Flgul'es SHEUIUF 2 PATENTEDUEI 22 m4 mmmw BACKGROUND OF THE INVENTION This invention relates to tennis rackets and similar rackets for use in sporting events, and is more particularly concerned with a racket in which the playing surface is readily removable and replaceable by another playing surface.

Tennis rackets, and the like, with removable strings have been known in the past, but prior art rackets have usually had such a complex arrangement to allow a string-frame to be inserted into the racket-frame that the entire racket became very unwieldy.

SUMMARY OF THE INVENTION .The present invention overcomes the abovementioned and other difficulties by providing a substantially conventional tennis racket in which the racket-frame is open to receive a string-frame which is inserted into the racket-frame. Means are also provided to retain the string-frame within the racket-frame; and when the string-frame is inserted into-the racket-frame the entire racket is rendered unitary with a small number of parts so that the racket remains light in weight and well balanced. Further, the racket of the present invention is so constructed that the ordinary tennis player can exchange the string-frame with relative ease.

These and other features and advantages of the present invention will become apparent upon a consideration of the following specification when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top-plan view of a racket embodying one form of the present invention;

FIG. 2 is a partial front-elevational view of the racket shown in FIG. 1, and showing the string-frame partially removed from the racket-frame;

FIG. 3 is an enlarged cross-sectional view taken substantially along the line 3-3 in FIG. 1;

FIG. 4 is an enlarged cross-sectional view taken substantially along the line 4-4 in FIG. 1;

FIG. 5 is an enlarged cross-sectional view taken sub-' stantially along the line 55 in FIG. 1;

FIG. 6 is an enlarged cross-sectional view taken substantially along the line 6-6 in FIG. 1;

FIG. 7 is a view similar to FIG. 1 but showing a modified form of the present invention;

FIG. 8 is an exploded front-elevational view of the racket shown in FIG. 7;

FIG. 9 is an enlarged cross-sectional view taken substantially along the line 99 in FIG. 7; and

FIG. 10 is a cross-sectional view taken substantially along the line 10--10 in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularly to the drawings, and to that embodiment shown in FIGS. 1 through 6 in the accompanying drawings, it will be seen that a tennis racket assembly 8 is provided which includes a handle or string-frame support 9 and a string-frame 15. The string-frame support includes an elliptically shaped or oval racket-frame 10 at one end, and a central shank ll terminating in a hand grip 12 at its other end. The racket-frame l0 and the shank 11 are here shown as formed integrally, but it will be understood by those skilled in-the art that the two pieces can be formed separately and joined together by numerous known means.

The racket-frame 10 has the usual oval configuration, and the racket-frame 10 is bifurcated along approximately one half the portion thereof remote from the shank 11 to form opening or slot 14 and is provided with an inwardly facing arcuate slot or channel 16 along its remaining internal surface adjacent shank 11 into which the string-frame 15 can be removed for inserted. The opening 14 extends substantially halfway around the end of the racket-frame 10 that is most remote from the shank l1 and channel 16 is aligned with opening 14.

The inwardly opening channel 16 is provided, substantially along the centerline of the racket, with an aligning hole 18 to receive an aligning peg 19 that is formed integrally with the string-frame 15.

It will be seen that, in the vicinity of the opening 14,

' the racket-frame 10 is reduced to a pair of

flat strips

20 and 21. These strips are, however, well supported when a string-frame 15 is placed within the racket-frame 10 as will be understood more fully hereinafter.

Referring now particularly to the string-frame 15, it will be seen that the half of the string frame 15 that corresponds with the opening 14 of the racket-frame 10 is substantially the same widthas the strips 20 and 2l, and is provided with an outwardly facing peripheral groove 22 to receive the strings 24. By this means the strings 24 are recessed within the racket to prevent undue abrasion of the strings.

Substantially along the centerline of the racket, and at the end more remote from the shank 11, fastening means are provided which comprise aligned

holes

25 and 26 in the

strips

20 and 21, respectively, of the racket-frame l0, and a hole 28 in the string-frame 15. It will be seen in FIG. 3 that the hole 25 and the hole 28 are sufficiently large to receive the shank 29 of a screw 30 while the hole 26 is threaded to receive the threaded end of the screw 30. Thus, the string-frame 15 can be placed within the racket-frame 10, and the screw 30 can be passed through the

holes

25 and 28 and then threadedly engaged in the hole 26 to secure or clamp together the entire outer end of the string-frame 15. The string-frame 15 is under cut on opposite sides thereof to form shoulders 31 so that the portion of the string-frame 15 that is to be adjacent to the shank 11 is sufficiently small to be received within the channel 16 of the racket-frame 10. Again, this portion of the string-frame 15 is provided with an outwardly facing channel 32 so that the strings 24 will not interfere with the string-frames fitting properly within the channel 16.

From the foregoing it should now be readily seen that a string-frame 15 can be inserted through the opening 14 in the racket-frame 10 until the aligning peg 19 is received within the hole 18. This assures precise alignment of the string-frame 15 with the racket-frame 10; then, the screw 30 will be passed through the

holes

25 and 28 which should now be aligned, and the screw 30 is rotated to engage the threaded hole 26 in the strip 21 of the racket-frame 10. Once the screw 30 is tightened, the string-frame 15 is well secured within the racketframe and the entire assembly is substantially unitary and ready for play.

It will be realized that the screw 30 can be provided with a slot such that a coin or the like can be used to remove and insert the screw so that the player need have no tools available in order to exchange the stringframe in his racket.

Attention is now directed to FIGS. 7 through 10 of the drawings wherein another embodiment of the racket is shown. It will be seen in FIG. 7 that the racket includes a racket-frame 110, a shank 111 connected thereto, and a handle 112 at the end of the shank 111.

