Pulley block for compound bow and novel compound bow

Abstract

A pulley block for a compound bow and a novel compound bow are provided. The pulley block includes a main string pulley, a first cable pulley, a second cable pulley and an axle. Each of the first and second cable pulleys includes a cable pulley body, an adjust rod, a coupler and a first reset spring. One end of the adjust rod is hingedly connected to the cable pulley body, and another end is a free end. The cable pulley body is provided with a first and second stop-rotating edges; the adjust rod is capable to lift up a cable when it rests against the first stop-rotating edge, and lift down the cable when it rests against the second stop-rotating edge. The coupler is capable to couple or decouple the adjust rod from the cable pulley body when the cable pulley body is rotated to a set position.

What is claimed is: 
     
         1 . A pulley block for a compound bow, comprising a main string pulley, a first cable pulley, a second cable pulley and an axle; wherein the first cable pulley and the second cable pulley are provided on both sides of the main string pulley and are fixedly connected to the main string pulley; each of the first cable pulley and the second cable pulley comprises a cable pulley body, an adjust rod, a coupler and a first reset spring; the adjust rod is hingedly connected to the cable pulley body at one end of the adjust rod, and another end is a free end; the cable pulley body is provided with a first stop-rotating edge and a second stop-rotating edge, the adjust rod is capable to lift up a cable when it rests against the first stop-rotating edge, the adjust rod is capable to lift down the cable when it rests against the second stop-rotating edge; the first reset spring is capable to make the adjust rod rest against the first stop-rotating edge, and the coupler is capable to couple or decouple the adjust rod from the cable pulley body when the cable pulley body is rotated to a set position. 
     
     
         2 . The pulley block for a compound bow according to  claim 1 , wherein the coupler comprises a lock block, a guide rod and a track transfer block; the cable pulley body is provided with a slide hole, the lock block is provided in the slide hole in a resilient and floated manner, the guide rod is fixedly provided on the lock block, the track transfer block is fixedly provided on the axle or on a limb of the compound bow, for driving the guide rod and the lock block move outwardly to decouple the adjust rod from the cable pulley body. 
     
     
         3 . The pulley block for a compound bow according to  claim 2 , wherein the track transfer block is provided with an inclined surface by which the guide rod is driven to move. 
     
     
         4 . The pulley block for a compound bow according to  claim 2 , wherein the lock block is provided with a recess, the recess is provided with a second reset spring, the second reset spring is resisted with the cable pulley body, for pushing the lock block to be in a locked position. 
     
     
         5 . The pulley block for a compound bow according to  claim 1 , wherein the cable pulley body is provided with a notch, and a hinged end of the adjust rod is provided in the notch. 
     
     
         6 . The pulley block for a compound bow according to  claim 1 , wherein the coupler is an electronic coupler. 
     
     
         7 . The pulley block for a compound bow according to  claim 6 , wherein the electronic coupler comprises an electromagnet and a position sensor; the position sensor is capable to detect whether the cable pulley body is rotated to the set position, and the electromagnet is operated when the cable pulley body is rotated to the set position, such that a core of the electromagnet is extended or retracted to couple or decouple the adjust rod from the cable pulley body. 
     
     
         8 . A compound bow, comprising a riser, an upper limb, a lower limb, an upper pulley block, a lower pulley block and a main string; wherein the novel compound bow further comprises a first cable, a second cable, a third cable, a fourth cable, a first cable hang ring, a second cable hang ring, a third cable hanging and a fourth cable hang ring; the upper pulley block and lower pulley block both adopt the pulley block for the compound bow according to  claim 1 ;
 the first cable hang ring and the second cable hang ring are provided on the axle of the lower pulley block, the third cable hang ring and fourth cable hang ring are provided on the axle of the upper pulley block;   one end of the first cable is hooked to the first cable pulley of the upper pulley block, with another end to the first cable hang ring;   one end of the second cable is hooked to the second cable pulley of the upper pulley block, with another end to the second cable hang ring;   one end of the third cable is hooked to the first cable pulley of the lower pulley block, with another end to the third cable hang ring; and   one end of the fourth cable is hooked to the second cable pulley of the lower pulley block, with another end to the fourth cable hang ring.   
     
     
         9 . The compound bow according to  claim 8 , wherein the coupler comprises a lock block, a guide rod and a track transfer block; the cable pulley body is provided with a slide hole, the lock block is provided in the slide hole in a resilient and floated manner, the guide rod is fixedly provided on the lock block, the track transfer block is fixedly provided on the axle or on a limb of the compound bow, for driving the guide rod and the lock block move outwardly to decouple the adjust rod from the cable pulley body. 
     
     
         10 . The compound bow according to  claim 9 , wherein the track transfer block is provided with an inclined surface by which the guide rod is driven to move. 
     
     
         11 . The compound bow according to  claim 9 , wherein the lock block is provided with a recess, the recess is provided with a second reset spring, the second reset spring is resisted with the cable pulley body, for pushing the lock block to be in a locked position. 
     
     
         12 . The compound bow according to  claim 8 , wherein the cable pulley body is provided with a notch, and a hinged end of the adjust rod is provided in the notch. 
     
     
         13 . The compound bow according to  claim 8 , wherein the coupler is an electronic coupler. 
     
     
         14 . The compound bow according to  claim 13 , wherein the electronic coupler comprises an electromagnet and a position sensor; the position sensor is capable to detect whether the cable pulley body is rotated to the set position, and the electromagnet is operated when the cable pulley body is rotated to the set position, such that a core of the electromagnet is extended or retracted to couple or decouple the adjust rod from the cable pulley body.