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.

Description

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM TO PRIORITY

This application claims the benefit of Korean Patent Application No. 10-2009-0015473, filed on Feb. 24, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference and to which priority is claimed.

FIELD OF THE INVENTION

The present invention relates to a compound bow and, more particularly, to a compound bow in which a force is mainly applied to an auxiliary pulley with a large radius when a bowstring is drawn so that a drawing force is reduced and in which a force is mainly applied to a main pulley with a small radius to project an arrow when the bowstring is restored to the original state so that propulsive force of the arrow can be increased.

BACKGROUND OF THE INVENTION

In general, a compound bow utilizes effect of a cam or a wheel such that a bowstring can be easily drawn without a large force, a shooting force is increased to an arrow when shooting so that shooting speed of the arrow is fast and a very strong force can be exhibited. The compound bow is chiefly used for hunting.

The existing compound bow, as illustrated in FIGS. 1 and 2, includes an aluminum handle 10, an upper limb 20 coupled with the upper side of the handle 10, and a lower limb 26 coupled with the lower side of the handle 10. Respective ends 22 and 28 of the upper limb 20 and the lower limb 26 have slits 21 and 27, and a cam is installed between the slits 21 and 27 to rotate about eccentric shafts 70.

The cam includes an upper cam 30 and a lower can 36, and a bowstring 50 is connected between the upper cam 30, the end 28 of the lower limb 26, and the lower cam 36. A first cable 40 and a second cable 46 pass cross each other.

A cable guard 60 is installed to a central side of the handle 10 in the lateral direction, and a slide 66 is installed on the cable guard 60 to move on the cable guard 60. The bowstring 50 is inserted into the slide 66.

The slide 66 is a device pushing the first and second cables 40 and 46 to one side. If the first and second cables 40 and 46 are not pushed to one side, the bowstrings 50 collides with the first and second cables 40 and 46 when shooting.

In the existing compound bow constructed as described above, when the bowstring 50 is drawn, the upper and lower cams 30 and 36 having the eccentric shafts 70 rotate and wind the first and second cables 40 and 46 to draw respectively, and simultaneously the upper limb 20 and the lower limb 26 are bent and the slide 66 moves toward the end of the cable guard 60. At this time, the upper and lower cams 30 and 36 are distorted.

In other words, as illustrated in FIG. 2, the upper cam 30 is coupled to the end 22 of the upper limb 20 by the eccentric shaft 70, one end of the bowstring 50 is coupled with a large diameter recess 31, the first cable 40 is coupled to a small diameter recess 32 and the end of the lower limb 26, the lower cam 36 is coupled with the end 28 of the lower limb 26 by the eccentric shaft 70, the other end of the bowstring 50 is coupled with a large diameter recess 37 of the lower cam 36, and the second cable 46 is coupled to a small diameter recess 38 of the lower cam 36 and the end 22 of the upper limb 20.

Thus, when the bowstring 50 is drawn, the upper and lower cams 30 and 36 rotate about the eccentric shafts 70. When the bowstring 50 is drawn and released such that portions with the largest diameter passes through a vertical position about the eccentric shafts 70, the arrow obtains a strong propulsive force due to a strong resilient force of the bowstring 50 fast returning to the original position.

However, the existing compound bow has a limit of reducing a force required to draw the bowstring 50 and of increasing the propulsive force to shoot the arrow when sizes of the large diameter recesses 31 and 37 and the small diameter recesses 32 and 38 of the upper cam 30 and the lower cam 36 are fixed.

SUMMARY OF THE INVENTION

To overcome the above problems or inconvenience of the conventional art, it is an object of the present invention to provide a compound bow for reducing a force required to draw a bowstring and for increasing a propulsive force of shooting an arrow.

To accomplish the above object of the present invention, there is provided 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.

A compound bow according to another embodiment of the present invention comprises 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.

A compound bow according to yet another embodiment of the present invention comprises 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.

A compound bow according to still another embodiment of the present invention comprises 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.

Also, 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.

Preferably, 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.

Preferably, 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.

Preferably, 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.

Also, 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.

Also, 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.

Preferably, the stopping pin are covered with anti-vibration covers preventing noise and vibration.

Also, the auxiliary pulley further includes an interference pin which moves along an movement hole formed in the main pulley.

Preferably, 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.

Preferably, the interference pin are covered with anti-vibration covers preventing noise and vibration.

Preferably, the main pulley and the auxiliary pulley are eccentrically installed on the rotation shaft.

Preferably, 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.

Preferably, 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.

Preferably, 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 to guide the cam cable and the bowstring.

Meanwhile, in the compound bow according to another embodiment of the present invention, 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.

Preferably, 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.

Preferably, the stopper member further includes a first torsion spring pressing the latch to be rotated in the direction that 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.

Preferably, 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.

Meanwhile, a compound bow according to the other embodiment of the present invention comprises 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.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features and advantages of the present invention will be more apparent from the following detailed description in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating an existing compound bow;

FIG. 2 is a perspective view partially illustrating a cam installing unit in FIG. 1;

FIG. 3 is a perspective view illustrating a compound bow according to a first embodiment of the present invention;

FIGS. 4 and 5 are exploded perspective views illustrating a main pulley, an auxiliary pulley, and a cam as shown in FIG. 3;

FIG. 6 is a view illustrating a modification that a bow string is connected to another string pulley;

FIG. 7 is a perspective view illustrating a connecting member of the compound bow according to the first embodiment of the present invention;

FIG. 8 is an exploded perspective view illustrating a stopper member of a compound bow according to a second embodiment of the present invention;

FIGS. 9 to 12 are schematic views subsequently illustrating operating states of the stopper member when the compound bow is operated, in which

FIG. 9 illustrates a state of the stopper member before the bowstring is drawn;

