Abstract:
A golf club head comprises a main body and a striking plate. The main body is provided with an opening formed with a first stepped portion and a second stepped portion. The first stepped portion and the second stepped portion define a groove therebetween. The first stepped portion supports the striking plate with a reduced contact surface area so as to increase the effective elastically deforming area of the striking plate. Further, when the striking plate is combined with the main body by welding, the groove of the main body can obstruct an overflow of melting metal from a welding seam between the main body and the striking plate. Thereby the groove of the main body enhances welding quality and thereby overcomes the problems of club head noises and disturbance caused by flux beads and an inadequate coefficient of restitution caused by insufficient deforming area of the striking plate.

Description:
FIELD OF THE INVENTION 
     The present invention relates to golf club heads, and more particularly to a golf club head having a groove extended around an inner rim of an opening of a main body for retaining overflow of melting metal in the process of welding the main body with a striking plate. 
     BACKGROUND OF THE INVENTION 
     A conventional golf club head comprises a main body  10  and a striking plate  20 , as shown in  FIGS. 1 and 2 . The main body  10  is a wood golf club, which is provided with an opening  11  and a stepped portion  12 . The stepped portion  12  is formed around an inner rim of the opening  11  for supporting a lip area around an outer periphery of a inner face of the striking plate  20 , so that the main body  10  and the striking plate  20  can be placed together for welding. Referring to  FIG. 2 , it is a further option that the outer periphery of the striking plate  20  can be bent to form a ring wall  21  so that a striking area of the striking plate  20  is increased. 
     Applying a welding means to combine the main body  10  and the striking plate  20 , the inner rim around the opening  11  of the main body  10  (namely, the welding seam) is constituted a curve that is varied in two-dimensional or three-dimensional space. To weld the main body  10  and the striking plate  20 , a welding machine must be preset a welding path in multi-dimensions corresponding to the curve of the main body  10 . However, in high-energy welding, a sophisticated welding path may result in a specific decrease in control of welding depth. As a result, the utilization of a relatively high energy welding means for assuring adequate welding depth may easily cause overflow of melting metal (molten metal) intruding into the interior of the main body  10 . The intruded melting metal is solidified and attached to an interface between the main body  10  and the inner face of the striking plate  20 , which reduces the effective elastically deforming area of the striking plate  20  and therefore the coefficient of restitution, COR, thereof. This also affects the appearance of the main body  10 . It is a further disadvantage that the intruded melting metal may fall into the interior of the main body  10  and result in flux beads that cause striking noises and disturbance while wielding a golf club. Moreover, an iron type of the golf club head is usually provided with a cavity at its rear portion. An undercut portion is formed between the cavity and a striking plate. The intruded melting metal will be solidified in the undercut portion and it is difficult to remove. This also affects the coefficient of restitution of the striking plate. 
     Alternatively, the utilization of a relatively lower energy welding means can avoid the intrusion of overflow of the melting metal, but it may result in an inadequate welding depth that may weaken the entire structure of the golf club head. To prevent melting metal intrusion, a conventional golf club head commonly adopts an enlarged contact area between the striking plate  20  and the stepped portion  12  of the main body  10 , which also reduces the effective area of elastic deformation of the striking plate  20 . Therefore, it is necessary to improve the structure of conventional golf club heads. 
     Accordingly, the present invention provides a golf club head whose main body is provided with an inner rim of an opening formed with a first stepped portion and a second stepped portion. The first stepped portion and the second stepped portion define a groove therebetween. When the striking plate is combined with the main body by welding, the groove of the main body can obstruct an overflow of melting metal from a welding seam between the main body and the striking plate. This enhances welding quality and thereby overcomes the problem of club head noises and disturbance caused by flux beads remained the main body. Further, the first stepped portion supports the striking plate with a reduced contact surface area so as to increase the effective elastically deforming area of the striking plate and thereby the striking distance of a golf club. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a golf club head in which a groove is extended around an opening of a main body. The groove is capable of retaining overflow of melting metal occurred in a high-energy welding process, which enhances welding quality and prevents from forming flux beads in the main body to thereby avoid making noises when wielding a golf club. 
     The secondary objective of the present invention is to provide a golf club head in which a first stepped portion and a groove are extended around an opening of a main body. Since outflow of melting metal is effectively retained within the groove, the first stepping portion is only required to reserve a thin contact area to support the main body. This may effectively increase the long-striking ability of a golf club. 
     A further objective of the present invention is to provide a golf club head, wherein a first stepped portion and a groove are extended around an opening of a main body. Since outflow of melting metal is effectively retained within the groove, the solidification of melting metal in an undercut portion can be avoided, which improves manufacturing quality of golf clubs. 
     Accordingly, a golf club head of the present invention comprises a main body and a striking plate. The main body is provided with an opening, around the inner rim of which is formed with a first stepped portion and a second stepped portion. The first stepped portion and the second stepped portion define a groove therebetween. The first stepped portion supports the striking plate with a reduced contact surface area so as to increase the effective elastically deforming area of the striking plate. Further, when the striking plate is combined with the main body by welding, the groove of the main body can obstruct an overflow of melting metal from a welding seam between the main body and the striking plate. Thereby the groove of the main body enhances welding quality and thereby overcomes the problems of club head noises and disturbance caused by flux beads and an inadequate coefficient of restitution caused by insufficient deforming area of the striking plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a cross-sectional view of a conventional golf club head in accordance with the prior art. 