The racket-frame 110 is provided with an opening 114 through which a string-frame 115 is inserted.

In this embodiment, the opening 114 in the racketframe 110 is formed by making the periphery of the racket-frame 110 in an L-shape in cross-section, as best seen in FIG. 9, so that there is a lower flange 121 while the upper side of the racket-frame 110 is open,

As a retaining means to hold the string-frame 115 in the racket-frame 110, there is provided .a snap-ring 130 to be received within a peripheral groove 125 in the racket-frame 110. The snap-ring 130 is of a substantially conventional variety in which the snap-ring 130 is made of a resilient material such as spring steel and is biased to spring open. The ends of the snap-ring 130 are provided with holes 129 so that a tool can be inserted into the holes to compress the snap-ring 130 and remove the snap ring from the groove 125 in order to remove the string-frame 115 from the racket-frame 110.

The string-frame 115 in this embodiment has a uniform perimeter which is provided with an outwardly facing groove 22 to allow the strings 124 to be recessed so that they will not interfere with the string-frames entering the racket-frame 110.

In the event the string-frame 115 is made of a relatively hard material it is possible that the corners of string-holes 140 may be sharp enough to cut the strings and thereby greatly reduce the life of the strings in the string-frame 115. To diminish this possibility, bushings 141 are placed within the holes 140 and provide blunt corners 142 to prevent cutting the strings 124. The bushings 141 may be made of a plastic material, or the like, so that the bushing will be relatively soft and unable to cut or otherwise damage the strings 124.

From the foregoing it will be seen that in this embodiment a string-frame 115 can be slipped through the opening 114 into the racket-frame 110. Since both the string-frame 115 and the racket-frame 110 are of an oval or otherwise non-circular configuration, there is little danger that the string-frame 115 will be misaligned with the racket-frame 110. When the string frame 115 is sufficiently well seated on the flange 121 of the racket-frame 110, the snap-ring 130 can be depressed by placing a simple tool such as a conventional pair of pliers, or the like, into the holes 120 of the snapring 130 and compressing the snap-ring 130 sufficiently to pass through the opening 114. The snap-ring 130 is then released to enter the groove 125 and be held therein by its own outward bias.

It will thus be seen that according to the present invention there is provided a very lightweight racket with very few parts, but one in which the string-frame can be readily exchanged by the ordinary player. Very few tools are required to make the exchange and extremely little mechanical skill is required to exchange the string-frame. Accordingly, a player can have one racket but carry several pre-strung stringframes. If the strings in the racket become too severely worn, or break, the entire string-frame can be very quickly removed, and another string-frame inserted so that play with the racket may be resumed.

While this invention has been described in detail with particular reference to preferred embodiments thereof, it willbe understood that variations and modifications can be effected within the spirit and scope'of the invention as described hereinbefore and as defined in the appended claims.

I claim:

1. A racket having a replaceable string-frame, said racket including a shank, a handle at one end of said shank and a racket-frame at the opposite end of said shank and fixed thereto, said racket-frame being configured to'hold said string-frame, said string-frame carrying a string playing surface, said string-frame having substantially the same configuration as said racketframe, said racket-frame having an upwardly extending flange means substantially perpendicular to the plane of said playing surface and an inwardly extending flange means, the inner periphery of said racketframe defining an opening therein, said inwardly extending flange extending into said opening to receive said string-frame, and retaining means to secure said string-frame within said racket-frame, said retaining means being removably located on said upwardly extending flange means and extending inwardly therefrom andbeing opposite saitfinwardly extending flange means and spaced therefrom a distance substantially equal to the thickness of said string-frame.

2. A racket according to claim 1 and further characterized in that the string-frame has an outwardly facing peripheral groove to recess the strings of the playing surface.

3. A racket according to claim 2 wherein said string-- frame has a plurality of holes communicating with said peripheral groove to recess the strings of the playing surface and a plurality of bushings is receivable within .the plurality of (holes).

, the playing surface and an inwardly extending flange to receive said string-frame an inwardly facing groove located in saidupwardly extending flange and away from said inwardly extending flange a distance substantially equal to the thickness of said string-frame, and a snap ring receivable within said inwardly facing groove for locking said string-frame in said racket-frame.

Claims

1. A racket having a replaceable string-frame, said racket including a shank, a handle at one end of said shank and a racket-frame at the opposite end of said shank and fixed thereto, said racket-frame being configured to hold said string-frame, said string-frame carrying a string playing surface, said stringframe having substantially the same configuration as said racketframe, said racket-frame having an upwardly extending flange means substantially perpendicular to the plane of said playing surface and an flange means, the inner periphery of said racketframe defining an opening therein, said inwardly extending flange extending into said opening to receive said string-frame, and retaining means to secure said string-frame within said racketframe, said retaining means being removably located on said upwardly extending flange means and extending inwardly therefrom and being opposite said inwardly extending flange means and spaced therefrom a distance substantially equal to the thickness of said string-frame.

3. A racket according to claim 2 wherein said string-frame has a plurality of holes communicating with said peripheral groove to recess the strings of the playing surface and a plurality of bushings is receivable within the plurality of (holes).

4. A racket having a replaceable string-frame, said racket including a shank, a handle at one end of said shank and a racket-frame at the opposite end of said shank and fixed thereto, said racket-frame being configured to hold said string-frame, said string-frame carrying a string playing surface, said string-frame having substantially the same configuration as said racket-frame, said racket-frame being approximately L-shaped in cross section comprising an upwardly extending flange substantially perpendicular to the plane of the playing surface and an inwardly extending flange to receive said string-frame an inwardly facing groove located in said upwardly extending flange and away from said inwardly extending flange a distance substantially equal to the thickness of said string-frame, and a snap ring receivable within said inwardly facing groove for locking said string-frame in said racket-frame.