Compound Bow

Abstract

Provided is a compound bow including: first and second cam cables between upper and lower pulley assemblies, wherein the lower cable of the first cam cable comprises: a one-side cable portion and the other-side cable portion on both sides of the pulley, in which either end of the lower cable is coupled to a fixing projection formed at either side of the pulley, and the one-side cable portion and the other-side cable portion of the lower cable are supported by a spacing member so as to maintain a constant interval, to thus make the one-side cable portion and the other-side cable portion of the lower cable wound on the respective cams formed at both sides of the pulley, while maintaining the one-side cable portion and the other-side cable portion of the lower cable to have the constant interval by the spacing member, as a bowstring is pulled.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Korean Patent Application No. 10-2015-0028183, filed on Feb. 27, 2015, in the Korean Intellectual Property Office, the disclosure of which is incorporated in its entirety herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a compound bow, and more particularly, to a compound bow which can prevent distortion of the bow and improve accuracy of an arrow when a bowstring is pulled.

BACKGROUND OF THE INVENTION

[0003] Typically, compound bows are configured so that a bowstring may be easily pulled without using a large force and arrow shooting power is increased during shooting, by using an effect of a cam or wheel, to thus result in a fast speed of an arrow and have very strong power, and are widely used mainly for hunting.

[0004] As shown in FIGS. 1 to 3, a conventional compound bow is configured to have upper limbs 20 that are coupled to the upper portion of a handle 10 at the center of which a grip portion is formed, and lower limbs 26 coupled to the lower portion of the handle 10. A cut-out portion 21 is formed between the upper limbs 20 whose edges 22 are spaced apart from each other, and a cut-out portion 27 is formed between the lower limbs 26 whose edges 28 are spaced apart from each other. Rotating shafts 70 are horizontally formed through the edges 22 of the upper limbs 20 and the cut-out portion 21, and through the edges 28 of the lower limbs 26 and the cut-out portion 27, respectively. Upper and lower pulleys 30 and 36 are rotatably combined with the respective rotating shafts 70.

[0005] A bowstring 50 is wound along a guide groove 31 or 37 of each pulley 30 or 36, and the respective ends of the bowstring 50 are combined with each pulley 30 or 36. In addition, a cam 32 or 38 rotating with the pulley 30 or 36 is coupled in each pulley 30 or 36. As the bowstring 50 is pulled, cam cables 40 and 46 are formed so as to be wound on the cams 32 and 38, respectively. One end of each cam cable 40 or 46 is coupled to a pulley 30 or 36 to which each cam 32 or 38 is coupled, and the other end of each cam cable 40 or 46 is coupled to each rotating shaft 70 at both sides of the cut-out portion 21 or 27 of each of the opposing limbs 20 and 26 in the form of Y-shaped buss cables 40a and 46a.

[0006] Further, a cable guard 60 is laterally mounted at one side of a center portion of a handle 10, in which the cable guard 60 pushes the cam cables 40 and 46 to one side of the bowstring 50 so that an arrow is not prevented from being shot during shooting. In addition, a slide 66 is movably mounted on the cable guard 60 in which the cam cables 40 and 46 are inserted into the slide 66.

[0007] When the bowstring 50 is pulled in the prior art compound bow that is configured as described above, the lower and upper pulleys 30 and 36 are rotated and thus the cams 32 and 38 coupled to the lower and upper pulleys 30 and 36 are rotated, to thereby wind and pull the cam cables 40 and 46. When the bowstring 50 is released in a let-off state, an arrow obtains a strong driving force by a strong elastic force of the bow which returns to an original position instantaneously.

[0008] However, in order to prevent the cam cables 40 and 46 which are located in front of the bowstring 50 from interfering with the shooting of an arrow in the compound bow, the cam cables 40 and 46 are compulsively supported in one direction by the cable guard 60 and the cams 32 and 38 are combined on an identical one side surface of the respective pulleys 30 and 36. Therefore, the pulleys 30 and 36 around which the bowstring 50 is wound are not located at the center of each of the limbs 20 and 26 as shown in FIG. 2. Accordingly, when the bowstring 50 is pulled, the bow limbs 20 and 26 and pulleys 30 and 36 are twisted as shown in FIG. 3. As a result, the inherent strength of the bow is not exhibited and the accuracy of the arrows is also dropped. Thus, although the buss cables 40a and 46a are adjusted with a tool to thereby control the bow limbs to be inclined to the left and right, it is very difficult to adjust the buss cables 40a and 46a for the left and right balance of the bow limbs 20 and 26 except for a person who has a skill of adjustment of the buss cables 40a and 46a, due to difference of the forces applied on the limbs when compared with an initial state of the limbs when the bowstring 50 is pulled.

SUMMARY OF THE INVENTION

[0009] To solve the above conventional problems or defects, it is an object of the present invention to provide a compound bow to minimize twisting of the bow, to exhibit inherent strength of the bow, and to improve accuracy of an arrow.

[0010] To accomplish the above and other objects of the present invention, according to an aspect of the present invention, there is provided a compound bow comprising: a bow main body including a handle at a central portion of which a grip portion is formed and a pair of limbs that are respectively coupled to both ends of the handle; upper and lower pulley assemblies each including a pulley that is rotatably coupled to a rotating shaft formed on the rear end of each limb, and a cam that is coupled to the pulley and is rotated with the pulley; a bowstring whose either end is wound on and coupled to the pulley of each of the upper and lower pulley assemblies; and first and second cam cables that are wound around the cam of each of the upper and lower pulley assemblies as the bowstring is pulled, in which one end of each of the first and second cam cables is coupled to one of the upper and lower pulley assemblies, and the other end thereof is coupled to the other of the upper and lower pulley assemblies or the rotating shaft of the other of the upper and lower pulley assemblies, wherein the respective cams are provided on one side and the other side of the pulley around the pulley in the lower pulley assembly, the first cam cable comprises: a central cable; an upper cable that is connected to the upper side of the central cable; and a lower cable that is connected to the lower side of the central cable, the upper cable comprises: a one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley of the upper pulley assembly, in which either end of the upper cable is coupled to the rotating shaft to which the upper pulley assembly is coupled at either side of the pulley of the upper pulley assembly, the lower cable comprises: a one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley of the lower pulley assembly, in which either end of the lower cable is coupled to a fixing projection that is formed at either side of the pulley of the lower pulley assembly, and the one-side cable portion and the other-side cable portion of the lower cable are supported by a spacing member so as to maintain a constant interval, to thus make the one-side cable portion and the other-side cable portion of the lower cable wound on the respective cams formed at both sides of the pulley of the lower pulley assembly, while maintaining the one-side cable portion and the other-side cable portion of the lower cable to have the constant interval by the spacing member, as the bowstring is pulled, to thereby minimize twisting of the bow limbs and improve accuracy of an arrow.

