Patent Publication Number: US-9423204-B2

Title: Recurved bow with improved vibration damping function

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Korean Utility-Model Application No. 20-2015-0000445, filed on Jan. 20, 2015, in the Korean Intellectual Property Office, the disclosure of which is incorporated in its entirety herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a recurved bow, and more particularly, to a recurved bow that damps vibrations generated in the end portions of limbs coupled to a handle in use of the recurved bow to thereby improve accuracy of an arrow. 
     BACKGROUND OF THE INVENTION 
     At present, recurved bows are used as bows for a game of European archery, and as shown in  FIG. 1 , each of the recurved bows includes: a handle  10  at the center of which a grip  11  grasped by a user is formed; a pair of limbs  20  coupled at both ends of the handle  10 ; and a bowstring  30  that is connected between the limbs  20 . In addition, as shown in  FIG. 2 , the limbs  20  are coupled with the handle  10  in which fixing pins  12  respectively formed at both end portions of the handle  20  are respectively inserted into fitting grooves  21  of the limbs  20 , to thus support each end of the limbs  20 , and coupling pins  22  respectively formed at both end portions of the limbs  20  are respectively coupled into coupling grooves  13  formed in both end portions of the handle  10 . 
     However, the conventional bow may cause the limbs  20  of the bow to be bent back when the bowstring  30  is pulled in use of the bow. Accordingly, as shown in  FIG. 2 , a displacement (a dashed line portion of  FIG. 2 ) may occur at one end of each of the limbs  20  coupled with the handle  10 . As a result, vibrations generated at the time of firing an arrow are finally transmitted to the handle to thereby degrade accuracy of the arrow. In this case, narrowing a distance between the fixing pin  12  and the coupling groove  13  that secure the limbs  20  in order to reduce the displacement, may have a problem of causing a small vibration amplitude but keeping the vibration for long. Meanwhile, widening the distance between the fixing pin  12  and the coupling groove  13  may have a problem of causing a large vibration damping speed but a large vibration amplitude. 
     SUMMARY OF THE INVENTION 
     To solve the above conventional problems or defects, it is an object of the present invention to provide a recurved bow for improving accuracy of an arrow by damping and rapidly absorbing vibrations generated in the end portions of limbs coupled to a handle. 
     In addition, it is another object of the present invention to provide a recurved bow for enhancing vibration damping functions in which the bow can damp vibrations generated from bow limbs without changing structure of an existing recurved bow, to thereby increase cost-efficiency. 
     To accomplish the above and other objects of the present invention, according to an aspect of the present invention, there is provided a recurved bow comprising: a handle at the center of which a grip grasped by a user is formed; a pair of limbs coupled at both ends of the handle; and a bowstring that is connected between the pair of limbs, wherein a coupling pin is formed in one end of a rear side of each of the limbs coupled to the handle, and a fitting groove is formed in one end of each of the limbs, wherein a coupling groove is formed in either end of the handle with which each of the limbs is coupled in which the coupling pin of each of the limbs is coupled into the coupling groove, and a fixing pin is formed at either end portion of the handle in which the fixing pin is inserted into the fitting groove of each of the limbs, to thus support each end of the limbs, wherein a projecting coupling member is provided in front of each of the limbs, and is extended forwardly from each of the limbs, and has a coupling portion in the front thereof, and is coupled with the coupling pin of a rear side of each of the limbs, and wherein a damper member is provided in which the damper member comprises a corresponding coupler that is screw-coupled with the coupling portion formed in front of each of the projecting coupling member, and a damper coupled with the front of the corresponding coupler, to thereby rapidly damp vibrations generated in one end of each of the limbs to thus enhance a vibration damping function. 
     Preferably but not necessarily, a female thread is formed in the front surface of the projecting coupling member as the screw-coupling portion formed in front of the projecting coupling member and a male thread is formed in the corresponding screw coupler of the damper member. 
     Preferably but not necessarily, the damper member is made of a rubber. 
     Preferably but not necessarily, a coupling projection is formed in the coupling pin of each of the limbs in which the coupling projection is protrudes to the rear of the coupling pin and is inserted into an insertion groove formed on the bottom of the coupling groove of the handle, and wherein a spring member that elastically supports the coupling projection is provided in an inner space of the coupling pin. 
     Preferably but not necessarily, the damper member is disposed on the same axial line as that of the spring member of the coupling pin. 
     As described above, the present invention provides a recurved bow with an improved vibration damping function in which the recurved bow quickly damps an amplitude of vibrations generated on limbs to improve accuracy of an arrow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a conventional recurved bow. 
         FIG. 2  is a partially enlarged view of  FIG. 1 . 
         FIG. 3  is a partially exploded perspective view of a recurved bow according to an embodiment of this invention. 
