Patent Publication Number: US-2006014594-A1

Title: Fe-Mn-Al alloy club body combining with a Ti alloy striking plate

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a Fe—Mn—Al alloy club body combining with a Ti alloy striking plate. More particularly, the present invention relates to a golf club head structure consisting of Fe—Mn—Al alloy and Ti alloy for improving vibration-absorbable ability and elastic deformation.  
      2. Description of the Related Art  
      Generally, a conventional golf club head includes a club body and a striking plate connected thereto. In manufacture, the club body is made of material selected from a group consisting of stainless steel, carbon steel and alloyed steel in consideration of manufacture cost, striking ability and entire structural strength. Correspondingly, the striking plate is made of Ti alloy. In comparison with the material of the club body, the material of the striking plate has lower Young&#39;s modulus. The Young&#39;s modulus is given by 
 
 E =stress/strain=load/displacement  kgf/mm   2  
          where E is the Young&#39;s modulus of material. The Young&#39;s modulus of material is inverse proportion to coefficient of restitution (COR). Namely, an increase of Young&#39;s modulus results in a decrease of coefficient of restitution. Hence, the striking plate employs lower Young&#39;s modulus of material to obtain higher coefficient of restitution for high deformation within elastic limit of the material while striking a golf ball. Accordingly, the striking plate can reduce a damping effect upon absorbing a striking stress that attenuates impact deformation of the golf ball. Consequently, it can avoid attenuating (losing) energy of a striking stress and increase a striking distance.        