         FIG. 2  is a cross-sectional view of an alternative conventional golf club head in accordance with the prior art. 
         FIG. 3  is an exploded perspective view of a golf club head in accordance with the first preferred embodiment of the present invention. 
         FIG. 4  is a cross-sectional view of the golf club head in accordance with the first preferred embodiment of the present invention. 
         FIG. 5  is an enlarged cross-sectional view of the golf club head in accordance with the first preferred embodiment of the present invention in welding process. 
         FIG. 6  is an exploded perspective view of a golf club head in accordance with the second preferred embodiment of the present invention. 
         FIG. 7  is a cross-sectional view of the golf club head in accordance with the second preferred embodiment of the present invention. 
         FIG. 8  is a cross-sectional view of a golf club head in accordance with the third preferred embodiment of the present invention. 
         FIG. 9  is a cross-sectional view of a golf club head in accordance with the fourth preferred embodiment of the present invention. 
         FIG. 10  is a cross-sectional view of a golf club head in accordance with the fifth preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The various objects and advantages of the present invention will be more readily understood from the following detailed description of preferred embodiments when read in conjunction with the appended drawing: 
       FIG. 3  shows an exploded perspective view of a wood of a golf club head in accordance with the first preferred embodiment of the present invention.  FIG. 4  shows a perspective view of the golf club head in accordance with the first preferred embodiment of the present invention in assembled relationship.  FIG. 5  shows an enlarged cross-sectional view,  FIG. 4 , of the golf club head in accordance with the first preferred embodiment of the present invention in welding process.  FIG. 6  shows an exploded perspective view of a wood of a golf club head in accordance with the second preferred embodiment of the present invention.  FIG. 7  shows a perspective view of the golf club head in accordance with the second preferred embodiment of the present invention.  FIG. 8  shows a cross-sectional view of an iron of a golf club head in accordance with the third preferred embodiment of the present invention.  FIG. 9  shows a cross-sectional view of a iron of a golf club head in accordance with the fourth preferred embodiment of the present invention.  FIG. 10  shows a cross-sectional view of an iron of a golf club head in accordance with the fifth preferred embodiment of the present invention. 
     Referring to  FIGS. 3 through 5 , reference numerals of the first embodiment has applied the identical numerals of the conventional golf club head, as shown in  FIGS. 1 and 2 . The golf club head of the second embodiment has the similar configuration and same function as that of the conventional golf club head and the detailed descriptions are omitted. 
     Referring to  FIGS. 3 and 4 , a golf club head in accordance with the first preferred embodiment of the present invention comprises a main body  10  and a striking plate  20 . The main body  10  further includes an opening  11 , a first stepped portion  12 , a second stepped portion  13  and a groove  14 . The main body  10  is a wood type of the club head that is constituted an enclosed body. The opening  11  is located on a front face of the main body  10 , which has an inner rim formed with the first stepped portion  12  and the second stepped portion  13 . The groove  14  is formed between the first stepped portion  12  and the second stepped portion  13 . The striking plate  20  is a metal plate formed with a flat plate or a cambered plate. It is further shaped to fit in the opening  11  of the main body  10 , so as to facilitate the subsequent high-energy welding process. More specifically, when embedded in the opening  11 , an outer rim  201  of the striking plate  20  is loosely connected with the inner rim  101  of the opening  11 . Further, the first stepped portion  12  supports an outer periphery  202  of the striking plate  20  facing the opening  11  of the main body  10  so that the striking plate  20  is spaced a proper distance from the second stepped portion  13 . 
     Referring to  FIGS. 4 and 5 , the main body  10  and the striking plate  20  are welded together, which uses high-energy welding means selected from laser welding, plasma-arc welding and electron-beam welding. Welding the main body  10  and the striking plate  20  together, the high-energy welding remains a welded seam  30  between the inner rim  101  of the opening  11  of the main body  10  and the outer rim  201  of the striking plate  20 . It generally happens that the melting metal  31  may overflow the welded seam  30  into the main body  10  through a space formed between the outer periphery  202  of the striking plate  20  and the first stepped portion  12  of the opening  11 . To prevent the intrusion of the melting metal to form beads that causes the noise problem of a conventional golf club head, the present invention utilizes the groove  14  to retain the overflow of the melting metal. It is a further advantage that, since the groove  14  provides accommodation for the intrusion of the melting metal, the first stepped portion  12  only requires a thin welded seam with an adequate area that supports the striking plate  20 . Meanwhile, the second stepped portion  13  is allowed to space from the striking plate  20 . A reduction of the first stepped portion  12  in contact with the striking plate  20  may result in an increase of deformation of the striking plate  20  that may, thus, extend the striking range of the golf club head. 
     It is a further measure that an appropriate amount of soldering flux can be applied to the groove  14  before the welding process so as to firmly mount the intrusion of overflow of the melting metal  31  therein. 
