Abstract:
The present invention relates to apparatus and methods for improving a stroke technique for a racquet sport comprising a frame extension or a modified-type racquet frame and a training mat. Other aspects of the invention are also provided.

Description:
RELATED APPLICATIONS  
       [0001]     This application is related to, claims priority to, and herein incorporates by reference in its entirety, including all drawings, U.S. Provisional Patent Application Ser. No. 60/587,229, entitled “TENNIS STROKE TRAINING APPARATUS AND METHOD”, which application was filed Jul. 12, 2004. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to an athletic training apparatus and method for practicing correct strokes with a racquet, such as with a tennis racquet, racquetball racquet, squash racquet, or any other racquet used in a racquet sport.  
       BACKGROUND OF THE INVENTION  
       [0003]     As it is well known to players and teachers of the game of tennis, there are many different strokes that are required to be mastered if a player is to progress in his proficiency in the game. The game can essentially be broken down into three major types of strokes used to impact a tennis ball. The first type of stroke is the forehand and backhand groundstrokes that a player uses while hitting a ball from the baseline of the tennis court. These are essentially long fluid swings of the racquet to send the ball back to the opposing side of the court. Because the tennis player is positioned in the back of the court, he has ample reaction time to produce a long fluid stroke. The second type of stroke is the overhead serve that a player uses to initiate a point. It is also a long fluid stroke that takes place over the shoulder of the player. The reason for the long fluid stroke is that because the player is initiating the point, he has plenty of time to decide when to contact the ball and thus wants to create as much power as possible thus using a longer stroke. The third type of stroke is known as the volley which a tennis player uses when he is near the middle of the full length of the court close to the net and is a short, punch-like stroke as a result of the little time afforded to prepare for the ball&#39;s arrival as well as the fact that little power is needed to return the ball to the opponents court.  
         [0004]     Various techniques have been tried over the years to provide players with help in practicing tennis swings. One type of such device comprises a practice ball, tethered to a support assembly separate from the racket. Examples of such apparatus are shown in U.S. Pat. No. 2,270,957 granted Jan. 27, 1942, to S. W. Mirrs, and U.S. Pat. No. 1,862,044, granted Jun. 7, 1932, to T. M. Flight. While the invention does provide for the imminent return of the ball, it does create a low return trajectory that a player must stoop to intercept, which is quite unlike the volley position in which a ball is struck usually from waist to shoulder height.  
         [0005]     Some of the devices developed over the years for improving a tennis stroke are attached directly to the player. An exemplary garment is worn by a player having a shaft slightly wider than the shoulder width which includes indicators at each end to give the player a visual cue for proper shoulder rotation (U.S. Pat. No. 6,102,809). Other devices exist where a tennis ball or the like is attached to the upper end of a flexible arm, and the player swings a racquet or the like to impact the ball thereby causing the flexible arm to rotate away from the player. Typically such devices have a spring or other mechanism such that the arm can rotate back towards the player so that the ball can be repeatedly hit. Although such devices can simulate the resistance of a ball during actual play, such devices typically offer the player little guidance on how to maintain a proper stoke technique. Many other variations of devices linking the racquet to the player have been described, such as for example in U.S. Pat. Nos. 3,937,465; 4,519,608; 5,618,040; 4,752,070; 5,060,942; 5,439,214; 6,062,993; 5,257,779; 5,476,257; and 3,693,973 and in WO92/07635, WO98/11957, US 2002/0165070 and US 2004/0077438.  
         [0006]     Other apparatus developed for improving the stroke of players involve making modifications or attachments to the tennis racquet which is used to play the game. For example, there is disclosed a pouch which can be attached to a stringless tennis racquet used for catching a ball (U.S. Pat. No. 3,503,611), and a signaling device which is attached to a tennis racquet which includes a plurality of mechanical reed members, the longitudinal axes of which are disposed with respect to the tennis racquet as to be aligned with the stroke direction when a proper stroke is performed (U.S. Pat. No. 4,094,504). Other racquet-based devices include those disclosed in U.S. Pat. Nos. 5,755,633; 4,027,881; 4,353,551; 3,907,292; 4,153,249; 4,478,416; 4,101,125; 4,128,240; 4,143,873; 4,163,552; 4,759,546; 4,094,504; 5,560,600; 4,063,730; 4,595,201; 5,807,196; 6,432,004; 5,409,217, and PCT applications WO00/10657, WO88/01890, WO93/24189, WO94/07577, WO80/00062, and WO01/97923.  
         [0007]     Still other devices for improving the stroke technique of players are those devices which are separate from the player as well as the instrument used to play the game. One of the earliest devices in the game of tennis is the backboard where an athlete hits a tennis ball toward a large, vertical wall, and the ball rebounds back to the player. Preferably, the wall will have a single, horizontal painted line to simulate the top of the net found in a tennis court. While the use of such a wall may be helpful for obtaining exercise and improving aim, basic tennis strokes cannot efficiently be practiced on such a device. Most players must direct their attention on running toward the ball and returning the same to the wall, and therefore have little time to concentrate on the actual stroke. The quick response necessary for practice against the wall increases the likelihood that the player will repeat bad habits which could irrevocably become engrained in the player&#39;s style. Additionally, such walls are typically located outdoors and consequently practice is impossible when inclement weather exists. Additionally, such walls are expensive to build and are subject to expensive maintenance particularly where the surface is wooded thereby requiring frequent repainting.  