[0011] Preferably but not necessarily, the spacing member is formed in a ring shape.

[0012] Preferably but not necessarily, a lower loop is formed at a lower end of the central cable, and a central portion of the lower cable and the lower loop of the central cable are supported on an outer circumferential surface of the spacing member so that the central cable and the lower cable are interconnected by the spacing member.

[0013] Preferably but not necessarily, the lower loop of the central cable is supported on a lower portion of the outer circumferential surface of the spacing member, and a central portion of the lower cable is supported on an upper portion of the outer circumferential surface of the spacing member.

[0014] Preferably but not necessarily, the lower loop of the center cable is made of two loops, and the central portion of the lower cable is supported on the outer circumferential surface of the spacing member between the two loops.

[0015] Preferably but not necessarily, a throughhole is formed at the center of the spacing member, and a damper member is coupled within the throughhole to thereby damp vibrations of the first cam cable.

[0016] Preferably but not necessarily, the damper member is configured as having a cylindrical central portion that is fitted in the throughhole of the spacing member, and both end portions of a larger diameter than the center portion in which both the end portions are located in both side surfaces of the spacing member.

[0017] Preferably but not necessarily, the one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley of the upper pulley assembly in the upper cable are supported by another spacing member so as to maintain a constant interval.

[0018] Preferably but not necessarily, the respective cams of each of the pulley assemblies comprise: a cam cable support portion supporting the cam cable; a cam module that is movably coupled in an arc trajectory on the pulley to which the cams are coupled; and a fixing unit that fixes the cam module at a desired position on the pulley in order to adjust a pulling length of a let-off state, in which the cam cable is supported on the cam cable support portion and then is wound on the outer circumferential surface of the cam module, when the bowstring is pulled, the second cam cable is coupled to the fixing projection that is formed in the cam module and moves along as the cam module moves, is wound on a cam cable winding portion that is penetrated by the rotating shaft via a compensation projection, and then extends toward the other side pulley assembly, and a front portion of the cam module is in contact with the second cam cable and thus the second cam cable is bent when the cam module is moved in which one end of the second cam cable is coupled to the fixing projection of the cam module in order to adjust the draw length of the let-off state, to thus release the second cam cable from the cam cable winding portion via the compensating projection from the fixing projection to which the second cam cable is coupled, to thereby maintain constant tension of the cam cable and keep the power of the bow.

[0019] Preferably but not necessarily, the compensating projection is made in a pulley form and is coupled to the pulley to which the compensating projection is coupled.

[0020] Preferably but not necessarily, the cam module is rotatably coupled at a predetermined angle from the cam cable support portion around a pivoting point at a position spaced apart from the rotating shaft of the pulley.

[0021] Preferably but not necessarily, an arc-shaped position adjusting hole is formed on the pulley on which the cam module is coupled, and the cam module is rotatably coupled to the pulley along the position adjusting hole.

[0022] According to another aspect of the present invention, there is also provided a compound bow comprising: a bow main body including a handle at a central portion of which a grip portion is formed and a pair of limbs that are respectively coupled to both ends of the handle; upper and lower pulley assemblies each including a pulley that is rotatably coupled to a rotating shaft formed on the rear end of each limb, and a cam that is coupled to the pulley and is rotated with the pulley; a bowstring whose either end is wound on and coupled to the pulley of each of the upper and lower pulley assemblies; and first and second cam cables that are wound around the cam of each of the upper and lower pulley assemblies as the bowstring is pulled, in which one end of each of the first and second cam cables is coupled to one of the upper and lower pulley assemblies, and the other end thereof is coupled to the other of the upper and lower pulley assemblies or the rotating shaft of the other of the upper and lower pulley assemblies, wherein the respective cams are provided on one side and the other side of each of the pulleys around the respective pulleys in the upper and lower pulley assemblies, each of the first and second cam cables comprises: a first cable that is coupled with one pulley assembly; and a second cable that is connected to the first cable and coupled with the other pulley assembly, the first cable comprises: a one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley, in which either end of the first cable is coupled to a fixing projection that is formed at either side of the pulley of the pulley assembly to which the first cable is coupled, and the one-side cable portion and the other-side cable portion of the first cable are supported by a spacing member so as to maintain a constant interval, to thus make the one-side cable portion and the other-side cable portion of the first cable wound on the respective cams formed at both sides of the pulley of the pulley assembly to which the first cable is coupled, while maintaining the one-side cable portion and the other-side cable portion of the first cable to have the constant interval by the spacing member, as the bowstring is pulled, to thereby minimize twisting of the bow limbs and improve accuracy of an arrow.

[0023] Preferably but not necessarily, the central portion of the first cable and a loop that is formed at one end of the second cable are supported on the outer circumferential surface of the spacing member and thus the first cable and the second cable are interconnected.

