Cross Reference

This is a continuation-in-part application of my co-pending application Ser. No. 07/675,406 filed March 21, 1991 entitled "Racket Handle", which is a continuation-in-part of Ser. No. 562,406 filed August 2, 1990 entitled "Racket Handle", which is a continuation of Ser. No. 414,596 filed September 27, 1989 entitled "Racket Handle" which has been abandoned, which was a continuation of Ser. No. 178,210 filed April 6, 1988 entitled "Racket Handle", which was a continuation of Ser. No. 833,633 filed February 25, 1986 entitled "Racket Handle", which has been abandoned, which was a continuation of Ser. No. 601,488 filed April 18, 1984, entitled "Racket Handle" which has been abandoned. The disclosures of each of the above-mentioned applications are incorporated herein by reference.

Background of the Invention Field of the Invention

This invention relates generally to rackets and handles therefor and, more particularly, concerns tennis rackets in which the correct orientation of a player's grip on the racket handle is facilitated by the shape of the handle.

Background Art

In the play of tennis, a tennis racket is generally gripped in a different fashion for a forehand stroke than for a backhand stroke. If the tennis racket is properly gripped for each of these strokes, the ball is struck by the head of the racket with the ball-

contacting surface of the head oriented so that a proper trajectory of the ball results. In such a case the ball- contacting surface, defined by the racket strings, is generally, though not necessarily exactly, perpendicular to the ground at the point of impact with the tennis ball.

In order to obtain the proper racket orientation in the player's hand, the player typically relies upon the feel of the racket handle to position the handle relative to the player's palm, fingers, and thumb. It is generally impractical for the player to actually view the orientation of the racket in the player's hand in the course of play due to the speed with which the correct grip, forehand or backhand, must be selected, while the player also establishes proper position for striking the ball.

In the construction of a typical tennis racket, the handle is symmetrical, when viewed in endwise cross- section, about the plane of the striking surface of the racket head. Often the handle is also symmetrical about a plane perpendicular to the plane of the racket head. In such racket handles, the principal, or longest, surfaces of the handle are generally either parallel or perpendicular to the plane of the strings of the head of the racket. Consequently, in order to effect the proper grip, whether forehand or backhand, on the racket handle, the player must, by sense of feel, locate the appropriate major surface to be engaged by the hand and, by rotation of the racket handle in the hand, arrive at the desired orientation of these surfaces in hand.

The principal "feel" of the racket handle is obtained by the contact of the palm, fingers, and thumb of the player's hand with the major surfaces of the racket handle. In gripping a typical tennis racket handle, the exact location of, for example, a major surface of the racket handle within the palm of the hand

may be readily obtainable for an expert tennis player. However, obtaining this proper handle orientation is much more difficult for a less experienced player. Since even a relatively small degree of misorientation of the racket in the player's hand can result in an improper trajectory for the ball, inaccuracies in a player's grip can have a greatly adverse effect upon the player's game. A variation in 1 degree of handle turn can vary where the ball lands by 5 or 6 feet.

Traditionally, tennis players have used the "Eastern grip" for grasping the tennis racket. The Eastern grip is obtained by "shaking hands" with the racket. In other words, the player's palm is placed flush against the handle's widest surface. Most players using an Eastern grip will have the racket head several degrees from vertical when striking a tennis ball. This is because players are taught to strike a ball as if they are striking with their hand vertical and when an Eastern grip is used most players will align the racket head several degrees from vertical. However, when the racket head is vertical or very close to vertical at the point of impact the most consistently accurate tennis shots can be made.

When using the Eastern grip most players find it necessary to rotate the racket handle in the hand to execute a backhand stroke. As a player changes from a forehand stroke to a backhand stroke, therefore, the racket must be continuously realigned, increasing the possibility of misalignment when striking a ball.

Many players who are gripping a typical tennis racket using an Eastern grip will compensate for the upwards orientation of the racket head by providing a rapid rotation (pronation) of the forearm as they swing through a ball to keep from hitting the ball off the court. This rapid pronation places unnecessary stress on

the forearm prior to and after impact and has been known to lead to several types of elbow injury.

