Abstract:
A golf swing training aid ( 10 ), to be fitted between a player&#39;s knees, has an elongate, telescopic body ( 11 ), with foam pads ( 16, 18 ) on respetive cross-heads ( 17, 19 ) at each end of the body ( 11 ). A flexible strap ( 20 ) releasably secures one cross-head ( 17 ) to one of the player&#39;s knees and the other cross-head ( 17 ) rests against the other knee. The knees are held stable on the backswing and first half of the downswing of the club, but the aid ( 10 ) releases the knees as the swing is completed.

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     THIS INVENTION relates to a golf swing training aid. 
     The invention is particularly suitable for, but not limited to, a swing training aid for sports such as golf, baseball, softball, tennis and the like. 
     Throughout the specification, the term “golf” shall be used to include the other sports hereinbefore described. 
     (2) Prior Art 
     Most golf training aids, designed to aid or improve a player&#39;s swing, are directed to the movement of the upper body and/or the arms. However, little attention has been given to the stability of the lower body during the different phases of the swing. 
     Ideally, the lower body (ie., hips down) will remain substantially immobile during the back swing and on the forward swing until the club/bat moves to, or past, the centre line of the body. 
     It has been known to use a bucket tied between the knees as an aid to stabilise the lower body. 
     However, such an arrangement holds the knees apart during the final phase of the forward portion of the swing and results in an unnatural swing. 
     Examples which have been proposed to control the movement of the player&#39;s legs during the swing are disclosed in GB 2,284,556 (BUCKINGHAM); U.S. Pat. Nos. 5,016,885 (QUIGLEY); 4,706,957 (JACKSON) and 4,088,326 (BIFULCO). 
     The latter three documents disclose aids where the player&#39;s knees (or lower legs) are bound together at a fixed spacing. In GB 2,284,556 (BUCKINGHAM), the golf training device is fitted between both knees below the knee joints, with side supports, secured by releasable straps, where a plastic swivel bar with a centre pivot interconnects the side supports and allows some controlled movement between the legs. While some movement between the knees can occur during the swing, both knees must be fastened to the device, generating an unnatural movement. 
     SUMMARY OF THE PRESENT INVENTION 
     It is an object of the present invention to provide a training aid which holds the knees substantially stabilised for approximately the first half of the swing, while allowing the knees to move as the swing is completed. 
     It is a preferred object of the present invention to provide such an aid where the knees will be released when the arms are approximately aligned with the centre line of the body. 
     It is a further preferred object of the present invention to provide such a training aid which can be releasably secured at, or adjacent, one of the player&#39;s knees, and be releasably engageable with the other of his/her knees. 
     It is a still further preferred object of the present invention to provide such an aid which can accommodate a range of spacings between the player&#39;s knees, eg., to accommodate players of different height and/or stances. 
     Other preferred objects of the present invention will become apparent from the following description. 
     In a broad aspect, the present invention resides in a swing training aid for golf or other sports, including: 
     an elongate body having respective first and second end portions engageable with a player&#39;s legs at, or adjacent, the player&#39;s knees; and 
     a releasable securement means at or adjacent one of the end portions to releasably secure the body to the adjacent one of the player&#39;s legs; so arranged that: 
     on a back swing and during at least a portion of a forward swing, the player&#39;s knees are maintained in a substantially fixed or stable relationship, the other end of the body being releasable from the player&#39;s legs to allow the player&#39;s knees to move during the completion of the forward swing. 
     Preferably, the body is variable in length and may have components which are telescopically interconnected. A releasable lock, clip, bolt, pawl or like means may be provided to enable the length of the body to be selectively set. 
     In one preferred embodiment, a pair of box-like members are telescopically inter-engaged; while in the second preferred embodiment, a pair of knee-engagement cups or yoke-like members are provided at the ends of a pair of telescopically inter-engaged tubes. 
     Preferably, the securement means is a strap, rope, thong or the like releasably securable about one of the player&#39;s legs. 