FIG. 10 illustrates a state of the stopper member when the bowstring is drawn by a predetermined distance; and

FIG. 11 illustrates a state of the stopper member before an arrow is shot;

FIG. 12 illustrates a state of the stopper member after an arrow is shot;

FIG. 13 is a perspective view illustrating a compound bow according to a third embodiment of the present invention;

FIG. 14 is an exploded perspective view of a stopper member illustrated in FIG. 13;

FIGS. 15 to 17 are schematic views illustrating operating states of the compound bow according to the third embodiment of the present invention, in which:

FIG. 15 illustrates a state before the bowstring is drawn according to the third embodiment of the present invention;

FIG. 16 illustrates a state that the bowstring is drawn by a predetermined distance according to the third embodiment of the present invention;

FIG. 17 illustrates a state the bowstring is fully drawn according to the third embodiment of the present invention;

FIG. 18 is a perspective view illustrating a compound bow according to a fourth embodiment of the present invention;

FIGS. 19 and 20 are exploded perspective views illustrating a main pulley, an auxiliary pulley, and a cam as shown in FIG. 18;

FIGS. 21 to 23 are schematic views illustrating operating states of the compound bow according to the fourth embodiment of the present invention, in which:

FIG. 21 illustrates a state before the bowstring is drawn;

FIG. 22 illustrates a state that the bowstring is drawn by a predetermined distance;

FIG. 23 is a view illustrating a state that the bowstring is fully drawn; and

FIG. 24 is a perspective view illustrating a compound bow according to a fifth embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a perspective view illustrating a compound bow according to a first embodiment of the present invention, FIGS. 4 and 5 are exploded perspective views illustrating a main pulley, an auxiliary pulley and a cam as shown in FIG. 3, FIG. 6 is a view illustrating a modification that a bow string is connected to another string pulley, and FIG. 7 is a perspective view illustrating a connecting member of the compound bow according to the first embodiment of the present invention.

As illustrated, a compound bow according to the first embodiment of the present invention comprises a main body 100 having a handle 102 grasped by a user and a pair of limbs 103 coupled to both ends of the handle 102; a dual pulley including a main pulley 110 installed to rotate around the rotation shaft 101 that is installed to one end of the main body 100 and an auxiliary pulley 120 having a radius greater than that of the main pulley 110 and rotatably installed around the rotation shaft 101; a driven pulley 190 rotatably installed on the rotation shaft 101 that is installed at the other end of the main body 100; a cam 130 installed to the main pulley 110; a balance cable 141 having both ends respectively connected to the main pulley 110 and the auxiliary pulley 120, and wound around the main pulley 110 and the auxiliary pulley 120 in the same direction; a connecting member 360 including a balance cable pulley 161 around which a middle portion of the balance cable is wound and which is positioned at a lower portion thereof; a bowstring 142 having one end coupled to an upper portion of the connecting member 360, a middle portion wound around the driven pulley 190 and the other end fixed to the main pulley 110, and being wound around the cam 130; and a cam cable 143 having one end fixed to the other end of the main body 100 and the other end fixed to the main pulley 110, and being wound around the cam 130 when the bowstring 142 is drawn for shooting an arrow.

The main body 100 includes the handle 102 grasped by a user, a pair of limbs 103 coupled to both ends of the handle 102 and having two branches at their rear ends, and a rotation shafts 101 installed with the pulleys which are rotatably connected between the two branches at the rear ends of the limbs.

The dual pulley includes the main pulley 110 and the auxiliary pulley 120, and is rotatably coupled to the rotation shaft 101 which is formed at one end of any one of the limbs 103. And, the balance cable 141 is wounded around the main pulley 110 and the auxiliary pulley 120, thereby both ends of which are connected to the main pulley 110 and the auxiliary pulley 120, respectively.

The auxiliary pulley 120 has an approximately oval plate shape, and has an eccentric through-hole 121 formed at the central region thereof into which the rotation shaft 101 is connected. The auxiliary pulley 120 has a guide recess 122 formed on the outer circumference thereof with a predetermined depth and a predetermined length such that the balance cable 141 can be wound around the outer circumference. A separation preventing unit 127 protrudes from one side of the guide recess 122 with a predetermined height along the guide recess 122, and prevents separation of the balance cable 141. An arc-shaped stopping pin slot 124 and an arc-shaped interference pin slot 125 are formed about the through-hole 121. The stopping pin slot 124 has a stopping pin 182 which protrudes by a predetermined height from the auxiliary pulley 120 and temporally contacts the limb 103 when the auxiliary pulley 120 rotates by a predetermined angle so that the auxiliary pulley 120 does not further rotate. The stopping pin slot 124 is for adjusting a user's force to be applied for shooting an arrow by changing a position where the stopping pin 182 is fastened, if necessary. The stopping pin 182 consists of a female screw and a male screw to be engaged with each other so that the user can easily adjust the position where the stopping pin 182 is fastened.

An interference pin 181 which protrudes toward the main pulley 110 is fastened in the interference pin slot 125 so that the interference pin 181 is inserted into a movement hole 116 formed in the main pulley 110. The interference pin 181 rotates with the main pulley 110 and the auxiliary pulley 120 when the bowstring 142 is drawn, and enables the main pulley 110 to rotate with the auxiliary pulley 120 after the main pulley 110 rotates by a certain angle when the bowstring 142 is released. Also, the interference pin slot 125 is for adjusting a user's force to be applied for shooting the arrow by changing a position where the interference pin 181 is fastened. The interference pin 181 also consists of a female screw and a male screw to be engaged with each other so that the user can easily adjust the position where the interference pin 181 is fastened. Moreover, at one end of the guide recess 122, a fixing protrusion 126 is formed to fix the balance cable 141 wound around the guide recess 122. The interference pin 181 and the stopping pin 182 are provided with anti-vibration covers 181a and 182a respectively to prevent vibration and noise generated upon contacting other elements.