Recently, top players have been rotating the traditional tennis racket grip a quarter turn to allow them to more consistently strike the ball with the racket head in a vertical alignment. This grip is called the "semi-Western" grip. In this way, it becomes easier for a player to accurately deliver a shot and to hit "over" the ball to produce a top spin, thus improving the quality of the player's game. Ivan Lendl, Boris Becker and most top Swedish players use this altered grip.

Using a traditional racket handle rotated in the player's hand to effect the semi-Western grip is difficult because, as discussed above, it is hard for players to feel when the racket head is properly aligned. In addition, when a ball is off center there is a tendency for the racket to twist from a proper alignment in the player's hand because no surface of the racket is flush with the player's palm.

In the past, various types of racket handles have been proposed which include such features as special contours, or finger and thumb-receiving grooves, for assisting in orienting a player's hand on the racket handle. Such proposed handles have been formed more or less in the shape of "pistol grips" and the like. Such grips, while they permit better orientation of the hand on a racket handle, have been found objectionable because they lack the "feel" of a conventional tennis racket handle to which players have become accustomed. In addition, such "pistol grip" types of formed racket handles often fail to provide proper hand orientation for both forehand and backhand grips. In most cases, such rackets must be custom made for each individual player, which greatly adds to the cost of the racket.

Summary of the Invention

It is consequently the general aim of the present invention to provide a tennis racket handle which can be easily and accurately positioned in a player's hand for either a forehand or a backhand stroke, and with which the "feel" of a conventional racket handle is retained. Also, an aim of the present invention is to provide a racket handle that facilitates proper alignment of the racket head in delivering either a forehand or backhand shot without rotating the handle. In addition, an aim of the present invention is to provide a tennis racket handle that facilitates a semi-Western grip or vertical alignment of the racket head as a tennis ball is struck to provide a more accurate shot. A further aim of the present invention is to provide a racket handle that aligns the racket as a natural extension of the skeletal structure of the human arm, i.e., which aligns the racket head parallel to the position of a player's hand when a ball is struck, and in which this alignment is vertical. An additional aim of the present invention is to provide a tennis racket handle that aligns the racket head with the palm of a player's hand in an anatomically correct position which decreases the stress on the player's forearm and elbow as the player swings through a ball.

These objectives have been accomplished in accordance with certain principles of the invention by the provision of a tennis racket having a head portion with a substantially planar ball-striking surface and a prism-shaped handle portion connected to the head portion in which the prism-shaped handle is asymmetric with respect to the plane defined by the planar striking surface.

In one form of the invention, the prism-shaped handle portion has a polygonal base in the shape of a regular hexagon. Two opposite and parallel sides of the regular hexagon are bisected by a second plane which

intersects the plane defined by the planar striking surface at an acute angle which ranges from greater than 0° to approximately 40°, preferably ranging from greater than 0° to approximately 30".

Brief Description of the Drawings

Other objects and advantages of the invention, and the manner of their implementation, will become apparent upon reading the following detailed description and upon reference to the drawings, in which:

Fig. 1 is a perspective view of a tennis racket having a head portion and a handle portion constructed in accordance with the present invention;

Fig. 2 is a cross-sectional view of the handle of Fig. 1 taken along the line 2-2 and in the direction of the arrows;

Figs. 3a and 3b are perspective views of a portion of the tennis racket handle showing a forehand grip thereon; ^*

Figs. 4a and 4b are perspective views of the handle portion of Figs. 3a and 3b showing a backhand grip thereon;

Figs. 5a-5c are cross-sectional views of modified forms of handle construction according to the present invention;

Figs. 6-11 are cross-sectional views of other modified forms of handle construction according to the present invention;

Figs. 12a and 12b are perspective views of a section of the handle of Fig. 2 which is in the shape of a prism; and

Fig. 13 is a cross-sectional view of a handle construction which is asymmetric with respect to the planar striking surface.