         [0008]     A still further type of tennis stroke training apparatus is disclosed in U.S. Pat. No. 4,105,204. The apparatus comprises a base having an upstanding member which receives a Z-shaped tube. The tube has a ball positioned on it whereby a user can place a stringless tennis racquet at the free end of the tube and practice his or her stroke by swinging the racquet throughout the length of the Z-shaped tube. Although the apparatus is useful in the sense that it offers more guidance on proper stroke technique than the typical hit-the-ball apparatus, it has the disadvantage that the user must use a stringless racquet. U.S. Pat. No. 6,645,094 discloses a swing training device consisting of a frame and rails, and U.S. Pat. 6,648,780 discloses a device which attaches to a tennis racquet by means of a cable and pulley fastened to a wall or ceiling. U.S. Pat. No. 6,213,924 discloses a torso twisting device and WO99/26704 describes an electronic sensor system for determining the spatial movement of a player in racquet swing. U.S. Pat. No. 5,156,402 describes a fixed frame attached to a variable resistance swing training element which is coupled to the floor.  
         [0009]     A system employing adhesive dots applied to a tennis court to indicate the relative position of a bouncing ball has been described in U.S. Pat. No. 4,948,372. A method of teaching and illustrating tennis strokes is disclosed in US2004/0038761.  
         [0010]     Thus despite the variety of tennis stroke training devices developed over the years, there still exists a need for a device which is inexpensive to make, easy to assemble and which does not require the need for any expensive, non-portable specialized equipment to use.  
         [0011]     It will be appreciated from the foregoing that there is still a definite need to provide a simple and inexpensive teaching tool that is simple, inexpensive, unobtrusive, light in weight, and easily attachable to the racquet, to create a conducive environment is which a stroke can be practiced in conditions similar to that experienced in a conventional game.  
         [0012]     The citation and/or discussion of cited references in this section and throughout the specification is provided merely to clarify the description of the present invention and is not an admission that any such reference is “prior art” to the present invention. Each of the cited art is incorporated herein by reference and may be used to by those skilled in the art with respect to the present invention and its description herein.  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention provides a novel racquet attachment comprising a circumferentially extended halo member ( 10 ) which is removably or permanently attached to the frame ( 20 ) of the racquet by at least one attachment means. The attachment means typically does not interfere with the stringed striking surface of the racquet, permitting the racquet to be used to contact and strike tennis balls or the like while the extended halo member is attached. A principle aspect of the invention is the use of said racquet attachment to provide perceptible feedback to the user regarding the angle of the racquet face relative to the plane perpendicular to the court surface or floor, with an objective typically being the maintenance of a consistent racquet angle (i.e., the angle between the racquet face plane and the ground) prior to the post-ballstrike wrap. The invention provides a feedback means to monitor that the racquet swing maintains a consistent racquet angle as the racquet traverses the hitting zone (i.e., the point in the swing where the racquet is anticipated to contact the tennis ball) and often during substantially the entire stroke by making it facile for the user to monitor the racquet angle by visual and/or tactile feedback provided by the extended halo member. In typical embodiments, the invention comprises a method of using a racquet comprising an extended halo member comprising the step of the user observing the position of the extended halo member (which may in some cases be an integral component of the racquet frame) during a tennis stroke and maintaining a predetermined racquet angle by monitoring visual and/or tactile feedback from said extended halo member. For a beginning tennis player user it is typically desirable for the user to maintain a zero angle (racquet face perpendicular to the floor or court surface) throughout the swing prior to the post-strike wrap. However, for intermediate and advanced player users it is often desirable for the user to maintain a racquet angle which is either an open-face angle or a closed-face angle, depending upon the desire of the user to practice a back-spin stroke or a top-spin stroke. It is important for the user to monitor the position of the extended halo member as the racquet traverses the hitting zone and make adjustments, if necessary, to maintain a consistent desired racquet angle through the hitting zone, and preferably through the entire stroke from beginning to finish in many embodiments.  
         [0014]     The extended halo member ( 10 ) can be coupled to the racquet in several different ways, including but not limited to: (i) permanent attachment to the racquet by being molded into the racquet frame as an integral member, (ii) permanent attachment to the racquet by any of various attachment means (e.g., fastener, glue, clamp, weld, etc.), (iii) removable attachment to the racquet by a removable means (e.g., magnet, Velcro, removable clamp, removable fastener, suction cup, string wrap, tape, reusable non-hardening glue, etc.), or (iv) by other means selected by those skilled in the art.  
         [0015]     The extended halo member ( 10 ) can be attached to the racquet frame ( 20 ) directly, or through at least one attachment member ( 21 ) which comprises an attachment point ( 22 ). The length of said attachment member can vary, but is typically at least 0.5 inches and often is in the range of 1 inch to 18 inches in length, most usually 3 to 6 inches providing a separation distance between the racquet frame ( 20 ) and the extended halo member ( 10 ). The separation distance between the extended halo member ( 10 ) and the racquet frame ( 20 ) will vary around the circumference of the racquet head ( 30 ) due in part to the eccentric shape of many racquet heads; a typical average separation distance is 3 to 4 inches. In an aspect of the invention, the extended halo member ( 10 ) is attached to the racquet frame ( 20 ) by at least one attachment member ( 21 ) through at least one attachment point ( 22 ) to the racquet head ( 30 ) and/or by at least one throat junction ( 41 ) to the racquet throat ( 40 ). The attachment point(s) ( 22 ) and throat junction(s) ( 41 ) are generically termed the halo-frame coupling point(s). Alternative halo-frame coupling points may include points on the grip ( 50 ) or substantially any part of the racquet frame, or in less preferred embodiments even the stringed racquet face ( 60 ).  