     Preferably, the adjacent end portion has a pad or tapered nose which provides a pivotal axis for the body when the other end is released from the player&#39;s other leg. 
     Preferably, the other end portion has an inclined face, preferably curved in plan view, so arranged that during the completion portion of the swing, the player&#39;s adjacent knee will tend to force that end portion of the body downwardly to release the aid from that knee. 
     Preferably, the body will be released from the player&#39;s other knee, when the arms, on the forward swing, are just in advance or pass, the centre of gravity of the aid, ie., approximately in alignment with the centre line of the player&#39;s body. 
     Preferably, for a right-handed golfer or batter, the aid will be secured to the left leg at, or above, the left knee, and the aid will releasably engage at or above the right knee of the player&#39;s right leg. For left-handed players, the arrangement will be reversed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To enable the invention to be fully understood, a preferred embodiment will now be described with reference to the accompanying drawings in which: 
     FIG. 1 is a perspective view of one embodiment of the training aid; 
     FIG. 2 is a schematic front view showing a right-hand golfer, at his initial stance, with the aid in position; 
     FIG. 3 is a schematic front view showing the golfer at the full back swing position; 
     FIG. 4 is a similar view at the mid-downswing position; 
     FIGS. 5 and 6 are similar views just before and after (respectively) release of the aid; 
     FIG. 7 is a similar views of the golfer at the mid-upswing position; 
     FIG. 8 is a similar view of the golfer at the completion of the stroke; 
     FIG. 9 is a schematic front view of the golfer showing the action of the aid when the golfer&#39;s hips sway, on the backswing; 
     FIG. 10 is a similar view when the golfer&#39;s hips have over-rotated on the backswing; and 
     FIG. 11 is a similar view where the hip action has been incorrect on the downswing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, the training aid  10  has an elongate body  11  (eg., moulded from suitable plastics material) having a first body leg  12  telescopically, not rotatably, engaged within the second body leg  13 . A locking pin  14  is releasably engageable in aligned holes  15 , (not shown) in the body legs  12 ,  13  to enable the length of the body  11  to be selectively adjustable. 
     A resilient (eg., plastic foam) pad  16  is provided on the outer face of a cross-head  17  on the first leg  12  and, as shown in FIG. 2, is adapted to engage a (right-handed) golfer&#39;s left knee just above the knee joint. The pad  16  (and cross-head  17 ) are of shallow concave shape in top plan view. 
     A second pad  18 , of similar material, is provided on the outer face of a cross-head  19  on the second leg  13 . This pad  18  is arranged to releasably engage the (right-handed) golfer&#39;s right knee, just above the knee joint, as in FIG.  2 . It will be noted that while the pad  18  is also of shallow concave profile in top plan view, it is inclined at an angle (eg., in the range of 10° to 30°) from the normal to the longitudinal axis of the elongate body  11 . The pad  18  may incorporate a shallow convex profile in end view, as shown in FIG.  1 . 
     The aid  10  is releasably secured to the player&#39;s leg by an elongate strap  20  which may be wrapped around the player&#39;s leg and be secured by a releasable fastener  21  incorporating the respective hooks and loop portions  21   a,    21   b  of “VELCRO” (Registered Trade Mark) material. 
     The strap  20  passes through a loop  22  at one end of an attachment strap  23 , which is attached to a post  24  on the second leg  13  by a releasable buckle  25 . 
     In alternative embodiments, not shown, the strap  20  may be secured about the player&#39;s leg by clips, buckles or other suitable releasable fasteners. 
     In an alternative embodiment not illustrated, the training aid has a box-like body (eg., moulded from suitable plastics material) having a first body component telescopically received within the second body component. A locking pin is receivably engaged in aligned pairs of holes in the body components to enable the length of the body to be selectively adjustable. 
     The “nose” at the distal end of the first body component is tapered in side view and substantially concave in plan view to releasably engage the left leg of the (right-handed) player at, or just above, the player&#39;s left knee. A strap assembly has a loop member releasably securable about the player&#39;s left leg. The loop member may be secured by clips, buckles, “Velcro” (Registered Trade Mark) material or like releasable fastening means to enable the training aid to be releasably secured to the player&#39;s leg. 