[0024] Preferably but not necessarily, the respective cams of each of the pulley assemblies comprise: a cam cable support portion supporting the cam cable; a cam module that is movably coupled in an arc trajectory on the pulley to which the cams are coupled; and a fixing unit that fixes the cam module at a desired position on the pulley in order to adjust a draw length of a let-off state, in which the cam cable is supported on the cam cable support portion and then is wound on the outer circumferential surface of the cam module, when the bowstring is pulled, the second cable is coupled to the fixing projection that is formed in the cam module and moves along as the cam module moves, is wound on a cam cable winding portion that is formed around the rotating shaft via a compensation projection, and then extends toward the other side pulley assembly, and a front portion of the cam module is in contact with the second cable and thus the second cable is bent when the cam module is moved in which one end of the second cable is coupled to the fixing projection of the cam module in order to adjust the draw length of the let-off state, to thus release the second cable from the cam cable winding portion via the compensating projection from the fixing projection to which the second cable is coupled, to thereby maintain constant tension of the cam cable and keep the power of the bow.

[0025] As described above, the present invention provides a compound bow capable of minimizing twisting of the bow when used, exhibiting an inherent strength of the bow and simultaneously enhancing accuracy of an arrow with an improved synchronizing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a perspective view of a conventional compound bow.

[0027] FIG. 2 is a rear view of the compound bow of FIG. 1.

[0028] FIG. 3 is a perspective view showing a twisted state of a pulley assembly coupled to a limb of FIG. 1.

[0029] FIG. 4 is a plan view showing a compound bow according to a first embodiment of the present invention.

[0030] FIG. 5 is a plan view showing an upper pulley assembly coupled to an upper limb of FIG. 4.

[0031] FIG. 6 is a perspective view of the upper pulley assembly coupled to the upper limb of FIG. 5.

[0032] FIG. 7 is a perspective view illustrating a structure that a central cable and an upper cable are connected by a ring in the compound bow according to the first embodiment of the present invention.

[0033] FIG. 8 is a side view as viewed from the rear side of the upper pulley assembly in the compound bow according to the first embodiment of the present invention.

[0034] FIG. 9 is a diagram showing a side of the lower pulley assembly coupled to the lower limb in FIG. 4.

[0035] FIG. 10 is a plan view as viewed from the opposite side of the lower pulley assembly of FIG. 9.

[0036] FIG. 11 is a side view as viewed from the rear side of the bow of the lower pulley assembly in the compound bow according to the first embodiment of the present invention.

[0037] FIG. 12 is a plan view showing a state where the cam module has been rotated in FIG. 9.

[0038] FIG. 13 is a plan view showing a compound bow according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0039] The above and/or other objects and/or advantages of the present invention will become more apparent by the following description of embodiments of the present invention.

[0040] Hereinbelow, a compound bow according to a first embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

[0041] Referring to FIGS. 4 to 12, a compound bow according to a first embodiment of the present invention comprises: a bow main body 300 including a pair of limbs 303 that are respectively coupled to both ends of a handle 302; upper and lower pulley assemblies 307 and 308 that are respectively coupled to the rear end of each limb 303; a bowstring 340; first and second cam cables 352 and 351 that are wound around a cam 400, 500 of each of the upper and lower pulley assemblies 307 and 308 as the bowstring 340 is pulled.

[0042] As shown, the compound bow according to the present invention will be described below in more detail. First, the bow main body 300 includes a handle 302 at a central portion of which a grip portion is formed so as to be gripped by a user, and a pair of limbs 303 that are respectively coupled to both ends of the handle 302 in which two branches are formed at the rear portion of each limb 303. A rotating shaft 301 is formed at the rear end of each limb 303, in which a pulley assembly 307 or 308 is rotatably coupled on the rotating shaft 301 between the two branches at the rear end of each limb 303. A cable guard 305 that pushes the first and second cam cables 352 and 351 to one side of the bowstring 340 is coupled at the central portion of the handle 302, in order to prevent an arrow from being interrupted during shooting.

[0043] Then, each of the upper and lower pulley assemblies 307 and 308 is rotatably coupled to the rotating shaft 301 at the rear end of each limb 303, and includes: a pulley 310 that is rotatably coupled to the rotating shaft 301 formed at the rear end of each limb 303; and a cam 400 or 500 coupled to the pulley 310 and rotating with the pulley 310.

[0044] Each pulley 310 is formed of an oval-like plate-shaped member, and has an eccentric through-hole that is formed at the center of the pulley 310 and through which the rotating shaft 301 is coupled. Further, a guide groove that is depressed down to a predetermined depth is formed on the outer circumferential surface of each pulley 310 so that the bowstring 340 may be wound on the outer circumferential surface of each pulley 310. A fixing protrusion 311 for fixing one end of the bowstring 340 wound on the guide groove is formed at one side of each pulley 310. In addition, fixing protrusions 312 are formed in each pulley 310 in which the first and second cam cables 352 and 351 are fixed to the fixing protrusions 312 respectively.

[0045] As shown in FIG. 5, a cam 400 is formed in a pulley 310 of the upper pulley assembly 307 and is rotated with rotation of the pulley 310, and includes: a cam cable support portion 410 fabricated in an arc-shaped form and on which the second cam cable 352 is wound; and a cam module 420 that is rotatably coupled by a predetermined angle from the cam cable support portion 410, around a pivot point "A" at a position spaced by a predetermined distance from a rotating shaft 301 of the pulley 310 to which the cam 400 is coupled, in which a cam cable winding groove is formed on the outer circumferential surface of the cam module 420, and the second cam cable 352 is wound around the cam cable support portion 410 and then sequentially wound on the outer circumferential surface of the cam module 420 when the bowstring 340 is pulled.

[0046] The cam cable support portion 410 is arc-shaped so that the second cam cable 352 is wound on the cam cable support portion 410, when the bowstring 340 is pulled, in which the second cam cable 352 is coupled to the fixing protrusions 312 that is located in the vicinity of the cam cable support portion 410. In addition, a cam cable winding groove is formed on the outer circumferential surface of the cam cable support portion 410 so that the second cam cable 352 is wound on the outer circumferential surface of the cam cable support portion 410.