Detailed Description of the Drawings

While the invention is susceptible to various modifications and alternative forms, certain illustrative embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but, on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Turning now to the figures, a tennis racket 10 includes a head portion 11 and a handle portion 12 joined by a neck portion 13. The particular construction of the head 11 and the neck 13, and the internal construction of the handle 12, are not critical to the practice of the present invention. As best shown in Fig. 2, the perimeter of the handle 12 is made up of six faces, identified A through F. The six surfaces are contiguous with each other, i.e., F is contiguous with D and B, etc. However, the corners at the juncture of any two contiguous surfaces might be altered, i.e., slightly rounded, flattened, without departing from the invention. In other words, A is adjacent to E and C and C is adjacent to A and B, etc. The surfaces A through F preferably are shown to have the same dimensions lengthwise of the handle portion 12 so that each surface is substantially rectangular, however, that is not necessary. The width of the surfaces may vary. Viewed in cross section, the handle is symmetrical about a plane 14 of the striking surface of the head 11 of the racket 10, which may be regarded as a plane in the center of the strings 16 in the racket head 11. That is, the cross section of the handle on opposite sides of the plane 14 is a mirror image of itself. The plane 14 coincides with a center line X for the racket extending through both the

head portion 11 and handle portion 12 in the embodiment shown. The central axis of the handle portion 12 need not, however, extend through the center of the head portion 11, as where the handle is offset or is slightly angled with respect to the plane of the ball striking surface. For simplification the strings 16 can be viewed as defining a plane with oppositely facing striking surfaces.

Another way of describing the handle is shown in Fig. 12a in which the handle has two parallel planes 20 and 22, which are perpendicular to the plane of the striking surface 14, intersect the handle 12 (dashed lines). Upon their intersection the planes 20, 22 and the handle 12 define a prism having two polygonal bases 24 and 26 and a plurality of rectangular surfaces 28 as shown in Fig. 12b. As will be seen in the Figures it is preferred that at least one of the plurality of rectangular surfaces 28 or sides of the polygonal bases 24 and 26 defines with a plane parallel to the plane of the striking surface an angle ranging from approximately 25° to 40°. Though the description to follow will define the handle with respect to the surfaces, it should be understood that any description of the length of the surfaces is applicable to corresponding sides of the polygonal bases 24 and 26. Thus, a lengthening of surface A would correspond to a lengthening of a corresponding side A of each polygonal base 24, 26. In the illustrated racket handle 12, the six handle surfaces include two longest, or major, surfaces A and B, two minor surfaces C and D, and two intermediate surfaces E and F. In the illustrated form of the invention, the minor surfaces C and D are perpendicular to the plane 14, and in the illustrated handle the surfaces D, E and F are equal in length, as viewed in the cross section of Fig. 2. The illustrated major surfaces A and B are also equal in length, as viewed in Figure 2, and form equal angles

"a" and "b" with planes parallel to the ball-striking plane 14. The angles "a" and "b" are between 25° and 40°, and preferably lie in the range of 29° to 37°. Preferably, surfaces E and F are parallel to surfaces B and A respectively throughout the entire contemplated range of angles for "a" and "b", i.e. DE and DF range between 115° and 130°, however this is not absolutely necessary. For angles for "a" and "b" within the range of 25° and 40°, it is presently believed that proper forehand and backhand grips on the racket, in a manner to be discussed, can be obtained by players having a range of forms in striking the ball. In rackets thus far constructed, it has been found that the angles "a" and "b" are between 31° and 36°. In the illustrated racket handle, the angles "a" and "b" are 34°.

In the cross section of Fig. 2, the handle 12 has two principal dimensions. The first is the distance between the minor surfaces C and D, indicated CD in the figure. The second principal dimension is the distance between the intersection points AE and BF, indicated W in the figure. In the illustrated form of the invention, the distance W is preferably greater than or equal to the distance CD.

A right-handed player grips the racket 10 for a forehand stroke as shown in Figs. 3a and 3b. In the forehand grip illustrated, for a righthanded player, the palm of the hand engages the major surface B of the handle 12. The thumb grasps the handle about the surfaces F and D, with the tip of the thumb extending onto the surface E. The bases of the fingers contact the surface C, with the fingertips extending about the handle into contact with the surfaces E and D. The fingers encircle the surface A, without significantly contacting the surface.