         [0016]     The invention comprises an extended halo racquet which comprises an extended halo member ( 10 ) coupled to a racquet frame ( 20 ) through an attachment means on at least one halo-frame coupling point. In an embodiment, the extended halo member ( 10 ) is affixed to the racquet frame ( 20 ) so that the longitudinal plane of the extended halo member ( 10 ) is parallel to the plane of the stringed portion of the striking surface ( 60 ) or in embodiments where the racquet is not strung, the longitudinal plane of the extended halo member ( 10 ) is parallel to the plane of the racquet head ( 30 ) formed by the major and minor axes of the head. In embodiments wherein the extended halo member ( 10 ) is in the same plane as the racquet head ( 30 ) or the stringed portion ( 60 ), the extended halo member ( 10 ) can be termed a circumferential halo member. In a variation, the attachment means can be reversibly removed and may be referred to as a removable attachment means which can link a removable extended halo member ( 10 ) with a racquet frame ( 20 ). In an alternative variation, the attachment means is substantially permanent, such as the extended halo member ( 10 ) comprising a molded portion of the racquet or being affixed to the racquet in a substantially permanent manner not intended for facile removal. In an embodiment, the extended halo member is affixed only to one side of the racquet frame or to the apex of the racquet frame. The extended halo member may be comprised of substantially the same material as the racquet frame or may be comprised of a material that has different chemical (e.g., metal, plastic, carbon-fiber, etc.), physical (e.g., density, elastic modulus, etc.), and/or appearance (e.g., coloration or texture) than the racquet frame, including in embodiments in which the extended halo member is permanently affixed to the racquet frame or molded into the frame itself.  
         [0017]     The invention comprises an extended halo member ( 10 ) which comprises a solid or hollow elongated material shaped to extend substantially around the periphery of a racquet frame head ( 30 ) and to be attached to the racquet frame ( 20 ) by at least one halo-frame coupling point. In an embodiment, the extended halo member ( 10 ) will further comprise at least one throat junction ( 41 ). In an embodiment, the extended halo member will further comprise at least one attachment point ( 22 ), and optionally will further comprise an attachment member ( 22 ) that is at least one-tenth centimeter in length and less than  180  centimeters in length. Alternatively, in some embodiments the extended halo member ( 10 ) may be coupled to the racquet frame ( 20 ) directly through an attachment point ( 22 ) which is integral to the extended halo member ( 10 ). According to some embodiments of the invention, the extended halo member ( 10 ) will further comprise at least one attachment point ( 22 ) to the racquet head ( 30 ) and/or by at least one throat junction ( 41 ) for coupling to the racquet throat ( 40 ). In variations of such embodiments, the extended halo member will further comprise between 1 and 200 attachment members ( 22 ) and between 1 and 8 throat junctions, with preferred embodiments comprising at least 2 attachment members ( 22 ) and at least one throat junction ( 41 ), and a more preferred embodiment having three attachment members ( 22 ) and two throat junctions ( 41 ) and wherein the attachment members are symmetrically attached to the racquet frame ( 20 ) so that the weight is balanced about the racquet and more preferentially it is balanced about the racquet head ( 30 ) center of gravity. In an embodiment, the distal portion of the racquet frame ( 31 ) and/or the throat junction ( 40 ) may further comprise weighting elements, such as removable weights, slidable weights, or other weighting means to adjust the center-of-gravity of the racquet and/or the weight balance of the racquet head ( 30 ).  
         [0018]     The invention comprises a racquet which comprises a substantially conventional racquet used for racquet sports and which further comprises an extended halo member ( 10 ) joined to said conventional racquet via attachment means. In a variation, the attachment means are reversible and/or removable attachment means. In a variation, the extended halo member consists of an extended integral portion of the racquet frame, such that the extended halo portion of the racquet is fabricated into the racquet frame as an integral component. The invention also comprises a halo-frame racquet having a unified frame comprising (1) an internal stringing frame portion wherein the racquet strings are attached to and (2) an integral halo member frame portion which is typically in the same plane as the internal stringing frame and which is circumferentially displaced (i.e., distal) to the exterior of the internal stringing frame portion. The integral halo member frame portion may be directly molded or forged into the halo-racquet frame as an integral structural component of the frame during frame manufacture.  
         [0019]     The invention comprises an extended halo member ( 10 ) which further comprises a distinctive coloration cue located on one or more positions on the extended halo member ( 10 ) which can be observed by the user during practice swings and which will indicate either proper or improper swing geometry based upon the face angle of the striking surface ( 60 ) of the racquet head ( 20 ). In an embodiment, a plurality of coloration cues are located on the extended halo member ( 10 ), with a first coloration cue comprising a first color located on the extended halo member ( 10 ) at a position which is substantially invisible to the user if the swing motion is correct and substantially visible to the user if the swing motion is incorrect in at least one respect, and with a second coloration which is substantially visible to the user if the swing motion is correct and substantially invisible to the user if the swing motion is incorrect in at least one respect. In an embodiment of the invention, the extended halo member which further comprises a distinctive coloration cue is permanently attached to or an integral component of the racquet frame.  