[0047] The cam module 420 is rotatably coupled by a predetermined angle from the cam cable support portion 410, around a pivot point "A" at a position spaced by a predetermined distance from a rotating shaft 301 of the pulley 310 to which the cam 400 is coupled, and is configured to have a gentle slope portion 422 formed of a gentle arc-shaped curve and a steep slope portion 423 that is extended from the gentle slope portion 422 to be close to the rotating shaft 301, to thus form a steep slope. Further, a cam cable winding groove on which the second cam cable 352 is wound is formed on the outer circumferential surfaces of the gentle slope portion 422 and the steep slope portion 423. Accordingly, the cam module 420 is rotated along with the pulley 310 when the bowstring 340 is pulled, and thus the second cam cable 352 is sequentially wound on the gentle slope portion 422 and the steep slope portion 423 of the cam module 420 adjacent to the cam cable support portion 410.

[0048] In addition, the cam 400 further includes a fixing unit that makes the cam module 420 rotated by a predetermined angle with respect to the pivot point "A" in order to control the draw length of the let-off state of the compound bow, and that makes the cam module 420 fixed to the pulley 310 at a position where the cam module 420 has been rotated.

[0049] The fixing unit makes the cam module 420 fixed to the pulley 310 at a position where the cam module 420 has been rotated. To this end, an arc-shaped position adjusting hole 316 centered at the pivot point "A" is formed in the pulley 310 to which the cam module 420 is coupled, and two coupling holes is formed in the cam module 420. Thus, when the cam module 420 is rotated by a predetermined angle around the pivot point "A", a bolt 317 inserted to the coupling hole formed in the cam module 420 and the position adjusting hole 316 is screw-coupled to a nut (not shown). In addition, a position display part indicated by numbers are provided in the periphery of the cam module 420, in order to display position at which the cam module 420 is fixed.

[0050] As shown in FIGS. 9 and 10, each cam 500 is formed on both sides of the pulley 310 of the lower pulley assembly 308 and is rotated with rotation of the pulley 310. Each cam 500 includes: a cam cable support portion 510 fabricated in an arc-shaped form and on which the second cam cable 351 is wound; and a cam module 520 that is rotatably coupled by a predetermined angle from the cam cable support portion 510, around a pivot point "A" at a position spaced by a predetermined distance from a rotating shaft 301 of the pulley 310 to which the cam 500 is coupled, in which a cam cable winding groove is formed on the outer circumferential surface of the cam module 520, and each end of the lower cable 352e of the first cam cable 352 is wound around the cam cable support portion 510 and then sequentially wound on the outer circumferential surface of the cam module 520 when the bowstring 340 is pulled.

[0051] The cam cable support portion 510 is arc-shaped so that the lower cable 352e is wound on the cam cable support portion 510, when the bowstring 340 is pulled, in which the lower cable 352e is coupled to the fixing protrusions 312 that is located in the vicinity of the cam cable support portion 510. In addition, a cam cable winding groove is formed on the outer circumferential surface of the cam cable support portion 510 so that the lower cable 352e is wound on the outer circumferential surface of the cam cable support portion 510.

[0052] The cam module 520 of the lower cam 500 is rotatably coupled by a predetermined angle from the cam cable support portion 510, around a pivot point "A" at a position spaced by a predetermined distance from a rotating shaft 301 of the pulley 310 to which the cam 500 is coupled, and is configured to have a gentle slope portion 522 formed of a gentle arc-shaped curve and a steep slope portion 523 that is extended from the gentle slope portion 522 to be close to the rotating shaft 301, to thus form a steep slope. Further, a cam cable winding groove on which the lower cable 352e is wound is formed on the outer circumferential surfaces of the gentle slope portion 522 and the steep slope portion 523. Accordingly, the cam module 520 is rotated along with the pulley 310 when the bowstring 340 is pulled, and thus the lower cable 352e is sequentially wound on the gentle slope portion 522 and the steep slope portion 523 of the cam module 520 adjacent to the cam cable support portion 510.

[0053] In addition, the cam 500 further includes a fixing unit that makes the cam module 520 rotated by a predetermined angle with respect to the pivot point "A" in order to control the draw length of the let-off state of the compound bow, and that makes the cam module 520 fixed to the pulley 310 at a position where the cam module 520 has been rotated.

[0054] The fixing unit makes the cam module 520 fixed to the pulley 310 at a position where the cam module 520 has been rotated. To this end, an arc-shaped position adjusting hole 316 centered at the pivot point "A" is formed in the pulley 310 to which the cam module 520 is coupled, and a coupling hole is formed in the cam module 520. Thus, when the cam module 520 is rotated by a predetermined angle around the pivot point "A", a bolt 317 inserted to the coupling hole formed in the cam module 520 and the position adjusting hole 316 is screw-coupled to a nut (not shown). If the one cam module 520 on one side of the lower pulley 310 is moved along the position adjusting hole 316, the other cam module 520 on opposite side of the lower pulley 310 is moved together because each cam module 520 on both sides of the lower pulley 310 is connected with the bolt 317. In addition, a position display part indicated by numbers are provided in the periphery of the cam module 520, in order to display position at which the cam module 520 is fixed.

[0055] The cam modules 420 and 520 having such a structure in the present invention can adjust the draw length of the bowstring 340. Thus, when the cam module 420 and 520 of the upper and lower pulley assemblies 307 and 308 is identically rotated by an identical angle from the cam cable support portions 410 and 510 around the pivot point "A" and the cam modules 420 and 520 are again secured to the pulley 310 at a position where the cam module 420 and 520 have been rotated, the length of the first and second cam cables 352 and 351 that is wound on the gentle slope portion 422 and 522 of the cam modules 420 and 520 increases in comparison with the previous embodiment. At last, the length of the first and second cam cables 352 and 351 that is wound from the cam cable support portion 410 and 510 to the cam module 420 and 520 until the let-off state increases, to thereby increase the draw length of the bowstring 340.

[0056] The bowstring 340 is wound in the guide groove of the pulley 310 of each pulley assembly 307 or 308 and thus both ends of the bowstring 340 are coupled to the fixing protrusions 311 formed on the respective pulleys 310.

[0057] The first and second cam cables 352 and 351 are formed between a pair of limbs 303, and are wound on cams 400 and 500 formed on respective pulleys 310 as a bowstring 340 is pulled. First, the first cam cable 352 includes: a central cable 352a; an upper cable 352d that is connected to the upper side of the central cable 352a; and a lower cable 352e that is connected to the lower side of the central cable 352a.