The principal gripping force on the racket is exerted between the surfaces B and E, with the spacing

between these surfaces cooperating with the arrangement of the other faces to produce the "feel" of a conventional tennis racket handle. The handle of the racket face is ensured to be substantially correct due to the angle "b" of the major surface B with the ball- contacting plane 14 of the racket face. The relative size of the surface B results in the accurate orientation of the racket in the player's hand to produce the proper orientation of the racket head when the ball is struck. To grip the handle for a backhand stroke, the racket handle may be grasped as shown in Figs. 4a and 4b. For a backhand stroke, by a righthanded player, the palm of the hand engages the surfaces D and E, with the thumb extending along the surface A. The bases of the fingers lie along the surface F, and the fingers extend around the surface B, without significant contact thereon, with the fingertips engaging the surface C and extending partially onto the surface A. The primary grasping force for the backhand stroke is exerted between (a) the surfaces D and E and (b) the surface C. Due to the spacing between these surfaces, and the contour of the other surfaces, the "feel" of the racket in the backhand grip is similar to that of a conventional racket.

Alternatively, when using the handle of the present invention a player may deliver a backhand stroke with the racket head properly aligned by grasping the racket as illustrated in Figs. 3A and 3B, i.e., without rotating the racket handle.

The forehand and backhand grips for the racket 12, for a lefthanded player, are analogous to those illustrated for a righthanded player. For a forehand grip, for example, a lefthanded player grasps the racket handle 12 with the player's palm engaging the surface A. For a backhand stroke, the palm-engaging surfaces are the surfaces D and F, or as discussed above, may be identical to the forehand grip.

The perimeter dimension of the handle 12 may be increased or decreased, preferably while maintaining the relative proportions of the handle surfaces, to properly size the handle dependent upon the size of the hand of the player. In this way, a racket handle of the configuration shown may be provided wherein the palm, fingers and thumb of any size hand lie on the requisite surfaces, as set forth above.

While only a single preferred embodiment of the present invention has thus far been described, those persons skilled in the art to which the invention pertains will readily appreciate that changes and modifications may be made without departing from the spirit of the invention. For example, the intermediate surfaces E and F and the minor surface D need not be of the same length, as viewed in the cross-sectional view of Fig. 2. As another example, the end of the handle may be of an enlarged cross-section relative to the remainder of the handle to reduce the tendency of the handle to slide from the player's grasp during play.

It has been found, as a further example, that the major surfaces A and B (as shown in Fig. 2) can be more easily located by making these surfaces slightly larger. This can facilitate obtaining a proper grip upon the racket handle.

As shown in Fig. 5, the major surfaces A' and B' are lengthened, and the intermediate surfaces E' and F' are slightly shortened (relative to the surfaces A, B, E and F of Fig. 2). The lengths of the minor surfaces C and D remain the same, and the angles "a" and "b" remain the same, as those shown in the handle of Fig. 2.

In the handle of Fig. 2, the angles DF and DE are about 124°. In the handles illustrated in Figs. 5a, 5b and 5c, these angles are increased, with resultant lengthening of the surfaces A' and B' (Figure 5a), A'' and B'' (Figure 5b), and A''' and B' ' ' (Figure 5c). In

Figure 5a the angles DF' and DE' are about 135°. In Figure 5b the angles DF" and DE'' are about 140-1/2°, and in Figure 5c the angles DF''' and DE''' are about 146°. The invention also contemplates all angles between 124° and 146°.