      Referring initially to  FIG. 1 , the club body is usually made of high Young&#39;s modulus material, 17-4 steel having Young&#39;s modulus of 20,765 kgf/mm 2  for example, in consideration of structural strength and manufacture cost in the industry. The higher Young&#39;s modulus material of the club body performs low elastic deformation ability and high coefficient of damping that results in excessive absorption of an impact force while striking a golf ball. Consequently, the excessive absorption of the club body affects normal elastic deformation and striking ability of the striking plate. Meanwhile, the excessive absorption of the club body is converted into a vibration and then transmitted to a club shaft and a club grip that affects striking stability, gripping feel for hands and structural strength of a connecting portion of the club body. In addition, the conventional club body is made of low-carbon steel, carbon steel or alloy steel which has poor heterogeneous welding quality for different metals. To avoid this task, the golf club body combines with a weight member by a method selected from consisting of snap-fitting, press-fitting and brazing instead of welding. Consequently, it may prolong the manufacture time of the golf club head.  
      The present invention intends to provide a Fe—Mn—Al alloy club body combining with a Ti alloy striking plate. In comparison with the club body made of stainless steel, carbon steel or other alloy steel, the Fe—Mn—Al alloy club body has lower Young&#39;s modulus that performs excellent vibration-absorbable ability and heterogeneous welding quality for different metals. Thereby, the Fe—Mn—Al alloy club body is able to transmit a complete striking stress to the Ti alloy striking plate that can attenuate vibration and maintain high elastic deformation to improve striking ability, striking stability, gripping feel for hands and combined strength of a weight member.  
     SUMMARY OF THE INVENTION  
      The primary objective of this invention is to provide a Fe—Mn—Al alloy club body which is able to transmit a complete striking stress to a striking plate. Thereby, the Fe—Mn—Al alloy club body reduces the possibility of attenuating the striking stress, and thus improves striking ability and striking distance.  
      The secondary objective of this invention is to provide a Fe—Mn—Al alloy club body which is combined with a Ti alloy striking plate. Thereby, the Fe—Mn—Al alloy club body can avoid vibration to enhance striking stability and gripping feel for hands.  
      Another objective of this invention is to provide a Fe—Mn—Al alloy club body which has excellent heterogeneous welding quality for different metals. Thereby, the Fe—Mn—Al alloy club body is suitable for welding a weight member and speeds the processing time.  
      The golf club head structure in accordance with the present invention includes a Fe—Mn—Al alloy club body and a Ti alloy striking plate. The Fe—Mn—Al alloy club body connects to the Ti alloy striking plate by press-fitting or brazing so that the combined club head structure obtains lower Young&#39;s modulus to transmit a complete striking stress from the Fe—Mn—Al alloy club body to the Ti alloy striking plate while striking a golf ball. The Fe—Mn—Al alloy club body can eliminate vibration to maintain high elastic deformation of the Ti alloy striking plate while striking a golf ball. Furthermore, a W—Fe—Ni alloy weight member connects to the Fe—Mn—Al alloy club body by welding since Fe—Mn—Al alloy performs excellent heterogeneous welding ability.  
      Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description and the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will now be described in detail with reference to the accompanying drawings wherein:  
       FIG. 1  is a table and a graph showing Young&#39;s modulus of a conventional golf club head made of 17-4 stainless steel;  
       FIG. 2  is an exploded cross-sectional view of a golf club head in accordance with a first embodiment of the present invention;  
       FIG. 3  is a cross-sectional view of the assembled golf club head in accordance with the first embodiment of the present invention;  
       FIG. 4  is a table and a graph showing Young&#39;s modulus of the golf club head in accordance with the first embodiment of the present invention;  
       FIG. 5  is an exploded cross-sectional view of a golf club head in accordance with a second embodiment of the present invention;  
       FIG. 6  is a cross-sectional view of the assembled golf club head in accordance with the second embodiment of the present invention; and  
       FIG. 7  is an exploded cross-sectional view of a golf club head in accordance with a third embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring initially to  FIGS. 2 through 4 , a golf club head in accordance with a first embodiment of the present invention includes a Fe—Mn—Al alloy club body  10  and a Ti alloy striking plate  20 . The Fe—Mn—Al alloy club body  10  is made of Fe—Mn—Al alloy which has Young&#39;s modulus of 144425 kgf/mm 2 . The Ti alloy striking plate  20  is made of Ti alloy which has lower Young&#39;s modulus.  
      Referring again to  FIGS. 2 and 3 , the construction of the Fe—Mn—Al alloy club body  10  and the Ti alloy striking plate  20  shall be described in detail. The Fe—Mn—Al alloy club body  10  forms an opening  11  at its front side. The opening  11  provides with a shoulder  12  which is adapted to engage with the Ti alloy striking plate  20 . Furthermore, the opening  11  includes a compensating protrusion  13  at its annular circumference (not labeled) for the punching process. Correspondingly, the Ti alloy striking plate  20  provides with a stepped portion  21  at its annular circumference for permitting deformation of the compensating protrusion  13 .  
      Referring still to  FIGS. 2 and 3 , in the assembling process, the Ti alloy striking plate  20  is initially inserted into the opening  11  of the Fe—Mn—Al alloy club body  10 . Subsequently, a punching machine (not shown) is used to punch the compensating protrusion  13  of the Fe—Mn—Al alloy club body  10  so that a compensation portion  13 ′ engages the stepped portion  21  of the Ti alloy striking plate  20 . Accordingly, a combined member of the Fe—Mn—Al alloy club body  10  and the Ti alloy striking plate  20  constitutes the golf club head.  
      Referring back to  FIGS. 1 and 4 , in comparison with the conventional club body made of 17-4 stainless steel, the material of the Fe—Mn—Al alloy club body  10  has adequate strength and lower Young&#39;s modulus of 14,425 kgf/mm 2 . Namely, on the basis of deformation within elastic limit of the material, the Fe—Mn—Al alloy club body  10  obtains greater coefficient of restitution and higher degrees of elastic deformation. In striking a golf ball, a part of the striking stress of the Ti alloy striking plate  20  may be transmitted to the Fe—Mn—Al alloy club body  10 . However, the Fe—Mn—Al alloy club body  10  performs higher elastic deformation and thus returns the complete striking stress to the Ti alloy striking plate  20 . Consequently, the combined member of the golf club head accomplishes the excellent striking ability and enhances the striking distance. Since the Fe—Mn—Al alloy club body  10  returns the complete striking stress to the Ti alloy striking plate  20 , the golf club head can avoid vibration and enhance gripping feel while striking a golf ball. Additionally, the golf club head reduces the possibility of generating cracks on the connection portion of the Fe—Mn—Al alloy club body  10  to the Ti alloy striking plate  20 .  
      Turning now to  FIGS. 5 and 6 , reference numerals of the second embodiment have applied the identical numerals of the first embodiment, as shown in  FIGS. 2 and 3 . The construction of the golf club head structure of the second embodiment has the similar configuration and same function as that of the first embodiment and the detailed descriptions are omitted.  
      Referring again to  FIGS. 5 and 6 , in comparison with the first embodiment, the Fe—Mn—Al alloy club body  10  of the second embodiment includes a compartment  14  at its underside. The compartment  14  is adapted to accommodate a weight member  30  for adjusting a center of gravity. In addition to the lower Young&#39;s modulus, the Fe—Mn—Al alloy club body  10  has excellent heterogeneous welding quality for different metals. In the assembling process, the weight member  30  is suitable for welding to the Fe—Mn—Al alloy club body  10  besides press fitting, brazing and punching. Thus, the welding the weight member  30  to the Fe—Mn—Al alloy club body  10  enhances combination strength, welding quality and processing time. Preferably, the welding process is selected from a group consisting of gas tungsten arc welding, brazing, laser beam welding, plasma arc welding and ion beam welding. Preferably, the weight member  30  is made of heavier material with specific gravity greater than 10.0 g/cm 3 , W alloy or W—Fe—Ni alloy for example. In comparison with the Fe—Mn—Al alloy material with specific gravity of 6.8 g/cm 3 , the heavier material of the weight member  30  can specifically lower a center of gravity.  
      Turning now to  FIG. 7 , reference numerals of the third embodiment have applied the identical numerals of the first embodiment, as shown in  FIGS. 2 and 3 . The construction of the golf club head structure of the third embodiment has the similar configuration and same function as that of the first embodiment and the detailed descriptions are omitted.  
      Referring again to  FIG. 7 , in comparison with the first and second embodiments, the Fe—Mn—Al alloy club body  10  of the third embodiment employs a solder ring  40  for brazing the Ti alloy striking plate  20 . The solder ring  40  is disposed on the shoulder  12  of the Fe—Mn—Al alloy club body  10  and sandwiched in between the Fe—Mn—Al alloy club body  10  and the Ti alloy striking plate  20 . In brazing, the solder ring  40  is pressed by the Ti alloy striking plate  20  and deformed in the opening  11  of the Fe—Mn—Al alloy club body  10 . Subsequently, the Fe—Mn—Al alloy club body  10  is heated to melt the solder ring  40  for brazing the Ti alloy striking plate  20 . Consequently, the combined member of the golf club head accomplishes the excellent striking ability and enhances the striking distance. As best shown in  FIGS. 5 and 6 , the Fe—Mn—Al alloy club body  10  of the third embodiment includes a compartment  14  or the like for accommodating a weight member  30 .  
      The conventional combined member of the club body and the striking plate may result in a reduction of the striking stress and considerable vibration. Referring back to  FIG. 3 , the combined member of the Fe—Mn—Al alloy club body  10  and the Ti alloy striking plate  20  accomplishes excellent heterogeneous welding, striking ability, striking stability, gripping feel and combination strength.  
      Although the invention has been described in detail with reference to its presently preferred embodiment, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.