The main pulley 110 has an approximately circular plate shape and a through-hole 112 formed at the central region and into which the rotation shaft 101 is inserted. The through-hole 112 may be eccentrically formed. The main pulley 110 has a guide recess 111 depressed from the outer circumference thereof by a predetermined depth such that the balance cable 141 can be wound thereon. And, an anti-vibration guide 172 is installed in the tangential direction of the outer circumference of the main pulley 110 at a position where the balance cable 141 swerves from the guide recess 111 before the bowstring 142 is initially drawn, to guide the balance cable 141. The anti-vibration guide 172 has a guide recess 172a into which the balance cable 141 is inserted, which is formed in the middle of the anti-vibration guide 172 in the longitudinal direction. The anti-vibration guide 172 is made of a rubber material to reduce vibration and noise.

The main pulley 110 has an arc-shaped movement hole 116 penetrated to control a moving distance where the interference pin 181 moves. The interference pin 181 is supported by one side of the movement hole 116 until the stopping pin 182 of the auxiliary pulley 120 contacts the limbs 103, and enables the main pulley 110 to rotate with the auxiliary pulleys 110. The interference pin 181 is supported by the other side of the movement hole 116 and enables the main pulley 110 and the auxiliary pulley 120 to rotate together after the main pulley 110 rotates by a certain angle when the bowstring 142 is released. And, at one end of the guide recess 111, a fixing protrusion 117 is formed to fix the balance cable 141 wound around the guide recess 111.

The cam 130 which is disposed between the main pulley 110 and the auxiliary pulley 120 is fixed to the main pulley 110. A through-hole 112 which is formed at the central region of the main pulley 110 is installed at one end of the cam 130. The cam 130 has a C-shaped curvature shape entirely, and includes a gradually curved portion 131 having a gradual arc-shape at one side thereof and a steep curved portion 132 having a steep arc-shape at the other side thereof. The steep curved portion 132 is provided with a through-hole 112 and has a radius of curvature smaller than that of the gradually curved portion 131, thereby forming a steep slant to become near to the rotation shaft 101. The gradually curved portion 131 and the steep curved portion 132 have a guide recess 133 around which the cam cable 143 and the bowstring 142 are wound. The gradually curved portion 131 includes a fixing protrusion 115 protruding by a predetermined height from the main pulley 110 near to the end of the gradually curved portion 131 to fix the cam cable 143, and the steep curved portion 132 includes a fixing protrusion 114 protruding by a predetermined height from the main pulley 110 near to the end of the steep curved portion 132 to fix the bowstring 142.

Meanwhile, the present embodiment has the structure that when the bowstring 142 is drawn for shooting the arrow in a state that the bowstring 142 is wound around the cam 130, the bowstring 142 is released from the cam 130 and the cam cable 143 is wound around the cam 130. But, as a modification, the bowstring 142 can be wound around a string pulley 310, as shown in FIG. 6. An end of the bowstring 142 is coupled to a fixing protrusion 317 of the string pulley 310. Here, the balance cable and the bowstring are not shown in FIG. 6 for the sake of convenience. One side of the balance cable is wound around a main pulley 340 and then is connected to one side of the main pulley 340, and the other side of the balance cable is wound around an auxiliary pulley 320 and then is fixed at a fixing protrusion (not shown) which is formed at one side of the auxiliary pulley 320. An end of the cam cable is coupled to one side of the main pulley 340 and is wound around a cam 330 when the bowstring is drawn.

Also, as shown in FIG. 6, an interference pin 381 formed at the auxiliary pulley 320 contacts an interference step 316 formed at one side of the outer circumference of the main pulley 340, and plays the same role as that of the above interference pin 181. Then, the main pulley 340, the cam 330 and the string pulley 310 are coupled and rotated together.

And, a stopping pin 382 is formed at a protruded end of a guide recess of the auxiliary pulley 320, and can play the same role as that of the above stopping pin 182. The auxiliary pulley 120 cannot rotate further in the state that the stopping pin 182 contacts the limb, which makes the balance cable not be released. But, as shown in FIG. 6, the stopping pin 382 allows the balance cable not to be further released after the auxiliary pulley 320 around which the balance cable is wound rotates by a predetermined angle. Also, the above interference pin 181 and stopping pin 182 can be identically formed in FIG. 6.

The driven pulley 190 has a circular plate shape and a guide recess 191 depressed from the outer circumference by a predetermined depth so that the bowstring can be wound thereon. And, an anti-vibration guide 172 is installed in the tangential direction of an outer circumference of the driven pulley 190 at a position where the bowstring 142 swerves from the guide recess 191 before the bowstring 142 is drawn, to guide the bowstring 142. The anti-vibration guide 172 has a guide recess 172a into which the bowstring 142 is inserted, which is formed in the middle of the anti-vibration guide 172 in the longitudinal direction. The anti-vibration guide 172 is made of a rubber material to reduce vibration and noise. It is preferable that the guide recess 172a has a width narrower than those of the guide recess 111 of the main pulley 110 and the guide recess 191 of the driven pulley 190.

Both ends of the balance cable 141 are coupled to the main pulley 110 and the auxiliary pulley 120 respectively, and wound around the main pulley 110 and the auxiliary pulley 120 in the same direction, of which a middle portion is wound around a balance cable pulley 161 of the connecting member 360. The balance cable 141 moves from side to side along the balance cable pulley 161 according as the bowstring 142 is drawn for shooting the arrow.