[0058] The central cable 352a is disposed between the upper cable 352d and the lower cable 352e, both ends of the central cable 352a are formed in a loop shape so as to be connected to the upper cable 352d and the lower cable 352e by rings 600 and 700, respectively, and either end of the central cable 352a is formed of one of two loops 352b and 352c. The upper cable 352d includes: a one-side cable portion and the other-side cable portion that are positioned on both sides of a pulley 310 of an upper pulley assembly 307, in which either end of the upper cable 352d is coupled to a rotating shaft 301 to which the upper pulley assembly 307 is coupled at either side of the pulley 310 of the upper pulley assembly 307. The one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley 310 of the upper pulley assembly 307 in the upper cable 352d are supported by a spacing member so as to maintain a constant interval. In this embodiment, the spacing member may be implemented in the form of the ring 600.

[0059] As shown in FIGS. 6-8, the ring 600 to which a central portion of the upper cable 352d is supported plays a role of allowing the one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley 310 of the upper pulley assembly 307 in the upper cable 352d to maintain a constant interval in parallel with each other, as well as connecting the upper cable 352d and the central cable 352a. The ring 600 includes: a cylindrical central portion 601 around which the upper cable 352d and an upper loop 352b of the central cable 352a are wound; and both end portions 602 of a larger diameter than the center portion 601 so that the upper cable 352d and the upper loop 352b of the central cable 352a are not separated from the ring 600.

[0060] When explaining a connection structure of the upper cable 352d and the central cable 352a in the ring 600, as shown in FIG. 7, the central portion of the upper cable 352d is wound in an approximately semicircular shape on the lower portion of the outer circumferential surface of the ring 600, and the upper loop 352b of the central cable 352a is wound in an approximately semicircular shape on the upper portion of the outer circumferential surface of the ring 600, to thereby allow the upper cable 352d and the central cable 352a to be connected with each other. In addition, as shown in the FIG. 7, the central portion of the upper cable 352d is wound, for example, between the two upper loops 352b of the central cable 352a that is wound on the upper side of the outer circumferential surface of the ring 600. Accordingly, a balance of forces exerted on the ring 600 by the upper cable 352d and the central cable 352a is kept and thus the posture of the ring 600 is held in a stable manner.

[0061] In addition, as shown in FIG. 8 according to the embodiment of the present invention, the one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley 310 of the upper pulley assembly 307 in the upper cable 352d are connected to the central cable 352a while maintaining a constant interval by the ring 600. Accordingly, directions of the forces exerted on the upper limb 303 by the upper cable 352d are parallel as the bowstring 340 is pulled to thus improve the left and right balancing of the upper limb 303 and minimize distortion of the bow limbs. In addition, as the bowstring 340 is pulled, twisting of the bow limbs is minimized, to thereby exhibit inherent strength of the bow and improve accuracy of an arrow.

[0062] In addition, a throughhole is formed at the center of the ring 600, and a damper member 610 is coupled within the throughhole. The damper member 610 is configured as having a cylindrical central portion 610a that is fitted in the throughhole of the ring 600, and both end portions 610b of a larger diameter than the center portion so that the damper member 610 is not separated from the ring 600. In this embodiment, the damper member 610 is made of a rubber material. In this way, in some embodiments of the present invention, it is possible to damp vibrations of the first cam cable 352 when an arrow is launched, since the damper member 610 is coupled to the throughhole of the ring 600.

[0063] As shown in FIG. 9, the lower cable 352e includes: a one-side cable portion and the other-side cable portion that are positioned on both sides of a pulley 310 of a lower pulley assembly 308, in which either end of the lower cable 352e is coupled to a fixing projection 312 that is formed at either side of the pulley 310 of the lower pulley assembly 308, and the one-side cable portion and the other-side cable portion of the lower cable 352e are supported by a spacing member so as to maintain a constant interval. In this embodiment, the spacing member that maintains a constant interval between the one-side cable portion and the other-side cable portion of the lower cable 352e is configured in the form of the ring 700.

[0064] In some embodiments of the present invention, the ring 700 plays a role of allowing the one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley 310 of the lower pulley assembly 308 in the lower cable 352e to maintain a constant interval in parallel with each other, as well as connecting the lower cable 352e and the central cable 352a. The structure of the ring 700 is same as that of the ring 600. That is, the ring 700 includes: a cylindrical central portion around which the lower cable 352e and a lower loop 352c of the central cable 352a are wound; and both end portions of a larger diameter than the center portion so that the lower cable 352e and the lower loop 352c of the central cable 352a are not separated from the ring 700.

[0065] When explaining a connection structure of the lower cable 352e and the central cable 352a in the ring 700, the central portion of the lower cable 352e is wound in an approximately semicircular shape on the upper portion of the outer circumferential surface of the ring 700, and the lower loop 352c of the central cable 352a is wound in an approximately semicircular shape on the lower portion of the outer circumferential surface of the ring 700, to thereby allow the lower cable 352e and the central cable 352a to be connected with each other. In addition, the central portion of the lower cable 352e is wound, for example, between the two lower loops 352c of the central cable 352a that is wound on the lower side of the outer circumferential surface of the ring 700. Accordingly, a balance of forces exerted on the ring 700 by the lower cable 352e and the central cable 352a is kept and thus the posture of the ring 700 is held in a stable manner.

[0066] In addition, in some embodiments of the present invention, as shown in FIG. 11, the one-side cable portion and the other-side cable portion of the lower cable 352e that extend from the central portion of the lower cable 352e are coupled on the fixing projections 312 that are positioned on both sides of the pulley 310 of the lower pulley assembly 308. And the one-side cable portion and the other-side cable portion of the lower cable 352e are positioned on both sides of the lower pulley 310 and are connected to the central cable 352a, while maintaining a predetermined interval by the ring 700. Accordingly, the one-side cable portion and the other-side cable portion that are formed on both sides of the lower pulley 310 in the lower cable 352e are wound on the respective cam modules 520 formed at both sides of the lower pulley 310. Accordingly, directions of the forces exerted on the lower limb 303 by the lower cable 352e are parallel as the bowstring 340 is pulled to thus improve the left and right balancing of the lower limb 303 and minimize distortion of the lower limb 303. In addition, as the bowstring 340 is pulled, twisting of the bow limbs 303 is minimized, to thereby exhibit inherent strength of the bow and improve accuracy of an arrow.

