Compound bow

Abstract

A compound bow reduces the force required to draw a bowstring and increases the propulsive force when shooting an arrow. The bow comprises a main body having a handle grasped, and a pair of limbs coupled to the ends of the handle; a dual pulley including a main pulley rotatably installed on a rotation shaft fixed to one end of the main body, and an auxiliary pulley having a radius greater than that of the main pulley and rotatably installed on the rotation shaft; a cam installed to the main pulley; a balance cable; a stopper member; a cam cable; a driven pulley rotatably fixed to the other end of the main body; and a bowstring.

1 . A compound bow comprising:
 a main body having a handle grasped by a user and a pair of limbs coupled to both ends of the handle;   a dual pulley including a main pulley installed to rotate around a rotation shaft which is installed to one end of the main body and an auxiliary pulley having a radius greater than that of the main pulley and rotatably installed around the rotation shaft;   a driven pulley rotatably installed on the rotation shaft which is installed at the other end of the main body;   a cam installed to the main pulley;   a balance cable having both ends respectively connected to the main pulley and the auxiliary pulley, and wound around the main pulley and the auxiliary pulley in the same direction;   a connecting member including a balance cable pulley around which a middle portion of the balance cable is wound and which is positioned at a lower side thereof;   a bowstring having one end coupled to an upper portion of the connecting member, a middle portion wound around the driven pulley and the other end connected to the main pulley, and being wound around the cam; and   a cam cable having one end connected to the other end of the main body and the other end connected to the main pulley, and being wound around the cam when the bowstring is drawn for shooting an arrow.   
     
     
         2 . The compound bow according to  claim 1 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         3 . The compound bow according to  claim 2 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         4 . A compound bow comprising:
 a main body having a handle grasped by a user and a pair of limbs coupled to both ends of the handle;   a dual pulley including a main pulley installed to rotate around a rotation shaft which is installed to one end of the main body and an auxiliary pulley having a radius greater than that of the main pulley and rotatably installed around the rotation shaft;   a driven pulley rotatably installed on the rotation shaft which is installed at the other end of the main body;   a cam installed to the main pulley;   a string pulley installed to rotate around the rotation shaft which is installed to one end of the main body and coupled with the main pulley;   a balance cable having both ends respectively connected to the main pulley and the auxiliary pulley, and wound around the main pulley and the auxiliary pulley in the same direction;   a connecting member including a balance cable pulley around which a middle portion of the balance cable is wound and which is positioned at a lower side thereof;   a bowstring having one end coupled to an upper portion of the connecting member, a middle portion wound around the driven pulley and the other end connected to the string pulley, and being wound around the string pulley; and   a cam cable having one end connected to the other end of the main body and the other end connected to the main pulley, and being wound around the cam when the bowstring is drawn for shooting an arrow.   
     
     
         5 . The compound bow according to  claim 4 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         6 . The compound bow according to  claim 5 , wherein the auxiliary pulley further includes an interference pin which contacts an interference step formed at one side of the outer circumference of the main pulley. 
     
     
         7 . A compound bow comprising:
 a main body having a handle grasped by a user, and a pair of limbs coupled to both ends of the handle;   rotation shafts fixed to both ends of the main body, respectively;   dual pulleys, each including a main pulley rotatably installed on the rotation shaft fixed to one end of the main body, and an auxiliary pulley having a radius greater than that of the main pulley and rotatably installed on the rotation shaft;   cams, each installed to the main pulley;   balance cables, both ends of which are connected to the main pulley and the auxiliary pulley and wound around the main pulley and the auxiliary pulley in the same direction;   connecting members, each including a balance cable pulley around which a middle portion of the balance cable is wound and which is positioned at one side thereof;   a bowstring, of which both ends are connected to the connecting members; and   cam cables, each having one end which is connected to any one of both ends of the main body and the other end which is connected to the main pulley which is formed at the rotation shaft installed to the other end of the main body, and being wound around the cam when the bowstring is drawn for shooting an arrow.   
     
     
         8 . The compound bow according to  claim 7 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         9 . The compound bow according to  claim 8 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         10 . The compound bow according to  claim 8 , wherein the auxiliary pulley further includes an interference pin which contacts an interference step formed in the main pulley. 
     
