Compound bow structure

Abstract

A compound bow structure includes a riser having a grip and a recess is defined in the inside of the grip. A first cam and a second cam are respectively connected to the two limbs and a string is connected between the first and second cams. Two cables each have a first end connected to the first/second cam corresponding thereto. The two cables each have a second end which has two split sub-cables. The sub-cables of the two cables are respectively connected to two sides of the first/second cam corresponding thereto. A protector is connected to the inside of the grip and located to cover the recess of the grip. The string bounces toward the protector along a plane that passes through the rear side of the protector. A gap is formed between the grip and the protector to accommodate the user's hand.

What is claimed is: 
     
         1 . A compound bow structure comprising:
 a riser having a grip and two extensions extending from two ends of the grip, a recess defined in an inside of the grip, two limbs respectively connected to two distal ends of the two extensions;   a protector connected to the inside of the grip and located between the two limbs, the protector having a front side and a rear side, the front side of the protector facing the recess and covering the recess of the grip, and   a control unit having a first cam and a second cam respectively connected to two respective distal ends of the two limbs, a string connected between the first and second cams, two cables each having a first end connected to the first/second cam corresponding thereto, the two cables each having a second end which has two split sub-cables, the sub-cables of the two cables respectively connected to two sides of the first/second cam corresponding thereto, the rear side of the protector facing the string, a distance “L” between a lowest point of the recess and the string being smaller than ⅕ of a length of the string, the string being pulled away from the protector, and bouncing toward the protector along a plane that passes through the rear side of the protector.   
     
     
         2 . The compound bow structure as claimed in  claim 1 , wherein the protector is an elongate plate which has two ends, the two ends of the protector are connected to two ends of the recess, a gap is formed between the grip and the protector so as to be adapted accommodate a user's hand. 
     
     
         3 . The compound bow structure as claimed in  claim 2 , wherein each of the two limbs has a notch to form a first arm and a second arm, the first and second cams are respectively located in the two notches of the two limbs, each of the first and second cams has an axle extending therethrough, the axle of each of the first and second cams is connected between the first and second arms corresponding thereto. 
     
     
         4 . The compound bow structure as claimed in  claim 3 , wherein the sub-cables of the cables are respectively connected to two ends of the axle of the first/second cam corresponding thereto to adjust a tension of the string and to adjust a distance “L” between the string and the riser. 
     
     
         5 . The compound bow structure as claimed in  claim 1 , wherein a coefficient of elasticity of each of the two limbs is larger than that of the riser. 
     
     
         6 . The compound bow structure as claimed in  claim 1 , wherein the distance “L” between the lowest point of the recess and the string is equal to ⅙ of the length of the string. 
     
     
         7 . The compound bow structure as claimed in  claim 1 , wherein the rear side of the protector is intersected with the plane that the string moves along at an angle. 
     
     
         8 . The compound bow structure as claimed in  claim 1 , wherein the rear side of the protector is tilt relative to the plane to have a larger entrance of the gap.