More particularly, the present invention relates to apparatus which can be releasably attached to a golf club and which aids golfers to effect the correct club swing when hitting a golf club.

In the game of golf it is generally accepted that the three most important factors when striking the ball, in order to obtain the best results, are that the eyes should focus on the ball without the head being lifted, the return swing should be taken at the correct speed and should not be forced, and the path of the club head on both the back and return swings should be correct especially in the twelve inches or thereabouts behind the ball and in front of it on the follow-through part of the stroke. For most purposes, the path is at 90° to the direction in which the golfer faces in addressing the ball, any deviation from this path tending to impart spin to the ball resulting in a hook or slice shot. In particular, the greatest difficulty for most people seems to be the exercise of self control to keep the eyes on the ball until it has been hit; there is a strong tendency for the head to come up and for the eyes to follow the anticipated path of the ball even before impact with the club.

Many devices are known in the prior art which can be used during practice to help the golfer drive the golf ball straight, but the problem of eye and head control has not been effectively solved.

According to one aspect of the present invention, apparatus for improving a golfer's club swing comprises a housing releasably attachable to a golf club and containing a light source which in use directs a light beam towards the eyes of the golfer, the housing included means to adjust and to encode the direction of the light beam, whereby a subjective pre-determined directional setting can be replicated.

In use, in movement of the club during both the back-swing and the return or down swing and with the golfer's eyes directed at the ball, the correct subjective direction of the light beam having been determined for the first time or set according to a pre-determined encoding, the movement of the club head is displayed as a streak of light in the retained peripheral vision of the golfer and he can accordingly take steps in succeeding practice strokes to compensate for any apparent errors or inaccuracies in his swing which would result in the ball being hooked or sliced. The need to concentrate on the ball and to observe the streak in relation thereto assists in overcoming the tendency to raise the head too early.

Preferably, the apparatus is used in conjunction with indicia placed on the ground as a reference mark to indicate the intended track of the club during the swing. Such indicia preferably are fluorescent or otherwise of high visibility, whereby they can readily be seen in the peripheral vision of the golfer. The ground-marking indicia may comprise a narrow strip of fluorescent, brightly coloured or otherwise highly visible plastics material, for example plastics ribbon, mounted on a thin backing and placed on the ground in alignment with the intended direction of the swing, although they may be merely tees placed in the ground at appropriate locations.

While the apparatus of the present invention is particularly intended for use in relation to the drive stroke, it can be equally effective for all the other golf strokes, particularly for the putting stroke. While being of particular use for the novice player, the apparatus may also help the experienced golfer to practise and achieve a deliberate hook or slice shot, by placing the indicia at appropriate angles to the usual 90° path.

Preferably, the inventive apparatus is attachable to the shaft of the golf club towards the head thereof. The housing is preferably aligned parallel with the longitudinal axis of the club shaft and is disposed above the club head for optimum visibility during at least the lower part of the swing. The angle of the light beam emitted by the light source is adjustable so as to be focused upwards directly into the eyes of the golfer, in use; once an optimum subjective angle for a given golfer using a given club has been determined, that angle can be encoded and the code recorded so that the optimum angle can be pre-set on another occasion. Preferably, the angle is adjustable in two mutually-orthogonal degrees of freedom.

The inventive apparatus includes means for releasable attachment to the golf club. Such means may comprise snap engagement-type fasteners but may equally well comprise straps and conventional fasteners such as buckles or touch-close fastener material, for example Velcro (trade mark). The housing may be profiled to receive a portion of the periphery of the shaft, thereby ensuring correct alignment of the housing with the shaft; the profiling may comprise a groove or channel which can receive the entire cross section of the shaft with snap-action engagement or may comprise a V-section groove to accommodate shafts or different diameters; the profiling may include resilient pads to enhance the grip between the shaft and the housing and to eliminate any looseness. Additionally or alternatively, further retaining means, especially such as to resist any tendency for the housing either to twist or to move downwards on the shaft under the forces generated by the down stroke, may be provided.

In one embodiment, to accommodate shafts of different diameters, the rear of the housing is formed with a longitudinal channel having a shallow V-shaped profile to receive the shaft, a clamp member is placed across the channel over the shaft and a cover member is positioned over the clamp member and attached to the rear of the housing to secure the clamp member against the shaft. Preferably, the cover member is removably pivoted to the housing and is locked in the closed position against the clamp member by a resilient snap-action latch member, shaft-engaging pressure being applied to the clamp member via spring means acting between the clamp and cover members. Advantageously, the housing contains a battery or other cell as power supply for the light source, although the power supply may be carried separately by the golfer and electrically connected to the light source. The apparatus preferably has an on-off switch.

To further improve the golfer's swing, the apparatus may be provided with means which deactivate the light source when the swing is poor, for example in the event of a jerky swing or a poor backswing. Such means may comprise an inertia switch.

The light source preferably comprises one LED which may be static or pulsed. Preferably, a pulsed LED is used for improved visibility during bright ambient-lighting conditions.