         [0020]     The invention comprises an extended halo member ( 10 ) having at least one position for attachment of ancillary devices such as: (i) weight components to adjust the relative weight distribution of the racquet and/or center of gravity of the racquet and/or racquet head, (ii) stabilizer bars which strengthen the rigidity of the extended halo member ( 10 ) relative to the racquet, (iii) level detectors (e.g., liquid-based bubble levels, laser levels, or the like), (iv) illumination sources, (v) acoustic holes or slits which provide a first sound frequency when the racquet face is oriented perpendicular to the airflow passing the racquet head and a second sound frequency when the racquet face is oriented other than perpendicular to the relative airflow passing the racquet head, (vi) vibrating means which provide a vibrational signal to the user when the racquet face is other than perpendicular to the ground or to the relative airflow, (vii) tactile means to provide a tactile, audible, or vibratory signal to the user to report completion of a proper wrap wherein the extended halo member ( 10 ) makes contact with the user&#39;s shoulder after completion of the racquet swing, and (viii) an electronic sensor to provide an electronic or radio signal reporting the relative angle of the racquet face to the ground and/or relative airflow. In some embodiments, one or more of these ancillary devices is integral to the extended halo member ( 10 ), such as for example and not limitation an ancillary device attached to the lower portion of the extended halo member ( 70 ) which makes contact with the user&#39;s shoulder upon correct swingthrough and wrap and, upon said contact, reports a detectable signal (tactile, audible, vibrational, visual, or the like) to the user. Each of these features and combinations thereof can also be included in an extended halo member portion of an integral halo-frame racquet; these features may themselves be permanently attached to the halo-frame racquet or they may be removably attached, or combinations thereof. An integral halo-frame racquet may include predetermined attachment points providing for removable or permanent attachment of at least one of these ancillary devices; in some variations the ancillary device(s) may be molded into the integral halo-frame racquet as a fixed (i.e., non-removable) component thereof.  
         [0021]     The extended halo member ( 10 ) may also comprise coloration cues, such as having the interior diameter of a first color and the exterior diameter of a second color or, alternatively, of having one hemispheric portion of the extended halo member of a first color and the other hemispheric portion of a second color, or other variations. When the user holds the racquet face in the plane perpendicular to the ground, the color cue indicates that the coloration on the interior diameter (or on the downside hemispheric portion) will be substantially invisible to the user; when the user holds the racquet face in a plane other than that perpendicular to the ground, the coloration on the interior diameter (or on the downside hemispheric portion) will be detectably visible to the user.  
         [0022]     The invention comprises an extended halo member ( 10 ) which is detachable into a plurality of smaller pieces which can be reversibly or irreversibly joined and/or which comprises a telescoping portion, such that handling and transportation of the extended halo member ( 10 ) is facilitated.  
         [0023]     The invention also comprises a training mat comprising a sheet or mat having demarcations indicating proper foot positioning and swing geometry of the racquet at various points of a proper tennis swing. A training mat typically comprises a foldable sheet or semisolid mat having at least two foot position markings for a first foot position and a second foot position, and a plurality of swing position markings denoting at least a first and second racquet swing position. In an embodiment, a first swing position marking is positioned at the point in the arc of the stroke swing which is the beginning of the hitting zone (i.e., the section of the swing arc where the racquet is expected to make contact with the ball) and a second swing position marking is positioned at the point in the arc of the stroke swing which is the end of the hitting zone, such that the two markings define the hitting zone. Typically, the user will employ these markings as visual cues to monitor the racquet angle via visual and/or tactile feedback from the extended halo member. In a preferred embodiment, the training mat will comprise at least two foot positions and at least five racquet swing positions. The foot position markings and the racquet swing position markings are placed at various positions throughout the stroke arc and may be color coordinated to the correct racquet face angle at each position; for most stroke practice the racquet face angle will be perpendicular to the ground and will not change throughout the stroke arc until the end-of-stroke wrap position. In a variation, the training mat comprises a first foot position and a second foot position and a first racquet swing position marking of a first color and a second racquet swing position marking of a second color, wherein the colors of the racquet swing position markings correspond to the coloration cue on the extended halo member ( 10 ) that would be visible to the user if the racquet face angle was correct at that point in the swing. In an alternate embodiment, the first racquet swing position would be at a point in the swing arc where an open face racquet angle is correct and the second racquet swing position would be at a point in the swing arc where a closed face racquet angle is preferred. However, for most applications the racquet angle is intended to be maintained consistently through the hitting zone and most often throughout substantially the entire are of the stroke swing. The training mat can comprise fixed racquet swing markings and fixed foot position markings or may comprised removable and repositionable racquet swing markings and/or foot position markings, or a combination thereof. In some embodiments the training mat will have a plurality of premarked position markings for foot positions and/or racquet swing positions and the user or his coach may select from among said plurality of markings and removably affix one or more colored visual markings to identify the selected positions; for example and not limitation, colored visual markings which can be removably affixed via magnetic or Velcro attachment to the training mat can be used to highlight the selected position marking(s) for the user.  
         [0024]     The invention provides a combination of an extended halo member ( 10 ) and a training mat. In a variation, the extended halo member ( 10 ) is a detachable device that can be reversibly attached to and removed from a conventional tennis racquet. In a preferred aspect, the invention provides a kit comprising an extended halo member and a training mat. In a variation, the extended halo member is an integral component of a halo-frame racquet and the kit comprises the halo-frame racquet and a training mat of the invention; in a subgenus of this variation the halo-frame racquet is unstrung and some variations the halo-frame racquet lacks frame holes for stringing (e.g., is designed to be used solely as an unstrung racquet); alternatively the halo-frame racquet may be provided in the kit in strung form.  
         [0025]     The invention provides an instructional booklet or video demonstrating the correct use of an extended halo member to train a proper racquet swing. In an embodiment, said booklet or video demonstrates the correct use of the extended halo member attached to a racquet and used in conjunction with a training mat of the invention. In an embodiment the extended halo member is an integrated portion of a halo-frame racquet which may be strung, unstrung, or unstringable.  
         [0026]     The invention further provides a kit comprising an extended halo member ( 10 ) and instructions for attaching said extended halo member to a conventional racquet (e.g., tennis racquet, squash racquet, racquetball racquet). In an aspect, the kit will further comprise an instructional booklet or video demonstrating the correct use of an extended halo member to train a proper racquet swing. In an aspect, the kit further comprises a training mat.  
         [0027]     The invention also provides for the use of an extended halo member ( 10 ), whether said extended halo member is reversibly attached to a conventional racquet or permanently attached thereto, including embodiments where the extended halo member is fabricated into racquet and is integral to the racquet frame.  