     
         11 . A compound bow comprising:
 a main body having a handle grasped by a user and a pair of limbs coupled to both ends of the handle;   a dual pulley including a main pulley installed to rotate around a rotation shaft which is installed to one end of the main body and an auxiliary pulley having a radius greater than that of the main pulley and rotatably installed around the rotation shaft;   a driven pulley rotatably installed on the rotation shaft which is installed at the other end of the main body;   a cam installed to the main pulley;   a string pulley installed to rotate around the rotation shaft which is installed to one end of the main body and coupled with the main pulley;   a balance cable having both ends respectively connected to the main pulley and the auxiliary pulley, and wound around the main pulley and the auxiliary pulley in the same direction;   a stopper member including a balance cable pulley around which a middle portion of the balance cable is wound and which is positioned at a lower side thereof, and temporarily fixing the balance cable when an arrow is shot;   a bowstring having one end coupled to an upper portion of the stopper member, a middle portion wound around the driven pulley and the other end connected to the string pulley, and being wound around the string pulley; and   a cam cable having one end connected to the other end of the main body and the other end connected to the main pulley, and being wound around the cam when the bowstring is drawn for shooting an arrow.   
     
     
         12 . The compound bow according to  claim 11 , wherein the stopper member includes a housing, to an upper portion of which one end of the bowstring is coupled and to one side of a central portion of which the balance cable pulley is rotatably installed; and
 a stopper, formed at a lower side of the housing, including a locking hook by which a clip is caught to be temporarily fixed, wherein the clip is mounted at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         13 . The compound bow according to  claim 12 , wherein the stopper is rotatably coupled to the housing, and further includes a locker of a stepped shape so that the clip is fastened by the locking hook by restricting the rotation of the stopper when the arrow is shot; and
 the stopper member further includes a trigger having a locking step which is formed at one end thereof and temporarily contacts the locker of the stopper to control the rotation of the stopper.   
     
     
         14 . The compound bow according to  claim 13 , wherein the trigger having the locking step formed at one end thereof is rotatably coupled to the housing; and
 the stopper further includes a pushing section which is spaced at a predetermined distance from and protrudes from the locking hook so that an upper portion of the clip contacts the stopper for its rotation when the clip moves into the housing; and   a support, of which one end is engaged with the stopper, and of which the other end contacts the other side of the trigger to rotate the trigger according to the rotation of the stopper and makes the locking step be caught to the locker.   
     
     
         15 . The compound bow according to  claim 14 , wherein the trigger further includes a contact which is formed at the other end thereof and contacts the balance cable near to the auxiliary pulley from the balance cable pulley, by which the balance cable rotates the trigger to have the locking step be separated from the locker when the balance cable is rewound around the main pulley and the auxiliary pulley after the arrow is shot. 
     
     
         16 . The compound bow according to  claim 11 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         17 . The compound bow according to  claim 16 , wherein the stopping pin is in a screw-coupled fashion and is fastened to a predetermined portion of a stopping pin slot formed in the auxiliary pulley. 
     
     
         18 . The compound bow according to  claim 16 , wherein the stopping pin are covered with anti-vibration covers preventing noise and vibration. 
     
     
         19 . The compound bow according to  claim 16 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         20 . The compound bow according to  claim 16 , wherein the auxiliary pulley further includes an interference pin which contacts an interference step formed in the main pulley. 
     
     
         21 . The compound bow according to  claim 19 , wherein the interference pin is in a screw-coupled fashion and is fastened to a predetermined portion of an interference pin slot formed in the auxiliary pulley. 
     
     
         22 . The compound bow according to  claim 19 , wherein the interference pin are covered with anti-vibration covers preventing noise and vibration. 
     
     
         23 . The compound bow according to  claim 16 , wherein the stopper member includes a housing, to an upper portion of which one end of the bowstring is coupled and to one side of a central portion of which the balance cable pulley is rotatably installed; and
 a stopper, formed at a lower side of the housing, including a locking hook by which a clip is caught to be temporarily fixed, wherein the clip is mounted at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         24 . The compound bow according to  claim 23 , wherein the stopper is rotatably coupled to the housing, and further includes a locker of a stepped shape so that the clip is fastened by the locking hook by restricting the rotation of the stopper when the arrow is shot; and
 the stopper member further includes a trigger having a locking step which is formed at one end thereof and temporarily contacts the locker of the stopper to control the rotation of the stopper.   
     
