Arrow shooting device

Abstract

The present invention relates to an arrow shooting device, and more specifically to, a new arrow shooting device and a draw weight adding method, wherein an arrow is shot not by a compound arrow or a compound crossbow, which have been conventionally used, but by a rubber band and a differential motion cam. The arrow shooting device according to the present invention is formed in the straight simple shape, wherein, as shown in FIG. 6 , the rubber band having superior elasticity is used rather than a limb in the energy storage method thereof and the retraction speed of the rubber band is converted using a differential motion cam or a differential motion cam so as to be suitable for shooting the arrow. In addition, it is possible to additionally hang the rubber band in the state when drawing is finished, or pull the rubber band by means of a winch, so that even people in general may shoot an arrow with a strong draw weight. Therefore, the arrow shooting device is light enough to easily be carried, is easy to manufacture and repair, and has much storage power so that an arrow may be shot far and shot straight. According to the present invention, it is possible to resolve the conventional problems of the complicated structure, heavy weight, noise and shock in the compound arrow and the compound crossbow and reduce the weight for convenience in movement.

1 . An arrow shooting device using a rubber band, comprising:
 a differential motion cam including:   a pair of outer pulleys each having a groove for receiving a string; and   an inner cam in which a rubber inner string connected with the rubber band is fixed at a fixing point of the outer side, and a spiral groove is symmetrically formed, the radius of which decreasing as the rubber inner string is inwardly wound, the inner cam having a straight groove the radius of which is smallest at the central portion as it meets the spiral groove.   
     
     
         2 . An arrow shooting device using a rubber band, comprising:
 a differential motion cam including:   a pair of outer pulleys each having a groove for receiving a strip; and   an inner pulley in which a rubber inner string connected with the rubber band is fixed at a fixing point of the outer side, the rubber inner string being inwardly wound after passing through an outer cylindrical portion, and passing through a diamond-shaped groove at the central portion.   
     
     
         3 . An arrow shooting device according to  claim 1 , wherein there is provided a trigger, and there is provided a way of increasing a draw weight in such a way that a string is drawn, and a rubber band is added and pulled toward the rubber band anchor and is hooked. 
     
     
         4 . An arrow shooting device according to  claim 1 , wherein there is provided a trigger, and there is provided a winch helping stop the rotation with a winch pawl in such way that a string is drawn, and a winch cable connected with the rubber band is pulled by turning a winch handle. 
     
     
         5 . An arrow shooting device according to  claim 1 , wherein there is provided a pair of string roller stopper which permit the movement of the string in a horizontal direction when the string starts moving after shooting, and limit the movement of the string in a vertical direction and hooks and stops the string. 
     
     
         6 . An arrow shooting device according to  claim 1 , wherein there is provided a stopper cable one end of which is connected to a portion where the rubber band inner string and the rubber band are connected, and the other end of which is connected to a fixing point of the body, thus stopping the contraction of the rubber band. 
     
     
         7 . An arrow shooting device according to  claim 2 , wherein there is provided a trigger, and there is provided a way of increasing a draw weight in such a way that a string is drawn, and a rubber band is added and pulled toward the rubber band anchor and is hooked. 
     
     
         8 . An arrow shooting device according to  claim 2 , wherein there is provided a trigger, and there is provided a winch helping stop the rotation with a winch pawl in such way that a string is drawn, and a winch cable connected with the rubber band is pulled by turning a winch handle. 
     
     
         9 . An arrow shooting device according to  claim 2 , wherein there is provided a pair of string roller stopper which permit the movement of the string in a horizontal direction when the string starts moving after shooting, and limit the movement of the string in a vertical direction and hooks and stops the string. 
     
     
         10 . An arrow shooting device according to  claim 2 , wherein there is provided a stopper cable one end of which is connected to a portion where the rubber band inner string and the rubber band are connected, and the other end of which is connected to a fixing point of the body, thus stopping the contraction of the rubber band.