The connecting member 360 includes a housing 162, a connector 162a which is formed at an upper portion of the housing 162 and to which one end of the bowstring 142 is coupled, the balance cable pulley 161 which is formed at a lower portion of the housing 162 and around which a middle portion of the balance cable 141 is wound, and a rotation pin 161a which supports the balance cable pulley 161 to be rotated.

Operations of the compound bow according to the first embodiment of the present invention will be described as follows.

When the bowstring 142 to which an arrow is notched is drawn back by a certain distance for shooting, the main body 100 is bent inward and the balance cable 141 allows the main pulley 110 and the auxiliary pulley 120 to rotate. And, the interference pin 181 of the auxiliary pulley 120 is supported by one end of the movement hole 116 of the main pulley 110 or one end of the interference step 316 shown in FIG. 6, and then the main pulley 110 and the auxiliary pulley 120 are rotated together. Since a released length of the balance cable 141 wound around the auxiliary pulley 120 with a large radius is longer than that of the balance cable 141 wound around the main pulley 110, the balance cable pulley 161 is driven to compensate a difference between the released lengths. In other words, the balance cable 141 passes through the balance cable pulley 161 and moves toward the main pulley 110.

As described above, since the drawing force of the bowstring 142 is divided and applied to the main pulley 110 and the auxiliary pulley 120 when the bowstring 142 is early drawn back, the bowstring 142 can be drawn even with a weak force due to the auxiliary pulley 120 with a large radius.

The auxiliary pulley 120 rotating together with the main pulley 110 does not rotate further after the stopping pin 182 installed to the auxiliary pulley 120 contacts the limb 103.

When the bowstring 142 is drawn further, the rotating cam 130 is in a let-off state. In other words, the bowstring 142 wound around the cam 130 passes through the gradually curved portion 131 and is positioned at the steep curved portion 132 so that the drawing force is rapidly reduced. Since the auxiliary pulley 120 cannot rotate further in a state that the stopping pin 182 contacts the limb 103, only the main pulley 110 rotates. When the main pulley 110 only rotates, the interference pin 181 supported by one side of the movement hole 116 is released. In FIG. 6, the interference pin 381 supported by the interference step 316 is released.

In this state, when the bowstring 142 is drawn back by maximum and then is released in a fully drawn state, the bowstring 142 is returned to the original state due to the resilient force of the main body 100 itself and the arrow is shot. At this time, a force is applied to the main pulley 110 and the balance cable 141 is drawn with a large force, so that a propulsive force of the arrow can be increased.

When the interference pin 181 again contacts one end of the movement hole 116 formed in the main pulley 110 rotating alone, the auxiliary pulley 120 rotates together with the main pulley 110 until the bowstring 142 is returned to the original state.

As described above, according to the compound bow of the first embodiment of the present invention, since a force is divided and applied to the main pulley 110 and the auxiliary pulley with a radius greater than that of the main pulley 110 when drawing the bowstring 142, a force required to draw the bowstring 142 is reduced.

When the bowstring 142 starts to return to the original state from a state of fully drawing the bowstring 142, a force is applied to the main pulley 110, and then the propulsive force of shooting the arrow is increased.

Next, the compound bow according to the second embodiment of the present invention will be described as follows.

FIG. 8 is an exploded perspective view illustrating a stopper member of a compound bow according to a second embodiment of the present invention, FIGS. 9 to 12 are schematic views subsequently illustrating operating states of the stopper member when the compound bow is operated, in which FIG. 9 illustrates a state of the stopper member before the bowstring is drawn, FIG. 10 illustrates a state of the stopper member when the bowstring is drawn by a predetermined distance, and FIG. 11 illustrates a state of the stopper member before an arrow is shot, and FIG. 12 illustrates a state of the stopper member after an arrow is shot.

As illustrated, a compound bow according to the second embodiment of the present invention includes a main body 100 having a handle 102 grasped by a user, rotation shafts 101 installed to both ends of the main body 100; a dual pulley including a main pulley 110 installed to rotate around the rotation shaft 101 that is installed to one end of the main body 100 and an auxiliary pulley 120 having a radius greater than that of the main pulley 110 and rotatably installed around the rotation shaft 101; a cam 130 positioned between the main pulley 110 and the auxiliary pulley 120 and installed to the main pulley 110; a balance cable 141 having ends fixed to the main pulley 110 and the auxiliary pulley 120 and wound around the main pulley 110 and the auxiliary pulley 120 in the same direction; a stopper member 260 for temporally fixing the balance cable 141, including a balance cable pulley 161 which is installed at one end thereof and around which a central portion of the balance cable 141 is wound; a cam cable 130 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 opposite direction to that of the balance cable; a driven pulley 190 rotatably installed on the rotation shaft 101 that is installed at an other end of the main body 100; and a bowstring 142 having one end coupled to the stopper member 260 and being wound around the driven pulley 190, and the other end fixed to the main pulley 110 and being wound around the cam 130 in the direction opposite to the cam cable 143.

Since the pulleys and cam of the compound bow according to the second embodiment of the present invention are the same as those of the first embodiment, the detailed description thereof will be omitted hereinafter. But, the second embodiment includes that a stopper member 260 is formed instead of the connecting member 360, and the balance cable 141 has a different construction from that of the first embodiment.

Both ends of the balance cable 141 are coupled to the main pulley 110 and the auxiliary pulley 120 respectively, and wound around the main pulley 110 and the auxiliary pulley 120 in the same direction, of which a middle portion is wound around a balance cable pulley 161 of the stopper member 260. Also, at one side of the balance cable 141 near to the main pulley 110 from the balance cable pulley 161, a clip 141a of a cylindrical shape having a diameter larger than that of the balance cable 141 is fastened. The balance cable 141 moves from side to side along the balance cable pulley 161 according as the bowstring 142 is drawn for shooting the arrow.