     
         25 . The compound bow according to  claim 24 , wherein the trigger having the locking step formed at one end thereof is rotatably coupled to the housing; and
 the stopper further includes a pushing section which is spaced at a predetermined distance from and protrudes from the locking hook so that an upper portion of the clip contacts the stopper for its rotation when the clip moves into the housing; and   a support, of which one end is engaged with the stopper, and of which the other end contacts the other side of the trigger to rotate the trigger according to the rotation of the stopper and makes the locking step be caught to the locker.   
     
     
         26 . The compound bow according to  claim 25 , wherein the trigger further includes a contact which is formed at the other end thereof and contacts the balance cable near to the auxiliary pulley from the balance cable pulley, by which the balance cable rotates the trigger to have the locking step be separated from the locker when the balance cable is rewound around the main pulley and the auxiliary pulley after the arrow is shot. 
     
     
         27 . The compound bow according to  claim 25 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         28 . The compound bow according to  claim 11 , wherein the main pulley and the auxiliary pulley are eccentrically installed on the rotation shaft. 
     
     
         29 . The compound bow according to  claim 11 , wherein each of the main pulley, the auxiliary pulley, and the driven pulley includes a guide recess, depressed from the outer circumference thereof, around which the balance cable or the bowstring are wound; and
 the auxiliary pulley includes a separation preventing unit protruding along the guide recess by a predetermined height to prevent separation of the balance cable.   
     
     
         30 . The compound bow according to  claim 11 , wherein the main pulley further comprises an anti-vibration guide which is formed at one side of the outer circumference thereof and has a guide recess installed in the tangential direction of the outer circumference thereof. 
     
     
         31 . The compound bow according to  claim 11 , wherein the cam includes:
 a gradually curved portion with an arc-shape;   a steep curved portion connected to one end of the gradually curved portion and forming a steep curve such that the other end thereof becomes near to the rotation shaft; and   guide recesses formed in the gradually curved portion and the steep curved portion.   
     
     
         32 . The compound bow according to  claim 11 , wherein the stopper member includes a housing having an upper portion to which the bowstring is connected, a central portion to which the balance cable pulley is rotatably installed, and a protrusion protruding from the other side by a predetermined length at a lower portion thereof; and
 a latch, fixed to the protrusion and having a locking hook for temporally fixing a locking ring which is installed at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         33 . The compound bow according to  claim 32 , wherein the latch is rotatably coupled to the protrusion and further includes a locker which is protruded to control a rotation; and
 the stopper member further includes a detent rotatably installed to the protrusion and having a locking step temporally contacting the locker of the latch to control the rotation of the latch, and a knob pin protruding toward the outside of the housing.   
     
     
         34 . The compound bow according to  claim 33 , wherein the stopper member further includes a first torsion spring pressing the latch to be rotated in the direction that the locking hook is locked with the locking ring; and
 a second torsion spring pressing the detent in the direction where the locker is supported by the locking step.   
     
     
         35 . The compound bow according to  claim 34 , wherein the knob pin of the detent further comprises a release wire having one end to which the cam cable is connected and the other end to which the knob pin of the detent is coupled such that the locking ring locked by the locker is separated during the rotation of the detent after an arrow is shot. 
     
     
         36 . The compound bow according to  claim 32 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         37 . The compound bow according to  claim 36 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         38 . A compound bow comprising:
 a main body having a handle grasped by a user, and a pair of limbs coupled to both ends of the handle;   a dual pulley including a main pulley rotatably installed on a rotation shaft fixed to one end of the main body, and an auxiliary pulley having a radius greater than that of the main pulley and rotatably installed on the rotation shaft;   a cam installed to the main pulley;   a balance cable, both ends of which are fixed to the main pulley and the auxiliary pulley and wound around the main pulley and the auxiliary pulley in the same direction;   a stopper member, including a balance cable pulley which is installed at one end thereof and around which a central portion of the balance cable is wound, and temporally fixing the balance cable when an arrow is shot;   a cam cable having one end fixed to the other end of the main body and the other end fixed to the main pulley, and being wound around the cam in the direction opposite to that of the balance cable;   a driven pulley rotatably fixed to the other end of the main body; and   a bowstring having one end connected to the stopper member and wound around the driven pulley, and the other end fixed to the main pulley and wound around the cam in the direction opposite to that of the cam cable.   
     