[0067] In addition, a throughhole is formed at the center of the ring 700, and a damper member 710 is coupled within the throughhole. The damper member 710 is configured as having a cylindrical central portion that is fitted in the throughhole of the ring 700, in the same manner as that of the damper member 710 coupled to the upper ring 600, and both end portions of a larger diameter than the center portion so that the damper member 710 is not separated from the ring 700. In this embodiment, the damper member 710 is made of a rubber material.

[0068] One end of the second cam cable 351 is coupled to the fixing projection 312 is formed on the pulley 310 of the upper pulley assembly 307, and extends to the lower pulley assembly 308. Then, the second cam cable 351 is wound around a cam cable winding portion 320 that is formed on the lower pulley 310 and through which the rotating shaft 301 is penetrated, and then the other end of the second cam cable 351 is fixed on a fixing projection 530 that is formed on the lower cam module 520 via a compensating projection 330.

[0069] The cam cable winding portion 320 is formed on one side of the lower pulley 310 to which the cam module 520 is coupled, and the rotating shaft 301 penetrates the cam cable winding portion 320. A cable winding groove on which the second cam cable 351 is wound is formed on the outer circumferential surface of the cam cable winding portion 320, and part of the outer circumferential surface of the cam cable winding portion 320 is formed in an arc shape.

[0070] The compensating projection 330 is formed in the lower pulley 310 between the cam cable winding portion 320 and a fixing projection 530 of the cam module 520, and an end of the second cam cable 351 is coupled to the fixing projection 530 of the cam module 520 via the compensating projection 330 from the cam cable winding portion 320. The compensating projection 330 is made up in a pulley form to then be rotatably coupled to the lower pulley 310, thereby reducing the friction between the cam cable and the compensating projection 330 when moving the cam module for adjustment of the draw length.

[0071] When describing the operation of the compound bow according to the first embodiment of the present invention having the configuration described above, bolts 317 to secure the cam modules 420 and 520 of the upper and lower pulley assemblies 307 and 308 to the pulleys 310 are loosened to thus release the fixed states of the cam modules 420 and 520. At the state where the fixed states of the cam modules 420 and 520 have been released, the cam modules 420 and 520 of the upper and lower pulley assemblies 307 and 308 are moved to desired positions from cam cable support portions 410 and 510 along position adjusting holes 316, respectively, and then the cam modules 420 and 520 are fixed to the respective pulleys 310 via the bolts 317. In this case, the lengths of the first and second cam cables 352 and 351 wound on smooth curved portions 422 and 522 of the cam modules 420 and 520 are increased when compared with the conventional case, and thus the lengths of the first and second cam cables 352 and 351 wound on the cam modules 420 and 520 from the cam cable support portions 410 and 510 up to a let-off state are eventually increased to thereby finally increase the draw lengths of the first and second cam cables 352 and 351.

[0072] In the case of the cam module 520 of the lower pulley assembly 308, when the cam module 520 is moved in the forward direction along the position adjusting hole 316, the cam cable winding portion 320 is positioned on the same plane as the cam module 520, and thus the second cam cable 351 is bent by the cam module 520 as shown in FIG. 12, at a state where the second cam cable 351 is in contact with the front portion of the cam module 520. When the second cam cable 351 is bent, tension of the second cam cable 351 becomes strong to thus finally change the power of the bow. It is not desirable to users who use the compound bow to change the power of the bow. In some embodiments of the present invention, the second cam cable 351 is coupled to the fixing projection 530 of the cam module 520 via the compensating projection 330 from the cam cable winding portion 320. Thus, when the cam module 520 is moved in the forward direction, the fixing projection 530 of the cam module 520 is also moved in the forward direction. As a result, the second cam cable 351 is unwound in the direction of the upper pulley assembly 307 from the cam cable winding portion 320 via the compensating projection 330 from the cam module 520. Therefore, even though the second cam cable 351 is bent by the cam module 520, tension of the second cam cable 351 is consistently maintained and thus the power of the bow is also kept constant.

[0073] Further, in some embodiments of the present invention, since the cam cable winding portion 320 is positioned on the same plane as the cam module 520, twisting of the bow limbs 303 is minimized to thereby improve stability of the bow, as the bowstring 340 is pulled.

[0074] Further, when the bowstring 340 is pulled for the launch of an arrow, the two end portions of the lower cable 352e extending from the central portion of the lower cable 352e and that are coupled to the fixing projections 312 formed on both sides of the lower pulley 310 are positioned at both side of the lower pulley 310 around the lower pulley 310, and are maintained to have a predetermined interval between the two end portions by the ring 700 to then be connected to the central cable 352a. Accordingly, as the bowstring 340 is pulled, the two end portions of the lower cable 352e are wound on the respective cam modules 520 formed on both sides of the lower pulley 310. Therefore, directions of the forces exerted on the lower limb 303 by the lower cable 352e are parallel to thus improve the left and right balancing of the lower limb 303 and minimize distortion of the lower limb 303. In addition, as the bowstring 340 is pulled, twisting of the bow limbs 303 is minimized, to thereby exhibit inherent strength of the bow and improve accuracy of an arrow.

[0075] Therefore, the compound bow according to the embodiment of the present invention can easily control the draw length, keep the power of the bow constant, and minimize twisting of the bow limbs 303, to thereby exhibit inherent strength of the bow and improve accuracy of an arrow.