         [0028]     The invention also provides a method of training for a racquet sport, said method comprising using an extended halo member in conjunction with a racquet to train a correct swing motion for said racquet sport. In an aspect, the method further comprises a user swinging a racquet having an extended halo member and said user or his coach observing the relative face angle of the extended halo member as a reporter of the face angle of the striking surface of the racquet face in at least one position along the swing arc and thus detecting whether the face angle is correct or incorrect for a proper swing. The method may further comprise use of a training mat and/or use of a booklet or video explaining the proper use of the extended halo member to report the face angle geometry.  
         [0029]     The invention also provides an online coaching system comprising a user employing an extended halo member racquet and reporting the user&#39;s results via computer connection, typically over a network (e.g., Internet), to an online coaching system. For example and not limitation, a user may submit a computer-readable video of himself using the extended halo racquet and the coaching system will report to the user specific coaching advice based upon the submitted video. In a variation, the online coaching system comprises a website and optionally a FAQ page comprising information about the use of the extended halo member and extended halo racquets (including but not limited to halo-frame integrated racquets), training mats, and combinations thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]      FIG. 1  shows an embodiment of an extended halo member ( 10 ) joined to a racquet frame ( 20 ) of a tennis or racquetball racquet. The extended halo member ( 10 ) is joined to the racquet frame ( 20 ) in the racquet throat ( 40 ) at two throat junctions ( 41 ) and via three attachment members ( 21 ) which join to the racquet head ( 30 ) via attachment points ( 22 ), thereby avoiding contact with the stringed racquet face ( 60 ) which can be used to strike a ball if desired. The apparatus is held in a proper hand grip using the grip portion ( 50 ) and is used to practice correct racquet stroke motion and swing geometry with special attention to the face angle of the striking surface as reported by the displacement of one lateral of the extended halo member as compared to the corresponding lateral of the extended halo member located on the opposite side of the racquet head. A wrap detector ( 70 ) is optional and will contact the user&#39;s shoulder upon a correct follow-through and wrap; in some embodiments, the extended halo member ( 10 ) will comprise an integral portion which will provide the function of ( 70 ) without necessitating a separate element ( 70 ). The extended halo member ( 10 ), throat junction(s) ( 41 ), attachment points ( 22 ) and attachment members ( 21 ) may be an integral portion of a halo-frame racquet in some embodiments.  
         [0031]      FIG. 2  shows an alternate embodiment wherein the extended halo member is designed such that an integral portion thereof forms the attachment point to the racquet frame at two positions. The attachment member ( 22 ) may optionally be omitted.  
         [0032]      FIG. 3  shows one representative embodiment of the extended halo member attached to a racquet and further comprising an ancillary device ( 23 ).  
         [0033]      FIG. 4  shows an alternative embodiment of an extended halo member attached to a racquet either removably or permanently (including being molded into the racquet frame to form a halo-frame racquet frame.  
         [0034]      FIG. 5  shows an alternative embodiment wherein the extended halo member comprises a plurality of radial spokes in the plane of the racquet face.  
         [0035]      FIG. 6  shows an extended halo member attached to a racquet via removable Velcro cuffs ( 70 ) and removable fabric belt loops ( 71 ).  
         [0036]      FIG. 7  shows one representative embodiment of the extended halo member attached to a racquet, wherein the attachment members are symmetrically distributed along one axis and asymmetrically distributed along a second axis.  
         [0037]      FIG. 8  shows one representative embodiment of the extended halo member attached to a racquet, wherein the extended halo member is attached to the racquet frame only at two throat junctions.  
         [0038]      FIG. 9  shows a preferred species of the invention wherein the extended halo member (shown in solid black) is integrally comprised in the racquet frame to form a halo-frame racquet. Although a wide variety of structural variations (e.g., number and position of attachment points of the extended halo member portion to the internal racquet face portion; shape, size, and thickness of the extended halo portion) will be apparent to those skilled in the art, the specific example provided in  FIG. 9  is to illustrate and not limit the invention.  
         [0039]      FIG. 10  shows an exemplary training mat wherein the foot locations are indicated and a plurality of swing arc positions are also indicated. Preferred swing arc positions for the forehand for a right-handed (RH) player are shown in the diagram, with the backswing checkpoint (A), one-quarter forward swing (B), contact point (C), three-quarter follow-through (D), and full follow-through (E) indicated. Foot positions are also often indicated on the training mat. In this embodiment the dotted foot outlines indicates the foot placement for the starting or ready position. The solid-traced foot outline closest to the back of the mat (closest to the backswing checkpoint [A]) indicates the placement of the turn-and-pivot foot as the first foot movement out of the ready position. The solid-traced foot outline toward the front of the mat (closest to the full follow-through point [El) indicates the foot placement of the front foot following backswing. For the left-handed (LH) player, the foot and swing positions are symmetrically reversed along the axial axis of swing, such that the LH mat positions are the mirror-image of the RH positions as compared along the mirror-plane parallel to the long axis (axial axis) of the swing. In an embodiment, the opposite face of the training mat will show the equivalent foot and racquet positions for performing a backhand stroke, such that the training mat may be used to first practice a forehand stroke and then flipped over to practice a backhand stroke, or vice-versa. A training may comprise both RH and LH foot and racquet positions, or alternatively separate RH and LH training mats may be used. In a variation, the various swing arc locations will be colored so as to match the correct coloration cue on the extended halo member at that point in the swing arc.  FIG. 10  shows some preferred locations (including exemplary measurements) for foot and racquet locations, with the relative locations indicated in inches from the reference point at the lower lefthand corner of a mat intended for use training a forehand swing for a RH player. Dimensions and locations for LH forehand are the mirror-image reverse, and positions for the RH and LH backhand swings are provided according to customary usage of tennis training professionals. In some embodiments the hitting zone may be more closely delineated by position markers on either side of the contact point (C) at positions that are predefined as the beginning point (C 0 ) and ending point (C 1 ) of the hitting zone, either to replace the marking at contact point (C) or in addition to the contact point (C). In a variation, the entire portion of the swing arc that is the hitting zone may be marked by a single marking that subtends the entire portion of the swing arc comprising the hitting zone (or a secant line thereof). The measured dimensions provided in  FIG. 10  are for example and not limitation and intended to illustrate only one particular implementation of the training mat. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
     DEFINITIONS  
       [0000]    
       
          BACKHAND—a stroke made from the side of the body when the hitting arm must move elbow-side first towards the net  
          BACKSPIN—the spin the ball has when hit with an under slice motion causing the ball to tend to bounce back toward the hitter  
          BUTT—the bottom of the handle end of the racket  
          CHOKE UP—to grip the racket at the upper portion of the handle and not at its base  
          CHOP—a stroke which puts heavy backspin on the ball  
          CLOSED FACE—the racquet is said to have a closed face when the string surface striking the ball looks downward, towards the ground  
          FOREHAND—the stroke when the ball is hit from the side of the body where the player&#39;s racket arm is  
          GRIP—the leather binding wrapped around the handle  
          GROUND STROKE—a stroke played from the back of the court after the ball has bounced  
          HEAD—the curved portion of the racket which borders the strings  
          INSIDE-OUT—shot in which the hand starts out close in to the body, then moves away. The ball&#39;s path gets curved.  