     
         39 . The compound bow according to  claim 38 , wherein the stopper member includes a housing, to an upper portion of which one end of the bowstring is coupled and to one side of a central portion of which the balance cable pulley is rotatably installed; and
 a stopper, formed at a lower side of the housing, including a locking hook by which a clip is caught to be temporarily fixed, wherein the clip is mounted at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         40 . The compound bow according to  claim 39 , wherein the stopper is rotatably coupled to the housing, and further includes a locker of a stepped shape so that the clip is fastened by the locking hook by restricting the rotation of the stopper when the arrow is shot; and
 the stopper member further includes a trigger having a locking step which is formed at one end thereof and temporarily contacts the locker of the stopper to control the rotation of the stopper.   
     
     
         41 . The compound bow according to  claim 40 , wherein the trigger having the locking step formed at one end thereof is rotatably coupled to the housing; and
 the stopper further includes a pushing section which is spaced at a predetermined distance from and protrudes from the locking hook so that an upper portion of the clip contacts the stopper for its rotation when the clip moves into the housing; and   a support, of which one end is engaged with the stopper, and of which the other end contacts the other side of the trigger to rotate the trigger according to the rotation of the stopper and makes the locking step be caught to the locker.   
     
     
         42 . The compound bow according to  claim 41 , wherein the trigger further includes a contact which is formed at the other end thereof and contacts the balance cable near to the auxiliary pulley from the balance cable pulley, by which the balance cable rotates the trigger to have the locking step be separated from the locker when the balance cable is rewound around the main pulley and the auxiliary pulley after the arrow is shot. 
     
     
         43 . The compound bow according to  claim 38 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         44 . The compound bow according to  claim 43 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         45 . The compound bow according to  claim 43 , wherein the stopper member includes a housing, to an upper portion of which one end of the bowstring is coupled and to one side of a central portion of which the balance cable pulley is rotatably installed; and
 a stopper, formed at a lower side of the housing, having a locking hook by which a clip is caught to be temporarily fixed, wherein the clip is mounted at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         46 . The compound bow according to  claim 45 , wherein the stopper is rotatably coupled to the housing, and further includes a locker of a stepped shape so that the clip is fastened by the locking hook by restricting the rotation of the stopper when the arrow is shot; and
 the stopper member further includes a trigger which is formed at one end thereof and has a locking step temporarily contacting the locker of the stopper to control the rotation of the stopper.   
     
     
         47 . The compound bow according to  claim 46 , wherein the trigger having the locking step formed at one end thereof is rotatably coupled to the housing; and
 the stopper further includes a pushing section which is spaced at a predetermined distance from and protrudes from the locking hook so that an upper portion of the clip contacts the stopper for its rotation when the clip moves into the housing; and   a support, of which one end is engaged with the stopper, and of which the other end contacts the other side of the trigger to rotate the trigger according to the rotation of the stopper and makes the locking step be caught to the locker.   
     
     
         48 . The compound bow according to  claim 47 , wherein the trigger further includes a contact which is formed at the other end thereof and contacts the balance cable near to the auxiliary pulley from the balance cable pulley, by which the balance cable rotates the trigger to have the locking step be separated from the locker when the balance cable is rewound around the main pulley and the auxiliary pulley after the arrow is shot. 
     
     
         49 . The compound bow according to  claim 45 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         50 . The compound bow according to  claim 38 , wherein the main pulley and the auxiliary pulley are eccentrically installed on the rotation shaft. 
     
     
         51 . The compound bow according to  claim 38 , wherein the cam includes:
 a gradually curved portion with an arc-shape;   a steep curved portion connected to one end of the gradually curved portion and forming a steep curve such that the other end thereof becomes near to the rotation shaft; and   guide recesses formed in the gradually curved portion and the steep curved portion.   
     
