referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention , the extensible exercise golf club as shown in fig1 , and 3 comprises an extensible shaft 10 defining a plurality of concentric , telescopically interlocking tubular shaft lengths 11a , 11b , and 11c , a pseudo - golf ball 13 containing a ball weight member 14 disposed at one end of the shaft and a cap 15 disposed at the other end of the extensible shaft 10 . that is , the pseudo - golf ball 13 is provided at the end portion of the tubular shaft length 11c and the cap 15 is provided at the top of the tubular shaft length 11a , with the shafts defining a space 17 disposed in the tubular shaft lengths 11a , 11b , and 11c . the tubular shaft length 11a is provided with a typical golf club grip member 12 disposed therearound for permitting a tight grasp of the golf club . the ball weight member 14 has an aperture 16 to facilitate its attaching to the end portion of the tubular shaft length 11c with a strong adhesive 16a as shown in fig3 . the ball weight member 14 is made of steel , rubber , or the like to add weight to the pseudo - golf ball 13 . as shown in fig3 the telescopic interlocking tubular shaft lengths 11a , 11b , and 11c contain extended raised portions 111a , 111b , 111c , and 111d which operatively interlock with each other at the end openings of the shaft lengths . accordingly , when the telescopic interlocking tubular shaft lengths 11a , 11b , and 11c are fully extended by the force of the swing of the player , the extended raised portions 111a and 111b , and 111c and 111d are tightly interlocked . at this time , a vacuum is generated in the space 17 of the telescopic interlocking tubular shaft lengths 11a , 11b , and 11c ( fig2 and 3 ). accordingly , when the swing of the golfer is finished , the fully extended tubular shaft lengths 11a , 11b , and 11c are caused to immediately collapse by the vacuum generated in the space 17 of tubular shaft lengths 11a , 11b , and 11c ( fig1 and 4 ). in assembly , first of all , the shaft length 11c is slidably inserted into the shaft length 11b so that the raised portion 111c of the shaft length 11c interlocks with the raised portion 111d of the shaft length 11b . thus , the shaft length 11b is engaged with the shaft length 11c ( fig3 ). thereafter , the shaft length 11b which is engaged with the shaft length 11c is slidably inserted into the shaft length 11a so that the raised portion 111b of the shaft length 11b interlocks with the raised portion 111a of the shaft length 11a . thus , the shaft length 11a is engaged with the shaft length 11b ( fig3 ). afterwards , the cap 15 is placed on the end opening of the shaft length lla and the grip member 12 is provided around the upper portion of the shaft length 11a ( fig3 ). thereafter , the pseudo - golf ball 13 containing the weight member 14 is attached to the lower end portion of the shaft length 11c by inserting the shaft member into the aperture 16 of the ball 13 with the strong adhesive 16a ( fig1 and 3 ). the weight member 14 is steel , rubber , or the like . in operation , as shown in fig5 when a golfer swings forward , the golf club is gradually extended in the direction indicated by arrows ( a ), ( b ), ( c ), ( d ), ( e ), ( f ), and ( g ) from a collapsed position ( a ) to the extended position ( b ). at that time , the pseudo - golf ball 13 rhythmically hits a point disposed on the ground 20 and the golfer can swing with very little effort being required by the golfer . accordingly , the extensible shaft lengths 11a , 11b , and 11c of the exercise golf club 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 swinging operation of the golf club for striking the ground 20 . 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 and automatically return to the collapsed position by the force of vacuum generated within the shaft as the shaft sections are telescopically extended .