         FIG. 4  is a partial side view of a recurved bow according to an embodiment of this invention. 
         FIGS. 5A and 5B  are graphical views for comparing vibrations generated from a conventional bow and a bow according to an embodiment of this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     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. 
       FIG. 3  is a partially exploded perspective view of a bow according to an embodiment of this invention.  FIG. 4  is a partial side view of a bow according to an embodiment of this invention.  FIGS. 5A and 5B  are graphical views for comparing vibrations generated from a conventional bow and a bow according to an embodiment of this invention. 
     As shown, a recurved bow includes: a handle  100  at the center of which a grip  11  (of  FIG. 1 ) grasped by a user is formed; a pair of limbs  200  coupled at both ends of the handle  100 ; and a bowstring that is connected between the pair of limbs  200 , wherein a coupling pin  220  is formed in one end of a rear side of each of the limbs  200  coupled to the handle  100 , and a fitting groove  210  is formed in one end of each of the limbs  200 , wherein a coupling groove  130  is formed in either end of the handle  100  with which each of the limbs  200  is coupled in which the coupling pin  220  of each of the limbs  200  is coupled into the coupling groove  130 , and a fixing pin  120  is formed at either end portion of the handle  100  so as to be inserted into the fitting groove  210  of each of the limbs  200 , wherein a projecting coupling member is formed with a coupling portion  240   a  of a male or female screw in the front thereof, and is disposed in front of each of the limbs  200 , and is coupled with the coupling pin  220  of a rear side of each of the limbs  200 , and wherein a damper member  300  is provided in which the damper member  300  comprises a corresponding coupler  310  that is screw-coupled with the coupling portion  240   a  formed in front of each of the projecting coupling member  240 , and a damper  320  coupled with the front of the corresponding screw coupler  310 . 
     The grip  11  (of  FIG. 1 ) grasped by a user is formed at the center of the handle  100 , and the pair of limbs  200  are coupled at both ends of the handle  100 . A coupling groove  130  is formed at either end of the handle  100  so that each of the limbs  200  is coupled with the handle  100 , and a fixing pin  120  is formed at a distance in the central direction of the coupling groove  130  from the coupling groove  130 . 
     The fixing pin  120  for fixing and supporting one end of each of the limbs  200  coupled to the handle  100 , is detachably screw-coupled with the handle  100 . A projecting height of a head portion of the fixing pin  120  is adjusted by rotating the fixing pin  120 , to thereby adjust the strength of each of the limbs  200 . 
     The coupling groove  130  is formed at either end of the handle  100 , in which a coupling pin  220  of each of the limbs  200  to be described later is inserted into the coupling groove  130 . The coupling pin  220  of each of the limbs  200  is inserted through the top of the coupling groove  130 , and then each of the limbs  200  is coupled downwards toward the center of the handle  100 . An opening width of a lower portion of the coupling groove  130  is formed smaller than that of the coupling pin  130  so that the coupled coupling pin  130  is not seceded to the front side. In addition, an insertion groove  140   a  is formed on the bottom surface of the coupling groove  130 , in which a coupling projection  250  protruded from the coupling pin  220  of each of the limbs  200  is inserted into and fixed to the insertion groove  140   a.    
     Meanwhile, in an example shown in  FIG. 3 , a T-shaped limb coupling block  140  that is coupled detachably to each of ends of the handle  100  is formed at each of ends of the handle  100 , so that the coupling groove  130  is formed in the limb coupling block  140 . However, the coupling groove  130  may be formed at the end of the handle  100  without a separate block, and a variety of modifications of the shape of the coupling groove  130  may be allowed as long as the coupling pin  220  is inserted into and fixed to the coupling groove  130 . 
     A fitting groove  210  is formed in a predetermined length at the end of each of the limbs  200  so as to be inserted into and fixed to the fixing pin  120  of the handle  100  in order to be coupled with the handle  100 . In addition, the coupling pin  220  coupled into the coupling groove  130  of the handle  100  is formed at one side of a rear surface of one end of each of the limbs  200 . 
     The coupling projection  250  projected in the rear side of the coupling pin  220  and inserted into the insertion groove  140   a  of the handle  100  is formed at the coupling pin  220 . In addition, a spring member  230  is inserted into the inner space of the coupling pin  220 , to thus elastically support the coupling projection  250 . Meanwhile, a thread  220   a  is formed in the front outer peripheral surface of the coupling pin  220 , so as to be screwed to the rear surface of the projecting coupling member  240 . 