     
         52 . The compound bow according to  claim 38 , wherein the stopper member includes a housing having an upper portion to which the bowstring is connected, a central portion to which the balance cable pulley is rotatably installed, and a protrusion protruding from the other side by a predetermined length at a lower portion thereof; and
 a latch, fixed to the protrusion and having a locking hook for temporally fixing a locking ring which is installed at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         53 . The compound bow according to  claim 52 , wherein the latch is rotatably coupled to the protrusion and further includes a locker which is protruded to control a rotation; and
 the stopper member further includes a detent rotatably installed to the protrusion and having a locking step temporally contacting the locker of the latch to control the rotation of the latch, and a knob pin protruding toward the outside of the housing.   
     
     
         54 . The compound bow according to  claim 53 , wherein the stopper member further includes a first torsion spring pressing the latch to be rotated in the direction that the locking hook is locked with the locking ring; and
 a second torsion spring pressing the detent in the direction where the locker is supported by the locking step.   
     
     
         55 . The compound bow according to  claim 53 , wherein the knob pin of the detent further comprises a release wire having one end to which the cam cable is connected and the other end to which the knob pin of the detent is coupled such that the locking ring locked by the locker is separated during the rotation of the detent after an arrow is shot. 
     
     
         56 . The compound bow according to  claim 52 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         57 . The compound bow according to  claim 56 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         58 . A compound bow comprising:
 a main body having a handle grasped by a user, and a pair of limbs coupled to both ends of the handle;   rotation shafts fixed to both ends of the main body, respectively;   dual pulleys, each including a main pulley rotatably installed on the rotation shaft fixed to one end of the main body, and an auxiliary pulley having a radius greater than that of the main pulley and rotatably installed on the rotation shaft;   cams, each installed to the main pulley;   balance cables, both ends of which are fixed to the main pulley and the auxiliary pulley and wound around the main pulley and the auxiliary pulley in the same direction;   stopper members, each including a balance cable pulley which is formed at one side thereof and around which a central portion of the balance cable is wound, and temporally fixing the balance cable when the arrow is shot;   cam cables, each having one end which is fixed to any one of both ends of the main body and the other end which is fixed to the main pulley formed at the rotation shaft installed to the other end of the main body, and being wound around the cam in the direction opposite to that of the balance cable; and   a bowstring, of which both ends are connected to the stopper members.   
     
     
         59 . The compound bow according to  claim 58 , wherein the stopper member includes a housing, to an upper portion of which one end of the bowstring is coupled and to one side of a central portion of which the balance cable pulley is rotatably installed; and
 a stopper, formed at a lower side of the housing, including a locking hook by which a clip is caught to be temporarily fixed, wherein the clip is mounted at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         60 . The compound bow according to  claim 59 , wherein the stopper is rotatably coupled to the housing, and further includes a locker of a stepped shape so that the clip is fastened by the locking hook by restricting the rotation of the stopper when the arrow is shot; and
 the stopper member further includes a trigger having a locking step which is formed at one end thereof and temporarily contacts the locker of the stopper to control the rotation of the stopper.   
     
     
         61 . The compound bow according to  claim 60 , wherein the trigger having the locking step formed at one end thereof is rotatably coupled to the housing; and
 the stopper further includes a pushing section which is spaced at a predetermined distance from and protrudes from the locking hook so that an upper portion of the clip contacts the stopper for its rotation when the clip moves into the housing; and   a support, of which one end is engaged with the stopper, and of which the other end contacts the other side of the trigger to rotate the trigger according to the rotation of the stopper and makes the locking step be caught to the locker.   
     
     
         62 . The compound bow according to  claim 61 , wherein the trigger further includes a contact which is formed at the other end thereof and contacts the balance cable near to the auxiliary pulley from the balance cable pulley, by which the balance cable rotates the trigger to have the locking step be separated from the locker when the balance cable is rewound around the main pulley and the auxiliary pulley after the arrow is shot. 
     
     
         63 . The compound bow according to  claim 58 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         64 . The compound bow according to  claim 63 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         65 . The compound bow according to  claim 63 , wherein the auxiliary pulley further includes an interference pin which contacts an interference step formed in the main pulley. 
     