[0076] Meanwhile, FIG. 13 shows a compound bow according to a second embodiment of the present invention. The compound bow according to the second embodiment shows an example of being applied to a dual cam system. The compound bow of the second embodiment differs from that of the first embodiment in that the upper and lower pulley assemblies are configured to have a vertically symmetric mirror image in the second embodiment. In other words, the configuration of the upper and lower pulley assemblies in the second embodiment is the same as that of the lower pulley assembly 308 in the first embodiment. When taking the lower pulley assembly 308 as an example in the second embodiment, the cam 500 is formed on either side of the pulley 310. Thus, when the cam module 520 formed on one side of the lower pulley 310 is moved, the cam module 520 formed on the other side of the lower pulley 310 is moved together.

[0077] In addition, when the first and second cam cables 353 and 354 in the second embodiment will be described, as shown in FIG. 13, the first cam cable 353 includes a first cable 353b, and a second cable 353a that is connected to the first cable 353b by a spacing member (a ring 700 in some embodiments of this invention), and the second cam cable 354 includes a first cable 354b, and a second cable 354a that is connected to the first cable 354b by a spacing member (a ring 700 in some embodiments of this invention). The first and second cam cables 353 and 354 have a vertically symmetric image.

[0078] Therefore, the first cam cable 353 will be described as an example. The second cable 353a in the first cam cable 353 is extended to the upper pulley assembly 308 and is wound around the cam cable winding portion 320 through which the rotating shaft 301 is penetrated in the upper pulley 310, and then the upper end of the second cable 353a is fixed to the fixing projection 530 formed in the upper cam module 520 via the compensating projection 330, identically to the structure that the second cam cable 351 is coupled to the lower pulley assembly 308 in the first embodiment. In addition, the connection structure of the first cable 353b and the second cable 353a by the ring 700 in the first cam cable 353 is the same as that of the central cable 352a and the lower cable 352e of the first cam cable 353 in the first embodiment, and the ring 700 in the second embodiment is also the same as that in the first embodiment.

[0079] In addition, the lower cam pulley assembly 308 of the second embodiment is the same as that in the first embodiment. Thus, the configuration that the first and second cam cables 353 and 354 are coupled to the lower pulley assembly 308 in the second embodiment is the same as the configuration that the first and second cam cables 352 and 351 are coupled to the lower pulley assembly 308 in the first embodiment shown in FIGS. 9 to 12. That is, when the first cable 353b of the first cam cable 353 in the second embodiment will be described again with reference to FIGS. 9 to 12, a one-side cable portion and the other-side cable portion of the first cable 353b extending from the central portion of the first cable 353b and that are coupled to the fixing projections 312 formed on both sides of the lower pulley 310 are positioned at both side of the lower pulley 310 around the lower pulley 310, and are maintained to have a predetermined interval between the one-side cable portion and the other-side cable portion of the first cable 353b by the ring 700 to then be connected to the second cable 353a. Accordingly, as the bowstring 340 is pulled, the one-side cable portion and the other-side cable portion formed at both side of the lower pulley 310 in the first cable 353b of the lower cable 352e are wound on the respective cam modules 520 formed on both sides of the lower pulley 310. Therefore, directions of the forces exerted on the limb 303 by the first cable 353b are parallel to thus improve the left and right balancing of the limb 303 and minimize distortion of the limb 303 identically to the first embodiment. In addition, as the bowstring 340 is pulled, twisting of the bow limbs 303 is minimized, to thereby exhibit inherent strength of the bow and improve accuracy of an arrow.

[0080] Thus, even in the case of the second embodiment of the present invention that can be applied to a compound bow of a dual cam system, the draw length can be easily adjusted identically to the first embodiment, to thus maintain the power of the bow, and improve stability of the bow.

[0081] Since other configurations and operational effects of the second embodiment are the same as those of the first embodiment, the detailed description thereof will be omitted here.

[0082] As described above, the present invention has been described with respect to particularly preferred embodiments such as one and half cams or a dual cam. However, the present invention is not limited to the above embodiments, and it is possible for one who has an ordinary skill in the art to make various modifications and variations, without departing off the spirit of the present invention. Thus, the protective scope of the present invention is not defined within the detailed description thereof but is defined by the claims to be described later and the technical spirit of the present invention.

Claims

1. A compound bow comprising: a bow main body including a handle at a central portion of which a grip portion is formed and a pair of limbs that are respectively coupled to both ends of the handle; upper and lower pulley assemblies each including a pulley that is rotatably coupled to a rotating shaft formed on the rear end of each limb, and a cam that is coupled to the pulley and is rotated with the pulley; a bowstring whose either end is wound on and coupled to the pulley of each of the upper and lower pulley assemblies; and first and second cam cables that are wound around the cam of each of the upper and lower pulley assemblies as the bowstring is pulled, in which one end of each of the first and second cam cables is coupled to one of the upper and lower pulley assemblies, and the other end thereof is coupled to the other of the upper and lower pulley assemblies or the rotating shaft of the other of the upper and lower pulley assemblies, wherein the respective cams are provided on one side and the other side of the pulley in the lower pulley assembly, the first cam cable comprises: a central cable; an upper cable that is connected to the upper side of the central cable; and a lower cable that is connected to the lower side of the central cable, the upper cable comprises: a one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley of the upper pulley assembly, in which either end of the upper cable is coupled to the rotating shaft to which the upper pulley assembly is coupled at either side of the pulley of the upper pulley assembly, the lower cable comprises: a one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley of the lower pulley assembly, in which either end of the lower cable is coupled to a fixing projection that is formed at either side of the pulley of the lower pulley assembly, and the one-side cable portion and the other-side cable portion of the lower cable are supported by a spacing member so as to maintain a constant interval, to thus make the one-side cable portion and the other-side cable portion of the lower cable wound on the respective cams formed at both sides of the pulley of the lower pulley assembly, while maintaining the one-side cable portion and the other-side cable portion of the lower cable to have the constant interval by the spacing member, as the bowstring is pulled, to thereby minimize twisting of the bow limbs and improve accuracy of an arrow.

2. The compound bow of claim 1, wherein the spacing member is formed in a ring shape.

3. The compound bow of claim 1, wherein a lower loop is formed at a lower end of the central cable, and a central portion of the lower cable and the lower loop of the central cable are supported on an outer circumferential surface of the spacing member so that the central cable and the lower cable are interconnected.

