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Publication numberUS3707288 A
Publication typeGrant
Publication dateDec 26, 1972
Filing dateMar 29, 1971
Priority dateMar 29, 1971
Publication numberUS 3707288 A, US 3707288A, US-A-3707288, US3707288 A, US3707288A
InventorsThomas B Edlefsen
Original AssigneeThomas B Edlefsen
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Racket with replaceable string frame
US 3707288 A
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.
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Description  (OCR text may contain errors)

United States Patent Edlefsen [54] RACKET WITH'REPLACEABLE STRING FRAME [72] Inventor: Thomas B. Edlefsen, 1315 N. June Street, Hollywood, Calif. 90028 [22] Filed: March 29, 1971 [21] Appl. No.2 129,059

[52] US. Cl. ..273/73 L [51] Int. Cl. ..A63b 51/00 [58] Field of Search ..273/73 R, 73 C, 73 D, 73 E,

. 273/73 G, 73 H, 73 J, 73 K [56] References Cited I UNITED STATES PATENTS 240,183 4/1881 Richardson, ..273 73 E 1,558,507 10 1925 Ryder .;.273/73 13 2,054,444 3/1936 Rauch et a]. .....273 73 E 2,224,567 12 1940 Reaeh ..273/73 c 2,369,145 2/1945 1 .....273 73 R 2,969,984 1 /1961 Presnick ..273 73 R 1151 3,707,288 [4 1 Dec. 26,1972

FOREIGN PATENTS OR APPLICATIONS 208,945 l/l957 Australia ..273/73 R 639,932 3/1928 France ..273/73 D 1,503,812 10/1967 France ..273/73 C 2,000,606 9/1969 France ..273/73 R 189,874 12/1922 Great Britain 273/73 C 227,012 l/l925 Great Britain 273/73 D 712,224 7/1954 Great Britain.... 273/73 J Primary Examiner-Richard C. Pinkham Assistant Examiner-Richard J. Apley Attorney-Jones & Thomas 57 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 racketframe and secured by fastening means.

5 Claims, 10 Drawing Figures PATENTED um 25 1912 sum 2 OF 2 mvsmon Thomas B.Edlefsen W" flame-4 ATTORNEYS 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. 1

Tennis rackets, and the like, with removable strings have been known in the past, but prior artrackets 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 above-menq tioned and otherdifficulties by providing a substantially conventional tennis racket in which the racketframe 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 renderedunitary 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 case.

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 33 in FIG. 1;

FIG. 4 is an enlarged cross-sectional view taken substantiallyalong the line4-4 in FIG. 1; y FIG. 5 is an enlarged cross-sectional view taken substantially along the line 5-5 in FIG. 1;

FIG. 6 is an enlarged cross-sectional view taken substantially along the line 66 in FIG. 1;

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

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

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

FIG. 10 is a cross-sectional view taken substantially along the line 1010 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 1 1 terminating ina hand grip 12 at its other end. The racket-frame 10 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 ll 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 or inserted. The opening 14 extends substantially halfway around the end of the racket-frame 10 that is most remote from the shank 11 and. channel 16 is aligned with opening 14. I

The inwardly opening channel 16 is provided, substantially along the centerline of the racket, with an aligning hole l8 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 width as the strips 20 and 21, 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 ll, 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 FIGS 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 l l 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 ofthe 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,

remove and insert the screw so that the player need have no tools available in order to exchange the stringframe 15 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 1 10 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 inan 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 1 10 is open.

As aretaining means to holdthe string-frame. 115 in the racket-frame 1 10, there is provided'a snap-ring 130 to be received within a peripheral groove125 in the rackebframe 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 The string-frame 1 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.