          OPEN FACE—the racquet is said to have an open face when the string surface hitting the ball looks upward towards the sky  
          RACQUET BALANCE—the weight relationships of the head and throat and handle.  
          SLICE—a shot which uses underspin, and therefore helps to keep it low and floating  
          THROAT—the portion of the racket between the head and the handle  
          TOPSPIN—the spin imparted to the ball by coming over the top of it in a low to high motion; thus, a spin that has the top of the ball going away from the hitter  
       
     
       THE INVENTION  
       [0056]     The present invention will help players ‘feel’ and ‘see’ their racquet face angle at all times during the tennis swing. The racquet attachment provides a dramatic visual that will help tennis players learn proper racquet fundamentals much easier. Specific points on the training aid can be color-coded so that the player can learn exactly where the racquet should be at each checkpoint of the tennis swing—ready position, backswing, contact point, ¾ follow-through, full follow-through, full follow-through including wrap position. In tennis, most errors are caused by the player hitting the ball into the net, or hitting the ball long. Usually the cause of this mistake is the player&#39;s inability to properly control their racquet angle during the swing. The extended halo member greatly assists players to learn, feel, and see their racquet angle throughout the entire swing.  
         [0057]     The player can immediately feel any racquet angle mistakes because the extended halo member makes the racquet feel balanced when it&#39;s on its edge—or in the correct position. Due to the size and weight of the extended halo member, the only way to finish with the proper follow-through is to swing properly during the entire swing. Also, the product may be accompanied by an instructional DVD/videotape. While viewing instruction with the training aid attachment on the player&#39;s racquet, the color-coded spots provide another great source of learning a fundamentally sound tennis swing.  
         [0058]     The invention comprises several aspects which can be used together, if desired. The first aspect of the invention is the extended halo member which comprises a hoop or racquet face attachment which mirrors the racquet angle throughout the swing via being parallel or in-plane with the striking surface of the racquet. The extended halo member is typically composed of a solid or hollow structure, sometimes tubular, which can be fabricated of any sufficiently rigid material, such as a plastic, composite fiber, titanium, aluminum, steel, magnesium, other metal or alloy, fiberglass, or even wood or very stiff cardboard and the like. The extended halo member is attached to the racquet frame at one or more points of attachment, typically including a throat point of attachment and also a head point of attachment. When desired, additional attachment points and/or attachment members can be used to increase the stiffness of the extended halo member so that it substantially does not vibrate or move except as exactly in parallel or in-plane with the racquet striking surface. The number and position of attachment points and/or attachment members is selected by those of skill in the art, and may reflect structural features of the materials used to fabricate the extended halo member and/or cosmetic and design advantages.  
         [0059]     The extended halo member can be attached to a conventional racquet either reversibly or irreversibly by attachment means. Those skilled in the art will apply any suitable attachment means they desire, from clamps, screws, adhesives, adhesive tapes, wrapping means, magnets, clips, binders, and the like—and combinations thereof. In some embodiments, the extended halo member is an integral part of the racquet frame design and may be fabricated as such and/or molded into the frame for substantially permanent attachment. In order to accommodate a variety of racquet frames, it can often be desirable to have the extended halo member attach to the stringed face of the racquet head, or to the upper portion of the grip, or even to the butt of the grip. In general, it is preferred for the extended halo member to be attached to the racquet frame in a secure and sturdy manner. In a preferred embodiment, the extended halo member is an integral portion of the racquet frame and is fabricated as part of a unitized racquet frame denoted as a halo-frame racquet frame.  
         [0060]     In order to provide a very stable combination, it is often preferred that the extended halo member be attached via one or more attachment members, which can act as stabilizer bars to reduce wobbling and reinforce the overall combination of racquet and extended halo member. The attachment members are preferably of stiff material such as a metal or composite fiber material, and may include vibration damping components in the design. In general, the design of the extended halo member and the selection of materials for it&#39;s fabrication and attachment are selected to retain desired racquet balance and centers of gravity for the racquet head and the racquet body, such that the feel of the racquet with the extended halo member attached is substantially similar to the feel and physical behavior of the racquet alone. In a preferred embodiment, the extended halo member is an integral portion of the racquet frame and is fabricated as part of a unitized racquet frame denoted as a halo-frame racquet frame and comprises the same material as the remainder of the racquet frame.  