Further modified forms of handle construction according to the present invention are depicted in Figs. 6-9. In Fig. 6, a simplified version of the inventive handle is shown at 50 designed for a right-handed individual. The handle portion 50 has an overall cylindrical shape with a central axis Y and a flat side AA. Another way of describing the handle is to have two parallel planes, which are perpendicular to the planar striking surface, intersect the handle 12 in a manner similar to that shown in Fig. 12a. The planes and the handle define a cylinder-like solid comprising two bases with a curved surface and a planar rectangular surface joining the two bases. As seen in Figure 6, the rectangular planar surface AA defines with a plane parallel to the planar striking surface an angle "a" ranging from approximately 25° to 40°. The similarities between the handle portion in Fig. 6 and that in Fig. 2 are demonstrated by illustrating the handle portion 50 circumscribed around a phantom representation of the Fig. 2 handle. The angle "a", as in the prior embodiments, ranges preferably between 25°-40°.

In Fig. 7, a handle portion is shown having a configuration similar to that of the handle in Fig. 2 and corresponding sides A ⁴ -F ⁴ . One of the differences between the Fig. 2 and Fig. 7 handles is that the surface C ⁴ , corresponding to surface C, is equal in length to the surface D ⁴ corresponding to the surface D in Fig. 2. Further, the handle in Fig. 7 has three oppositely facing or diametrically opposed pairs of parallel sides - A ⁴ , F ⁴ ; B ⁴ , E ⁴ ; and C ⁴ , D ⁴ . The lengths of sides A ⁴ , B ⁴ , E ⁴ and F ⁴

are approximately the same and less than the lengths of C and D ⁴ .

The surfaces E ⁴ and A ⁴ meet either at a point 54, as shown in solid lines in Fig. 7, or alternatively are connected by flat surface 56, shown in phantom. On the opposite side of the Fig. 7 handle portion, surfaces B ⁴ , F ⁴ , meet either at a point 58, as shown in solid lines in Fig. 7, or are connected by a flat surface 60.

In Fig. 8, a handle is shown similar to that in Fig. 7 with the difference being that surfaces C ⁵ and D ⁵ , corresponding to C ⁴ and D ⁴ in Fig. 7, are of the same length and shorter than surfaces A ⁵ , B ⁵ , E ⁵ and F ⁵ , all of which are of equal length. The handle surfaces A ⁵ , E ⁵ and B , F in Fig. 8 meet each other at apexes 54', 58', respectively, or are joined to each other by surfaces 56', 60', corresponding to surfaces 56, 60 in Fig. 7.

In Fig. 9, a handle is shown similar to that in Figs. 7 and 8., however, surfaces corresponding to C ⁴ , D ⁴ , C , and D ⁵ have been eliminated. The surfaces E ⁵ , F ⁵ in Fig. 9 directly connect at apex 64 while surfaces A ⁵ , B ⁵ , meet at apex 66. The handle in Fig. 9 may have surfaces shown in phantom at 56'', 60'' to connect surfaces E ⁵ , A ⁵ and B ⁵ , F ⁵ , respectively, to eliminate apexes 54'' and 58' ' .

In the embodiments for the inventive handle shown in Figs. 7-9, the angle "a" makes an angle preferably between 25°-40° with the plane 14 of the striking surface of the head 11 of the racket 10.

In Fig. 10, the handle portion is shown having a configuration similar to that of the handle in Fig. 7 and with corresponding sides A ⁶ -F ⁶ . The principle difference between Fig. 7 and Fig. 10 is that the surfaces A ⁶ -F ⁶ corresponding to surfaces A -F are substantially equal in length to each other. In addition, the planes formed by surfaces D ⁶ and C ⁶ are

substantially perpendicular to the ball-contacting plane 14 of the racket face. Finally, the angles "a" and "b" make an angle of about 25° to 40° with the plane 14 of the striking surface of the head 11 of the racket 10. An angle of about 33° is preferred. The angles D ⁶ F ⁶ , D ⁶ E ⁶ , B ^B C ^ε , C ⁶ A ⁶ , E ⁶ A ⁶ and F ^ε B ⁶ may be any angle between about 125° and 110°. In the embodiment of Fig. 10, the angles D ⁶ F ⁶ , D ⁶ E ⁶ , B ⁶ C ⁶ and C ⁶ A ^ε are preferably about 123° and the angles E ^ε A ⁶ and F ⁶ B ⁶ are about 114°.