4. The compound bow of claim 3, wherein the lower loop of the central cable is supported on a lower portion of the outer circumferential surface of the spacing member, and a central portion of the lower cable is supported on an upper portion of the outer circumferential surface of the spacing member.

5. The compound bow of claim 3, wherein the lower loop of the center cable is made of two loops, and the central portion of the lower cable is supported on the outer circumferential surface of the spacing member between the two loops.

6. The compound bow of claim 1, wherein a throughhole is formed at the center of the spacing member, and a damper member is coupled within the throughhole to thereby damp vibrations of the first cam cable.

7. The compound bow of claim 6, wherein the damper member is configured as having a cylindrical central portion that is fitted in the throughhole of the spacing member, and both end portions of a larger diameter than the center portion in which both the end portions are located in both side surfaces of the spacing member.

8. The compound bow of claim 1, wherein the one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley of the upper pulley assembly in the upper cable are supported by another spacing member so as to maintain a constant interval.

9. The compound bow of claim 8, wherein the other spacing member is formed in a ring shape.

10. The compound bow of claim 8, wherein an upper loop is formed at an upper end of the central cable, and a central portion of the upper cable and the upper loop of the central cable are supported on an outer circumferential surface of the other spacing member so that the central cable and the upper cable are interconnected.

11. The compound bow of claim 1, wherein the respective cams of each of the pulley assemblies comprise: a cam cable support portion supporting the cam cable; a cam module that is movably coupled in an arc trajectory on the pulley to which the cams are coupled; and a fixing unit that fixes the cam module at a desired position on the pulley in order to adjust a draw length of a let-off state, in which the cam cable is supported on the cam cable support portion and then is wound on the outer circumferential surface of the cam module, when the bowstring is pulled, the second cam cable is coupled to the fixing projection that is formed in the cam module and moves along as the cam module moves, is wound on a cam cable winding portion that is penetrated by the rotating shaft via a compensation projection, and then extends toward the other side pulley assembly, and a front portion of the cam module is in contact with the second cam cable and thus the second cam cable is bent when the cam module is moved in which one end of the second cam cable is coupled to the fixing projection of the cam module in order to adjust the draw length of the let-off state, to thus release the second cam cable from the cam cable winding portion via the compensating projection from the fixing projection to which the second cam cable is coupled, to thereby maintain constant tension of the cam cable and keep the power of the bow.

12. The compound bow of claim 11, wherein the cam module is rotatably coupled at a predetermined angle from the cam cable support portion around a pivoting point at a position spaced apart from the rotating shaft of the pulley.

13. The compound bow of claim 12, wherein an arc-shaped position adjusting hole is formed on the pulley on which the cam module is coupled, and the cam module is movably coupled to the pulley along the position adjusting hole.

14. A compound bow comprising: a bow main body including a handle at a central portion of which a grip portion is formed and a pair of limbs that are respectively coupled to both ends of the handle; upper and lower pulley assemblies each including a pulley that is rotatably coupled to a rotating shaft formed on the rear end of each limb, and a cam that is coupled to the pulley and is rotated with the pulley; a bowstring whose either end is wound on and coupled to the pulley of each of the upper and lower pulley assemblies; and first and second cam cables that are wound around the cam of each of the upper and lower pulley assemblies as the bowstring is pulled, in which one end of each of the first and second cam cables is coupled to one of the upper and lower pulley assemblies, and the other end thereof is coupled to the other of the upper and lower pulley assemblies or the rotating shaft of the other of the upper and lower pulley assemblies, wherein the respective cams are provided on one side and the other side of each of the pulleys around the respective pulleys in the upper and lower pulley assemblies, each of the first and second cam cables comprises: a first cable that is coupled with one pulley assembly; and a second cable that is connected to the first cable and coupled with the other pulley assembly, the first cable comprises: a one-side cable portion and the other-side cable portion that are positioned on both sides of the pulley, in which either end of the first cable is coupled to a fixing projection that is formed at either side of the pulley of the pulley assembly to which the first cable is coupled, and the one-side cable portion and the other-side cable portion of the first cable are supported by a spacing member so as to maintain a constant interval, to thus make the one-side cable portion and the other-side cable portion of the first cable wound on the respective cams formed at both sides of the pulley of the pulley assembly to which the first cable is coupled, while maintaining the one-side cable portion and the other-side cable portion of the first cable to have the constant interval by the spacing member, as the bowstring is pulled, to thereby minimize twisting of the bow limbs and improve accuracy of an arrow.

15. The compound bow of claim 14, wherein the spacing member is formed in a ring shape.

16. The compound bow of claim 14, wherein a central portion of the first cable and a loop that is formed at one end of the second cable are supported on the outer circumferential surface of the spacing member and thus the first cable and the second cable are interconnected.

17. The compound bow of claim 14, wherein a throughhole is formed at the center of the spacing member, and a damper member is coupled within the throughhole to thereby damp vibrations of the cam cables.

18. The compound bow of claim 1, wherein the respective cams of each of the pulley assemblies comprise: a cam cable support portion supporting the cam cable; a cam module that is movably coupled in an arc trajectory on the pulley to which the cams are coupled; and a fixing unit that fixes the cam module at a desired position on the pulley in order to adjust a pulling length of a let-off state, in which the cam cable is supported on the cam cable support portion and then is wound on the outer circumferential surface of the cam module, when the bowstring is pulled, the second cable is coupled to the fixing projection that is formed in the cam module and moves along as the cam module moves, is wound on a cam cable winding portion that is formed around the rotating shaft via a compensation projection, and then extends toward the other side pulley assembly, and a front portion of the cam module is in contact with the second cable and thus the second cable is bent when the cam module is moved in which one end of the second cable is coupled to the fixing projection of the cam module in order to adjust the draw length of the let-off state, to thus release the second cable from the cam cable winding portion via the compensating projection from the fixing projection to which the second cable is coupled, to thereby maintain constant tension of the cam cable and keep the power of the bow.