the following descriptions are of exemplary embodiments only , and are not intended to limit the scope , applicability or configuration of the invention in any way . rather , the following description provides a convenient illustration for implementing exemplary embodiments of the invention . various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims . referring to fig2 and 3 , there is shown a golf ball dispensing device comprising a device seat ( a ) mounted with an elevating device 1 , a ball seat 2 and a railing device 3 . the elevating device 1 includes a seat body 11 , an elevating power module 12 , a sliding block 13 and a first to forth sensors s 1 , s 2 , s 3 , s 4 ( as shown in fig4 and 6 ). the seat body 11 is mounted onto the body of the device seat ( a ) and is connected to the elevating power module 12 and the sensors s 1 , s 2 and s 3 . the sliding block 13 is pivotally mounted to the elevating power module 12 . the motion of the elevating power module 12 provides elevation or lowering to the upper and lower end point ( as shown in fig5 ). the elevating power module 12 is provided with a motor ( m 1 ). the first and second sensors s 1 and s 2 are respectively mounted on the upper and lower portions of the seat body 11 between which the sliding block 13 can slide . the motor ( m 1 ) is connected with the elevating power module 12 so that the motor ( m 1 ) will be moved in unison with the elevating power module 12 . the third sensor s 3 is mounted on the sliding block 13 of the seat body 11 . the fourth sensor s 4 is mounted on the ball seat 2 for detecting whether there is a ball on the ball seat 2 and can move in unison with the first motor ( m 1 ). the preferred embodiment of the elevating power module 12 comprises a motor ( m 1 ), two gears 121 and a chain 122 . the two gears 121 are driven by the first motor m 1 so as to elevate or lower the seat body 11 to move to the upper and lower end point ( as shown in fig4 ). the chain 122 surrounds the gears 121 and there is a protrusion 123 on the chain 122 . the protrusion 123 passes through a long slot 131 at the sliding block 13 . the two lateral sides of the sliding block 13 are provided with a through hole 132 and two protruded bodies 14 at the seat body 11 pass through the through hole 132 . when the chain 122 rotates , the long slot 131 moves to drive the sliding block 13 such that the sliding block 13 moves up and down ( as shown in fig4 and 5 ) along the two protruded bodies 14 . the ball seat 2 ( as shown in fig2 and 4 ) includes a base seat 21 thereunder and a ball holding rod 22 thereabove . the base seat 21 has a center hole for the passage of the ball holding rod 22 which is fastened on the bottom side of the base seat 21 . the fourth sensor s 4 is mounted on the bottom side of the base seat 21 and located close to the center hole of the base seat 21 ( see fig6 ). the base seat 21 is mounted onto the sliding block 13 of the elevating device 1 such that the entire ball seat 2 moves up or down together with the sliding block 131 . the base seat 21 is extended externally with an extension rod 4 such that when the ball seat 2 and the sliding ball 13 move to the upper end point and lower end point , the extension rod 4 is sensed by the first and the second sensors s 1 , s 2 so that the elevating power module 12 is restricted . the extension rod 4 of the base seat 21 of the ball seat 21 is provided with a masking rod 23 at one side . the extension rod 4 for sensing the first and the second sensor s 1 , s 2 is also mounted on the sliding block 13 . the railing device 3 includes at least two railing plates 31 , a railing body 32 , a second motor m 2 and a ball - pushing seat 33 ( as shown in fig3 and 4 ). the two railing plate 31 is connected to the device seat ( a ), and the railing body 32 is mounted between the two railing plates 31 to form a ball - entering rail . the second motor m 2 is connected with the third sensor s 3 and mounted to the railing plate 31 and drives the ball seat 33 to rotate . one side of the ball seat 33 is a ball - holding section 331 and the ball - holding section 331 is a circular arch to provide rotation for the golf ball 5 on the railing body 32 by the second motor m 2 . the ball - holding section 331 pushes the ball body 5 to move forward to the elevating device 1 so that the ball body 5 is dropped onto the ball - holding rod 22 of the ball - holding section 332 . further , the railing body 32 is inclined ( as shown in fig6 ) at the elevating device 1 , and the railing body 32 is curved so as to provide two recesses ( as shown in fig6 ) as the ready region 321 and the dispensing region 322 . the railing device 3 is provided further with a third motor m 3 and another ball - pushing seat 33 so that the second motor m 2 and the ball - pushing seat 33 are provided at the dispensing region 322 . the third motor m 3 and the ball - pushing seat 33 are provided at the ready region 321 and are respectively provided with a fifth sensor s 5 and a sixth sensor s 6 . when the second motor m 2 drives the ball - pushing seat 33 to dispense a ball , the fifth sensor s 5 informs the third motor m 3 to move . the ball - pushing seat 33 pushes a ball into the dispensing region 322 . the sixth sensor s 6 informs the ball supplementary device to the ready region 321 . the ready region 321 and the dispensing region 322 are designed to place specific number of balls . if there is a change in number of balls , the fifth and the sixth sensor s 6 are detected , for instance , if a ball or four balls are placed on . when a ball is on the ball - holding rod 22 and the ball seat 2 is at the upper point ( as shown in fig6 ), the first sensor s 1 will inform the first motor m 1 to stop and ready for the ball to be impacted . when the ball is impacted , the forth sensor s 4 senses that there is no ball on the ball - holding rod 22 , the motor m 1 moves to drive the elevating power module 12 so that the ball seat 2 is lowered . in the lowering process , the third sensor s 3 senses that there is no ball on the ball holding rod 22 and the second motor m 2 causes the ball - pushing seat 33 to move forward the ball body 5 to drop at the ball seat 2 . when the ball seat 2 is at the lower end point , the second sensor s 2 informs the motor m 1 to stop , and when the ball - holding rod 22 gets the ball body 5 , the forth sensor s 4 will sense and will inform the first motor m 1 to move so that the elevating power module 12 is activated to drive the ball seat 2 to move upward to the upper end point . the first sensor s 1 informs the first motor m 1 to stop and the ball is ready . the movement is repeated . in addition , the elevation path of the ball seat 2 is provided with a seventh sensor s 7 ( as shown in fig6 ) to sense the ball - holding rod 22 whether the ball is present . if the ball - holding rod 22 is absent , the seventh sensor s 7 will inform the power module to stop , ready for maintenance . it will be understood that each of the elements described above , or two or more together may also find a useful application in other types of methods differing from the type described above . while certain novel features of this invention have been shown and described and are pointed out in the annexed claim , it is not intended to be limited to the details above , since it will be understood that various omissions , modifications , substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention .