Compound bow

Abstract

A compound bow includes a riser, a limb, a pulley block, a string, a first coupler, a second coupler, a first cable and a second cable, the pulley block includes a pulley for string, a first pulley for cable and a second pulley for cable, the first pulley for cable and the second pulley for cable are located on two sides of the pulley for string respectively, the first coupler is configured to couple or decouple the first pulley for cable and the pulley for string at a set position, the second coupler is configured to couple or decouple the second pulley for cable and the pulley for string in the set position.

What is claimed is: 
     
         1 . A compound bow, comprising a riser, a limb, a pulley block and a string, wherein an inner end of the limb is provided on the riser, an outer end of the limb is provided with an axle, the pulley block is provided on the axle, the compound bow further comprises a first coupler, a second coupler, a first cable and a second cable, the axle is provided with a first cable hanging ring and a second cable hanging ring, the pulley block comprises a pulley for string, a first pulley for cable and a second pulley for cable, the first pulley for cable and the second pulley for cable are located on two sides of the pulley for string respectively, the first coupler is configured to keep the first pulley for cable and the pulley for string in a coupled state before the pulley for string is pulled to a set position while decoupling the first pulley for cable and the pulley for string after the pulley for string is pulled to the set position, the first coupler is further configured to keep the first pulley for cable and the pulley for string in a decoupled state before the pulley for string is released to the set position while coupling the first pulley for cable and the pulley for string after the pulley for string is released to the set position, the second coupler is configured to keep the second pulley for cable and the pulley for string in the decoupled state before the pulley for string is pulled to the set position while coupling the second pulley for cable and the pulley for string after the pulley for string is pulled to the set position, and the second coupler is further configured to keep the second pulley for cable and the pulley for string in the coupled state before the pulley for string is released to the set position while decoupling the second pulley for cable and the pulley for string after the pulley for string is released to the set position. 
     
     
         2 . The compound bow according to  claim 1 , further comprising a first reset torsion spring and a second reset torsion spring, wherein the first reset torsion spring is configured to be sleeved on the axle to attach the first pulley for cable to a first anti-rotation point of the pulley for string and to inhibit a relative movement between the pulley for string and the first pulley for cable, and the second reset torsion spring is configured to be sleeved on the axle to attach the second pulley for cable to a second anti-rotation point of the pulley for string and to inhibit a relative movement between the pulley for string and the second pulley for cable. 
     
     
         3 . The compound bow according to  claim 2 , wherein the first coupler and the second coupler are electronic couplers. 
     
     
         4 . The compound bow according to  claim 3 , wherein the pulley for string is configured with a first coupling hole and a second coupling hole, the first coupler is provided on the first pulley for cable, the first coupler comprises a first electromagnet and a first sensor, the first sensor is configured to detect whether the pulley for string is rotated to the set position, the first electromagnet is configured to act when the pulley for string is rotated to the set position, so as to insert or withdraw an iron core of the first electromagnet into or from the first coupling hole to couple or decouple the first pulley for cable and the pulley for string, the second coupler is provided on the second pulley for cable, the second coupler comprises a second electromagnet and a second sensor, the second sensor is configured to detect whether the pulley for string is rotated to the set position, and the second electromagnet is configured to act when the pulley for string is rotated to the set position, so as to insert or withdraw an iron core of the second electromagnet into or from the second coupling hole to couple or decouple the second pulley for cable and the pulley for string. 
     
     
         5 . The compound bow according to  claim 2 , wherein the pulley for string is configured with a first coupling hole and a second coupling hole, the first coupler comprises a first lock block, a reset spring for first lock block, a first guide module and a first track transfer block, the first pulley for cable is configured with a receiving hole for first lock block, the first lock block is slidably provided in the receiving hole for first lock block, the first guide module is fixedly provided on the first lock block, the first track transfer block is provided on the axle and configured to drive the first guide module to move when the first pulley for cable rotates, the first guide module then drives the first lock block to slide in the receiving hole for first lock block, the first lock block is configured to be inserted into or withdrawn from the first coupling hole during sliding to couple or decouple the first pulley for cable and the pulley for string, the reset spring for first lock block is configured to push the first lock block into the first coupling hole, the second coupler comprises a second lock block, a reset spring for second lock block, a second guide module and a second track transfer block, the second pulley for cable is configured with a receiving hole for second lock block, the second lock block is slidably provided in the receiving hole for second lock block, the second guide module is fixedly provided on the second lock block, the second track transfer block is provided on the axle and configured to drive the second guide module to move when the second pulley for cable rotates, the second guide module then drives the second lock block to slide in the receiving hole for second lock block, the second lock block is configured to be inserted into or withdrawn from the second coupling hole during sliding to couple or decouple the second pulley for cable and the pulley for string, and the reset spring for second lock block is configured to push the second lock block into the second coupling hole. 
     
     
         6 . The compound bow according to  claim 5 , wherein the first track transfer block is provided with a first inclined surface, the first guide module is driven to move through the first inclined surface, the second track transfer block is provided with a second inclined surface, and the second guide module is driven to move through the second inclined surface. 
     
     
         7 . The compound bow according to  claim 1 , further comprising a cable splitter on the riser, wherein the cable splitter comprises a mounting base, a first pulley for splitting cable, a second pulley for splitting cable and a third pulley for splitting cable, the first pulley for splitting cable, the second pulley for splitting cable and the third pulley for splitting cable are arranged on the mounting base in a triangular shape, the string is hooked on a string post of the pulley for string, a first end of the first cable is hooked on a cable post of the first pulley for cable, a second end of the first cable is hooked on the first cable hanging ring, the first cable is further hooked on the first pulley for splitting cable in a middle of the first cable, a first end of the second cable is hooked on a cable post of the second pulley for cable, a second end of the second cable is hooked on the second cable hanging ring, and the second cable is further hooked on the second pulley for splitting cable and the third pulley for splitting cable in a middle of the second cable. 
     
     
         8 . The compound bow according to  claim 1 , wherein the string is hooked on a string post of the pulley for string, a first end of the first cable is hooked on a cable post of the first pulley for cable, a second end of the first cable is hooked on the first cable hanging ring, a first end of the second cable is hooked on a cable post of the second pulley for cable, and a second end of the second cable is hooked on the second cable hanging ring.