The LED is preferably recessed within a sleeve member to provide shading over the light source, again to achieve greater visibility in high ambient-lighting conditions. The sleeve member may form a turret which is pivotably mounted in a recess in the housing for movement between a recessed or storage position and an angularly-extended use position.

Where the LED is pulsed, the frequency is preferably such that the golfer sees a series of bright dots in his retained vision at the correct swing speed. The frequency may be adjustable for different swing speeds as between driving and putting, for example. The beam produced by the light source may be white or may be coloured to improve visibility in bright conditions. Optionally more than one light source or coloured filters are provided to change the colour of the light beam as desired.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows one embodiment of the apparatus attached to a golf club, and a teed golf ball viewed towards the face of the club; Figure 2 shows a plan view of the apparatus of Figure 1, together with strips of indicia material placed on the ground; and Figure 3 shows an exploded perspective view from the front of another embodiment attached to a golf club.

Referring to Figures 1 and 2 there is shown a golf club, generally indicated 10, consisting of a shaft 11 and a head 12. The golf swing improvement apparatus 13 is releasably attached to the shaft 11 above the head 12 and in a central position when viewed from above (Figure 2). The club is shown in the address position in relation to a golf ball 14 on a tee 15. On each side of the golf ball 14 and in a straight line aligned with the intended direction of travel of the ball towards the hole (real or imaginary) are strips of coloured fluorescent tape or ribbon 16,17, which are weighted to ensure that they remain in position while the golf stroke is being practised. Alternatively, the strip may be mounted on a backing material and secured to the ground with pegs, conveniently golf tee pegs.

Referring to Figure 3, the apparatus consists of a housing formed in two parts, a front or upper part 31 and back or lower part 32. The housing is attached to a golf club shaft 33 as more fully explained below, at a position adjacent the head 34 of the club. At the lower or club end of the housing is mounted a barrel-shaped part 35 carrying a recessed LED 36 connected to batteries and a pulsing circuit within the housing and activated by an on-off slider switch 37.

The barrel 35 carries at each end a respective knob 38,39. Knob 38 is operatively connected with the LED 36 to adjust the direction of the beam thereof along axis X-X; knob 39 is also operatively connected to the LED to adjust the beam from side to side along axis Y-Y, the axes being mutually orthogonal. Each knob is provided with calibration marks, letters in the case of knob 38 and numbers in the case of knob 39, so that a given angular position of the LED can be replicated by merely turning the knobs to the desired position.

The lower part 32 of the housing contains at one side a pair of depending hinge plates (not shown in the drawing) including circular recesses and, on the other side, a depending resilient latch member 40. The housing is maintained securely in position on the shaft 33 by means of pressure plate 41 which includes lugs 42 and recesses or cavities 43 which engage with corresponding formations (not shown) on the hinge side of the lower part of the housing. The clamp plate is retained in position by clamp cover member 44 which is pivotably mounted in the hinge plates of the lower part 32 of the housing by means of latterly-protuding disks 45. The inside of the clamp cover carries upstanding cylindrical locators 46 for helical springs 47 (1 only shown for clarity) and the longitudinal wall 48 remote from the hinges is formed with an internal complementary formation to the latch member 40, whereby, with the clamp cover hinged and latched in the closed position, the helical springs 47 bias the clamp plate into firm engagement with the club shaft 33. It will be appreciated that this arrangement allows for different diameters of shaft to be accommodated with equivalent gripping force.

The LED is preferably a high-intensity 7° LED powered by AAA batteries. The LED may be set to come on at either a HIGH or LOW power according to the ambient lighting conditions.

In use, the golfer attaches the apparatus to the shaft of a selected club and adjusts the LED until the light beam shines directly in his eyes when he adopts the correct position for addressing the ball. The setting of the LED can then be recorded, for example, D4, for that club. The LED, emitting a narrow beam and being set in a recessed position in the barrel 35, shines into the golfer's eyes for only as long as the club head remains in the correct position relative to the golfer's face as the club is moved. If, for example, the golfer does not take the club head smoothly away from the ball or breaks his wrists as he does so, the narrow beam of light will no longer shine in his eyes and an image thereof will no longer be apparent. When the golfer makes his swing, he will clearly see in his retained vision a series of bright dots which will form the path that his club head has taken, therefore teaching him to take the correct path for the intended shot. Because the golfer is watching for the series of dots after having made contact with the ball, he must not move his head during the swing, until after impact with the ball has taken place. If he swings the club head too fast, his retained vision will not have time to hold an image of the dots, therefore teaching the golfer to swing the club at the proper rhythmic pace. Also, because of the recessed setting of the LED, it is important for the golfer to maintain his hands in the correct position since, if they get in front of the ball at impact, the light will effectively have been obliterated and will no longer be visible.

The device can be transferred to another club and the process repeated, if necessary using a different angular LED setting. On reverting to the first club the correct angle (D4) can be pre-set without need for experiment.