     
         66 . The compound bow according to  claim 63 , wherein the stopper member includes a housing, to an upper portion of which one end of the bowstring is coupled and to one side of a central portion of which the balance cable pulley is rotatably installed; and
 a stopper, formed at a lower side of the housing, having a locking hook by which a clip is caught to be temporarily fixed, wherein the clip is mounted at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         67 . The compound bow according to  claim 66 , wherein the stopper is rotatably coupled to the housing, and further includes a locker of a stepped shape so that the clip is fastened by the locking hook by restricting the rotation of the stopper when the arrow is shot; and
 the stopper member further includes a trigger which is formed at one end thereof and has a locking step temporarily contacting the locker of the stopper to control the rotation of the stopper.   
     
     
         68 . The compound bow according to  claim 67 , wherein the trigger having the locking step formed at one end thereof is rotatably coupled to the housing; and
 the stopper further includes a pushing section which is spaced at a predetermined distance from and protrudes from the locking hook so that an upper portion of the clip contacts the stopper for its rotation when the clip moves into the housing; and   a support, of which one end is engaged with the stopper, and of which the other end contacts the other side of the trigger to rotate the trigger according to the rotation of the stopper and makes the locking step be caught to the locker.   
     
     
         69 . The compound bow according to  claim 68 , wherein the trigger further includes a contact which is formed at the other end thereof and contacts the balance cable near to the auxiliary pulley from the balance cable pulley, by which the balance cable rotates the trigger to have the locking step be separated from the locker when the balance cable is rewound around the main pulley and the auxiliary pulley after the arrow is shot. 
     
     
         70 . The compound bow according to  claim 66 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         71 . The compound bow according to  claim 58 , wherein the main pulley and the auxiliary pulley are eccentrically installed on the rotation shaft. 
     
     
         72 . The compound bow according to  claim 58 , wherein each of the main pulley and the auxiliary pulley includes a guide recess, depressed from the outer circumference thereof, around which the balance cable is wound; and
 the auxiliary pulley includes a separation preventing unit protruding along the guide recess by a predetermined height to prevent separation of the balance cable.   
     
     
         73 . The compound bow according to  claim 58 , wherein the main pulley further comprises an anti-vibration guide which is formed at one side of the outer circumference thereof and has a guide recess installed in the tangential direction of the outer circumference thereof. 
     
     
         74 . The compound bow according to  claim 58 , wherein the cam includes:
 a gradually curved portion with an arc-shape;   a steep curved portion connected to one end of the gradually curved portion and forming a steep curve such that the other end thereof becomes near to the rotation shaft; and   guide recesses formed in the gradually curved portion and the steep curved portion.   
     
     
         75 . The compound bow according to  claim 58 , wherein the stopper member includes a housing having an upper portion to which the bowstring is connected, a central portion to which the balance cable pulley is rotatably installed, and a protrusion protruding from the other side by a predetermined length at a lower portion thereof; and
 a latch, fixed to the protrusion and having a locking hook for temporally fixing a locking ring which is installed at one side of the balance cable near to the main pulley from the balance cable pulley.   
     
     
         76 . The compound bow according to  claim 75 , wherein the latch is rotatably coupled to the protrusion and further includes a locker which is protruded to control a rotation; and
 the stopper member further includes a detent rotatably installed to the protrusion and having a locking step temporally contacting the locker of the latch to control the rotation of the latch, and a knob pin protruding toward the outside of the housing.   
     
     
         77 . The compound bow according to  claim 76 , wherein the stopper member further includes a first torsion spring pressing the latch to be rotated in the direction that the locking hook is locked with the locking ring; and
 a second torsion spring pressing the detent in the direction where the locker is supported by the locking step.   
     
     
         78 . The compound bow according to  claim 76 , wherein the knob pin of the detent further comprises a release wire having one end to which the cam cable is connected and the other end to which the knob pin of the detent is coupled such that the locking ring locked by the locker is separated during the rotation of the detent after an arrow is shot. 
     
     
         79 . The compound bow according to  claim 75 , wherein the auxiliary pulley further comprises a stopping pin which is installed to the auxiliary pulley and temporally contacts the main body when the auxiliary pulley rotates by a predetermined angle such that the auxiliary pulley does not rotate further. 
     
     
         80 . The compound bow according to  claim 79 , wherein the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley. 
     
     
         81 . The compound bow according to  claim 79 , wherein the auxiliary pulley further includes an interference pin which contacts an interference step formed in the main pulley.