In Fig. 11, the handle portion is shown with a configuration similar to Fig. 10 and with corresponding sides A ⁷ -F ⁷ . In Fig. 11 the angles D ⁷ F ⁷ , D ⁷ E ⁷ , B ⁷ C ⁷ , C ⁷ A ⁷ , E ⁷ A ⁷ and F ⁷ B ⁷ are all equal to 120° and the sides A ⁷ -F ⁷ are equal width. Thus, the cross-section of the handle of Fig. 11 is a regular hexagon. When the surfaces D and E are perpendicular to the plane of the racket head as shown in Fig. 11, the angles a and b are 30°. The angle "a" may be between about 25° and 40°, which of course would cause the surfaces D and-C to not be perpendicular to the ball striking surface (except when a and b are exactly 30°) and resulting to the prism-shaped handle being asymmetric with respect to a plane parallel to the planar striking surface. As seen in Fig. 13, having the angle "a" ranging between about 25° and 45° results in the plane of the striking surface 14 forming an angle (θ) between the plane 14 and a plane of symmetry 16 which ranges from approximately -5° to approximately 10°, wherein a negative angle denotes that plane 14 intersects side D to the right of the plane of symmetry 16 and a positive angle denotes intersection to the left of the plane 16.

Furthermore, it has been discovered that for a prism-shaped handle improved "feel" and orientation are achieved when the prism-shaped handle is asymmetric with respect to a first plane parallel to or defined by the planar striking surface. This is illustrated in Fig. 13

where the orientation between a regular hexagon and the plane 14 defined by the planar striking surface is shown. The plane 14 of the striking surface preferably intersects the center 30 of the regular hexagon, but may also be displaced from the center 30. The plane 14 of the striking surface is angled with respect to a second plane 16 defines a plane of symmetry for the prism-shaped handle and preferably bisects and is perpendicular to the two parallel sides C ⁸ and D ⁸ . The acute angle (θ) between the planes 14 and 16, measured from either the left or right of plane 16, ranges from greater than 0° to approximately 40° and preferably ranges from greater than 0° to approximately 30°. Similarly, it is also contemplated that the plane of the striking surface and a plane of symmetry for the regular hexagon inscribed by the cylinder-like handle of Fig. 6 define an angle ranging from greater than 0° to approximately 40° and preferably from greater than 0° to approximately 30°.

The" racket handle of the present invention is a significant improvement over traditional racket handles in that, when the plane of the striking surface defines an acute angle ranging from greater than 0° to approximately 40° with respect to a plane of symmetry of the prism-shaped handle, the racket head is automatically aligned consistent with the semi-Western grip. The handle therefore facilitates a grip which aligns the racket as a natural extension of the skeletal structure of the human arm with the racket head parallel to the position of a player's hand when a ball is struck, i.e., with the racket head vertical. By facilitating a semi- Western grip and a vertical orientation of the racket head when a tennis ball is struck, the consistency and accuracy of tennis strokes are improved and it becomes easier to add top spin to a tennis ball. Moreover, this orientation reduces the stress on many players' forearms

and elbows which results from trying to properly align the racket head using an Eastern grip.

The racket handle illustrated in Fig. 10 has been found particularly advantageous for use by the general population. Tests conducted by major research universities have indicted that using a tennis racket handle of the present invention which aligns the palm of the player's hand at about a 33° angle from the plane of the racket head provides a significant improvement in the play of most novice players. Indeed, tests conducted by these institutions have shown that between 50% and 80% of tennis players will have an improved racket head alignment using such handles.

The improvement in such a large percentage of the tennis playing population could have a significant impact on the tennis industry. One report estimates that there are approximately 10 million casual players and 20 to 30 million ex-players in the United States alone. Improving the play of this population undoubtedly will increase their interest in the game and lead to a corresponding increase in the sale of tennis rackets and other tennis equipment. It has even been suggested that by promoting the use of the semi-Western grip Americans can match the competitive edge such European players as Ivan Lendl, Boris Becker and several top Swedish players have enjoyed in recent years of international competition.