     Referring to  FIGS. 6 and 7 , it illustrates a golf club head in accordance with the second preferred embodiment of the present invention. In comparison with the first preferred embodiment, the striking plate  20  of the second preferred embodiment includes a bent ring wall  21  integrally formed on an outer rim thereof and erected therefrom. Corresponding to an inner surface of the ring wall  21 , an opening  11  of the main body  10  includes an outer rim formed with a first stepped portion  12 , a second stepped portion  13  and a groove  14 . Identical with the first preferred embodiment, the groove  14  is capable of retaining an intrusion of overflow of the melting metal in the welding process, as shown in FIG.  5 . Moreover, the second preferred embodiment utilizes the bent ring wall  21  to thereby enlarge an effective area of elastic deformation of the striking plate  20  in addition to an accommodation of the groove  14  for the intrusion of overflow of the melting metal. Consequently, the enlarged area of the elastic deformation of the striking plate  20  may extend the striking range of the golf club. 
     Referring to  FIG. 8 , it illustrates a golf club head in accordance with the third preferred embodiment of the present invention. In comparison with the first and the second preferred embodiments, the main body  10  of the third preferred embodiment is an iron type of the golf club head. A front surface of the main body  10  includes an opening (so-called “cavity”)  11 , a first stepped portion  12 , a second stepped portion  13  and a groove  14 . The main body  10  has a rear side opposite to the opening  11 , which designed an opening or an enclosed portion. The striking plate  20  is firstly embedded in the opening  11  of the main body  10  and then welded thereto by a high-energy welding means. When the striking plate  20  is embedded in the opening  11 , the outer rim  201  around the striking plate  20  connects with the inner rim  101  around the opening  11  of the main body  10 . And the first stepped portion  12  of the main body  10  supports the outer periphery  202  around the inner face of the striking plate  20 , while the second stepped portion  13  is spaced from the inner face of the striking plate  20  a predetermined distance. In the welding process, the groove  14  effectively retains the intrusion of overflow of the melting metal from the welded seam between the first stepped portion  12  and the striking plate  20 , as shown in FIG.  5 . The retaining effect of the groove  14  prevents the undercut portion between the opening  11  and the main body  10  from irregular flux beads formed by the intruded melting metal. Therefore, the present invention can omit a cleaning step for flux beads after the welding process that the welding quality is enhanced. In addition, the present invention can avoid the flux beads formed on the striking plate  20  to thereby ensure elastic deformation of the striking plate  20 . 
     Referring to  FIG. 9 , it illustrates a golf club head in accordance with the fourth preferred embodiment of the present invention. Also, the main body  11  is an iron type of the golf club head. In comparison with the first through third embodiments, the striking plate  20  of the fourth embodiment includes a bent ring wall  21  integrally formed on an outer rim thereof, and erected therefrom. Corresponding to the inner surface of the ring wall  21 , an opening  11  of the main body  10  includes an outer rim formed with a first stepped portion  12 , a second stepped portion  13  and a groove  14 . The groove  14  is capable of retaining an intrusion of overflow of the melting metal in the welding process, as shown in FIG.  5 . This prevents the undercut portion between the opening  11  and the main body  10  from irregular flux beads formed by the intruded melting metal so that the welding quality is enhanced. Moreover, the fourth preferred embodiment utilizes the bent ring wall  21  to thereby enlarge an effective area of elastic deformation of the striking plate  20 . Consequently, the enlarged area of the elastic deformation of the striking plate  20  may extend the striking range of the golf club. Moreover, the main body  10  has a rear side opposite to the opening  11 , which designed an opening or an enclosed portion. 
     Referring to  FIG. 10 , it illustrates a golf club head in accordance with the fifth preferred embodiment of the present invention. Also, the main body  11  is an iron type of the golf club head. In comparison with the first through fourth embodiments, a lip area  12 ′ of the fifth embodiment is formed on an outer rim around the opening  11  of the main body  10 , which substitutes the first stepped portion  12 . Extending inwardly from the opening  11 , a groove  14  and a second stepped portion  13  are formed around the inner rim of the opening  11 . The striking plate  20  therefore can be attached to the lip area  12 ′ on a front side of the main body  10  for facilitating the subsequent high-energy welding process. The groove  14  effectively retains the intrusion of overflow of the melting metal from the welded seam between the lip area  12 ′ and the striking plate  20 , as shown in FIG.  5 . This prevents the undercut portion between the opening  11  and the main body  10  from irregular flux beads formed by the intruded melting metal so that the welding quality is enhanced. Moreover, the main body  10  has a rear side opposite to the opening  11 , which designed an opening or an enclosed portion. 
     As disclosed by these preferred embodiments, the present invention indeed overcomes the disadvantages of melting metal intrusion and the reduction of effective elastically deforming area of a striking plate by solidified welding metal. This is simply achieved by introducing a groove  14  within the main body  10  to prevent the intrusion of melting metal  31 , which enhances not only welding quality but also striking range of a golf club. 
     The present invention is thus disclosed by the above-mentioned preferred embodiments, and it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.