The stopper member 260 is for temporally fixing the balance cable 141 when the arrow is shot, and includes the balance cable pulley 161, a stopper 165, a trigger 166, and a housing 162 for holding these elements.

The housing 162 includes a connector 162a which is formed at the upper portion thereof and to which the bowstring 142 is coupled, a rotation pin 161a which is formed at one side of the central portion thereof and supports a balance cable pulley 161 to be rotated, and a rotation pin 166a which is formed at the other side of the central portion thereof and supports the trigger 166 to be rotated.

Also, at one side of the lower portion of the housing 162, a rotation pin 165a is formed below the rotation pin 166a to support the stopper 165 rotatably. And, at the other side of the lower portion of the housing 162, a rest portion 162d having a rest groove 162c in which a contact 166c of the trigger 166 is secured is formed.

The stopper 165 is connected to the rotation pin 165a at the center thereof, of which the right side is in a semicircular shape, and at the left upper side of which a pushing section 165e protruded to the left side is formed to contact an upper end of the clip 141a, and at the left lower side of which a locking hook 165b is spaced from the pushing section 165e at a predetermined distance and temporarily supports a lower end of the clip 141a. And, a movement recess 165c is respectively depressed from each of the left ends of the pushing section 165e and the locking hook 165b by a predetermined distance. The balance cable 141 is inserted into the movement recess 165c and can moves up and down. Also, a locker 165f of a stepped shape is formed at the upper outer circumference of the stopper 165 so that a locking step 166b of the trigger 166 is caught. Also, the stopper 165 includes a support 165d, of which one end is engaged with the stopper 165 to rotate the trigger 166 so that the locking step 166b is caught to the locker 165f when the stopper 165 rotates, and of which the other side being wound around the rotation pin 165a twice or three times is protruded and formed to contact the other side of the trigger 166. The support 165d is preferably made of spring.

The trigger 166 for preventing the rotation of the stopper 165 when the clip 141a is positioned between the pushing section 165e and the locking hook 165b of the stopper 165 before the arrow is shot. One side of the trigger 166 is rotatably connected to a rotation pin 166a, and the other side thereof extends toward the balance cable 141 which is near to the auxiliary pulley 120 from the balance cable pulley 161. Also, one side of the trigger 166 to which the rotation pin 166a is connected has a cylindrical shape with a cut side such that a locking step 166b by which the locker 165f is temporally supported can be formed. At the other side end of the trigger 166, a contact 166c is formed to contact the balance cable 141.

Operations of the compound bow according to the second embodiment of the present invention will be described as follows.

As illustrated in FIG. 9, before drawing the bowstring 142, the locking step 166b of the trigger 166 is separated from the locker 165f of the stopper 165. Therefore, at this state, when the bowstring 142 is drawn back by a certain distance, the main body 100, is bent inward and the balance cable 141 allows the main pulley 110 and the auxiliary pulley 120 to rotate. And, the interference pin 181 of the auxiliary pulley 120 is supported by one end of the movement hole 116 of the main pulley 110, and then the main pulley 110 and the auxiliary pulley 120 are rotated together. Since a released length of the balance cable 141 wound around the auxiliary pulley 120 with a large radius is longer than that of the balance cable 141 wound around the main pulley 110, the balance cable pulley 161 is driven to compensate a difference between the released lengths. In other words, the balance cable 141 passes through the balance cable pulley 161 and moves toward the main pulley 110. As described above, during the movement of the balance cable 141 toward the main pulley 110, the clip 141a moves downward the stopper member 260, as illustrated in FIG. 10, whereby the clip 141a pushes the locking hook 165b and the stopper 165 rotates by a predetermined angle counterclockwise. At this time, a difference between the auxiliary pulley 120 and the main pulley 110 in size causes the balance cable 141 to get broad about the balance cable pulley 161.

As described above, since the drawing force of the bowstring 142 is divided and applied to the main pulley 110 and the auxiliary pulley 120 when the bowstring 142 is early drawn back, the bowstring 142 can be drawn even with a weak force due to the auxiliary pulley 120 with a large radius.

The auxiliary pulley 120 rotating together with the main pulley 110 does not rotate further after the stopping pin 182 installed to the auxiliary pulley 120 contacts the limb 103.

When the bowstring 142 is drawn further, the rotating cam 130 is in a let-off state. In other words, the bowstring 142 wound around the cam 130 passes through the gradually curved portion 131 and is positioned at the steep curved portion 132 so that the drawing force is rapidly reduced. Since the auxiliary pulley 120 cannot rotate further in a state that the stopping pin 182 contacts the limb 103, only the main pulley 110 rotates. When the main pulley 110 only rotates, the interference pin 181 supported by one side of the movement hole 116 is released and the clip 141a gradually approaches to the stopper 165 again.

In this state, when the bowstring 142 is drawn back by maximum to achieve a state as illustrated in FIG. 11, the clip 141a pushes the pushing section 165e of the stopper 165 and rotates the stopper 165 by a predetermined angle clockwise. When the stopper 165 rotates, the support 165d which contacts the other side of the trigger 166 rotates the trigger 166, and the locking step 166b is positioned so that the locker 165f of the stopper 165 is caught thereto.

Next, when the bowstring 142 is released in a fully drawn state, as shown in FIG. 12, the locker 165f of the stopper 165 is caught to the locking step 166b of the trigger 166 to thereby make the stopper 165 not rotate, and thus a lower end of the clip 141a is fastened by the locking hook 165b of the stopper 165.

Like this, when the bowstring 142 is released in the state that the clip 141a is locked by the locking hook 165b of the stopper 165, the bowstring 142 is returned to the original state due to the resilient force of the main body 100 itself and an arrow is shot. At this time, a force is applied to the main pulley 110 and the balance cable 141 is drawn with a large force, so that the balance cable 141 is wound around only the main pulley 110.