         [0061]     The apparatus of the invention may include a number of accessories that attach to the extended halo member itself. Weight bars/clips, strength bars/clips, level assister&#39;s (level assister&#39;s similar to how contractor&#39;s use fluid or laser light to determine if something is level), and the like. These accessories may be referred to as ancillary items and can be reversibly or permanently attached to the racquet frame and/or extended halo member (or to a halo-frame racquet frame).  
         [0062]     The extended halo member may come in separate parts so that it can fit easily into a player&#39;s racquet bag. Because its final design is rather large, the trainer may come in various parts that attach to each other and to the racquet frame, or may be assembled via other means. For example, it may telescope outward/inward to achieve its eventual size and in this way be smaller in its non-use stage. Alternatively the extended halo member may be integrated into the racquet frame to form a halo-frame racquet.  
         [0063]     The invention also embodies the use of coloration cues on various lateral surfaces of the extended halo member, such that the angle of tilt of the striking face will be reported by the visibility (or invisibility) of one or more coloration cues. When used in conjunction with a training mat having color-cued swing position demarcations, a user can adjust his swing so that the coloration cues of the extended halo member will match the color-cued swing position demarcations at each point throughout the swing arc. This trains the user to modify the face angle as appropriate from open-faced to closed-faced (or vice versa) at the appropriate points throughout the swing arc for the desired stroke (e.g., backhand, forehand).  
         [0064]     The invention also provides instructional materials disclosing how to optimally use the apparatus for stroke training for a racquet sport, such as for example and not limitation tennis. The instructional materials may include a booklet, video (videotape, DVD, or other recording or on-line format) which describes the use of the extended halo member in conjunction with a racquet and/or a halo-frame racquet having an integral halo member portion, and optionally also in conjunction with the training mat.  
         [0065]     The extended halo member used while swinging a racquet to which it is attached, typically the racquet is a tennis racquet. The combination of the racquet and extended halo member can be used as a trainer only—swung without hitting a tennis ball—or used while actually practicing and hitting a tennis ball. The shape of the extended halo member may be varied, with preferred configurations including circular, oval, ellipsoid, and shaped to match the racquet head shape for a given racquet design. The distance between the extended halo member and the racquet frame may also vary, not only between embodiments, but also may vary at different positions within the same embodiment.  
         [0066]     The invention also provides a training mat comprising a rigid or flexible mat or fabric sheet comprising markings for foot placement and racquet position at various positions of a correct swing. In an embodiment of a swing trainer mat, the mat may comprise a plurality of foot position markings and a plurality of racquet position markings, wherein a first foot position marking indicates the correct foot placement at the initial point or ready position and a second or subsequent foot position marking shows the correct foot placement at a subsequent point in a correct swing movement, and wherein a first racquet position marking indicates the correct racquet location in a racquet stroke swing arc at a first time and a second or subsequent racquet position marking indicates the correct racquet location in said racquet stroke swing arc at a second or subsequent time. The foot position markings can be color-coded and/or numbered to indicate the sequence of movement. Similarly, the racquet position markings can be color-coded to correspond to color cues on the racquet and/or extended halo member, and/or optionally to correspond to the color-coding of the foot markings. In this way, as the racquet (with or without extended halo member) moves through the swing arc, the user can ensue correct positioning of the feet and racquet face by coordinating the color cues located on the training mat, with the color cues located on the racquet and/or extended halo member. In an embodiment, a tennis swing training mat can comprise a mat or sheet having a plurality of racquet position markings and a plurality of foot position markings; the foot position markings may be numbered, lettered, or color-coded and the racquet position markings may be numbered, lettered, or color-coded. In one preferred embodiment, the plurality of foot position markings comprises a right foot ready position marking, a left foot ready position marking, a turn-and-pivot foot marking, and a front-foot-following-backswing foot marking. In a preferred embodiment, the plurality of racquet position markings comprise the following positions: checkpoint (A), one-quarter forward swing (B), contact point (C), three-quarter follow-through (D), and full follow-through (E).  
         [0067]     In a variation of the swing training mat, the markings for the racquet swing points and /or the foot positions are movable, typically by employing a releasable attachment means for coupling the position markings to the mat surface. For example and not limitation, the mat may comprise a Velcro-binding substrate and the markings may comprise a complementary Velcro-binding substrate, such that the markings may be removed and placed anywhere desired on the mat; alternatively, the mat may comprise a ferromagnetic or paramagnetic substance which can releasably bind to magnetic or magnetized markings. This variation allows for easier modification of the relative locations of the various foot and/or racquet position markings on the mat, such as may be preferred by individual users and their trainers to accommodate the user&#39;s size, style, and other features. The swing training mat may provide visual indicators for one or more suggested positions (reference points) for each foot position marking or racquet position marking, with the exact placement of the markings themselves to be determined by the user, and emplaced according to their judgment, the judgment of their coach, and/or according to the instructions provided with the training mat. In this variation, the training mat may have visual indicators (reference points) for the recommended placement of the foot position markings and racquet position markings for a typical player of average stature and stance, typically comprising a set of reference points for placement of the foot markings and racquet position markings for RH players (forehand and backhand) and a set for LH players (forehand and backhand). In one variation, it is convenient for one side of the mat to provide the reference points for the RH player forehand and backhand swings and the other side of the mat to provide the reference points for the LH player forehand and backhand swings; alternatively one side may provide the reference points for the forehand swings of both the RH player and LH player and the reverse side may provide the reference points for the backhand swings of the RH player and LH player; alternatively all reference points for the forehand and backhand swings of both the RH and LH player may be provided on one side of the mat. An instruction manual accompanying the training mat can provide guidance to the individual user regarding where the foot position markings and racquet position markings are placed relative to the reference points provided on the mat for his or her particular physical characteristics or to help correct a problematic swing movement. In an embodiment of this variation, a training mat will comprise a mat or sheet to which removable markings may be releasably attached and releasably attachable markers that indicate foot and/or racquet position for a correct racquet swing. Often, the mat or sheet will provide a plurality of racquet position reference points on which or near which a plurality of releasable racquet position markings can be attached; preferably the plurality of releasable racquet position markings will comprise a plurality of colors; in some variations the colors of the racquet position markings will correspond to one or more color cues located on the racquet and/or on the extended halo member, such that the user will obtain visual information on the coordination of the racquet attitude and orientation with the position in the swing arc by viewing the racquet (and/or extended halo member) color cue in conjunction with the racquet position marking color at each point in the swing arc. The racquet position markings may comprise a plurality of numbers or letters. Often the mat or sheet will provide a plurality of foot position reference points on which or near which a plurality of releasable foot position markings can be attached; preferably the plurality of releasable foot position markings will comprise a plurality of numbers, letters, and or colors, such as to indicate the order of foot movement.  