1n 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 l 15 can be slipped through the opening 114 into the racket-framev 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 v 4 readily exchanged by the ordinary player. Very few tools are required to make the exchange and extremely little mechanical skill is required to exchange thestring-frame. Accordingly, a 'player can "have one racket but carry several pre-strung string-frames. 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 r particular reference to preferred embodiments thereof,

I with said slot along the remaining portion thereof, an

of the racket-frame 110, the snap-ring 130 can be 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 adapted to-hold'the playing surface, a string-frame carrying the playing surface, said string frame having substantiallythe same configuration as the racket-frame, said racket-frame having a continuous periphery, a portion of the periphery of said racket-frame defining an inwardly facing channel, said racket-frame having an opening therein to receive the string-frame, said channel being opposite said opening and aligned therewith so that said string-frame is received within said opening and within said channel, and retaining means to secure the string-frame within the racket-frame.

2. A racket according to claim 1 wherein said opening to receive the string-frame is in the end of the racket-frame that is opposite from the shank, said opening extending substantially halfway around the racket-frame.

3. A racket according to claim 2 wherein said racketframe includes strips defining the opening, said stringframe substantially filling the opening and said retaining means acting to secure the string-frame to the strips. g

4. A racket according to claim 3 and further including an aligning pin extending from the string-frame, 7 said racket-frame having an aligning hole located along the centerline of the said shank and adapted to receive the aligning pin.

5. A tennis racket assembly comprising a stringframe support including a shank, a handle grip at one end of saidshank, and a generally oval racketframe at the other end of said shank, saidracket frame being bifurcated along approximately the one-half portion thereof remote from said shank to form a slot and formed with an inwardly facing channel in alignment aligning hole defined in said racket frame adjacent said shank, a generally oval string frame generally of a size and shape corresponding to the size and shape of said racket frame and of a thickness sufficient to be'snugly received in the slot and channel of said racket frame, said string frame being of smaller width in the portion thereof adjacent said shank and including outwardly extending shoulders at the junction of the slot and channel of said racket frame, said string frame including an aligning peg projecting therefrom and received in the aligning hole of said racket frame, and fastening 3,707,288 6 means positioned at the end of said racket frame remote from said shank for clamping said racket frame against said string frame.

2157 IOMHZ 0H0

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US240183 *Apr 12, 1881 richardson
US1558507 *May 26, 1921Oct 27, 1925Ambrose RyderTennis racket
US2034444 *Mar 8, 1934Mar 17, 1936Antonin RauchTennis racket with pneumatic tightener
US2224567 *Jun 20, 1939Dec 10, 1940Reach Milton BRacket or the like
US2369145 *Sep 18, 1942Feb 13, 1945Kent Horace HGame racket
US2969984 *Jan 20, 1958Jan 31, 1961Michael C PresnickRacquet
AU208945A * Title not available
FR639932A * Title not available
FR1503812A * Title not available
FR2000606A1 * Title not available
GB189874A * Title not available
GB227012A * Title not available
GB712224A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4135717 *Oct 28, 1975Jan 23, 1979Dileo Philip FTennis racquet with insert
US4274634 *Nov 29, 1979Jun 23, 1981Nando BerlutiTennis rackets
US5005834 *Mar 16, 1990Apr 9, 1991Ferrari Importing CompanyMulti-frame racket
US5211396 *Feb 19, 1991May 18, 1993Ferrari Importing CompanyMulti-frame racket
US8192308Jun 5, 2012Demasi Gary MTennis racquet with replaceable playing surface
USRE45866May 31, 2014Jan 26, 2016Gary M. DeMasiTennis racquet with replaceable playing surface
WO1991013657A1 *Mar 12, 1991Sep 19, 1991Ferrari Importing Company, Inc.Multi-frame racket
WO1998040129A1 *Feb 16, 1998Sep 17, 1998Kneissl Dachstein Sportartikel AgBall striking implement, in particular tennis, squash or badminton racket
Classifications
U.S. Classification473/532
International ClassificationA63B49/02
Cooperative ClassificationA63B49/0294
European ClassificationA63B49/02F