In this case, since the force is not applied to the auxiliary pulley 120, the balance cable 141 wound around the auxiliary pulley 120 is relatively loose. But, the separation preventing unit 127 of the auxiliary pulley 120 is protruded from the guide recess 122 and the balance cable 141 is placed in the separation preventing unit 127.

When the interference pin 181 again contacts one end of the movement hole 116 formed in the main pulley 110 rotating alone, the auxiliary pulley 120 rotates together with the main pulley 110 until the bowstring 142 is returned to the original state.

Then, since the balance cable 141 is again wound around the main pulley 110 and the auxiliary pulley 120, the balance cable 141 is in a parallel state around the balance cable pulley 161, as shown in FIG. 9. And, the balance cable 141 near to the auxiliary pulley 120 from the balance cable pulley 161 slides on the contact 166c of the trigger 166, and makes the trigger 166 rotate counterclockwise. The locking step 166b is separated from the locker 165f of the stopper 165 according as the trigger 166 rotates counterclockwise.

As described above, according to the compound bow of the second embodiment of the present invention, since a force is divided and applied to the main pulley 110 and the auxiliary pulley with a radius greater than that of the main pulley 110 when drawing the bowstring 142, a force required to draw the bowstring 142 is reduced.

When the bowstring 142 starts to return to the original state from a state of fully drawing the bowstring 142, a force is applied to the main pulley 110 because of the coupled state of the clip 141a by the locking hook 165b of the stopper, so that the bowstring 142 is wound with a large force and the propulsive force of shooting the arrow is increased, which is larger than the propulsive force done in the first embodiment.

Hereinafter, a compound bow according to a third embodiment of the present invention will be described in detail with reference to the accompanying drawings as follows.

FIG. 13 is a perspective view illustrating a compound bow according to a third embodiment of the present invention, FIG. 14 is an exploded perspective view of a stopper member illustrated in FIG. 13, and FIGS. 15 to 17 are schematic views illustrating operating states of the compound bow according to the third embodiment of the present invention, in which FIG. 15 illustrates a state before the bowstring is drawn according to the third embodiment of the present invention, FIG. 16 illustrates a state that the bowstring is drawn by a predetermined distance according to the third embodiment of the present invention, and FIG. 17 illustrates a state the bowstring is fully drawn according to the third embodiment of the present invention.

Differences between the compound bow according to the third embodiment of the present invention and that of the second embodiment will be described as follows. Instead of the clip 141a which is coupled to the balance cable 141 in the second embodiment, a fixed plate 150 with a locking ring 151 is connected to the balance cable 141, and the construction of the stopper member 160 is different from that of a stopper member 260 in the first embodiment. The fixing plate 150 is formed with a coupling hole 152 penetrating the fixing plate 150 in a longitudinal direction, into which the balance cable 141 is inserted and fixed.

In the embodiment, the stopper member 160, as shown in FIG. 14, includes a housing 162 having a connector 162a formed at one side thereof and to which the bowstring 142 is connected, a rotation pin 161a formed at the central portion thereof and supporting a balance cable pulley 161 to be rotated, and a protrusion 162b protruding from the other end of the housing 162 by a predetermined length, a latch 163 rotatably installed on the rotation pin 163d fixed to the end of the protrusion 162b, a first torsion spring 163c pressing the latch 163 to rotate in a direction, a detent 164 rotatably installed on the rotation pin 164d fixed to the central portion of the protrusion 162b, and a second torsion spring 164c pressing the detent 164 to rotate in a direction.

The latch 163 has a circular ring shape and a locking hook 163a bent and protruding from one side to temporally fix the locking ring 151. The latch 163 includes a locker 163b protruded from the other side thereof and controlling a rotation. The first torsion spring 163c presses the locking hook 163a in the direction that the locking hook 163a is coupled with the locking ring 151.

The detent 164 has a circular ring shape with a cut side such that a locking step 164a by which the locker 163b is temporally supported can be formed at one side. The detent 164 includes a knob pin 164d protruding from the other side thereof toward the outside of the housing 162. The second torsion spring 164c presses the detent 164 in the direction where a state of the locker 163b being locked by the locking step 164a is maintained.

The knob pin 164b may be driven manually by a user or automatically by which one end of the knob pin 164b is connected to one side of the cam cable 143 by a release wire (not shown) and the drawn bowstring 142 is returned to the original state. In this case, a position on the cam cable 143 to which the release wire is connected is fixed between a position where the release wire contacts the stopper member 160 and a position of the cam 130 to which the release wire is fixed.

Since other constructions are the same as those of the second embodiment, the detailed description thereof will be omitted.

Operations of the compound bow according to the third embodiment of the present invention will be described as follows.

As illustrated in FIG. 15, before drawing the bowstring 142, the knob pin 164b of the stopper member 160 is pressed to release the locked state of the locker 163b locked by the locking step 164a and the latch 164 rotates such that the locking ring 151 inserted into the locking hook 163a is separated, and then the stopper member 160 and the locking ring 151 are separated from each other.

In this state, when the bowstring 142 is drawn by a distance, the main body 100, as illustrated in FIG. 16, is bent inward, and the balance cable 141 have the main pulley 110 and the auxiliary pulley 120 rotated. At this time, while the balance cable 141 moves toward the main pulley 110, a distance between the stopper member 160 and the locking ring 151 becomes farther. Until this state, the interference pin 181 is still supported by one side of the movement hole 116.

The auxiliary pulley 120 rotating together with the main pulley 110 does not rotate further after the stopping pin 182 mounted to the auxiliary pulley 120 contacts the limb 103, and only the main pulley 110 rotates. When the main pulley 110 only rotates, the interference pin 181 supported by one side of the movement hole 116 is released, and the locking ring 151 gradually approaches to the stopper member 160 again.

