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Publication numberUS1539019 A
Publication typeGrant
Publication dateMay 26, 1925
Filing dateFeb 7, 1924
Priority dateFeb 7, 1924
Publication numberUS 1539019 A, US 1539019A, US-A-1539019, US1539019 A, US1539019A
InventorsNikonow John P
Original AssigneeNikonow John P
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Tennis racket
US 1539019 A
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Description  (OCR text may contain errors)

May 26, 1925. 1,539,019

J. P. NIKONOW TENNIS RACKET Filed Feb. '7, 1924 2 9 E2, 3 F123? Eg 5 Patented May 2 6, 1925.

um'rao STATYE'S PATENT omen.

' some 2. manager mrw Yonx, N. Y. I

Application filed February 7, 1984. SerialNo. 691,174.

To all whom it may concern.

Be it known that I, JoHN P. Nmonow, citizen of the United States, and resident of New York, in the county of New York i and State of New York, have invented certain new and useful Improvements in Tennis Rackets, of which the following is a speci fication.

My invention relates to tennis rackets and has for its object to provide a racket with greater efficiency for striking the ball.

In ordinary tennis rackets the weights are so distributed that the center of gravity is located approximately in the mi dle of the racket length, consequently its center of percussion, or center of application of the force of the blow for a circular swing around its handle, is located near the racket end of the gut, and not in its center. But since in most cases the ball is struck with the center of the'racket face (or gut), it follows, that with ordinary rackets a more or less large part of the force of the blow is wasted in reaction'on the players hand. In my racket I provide a construction in which the weights are so distributed that the center of percussion for a wrist swing, or a swing around the handle, is' located at the center of the racket face.

My invention is more fully described in the accompanying specification and drawing in which- Fig. 1 is a plan view of my racket, Fig. 2 is a side view, Fig. 3 is a section of the handle on a line A-A, Fig. 4 is a section B-B, and Fig. 5 is a section C-C.

My racket is provided with a handle 1 of a standard size of a sufiicient length only for a hand grip, made of some light material, such as a light sort of wood. The intermediate portion 2 of the racket is made of a light section reinforced only in a transverse direction (section AA) to render this racket sufliciently stiff and, at the same time, to reduce the air resistance to the rapid movement of the racket. The racket oval 3 is also made light and of a streamline sec tion (B-B) to reduce the air resistance. The end of the racket oval is made substan- 0 tially heavier by increasing its width (section C-C), this increased width also help ing to reduce the air resistance by improving its streamline effect. An additional weight 4 may be also added in the form of a metal strip, or of some other heavy material. An ordmary racket gut 5 is strung in the oval 3.

It should be noted that the oval 3 may be of any ordinary shape, even approaching an octagonal, s uare or round shapes and will be called an oval in this general meaning.

The ob ect of such weight distribution is to dlsplace the center of gravity G towards the oval end of the-racket to. such distance X from the handle end, that the center of percusslon P for an axis passing through its handle end (axis 2z Fig. 1) becomes located in the middle of the oval, or at its geometrical center.

We have a formula for determining this distance Y from the center of percusslon to the handle end:

Y I/wX Where I is a moment of inertia of racket in relation to the axis 2z, w-weight of the racket, and X--distanc-e ofits center of gravity. Expressing'in terms of a moment of inertia in relation to the center of gravity (which we denote I0), we have:

I Io X 'w From this equation we can determine the distance X for a given distance Y, as the weight of the racket w and the moment of inertia Io are known.

It can be seen from this equation that in order to move the center of gravity inside of the oval it is necessary to increase or Io.

The distance X can be lengthened by reducing the weight of the handle and increasing the weight of the oval. The moment of inertia forthe same weight can be increased by concentrating a large part of this weight near the racket end.

This may be accomplished best by increasing the racket section C-O near its end and by adding an extra heavy metal strip 4. The section should be increased in a streamline fashion in a direction perpendicular to the face of the oval so as to reduce the air resistance.

An ordinary racket is about 26 inches long with center of gravity at about 13 in. from the end, and wlth the center of the oval at about 19 inches from the handle end, the center of percussion being at about 16 in. from the handle end.

In order to have the center of percussion the middle of the oval, the'distance X should be made about 16 inches, or from 15 to 17, depending on the distribution of the weights it will 'be shorter for greater additional weight 4.

With he center of percussion at the middle of the oval it is possible to use lighter racket for the same effect in strikin the ball, for instance, a 12 oz. racket may eve op just as much power in driving the ball at the same. spee as a 14% oz. ordinary racket. The muscular effort will be reduced by having a lighter racket to swing, and the accuracy of driving may be improved on account of more uniform force of striking the ball, as in my racket the force is about the same on both sides of the center of the oval, while in an ordinary racket the force is much lower at one end of the oval, and greater nearer the handle.

Im ortant advantages of my racket are that it can be made lighter for the same striking force, or may give greater force for the same weight, also that it relieves the layers hand from the reaction when the Ball is struck too far from the center of percussion. Consequently the racket may beheld loosely relieving the hand muscles, and the driving may be more accurate on account of more uniform striking force.

I claim as my invention:

1. In a tennis racket, the combination with an oval, a gut strung in said oval, a handle an intermediate member connecting said oval with said handle, said intermediate member and said oval being shaped in a streamline him in a direction perpendicular to the face of said racket.