     The “tail” at the distal end of the second body component is downwardly inclined in side view and concave in plan view and may be provided with cushioning strips. The “tail” is arranged to engage the (right-handed) player&#39;s right leg at, or just above, the player&#39;s right knee and is configured so that as the player&#39;s right knee swings inwardly, when his arms have reached, or pass the centre of gravity of the aid, the forces applied by the knee to the aid will cause the tail of the training aid to move downwardly to be released from the knee. 
     For a left-handed player, the “nose” will be secured to the is player&#39;s right leg and the “tail” will releasably engage the left leg. 
     Referring now to FIG. 2, the training aid  10  is fitted between the knees  101 ,  102  of the player  100 , just above the respective knee joints. The length of the body  11  of the aid  10  is adjusted for a comfortable stance. The cross-head  17  (and pad  16 ) on the first leg  12  are secured to the left knee  102  (of a right-handed player) by the strap  20 . 
     As the player  100  makes the backswing of his club  110 , the training aid  10  maintains the knees  101 ,  102 , and thereby the lower body  103 , substantially stable, as the players arms  104 ,  105  go through the motion of the backswing. 
     This places the left upper body side muscles in tension, to act as a spring on the downswing. 
     On the downswing (see FIGS.  4  and  5 ), the aid  10  locates the knees  101 ,  102  to provide correct body control and movement. 
     As the golf club  110  approaches, or passes, the player&#39;s right foot  106 , see FIG. 6, the knees  101 ,  102  are permitted to move apart to release the cross-head  19  (and pad  18 ) from the player&#39;s right knee  101 . The aid  10  drops free, suspended from the left knee  102  by the strap  20 . 
     The actual point in the downswing at which release of the aid  10  from the right knee  101  will occur will be variable but will usually fall in the range of the club  110  closely adjacent to, or passing, the right foot  106  to a point mid-point between the player&#39;s feet  106 ,  107  (ie., adjacent the centre of gravity of the training aid  10 ). 
     As shown in FIGS. 7 and 8, the player  100  is then able to complete his swing without interconnection between his knees, resulting in a more natural swing than is possible with the prior art aids hereinbefore discussed. 
     As shown in FIGS. 9 to  11 , the training aid  10  can indicate the type of faults in a golfer&#39;s swing. 
     In FIG. 9, where the player&#39;s hips have swayed, the training aid  20  becomes locked between the player&#39;s knees  101 ,  102  as the right knee  102  moves in the direction of arrow A. 
     In over-rotation of the player&#39;s hips, see FIG. 10, the training aid  10  becomes locked between the player&#39;s legs and cross-head  19  (and pad  18 ) rides up the right leg, ie., to move in the direction of arrow B above the right knee  101  and be locked between the legs. 
     In FIG. 11, if the swing is incorrect, the training aid  10  will remain locked between the knees  101 ,  102  as the downswing is completed. 
     (In certain instances, errors in the downswing will cause the training aid  10  to be released from the right knee  101  before the golf club  110  reaches the right foot  106 .) 
     In tests carried out by the inventor, it has been established that for golf swings, the training aid  10  maintains the lower body  103  substantially stable during the back swing and approximately the first half  30  of the downswing, the upper body (or torso)  108  being “twisted” like a torsion spring to provide power to the arms  104 ,  105 , and thereby the club  110  (or bat) on the forward swing. 
     As the training aid releases the player&#39;s knees  101 ,  102  in the second half of the forward swing, the knees are allowed to move, so that portion of the swing remains natural. 
     As shown in FIGS. 9 to  11 , the aid  10  can also indicate the problem(s) with the player&#39;s swing. 
     The aid is easy to fit and can be easily reduced in size for transport or storage. The aid is also relatively inexpensive to manufacture and does not rely on any supplementary equipment. 
     Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.