In this state, when the bowstring 142 is drawn by maximum to achieve a state as illustrated in FIG. 17, the locking ring 151 contacts the locking hook 163a and is temporally coupled therewith. A contact surface of the locking hook 163a that the locking ring 151 contacts forms a slope such that the locking ring 151 is easily inserted into the locking hook 163a.

Then, when the bowstring 142 is released in the state of fully drawing the bowstring 142, the bowstring 142 is returned to the original state due to the resilient force of the main body 100 and the arrow is shot.

As described above, when the bowstring 142 is released at the state that the locking ring 151 is locked by the locking hook 163a, a force is concentrated to the main pulley 110 and the balance cable 141 is drawn with a large force so that the balance cable 141 is wound around only the main pulley 110.

When the bowstring 142 is returned to the original state, the arrow is shot and the locking ring 151 still maintains the locked state in the locking hook 163a.

Next, when the user presses the knob pin 164a and releases the locking ring 151 from the locking hook 163a before the shooting, it is possible to shoot the next arrow. Other operations and effect are the same as those of the second embodiment.

Hereinafter, a compound bow according to a fourth embodiment of the present invention will be described in detail with reference to the accompanying drawings as follows.

FIG. 18 is a perspective view illustrating a compound bow according to a fourth embodiment of the present invention, FIGS. 19 and 20 are exploded perspective views illustrating a main pulley, an auxiliary pulley, and a cam as shown in FIG. 18, and FIGS. 21 to 23 are schematic views illustrating operating states of the compound bow according to the fourth embodiment of the present invention, in which FIG. 21 illustrates a state before the bowstring is drawn, FIG. 22 illustrates a state that the bowstring is drawn by a predetermined distance, and FIG. 23 is a view illustrating a state that the bowstring is fully drawn.

As illustrated, the compound bow according to the fourth embodiment of the present invention includes a main body 100 having a handle 102 grasped by a user and a pair of limbs 103 coupled to both ends of the handle 102 and having two branches at the rear ends thereof, rotation shafts 101 respectively installed to both ends of the main body 100, that is, ends of the limbs 103, dual pulleys including a main pulleys 210 installed to rotate around the rotation shafts 101 and auxiliary pulleys 220 having a radius greater than those of the main pulleys 210 and installed to rotate around the rotation shafts 101, which are respectively installed on the rotation shafts 101 of both ends of the main body 100, cams 230 disposed between the main pulleys 210 and the auxiliary pulleys 220 and installed to the main pulleys 210, stopping pins 282 installed to the auxiliary pulleys 220 to protrude toward the limbs 103, balance cables 241 having both ends fixed to the main pulleys 210 and the auxiliary pulleys 220 and wound around the main pulleys 210 and the auxiliary pulleys 220 in the same direction, locking rings 151 respectively installed on the central portions of the balance cables 241 near to the main pulleys 210, stopper members 160 positioned at the central portions of the balance cables 241 and to which the locking rings 151 are temporally fixed, cam cables 243, each respectively having one end coupled to any one of both ends of the main body 100 and the other end thereof fixed to the main pulley 210 installed at the rotation shaft 101 which fixed to the other end of the main body 100, and wound around the cam 230 in the direction opposite to that of the balance cables 241, and a bowstring 242 of which both ends are connected to the stopper members 160, respectively.

Configurations of the stopper members 160 and the locking rings 151 are identical to those of the third embodiment and their detailed description will be omitted.

Each of the auxiliary pulleys 220 has an approximately oval plate shape and has an eccentric through-hole 221 formed at the central region thereof. The auxiliary pulley 220 has a guide recess 222 formed on the outer circumference thereof by a predetermined depth and a predetermined length such that the balance cable 241 can be wound around the outer circumference thereof. A separation preventing unit 227 protrudes from one side of the guide recess 222 by a predetermined height along the guide recess 222 and prevents separation of the balance cable 241. An arc-shaped stopping pin slot 224 and an arc-shaped interference pin slot 225 are formed about the through-hole 221. A stopping pin 282 which protrudes by a predetermined height and temporally contacts the limb 103 is screwed in the stopping pin slot 224. An interference pin 281 protruding toward the main pulley 210 is screwed in the interference pin slot 225. Since the stopping pin 282 and the interference pin 281 are screwed, it is possible to adjust positions of the pins 282 and 281 to satisfy user's favorites, and their functions are identical with those of the above embodiments. At one end of the guide recess 222, a fixing protrusion 226 is formed to fix the balance cable 241 wound around the guide recess 222.

Each of the main pulleys 210 has an approximately circular plate shape and a through-hole 212 formed at the central region thereof and into which the rotation shaft 101 is inserted. The through-hole 212 may be eccentrically formed. The main pulley 210 has a guide recess 211 depressed from the outer circumference thereof by a predetermined depth such that the balance cable 241 can be wound. The main pulley 210 has an interference step 216 protruding from a predetermined portion of the outer circumference thereof such that the interference pin 281 can temporally contact.

Differently from the first embodiment, the present embodiment describes that the main pulley 210 has the interference step 216 with which the interference pin 281 contacts. But, the movement hole 116 into which the interference pin is inserted may be formed as in the first embodiment. At one end of the guide recess 211, a fixing protrusion 217 is formed to fix the balance cable 241 wound around the guide recess 211.

