Structure for horizontal pole and weight for tennis practice device

Abstract

Disclosed is a tennis practice device, wherein a horizontal pole is affixed in a vertical direction at a point on a vertical part of a building or structure to form a basic frame of the device, and a string is hung from an end of the horizontal pole, with a tennis ball is attached to an end of the string; the ball thus suspended is struck with a racket for tennis practice. While useable for personal purposes, the device suits public use when installed on a riverside of a city or on school grounds, where anyone can bring a racket and ball to practice tennis in a fun, realistic way; here, the device must be high in height. Accordingly, techniques are provided to minimize problems, including connecting or disconnecting the ball string to the high-positioned horizontal pole and unexpected situations where the ball string gets caught on the horizontal pole.

1 . The structure for a tennis practice device comprising:
 the tennis practice device, which comprises:
 a horizontal pole ( 120 ), which is mounted in a horizontal direction at a certain point of a vertical portion ( 110 ) of a building or building structure; 
 an O-ring ( 121 ), which is installed at an end of the horizontal pole ( 120 ); 
 a front-end connection string ( 140 ), which starts from a roller ( 112 ) installed on the vertical portion of the building or building structure or the horizontal pole and passes through the O-ring ( 121 ) of the horizontal pole ( 120 ); 
 a pulling string O-ring ( 132 ), which is
 coupled with or bound to the end of the front-end connection string ( 140 ) that penetrates the O-ring ( 121 ) of horizontal pole ( 120 ), or 
 is penetrated by the front-end connection string ( 140 ); 
 
 a front-end connection string O-ring ( 141 ), which functions as a stopper to the pulling string O-ring ( 132 ) and is coupled with or bound to the end of the front-end connection string ( 140 ), when the front-end connection string ( 140 ) penetrates the pulling string O-ring ( 132 ); 
 a pulling string ( 130 ), which is coupled with or bound to the pulling string O-ring ( 132 ) and is capable of lowering the end of the front-end connection string ( 140 ) near to the ground ( 100 ) by pulling the pulling string O-ring ( 132 ) in a vicinity of the ground ( 100 ) toward the ground ( 100 ); 
 a ball string ( 151 ) connected to the pulling string O-ring ( 132 ), or connected to the front-end connection string O-ring ( 141 ) vertically downward when the front-end connection string ( 140 ) penetrates the pull string O-ring ( 132 ); and 
 a ball ( 150 ) hanging at a lower end of the ball string ( 151 ); 
   wherein the horizontal pole O-ring ( 121 ) is of a magnetic material, and at least one row of magnets ( 122 ) are densely and insertedly arranged on a lower surface of the horizontal pole ( 120 ), and thus when the pulling string O-ring ( 132 ) comes into close contact with the horizontal pole O-ring ( 121 ) by winding the roller ( 122 ), the pulling string O-ring ( 132 ) is attached to the horizontal pole O-ring ( 121 ) and an upper portion ( 131 ) of pulling string ( 130 ) is attached automatically and serially to the magnets ( 122 ) installed on the lower surface of the horizontal pole ( 120 ), by the magnetic material or magnetic force of the magnets ( 122 ) and a middle part and a lower part of the pulling string ( 130 ) comes adjacent to the vertical portion ( 110 ) of the building or building structure and are directed toward the ground ( 100 ).   
     
     
         2 . The structure for a tennis practice device according to  claim 1 , wherein: where the end of the front-end connection cord ( 140 ) penetrates and passes through the pulling string O-ring ( 132 ) and is then coupled with or bound to the front-end connection cord O-ring ( 141 ),
 when the roller ( 112 ) is operated in a released or wound state, an end of the front-end connection cord ( 140 ) is lowered toward the ground ( 100 ) by a load applied to the front-end connection cord ( 140 ) by the weight ( 200 ), which is coupled to the front-end connection cord O-ring ( 141 ) without having the pulling string ( 130 ) or the ball string ( 151 ) pulled from the ground side.   
     
     
         3 . The structure for a tennis practice device according to  claim 1 , wherein
 the weight ( 200 ) is any one of:
 the weight made of partly or entirely of a soft material, including rubber or silicon, and not a hard material, including wood, stone, and steel; OR 
 the weight having an outer peripheral surface ( 203 ,  204 ,  205 ) made of one layer or multiple layers of the soft material and a center portion ( 206 ) made of the hard material including steel. 
   
     
     
         4 . The structure for tennis practice device according to  claim 2 , wherein,
 the weight ( 200 ) is any one of:
 the weight made of partly or entirely of a soft material, including rubber or silicon, and not a hard material, including wood, stone, and steel, OR 
 the weight having an outer peripheral surface ( 203 ,  204 ,  205 ) made of one layer or multiple layers of the soft material and a center portion ( 206 ) made of the hard material including steel.