BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an extensible exercise golf club for training golfers and more particularly, to an exercise golf club which includes a plurality of telescopic interlocking tubular shaft lengths which can optionally include a spring disposed therein for causing the telescoped shaft members to extend from a collapsed position to a fully extended position. Thus golf beginners can learn to swing very well with very little effort, thus effectively reducing the training period. 
     2. Description of the Prior Art 
     Several types of collapsible golf clubs are known in the art. For example, such golf clubs include those which possess adjustable shaft lengths; means for varying the grip of golf clubs axially collapsible shafts, or the like. However, such collapsible golf clubs suffer from many problems. For example, it is difficult for a beginning golfer to timely hit a golf ball by using such golf clubs and to properly control the power transferred from the legs of the golfer to a golf club head. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved exercise golf club for use in training golfers. 
     Another object of the present invention is to provide an extensible exercise golf club which includes a plurality of concentric, telescopic interlocking tubular light shafts containing springs disposed therein within several tubular shaft lengths starting from the handle member. Alternatively, the springs are replaced with a plurality of friction locks between tubular shaft lengths. 
     A further object of the present invention is to provide an extensible golf club which includes, alternatively, a channel and a rail disposed on the inner and outer surfaces of adjacent telescopic tubular shaft lengths, respectively, for preventing the shaft lengths from twisting. 
     Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     Briefly described, the present invention relates to an extensible exercise golf club including a golf club shaft which comprises a plurality of telescopic interlocking shaft lengths which function to extend from a collapsed position to a fully extended position as a result of the force generated by the swinging action of the golf club. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is a perspective view of an extensible golf club according to the present invention in a fully collapsed position, showing in cut away portions thereof the basic components of the present invention; 
     FIG. 2 is a front view of the extensible club according to the present invention in a fully extended position; 
     FIG. 3 is a sectional view of FIG. 2, taken along line 3--3, showing the connecting portions of a tubular shaft length; 
     FIG. 4 is a cross-sectional view of FIG. 1, taken along line 4--4; 
     FIG. 5 is a perspective view of the extensible tubular sections according to the present invention; 
     FIG. 6 is a pictorial view, showing a golfer using the extensible golf club according to the present invention. 
     FIG. 7 is perspective view of an additional embodiment of an extensible golf club according to the present invention in a fully collapsed position showing, in cut away portions thereof, the basic components of the present invention; 
     FIG. 8 is a front view of the additional embodiment of the extensible golf club of FIG. 7 in a fully extended position of the present invention; and 
     FIG. 9 is a sectional view of FIG. 8, taken along line 8--8 showing the connecting portions of the tubular shaft lengths. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, the extensible exercise golf club 10 as shown in FIGS. 1, 2, and 3 comprises an extensible shaft 10 defining a plurality of concentric, telescopic interlocking tubular shaft lengths 11a, 11b, 11c, 11d, and 11e, a club head 13 at one end, a tubular handle member 12 at the other end of the extensible shaft 10, and a cap 20 for covering the top of the tubular handle member 12. 
     The handle member 12 is provided with a typical golf club grip member 15 disposed therearound for permitting a tight grasp of the club. The club head includes a ball engaging surface 17. The cap 20 is provided with a spring 18 suspended from the inner surface thereof. The telescopic interlocking tubular length shafts 11a, 11b, 11c, 11d, and 11e include extended lids 23a, 23b, 23c, 23d, and 23e disposed at the top and end openings 26a, 26b, 26c, and 26d disposed at the bottom thereof, respectively. The shaft length 11e is provided with an end portion 26e for receiving a heel shaft 14 which extends into the club head 13. The tubular handle 12 is provided with an end opening 26. The extended lid 23a is extends a short distance into the end opening 26 of the tubular handle member 12. Similarly, the extended lids 23b, 23c, 23d, and 23e extend a fraction of their shaft length into the end openings 26a, 26b, 26c, and 26d, respectively. The extended lids 23a, 23b, and 23c contain springs 18a, 18b, and 18c disposed on the inner surfaces thereof, respectively, and also the extended lids 23a, 23b, 23c, and 23d contain hooks 28a, 28b, 28c, and 28d disposed on the outer surface thereof for tightly engaging the springs 18, 18a, 18b, and 18c in its assembly (FIG. 3). 
     As shown in FIGS. 4 and 5, the telescopic interlocking tubular length shafts 11a, 11b, 11c, 11d, and 11e contain channels 21a, 21b, 21c, 21d, and 21e disposed on the outer surfaces and alternatively contain rails 22a, 22b, 22c, 22d, and 22e disposed on the inner surfaces thereof. Also, the heel shaft 14 contains a channel 21 disposed on the outer surface thereof and the tubular handle 12 contains a rail 22 disposed on the inner surface thereof. Therefore, the rails 22, 22a, 22b, 22c, 22d, and 22e are operatively interengaged with the channels 21a, 21b, 21c, 21d, 21e, and 21f for operatively extending the length shafts 11a, 11b, 11c, 11d, and 11e and effectively preventing the shaft length 10 from twisting while the golfer swings. 
     In assembly, first of all, the shaft length 11e receives the heel shaft 14 of the club head 13. Shaft length 11d is easily inserted into the end opening 26d of shaft length 11d to the extended lid 23e of the shaft length 11e. The shaft length 11d is similarly engaged with the shaft length 11c. At that time, the spring 18 suspended from the expanded lid 23c is tightly engaged with the hook 28d of the shaft length 11d. Thereafter, the extended lid 23c is slidably inserted into the end opening 26b of the shaft length 11b. Thus, the shaft length 11b is engaged in the shaft length 11a and the shaft length 11a is engaged in the tubular handle 12 (FIGS. 2 and 3). 
     In operation, as shown in FIG. 6, when a golfer swings forward, the golf club 10 is gradually extended in the direction indicated by arrows (a), (b), (c), (d), (e), (f), and (g) from the collapsed position (C) to the extended position (E). At that time, the club head 13 rhythmically hits a golf ball 26 disposed on the ground 27 and the golfer can play with a little effort being required by the golfer. 
     Referring in detail to FIGS. 7, 8 and 9, there is illustrated an additional embodiment of an extensible exercise golf club 110 in accordance with the present invention. 
     FIG. 7 is perspective view of an additional embodiment of an extensible golf club according to the present invention in a fully collapsed position showing in cut away portions thereof the basic components of the present invention. FIG. 8 is a front view of the additional embodiment of the extensible golf club of FIG. 7 in a fully extended position. FIG. 9 is a sectional view of FIG. 8, taken along line 9--9 showing the connection portions the of tubular shaft lengths. 
     The extensible exercise golf club 110 comprises an extensible shaft 111 which defines a plurality of telescopic interlocking shaft lengths 111a, 111b, 111c, 111d, and 11e, a club head 13 at one end thereof, a tubular handle member 120 at the other end of the extensible shaft 111, and a cap 120 for covering the top of the tubular handle member 120. 
     Thus, the extensible exercise golf club 110, according to the present invention, is distinguishable from the extensible exercise golf club 10 in that the extensible golf club 110 does not contain springs disposed within the tubular handle member 112 and shaft lengths 111a, 111b, and 111d, respectively. 
     In the operation, the extensible members of the exercise golf club 110 are slidably and frictionally engaged with each other so that the force of the swing overcomes the frictional engagement for freely extending the club shaft during the swing operation of the golf club for striking the ball 26 positioned in the ground 27. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included in the scope of the following claims.
An extensible exercise golf club including a golf club shaft comprising a plurality of telescopic interlocking shaft lengths which function to extend from a collapsed position to a fully extended position as a result of the force generated by the swinging action of the golf club.