     The projecting coupling member  240  is disposed in front of each of the limbs  200  and is coupled with the coupling pin  220  through a throughhole  200   a  formed in each of the limbs  200  at the rear side of the projecting coupling member  240 . The projecting coupling member  240  is coupled with the damper member  300  in front of the projecting coupling member  240 . The projecting coupling member  240  is extended forwardly so as to protrude by a predetermined length from each of the limbs  200 . A female screw is formed at the rear surface of the projecting coupling member  240  for coupling with the coupling pin  220 , and is screw-coupled with the thread  220   a  formed in front of the outer peripheral surface of the coupling pin  220 . In addition, coupling portion  240   a  is formed in the front surface of the projecting coupling member  240  for coupling with the corresponding coupler  310  of the damper member  300 . As shown in this embodiment, the female screw is formed as the coupling portion  240   a  of the projecting coupling member  240 . 
     The damper member  300  is coupled to the front surface of the projecting coupling member  240  to thus damp the vibrations of each of the limbs  200 , and is disposed on the same axial line as that of the spring member  230 . In addition, the damper member  300  includes: the corresponding screw coupler  310  that is screw-coupled with the screw-coupling portion  240   a  formed in front of each of the projecting coupling member  240 , and the damper  320  coupled with the front of the corresponding screw coupler  310 . The corresponding screw coupler  310  is made of a male screw so as to be coupled to a female screw of the projecting coupling members  240 . The damper  320  is coupled to the front of the corresponding screw coupler  310 , and is made of a rubber material in a bar form in this embodiment. Meanwhile, according to the present embodiment, the corresponding screw coupler  310  is made of a male screw. However, in other embodiments, a male screw may be formed in front of the projecting coupling member  240  and a female screw may be formed in the corresponding screw coupler  310  so as to be coupled with the projecting coupling member  240 . And, besides screw coupling, another coupling structure between the projecting coupling member  240  and the damper member  300  is also possible. 
     Vibrations generated from the recurved bow according to an embodiment of this invention having the configuration as described above, when the bowstring is released, are compared with vibrations generated from an existing recurved bow as in  FIG. 1 , when the bowstring is released, and thus the vibrations results are illustrated in  FIGS. 5A and 5B , in which the x-axis indicates the time, and the y-axis indicates the amplitude.  FIG. 5A  shows vibrations generated from an existing recurved bow as in  FIG. 1 , when the bowstring is released, and  FIG. 5B  shows vibrations generated from the recurved bow according to an embodiment of this invention having the configuration as described above, when the bowstring is released. As it can be seen from  FIGS. 5A and 5B , it can be seen that the amplitude of the vibrations of the recurved bow according to an embodiment of this invention when the bowstring is released has been significantly reduced when compared with those of the existing recurved bow, and it can be also seen that the reduction in the time has been also significantly reduced. This means not only the size of the vibration is decreased but duration of vibration is also reduced. 
     In the conventional recurved bow, the limbs of the recurved bow are bent back when the bowstring is pulled, and a displacement may occur at one end of each of the limbs coupled with the handle. As a result, vibrations generated from the limbs at the time of firing an arrow are finally transmitted to the handle to thereby degrade accuracy of the arrow. However, according to the embodiments of the present invention, the projecting coupling member  240  is coupled with the coupling pin  220  of each of the limbs  200  so as to be coupled with and at the end of the handle  100  and the projecting coupling member  240  is coupled with the damper member  300 , to thereby damp vibrations generated from the limbs when the bowstring is released significantly and quickly. 
     In particular, the limbs  200  are bent back when the bowstring  30  is released, and the coupling pin  220  that secures each of the limbs  200  to the handle  100  is positioned at the distal end from the middle of the handle  100 . According to the embodiments of the present invention, as described above, the damper member  300  is coupled on the axial line of the coupling pin  220  with the coupling pin  220  through the projecting coupling member  240  so that the damper member  300  protrudes forwardly in which the coupling pin  220  serves to act as a support point at the end of the handle  100 , to thereby lead to a remarkable vibration damping effect as described above. 
     In addition, according to the embodiments of the present invention, the damper member  300  is coupled with the coupling pin  220  through the projecting coupling member  240 , and the spring member  230  that elastically supports the insertion projection  250  is formed in the coupling pin  220  to be fixed to the coupling groove  130  of the handle  100 . Since the damper member  300  is coupled on the same axial line as that of the spring member  230 , the spring member  230  that is formed on the same axial line as that of the damper member  300  leads to a synergistic effect on the damping of the vibrations generated from the limbs when the bowstring is released. 
     Therefore, in the case of the recurved bows in accordance with the embodiments of the present invention, vibrations transmitted to the handle from the limbs at firing an arrow are reduced significantly and quickly, to thus also provide an effect of enhancing accuracy of the arrow. 
     As described above, the present invention has been described with respect to particularly preferred embodiments. 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.