2. In a tennis racket, the combination with an oval, a gut strung in said oval, a handle, an intermediate member connecting said handle with said oval, said intermediate member and said oval being flattened and sharpened in a direction perpendicular to the face of saidracket. '3. In a tennis racket, the combination with an oval, a gut strung in said oval, a handle, an intermediate member connecting said handle with said oval, said oval with said intermediate member being of a flattened section with sharp edges extending in a direction perpendicular to the face of said racket, the cross-sectional area of said oval being greater at the end opposite to said handle.

4. In a tennis racket, the combination with an oval, a gut strung in said oval, a handle, an intermediate member connecting said oval with said handle, the weight of said oval being greater than the weight of said handle with said intermediate member, said oval being of a heavier section at the end opposite to said handle.

5. In a tennis racket, the combination with an oval frame, a gut strung in said frame, and a handle extending from said frame, the cross-sectional area of said frame being greater at the end opposite to said handle.

Signed at New York in the county of New York and State of New York this 5th day of February A. D. 1924.

JOHN P. NIKONOW.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3801099 *Jun 23, 1971Apr 2, 1974J LairTennis racquet
US3907292 *Sep 27, 1973Sep 23, 1975James P MorelandDynamically variable tennis racket
US3913911 *Jan 9, 1974Oct 21, 1975Peterson Kenneth AlanTennis racket with head frame weighting means
US3917267 *Mar 23, 1973Nov 4, 1975Mcgrath Charles ATennis racket
US3986716 *Sep 23, 1974Oct 19, 1976Arundale Manufacturers, Inc.Composite racquet structure
US3999756 *Sep 10, 1975Dec 28, 1976Prince Manufacturing, Inc.Tennis racket
US4153249 *Jun 3, 1977May 8, 1979Motion Analysis, Inc.Bioengineered game racket
US4165071 *Jan 5, 1976Aug 21, 1979Frolow Jack LTennis racket
US4196901 *Mar 7, 1977Apr 8, 1980Durbin Enoch JTennis racquet
US4239215 *Feb 23, 1979Dec 16, 1980Tecsports of Oxford LimitedDevices for practising ball-game stroke play
US4291574 *Mar 26, 1979Sep 29, 1981Frolow Jack LTennis racket
US4367874 *Jan 4, 1979Jan 11, 1983Starwin Industries, Inc.Tennis racquet and method of making same
US4732384 *Jul 27, 1984Mar 22, 1988Seymour Robert JRacquet having centralized sweet spot
US5037098 *Feb 7, 1990Aug 6, 1991Prince Manufacturing, Inc.Tennis racquet with tapered profile frame
US5062634 *Aug 31, 1990Nov 5, 1991Wilson Sporting Goods Co.Squash racket
US5183265 *Sep 11, 1990Feb 2, 1993Head Sportgerate Gesellschaft M.B.H. & Co. OhgRacquets, in particular tennis racquets
US5277422 *Sep 22, 1992Jan 11, 1994Dunlop LimitedGames racket frame
US5312102 *Feb 4, 1993May 17, 1994Lisco, Inc.Variable inertia head racket
US5540434 *Aug 21, 1990Jul 30, 1996Wilson Sporting Goods Co.Tennis racket
US5762571 *Aug 5, 1994Jun 9, 1998Degaris; Kenneth GodfreyUltra thin racquet frame
US5893810 *Aug 9, 1996Apr 13, 1999Head Sport AktiengesellschaftTennis rackets
US5980402 *Jun 4, 1998Nov 9, 1999Degaris; Kenneth GodfreyUltra-thin racquet frame
US6062994 *Apr 10, 1998May 16, 2000Ef Composite Technologies, L.P.Reinforced racquet with flat string bed
US6234921May 5, 1999May 22, 2001Benetton Sportsystem Usa, Inc.Sports racquets with tripod weighting
US6958104Aug 20, 2002Oct 25, 2005Ef Composite Technologies, L.P.Sports racket with undulations in frame interior surface
USRE31419 *Jan 28, 1981Oct 18, 1983 Tennis racket
USRE34067 *Jul 6, 1990Sep 15, 1992EktelonRacquetball racquet with increased hitting area improved racquetball racquet construction
USRE34068 *Jul 9, 1990Sep 15, 1992EktelonRacquetball raquet with increased hitting area
DE2932996A1 *Aug 14, 1979Feb 26, 1981Enoch Job Prof DurbinTennisschlaeger
DE3434898A1 *Sep 22, 1984Apr 17, 1986Siegfried KueblerSchlaeger fuer spiele mit begrenzt elastischem ball
DE4116901A1 *May 23, 1991Nov 26, 1992Donnay Int SaTennis racket with stiff head on flexible connecting arm
DE4322453C1 *Jul 6, 1993Feb 16, 1995Kuni TsengStrung racquet
EP0013595A1 *Jan 3, 1980Jul 23, 1980Starwin Industries Inc.Improvements in tennis racquets
EP0176021A2Sep 17, 1985Apr 2, 1986Siegfried KueblerTennis racket
EP0310169A2 *Sep 17, 1985Apr 5, 1989Siegfried KueblerRackets for ball games, especially tennis rackets
WO1980002510A1 *May 17, 1979Nov 27, 1980J FrolowTennis racket
WO1991003283A1 *Sep 11, 1990Mar 21, 1991Head Sportgeraete GmbhRacquets, especially tennis racquets
Classifications
U.S. Classification473/537
International ClassificationA63B49/02
Cooperative ClassificationA63B2049/0211, A63B49/02
European ClassificationA63B49/02