Each of the cams 230 disposed between the main pulleys 210 and the auxiliary pulleys 220 is fixed to the main pulley 210. The cam 230 has an approximately fan plate shape, and includes a gradually curved portion 231 having a gradual arc-shape and a steep curved portion 232 connected to the end of the gradually curved portion 231 and having a steep arc-shape so that the other end thereof is near to the rotation shaft 101. The gradually curved portion 231 and the steep curved portion 232 have a guide recess 233 depressed by a predetermined depth to guide the cam cables 243. As illustrated, it is also preferable that another gradually curved portion having the same shape as that of the gradually curved portions 231 extends to a side of the main pulley 210. At the ends of the gradually curved portions 231 or the extending gradually curved portions, fixing protrusions 214 protrude from the main pulleys 210 by a predetermined height to fix the cam cables 243 wound around the cams 230.

Although not illustrated, it is preferable that anti-vibration guides 172 (not shown) are installed to the main pulleys 210 like the above-mentioned embodiments of the present invention.

Anti-vibration covers 281a and 282a are provided for covering on the interference pins 281 and the stopping pins 282 in order to reduce vibration and noise.

Operations of the compound bow according to the fourth embodiment of the present invention will be briefly described as follows.

As illustrated in FIG. 21, before drawing the bowstring 242, the knob pins 164b of the stopper members 160 are pressed to separate the locking rings 151 inserted into the locking hooks 163a such that the stopper members 160 and the locking rings 151 are separated from each other. The stopper members 160 respectively formed at both ends of the bowstring 242 must be separated from the locking rings 151.

In this state, when the bowstring 242 is drawn by a distance, the main body 100, as illustrated in FIG. 22, is bent and the balance cables 241 have the main pulleys 210 and the auxiliary pulleys 220 rotated. At this time, the balance cable pulleys 161 are driven to compensate a difference between the released lengths of the balance cables 243 released from the main pulleys 210 and the auxiliary pulleys 220. In other words, during the movement of the balance cables 241 toward the main pulleys 210, a distance between the stopper members 160 and the locking rings 151 becomes farther. Until this state, the interference pins 281 are still supported by the interference steps 216.

As described above, since the drawing force of the bowstring 242 is divided and applied to the main pulleys 210 and the auxiliary pulleys 220 when the bowstring 242 are early drawn, the bowstring 242 can be drawn even with a weak force due to the auxiliary pulleys 220 with a large radius.

The auxiliary pulleys 220 rotating together with the main pulleys 210 do not rotate further after the stopping pins 282 installed to the auxiliary pulleys 220 contact the limbs 103.

When the bowstring 242 is drawn further, the rotating cams 230 are in a let-off state. In other words, the cam cables 243 wound around the cams 230 passes through the gradually curved portions 231 and are positioned at the steep curved portions 232 so that the drawing force is rapidly reduced. Since the auxiliary pulleys 220 cannot rotate further in a state that the stopping pins 282 contact the limbs 103, only the main pulleys 210 rotate. When the main pulleys 210 only rotate, the interference pins 281 contacting the interference steps 216 are released from the supported state, and the locking rings 151 gradually approach to the stopper members 160 again.

In this state, when the bowstring 242 is drawn by maximum to achieve a state as illustrated in FIG. 23, the respective locking rings 151 are temporally locked by the locking hooks 163a.

When the bowstring 242 is released in the state of fully drawing the bowstring 242, the bowstring 242 is returned to the original state due to the resilient force of the main body 100 and an arrow is shot.

As described above, when the bowstring 242 is released at the state that the locking rings 151 are engaged with the locking hooks 163a, a force is concentrated to the main pulleys 210 and the balance cables 241 are drawn with a large force so that the balance cables 241 are wound around only the main pulleys 210.

Next, when the main pulleys 210 rotate by a predetermined angle, the interference steps 216 which are formed at the main pulleys 210 rotating alone contact the interference pins 281, and the auxiliary pulleys 220 rotate together with the main pulleys 210 until the bowstring 242 is returned to the original state.

As described above, according to the compound bow of the fourth embodiment of the present invention, since a force is divided and applied to the main pulleys 210 and the auxiliary pulleys 220 when drawing the bowstring 242, like in the above-mentioned embodiments of the present invention, a force required to draw the bowstring 242 is reduced.

And, since the stopper members 160 are provided at both ends of the bowstring 242, the propulsive force of shooting the arrow is doubled.

Next, the compound bow according to a fifth embodiment of the present invention will be described with reference to FIG. 24. FIG. 24 is a perspective view illustrating a compound bow according to the fifth embodiment of the present invention. Differences between the fifth embodiment and the fourth embodiment of the present invention are that the stopper members 160 of the compound bow in the fourth embodiment are identical with that of the third embodiment, but the compound bow in the fifth embodiment adopts the stopper member 260 of the second embodiment.

The operations of the main pulleys, auxiliary pulleys and cams coupled to the main body in the fifth embodiment are identical with those of the fourth embodiment, and the operations of the stopper members 260 are identical with that of the second embodiment and the effect of the fifth embodiment is the same as that of the fourth embodiment.

That is, according to the compound bow of the fifth embodiment of the present invention, since a force is divided and applied to the main pulleys 210 and the auxiliary pulleys 220 when drawing the bowstring 242, like in the above-mentioned embodiments of the present invention, a force required to draw the bowstring 242 is reduced.

And, since the stopper members 260 are provided at both ends of the bowstring 242, the propulsive force of shooting an arrow is doubled.

Also, as still other embodiment, the compound bow of the fourth embodiment can adopt the connecting member 360 of the first embodiment instead of the stopper member 160. In this case, the operations and effect of the connecting member are the same as those of the first embodiment.

As described above, the compound bow according to the present invention provides an effect of improving the efficiency of the compound bow by reducing the force required to draw a bowstring and increasing the propulsive force of shooting the arrow.

Although exemplary embodiments of the present invention have been described in detail hereinabove, it should be understood that many variations and modifications of the basic inventive concept herein described, which may appear to those skilled in the art, will still fall within the spirit and scope of the exemplary embodiments of the present invention as defined in the appended claims.

Claims

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.