         [0068]     The invention also provides a kit comprising a swing training mat and instructions for its use in training a correct swing movement. The kit may comprise a training mat wherein the foot position markings and racquet position markings are permanently affixed to the mat, and/or the kit may comprise releasable racquet position markings and/or foot position markings. The instructions typically describe the use of the mat and in some embodiments also describe the selection of placement of the releasable racquet location markings and/or foot location markings (if provided) for various user sizes and swing correction modes. Some kits may include an extended halo member, often with instructions for its attachment to a standard racquet and its use alone or in conjunction with a training mat. Some kits may include a halo-frame racquet which has the extended halo member integrated into the racquet frame as a permanent structural feature. Some kits may also include other racquet attachments, including but not limited to those described herein. Often, a kit of the invention will include a video (videotape, DVD, SCVD, VCD, or other video recording format) or a website address to download a video, often including a password or other download access key code, such that the user may view a video demonstration of the proper assembly and usage of the materials in the kit.  
         [0069]     The invention also provides for a removable attachment that can be releasably affixed to a tennis racquet directly or via attachment to an extended halo member approximately at a position such that it will make contact with the user&#39;s shoulder subsequent to a correct follow-through and wrap (see  FIG. 9 ).  FIG. 1  shows the wrap detector ( 70 ) affixed to an extended halo member ( 10 ). Some embodiments of the extended halo member will comprise a non-detachable, integral portion which contacts the user&#39;s shoulder following a correct follow-through and wrap (shown in  FIG. 9 ) and which provides the feedback function of the wrap detector ( 70 ) without the need for a separate attachment. In some embodiments of the extended halo member, such as those extended halo member species which do not have an extended portion near a throat junction or lower (proximal to the grip) portion of the racquet head ( 30 ), and in cases where an extended halo member is not used, a wrap detector comprising a means for releaseable attachment to the racquet (e.g., a Velcro cuff, a frame clip, and the like) and an extended structural member (e.g., such as a loop of rigid plastic) of dimension sufficient to report a correct follow-through and wrap by contacting the user&#39;s shoulder can be attached directly to the racquet at an appropriate point selected by the practitioner based upon the architecture and dimensions of the specific racquet, but often in the region around the throat junction ( 40 ) or proximal (inboard towards the throat junction) aspect of the racquet head ( 30 ). At the conclusion of a correct forehand swing, the wrap detector ( 70 ) will be located over the user&#39;s shoulder blade or rest on the user&#39;s follow-through shoulder (RH players will follow-through to their left shoulder, and vice-versa for LH players).  
         [0070]     The invention also provides for color-coded racquet position markings that can be releasably attached directly to a racquet without requiring attachment of an extended halo member. These color-coded racquet position markers may comprise colored cuffs of Velcro that fit circularly around the racquet frame attaching via portions that pass between strings of the racquet face, or which may comprise colored clips (e.g., plastic or metal) which clip over the racquet frame at various positions of the racquet. Such color-coded racquet position markers are often used in conjunction with the training mat, typically when an extended halo member is not simultaneously used. In some embodiments, a training kit will comprise such color-coded racquet position markers which attach directly to the racquet and/or to an extended halo member (if used), and a training mat having complementary color-coded markings for foot position and racquet position.  
         [0071]     Most players have a lot of trouble changing their swing even with the help of a qualified professional. The present invention allows the student to learn a fundamentally sound tennis swing with or without hitting a tennis ball. It gives the player instant feedback throughout the swing whether they are completing a proper swing with the proper racquet angle for that particular shot (ground stroke, volley, etc.). If the player alters the racquet angle from its correct position, the player can immediately feel it. The invention has an added benefit of not allowing the student to easily return to the correct racquet angle position. The apparatus is dramatically visual, and because it provides the player with the feel of the racquet angle, the player can learn proper muscle memory much easier.  
         [0072]     The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and the accompanying figures. Such modifications are intended to fall within the scope of the appended claims. Many variations and combinations of the aspects of the present invention will be apparent to those skilled in the art in view of this specification.  
         [0073]     It is further to be understood that all values are approximate, and are provided for description.  
         [0074]     Numerous references, including patents, patent applications, and various publications are cited and discussed in the description of this invention. The citation and/or discussion of such references is provided merely to clarify the description of the present invention and is not an admission that any such reference is “prior art” to the present invention. All references cited and discussed in this specification are incorporated herein by reference in their entirety and to the same extent as if each reference was individually incorporated by reference.