Patent Publication Number: US-2006003852-A1

Title: Golf club head structure for casting in Fe-Mn-Al alloy

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a golf club head structure for casting in Fe—Mn—Al alloy. More particularly, the present invention relates to a golf club head structure consisting of a striking plate member and a weight member, wherein the striking plate member is cast in Fe—Mn—Al alloy to improve vibration-absorbable characteristic.  
      2. Description of the Related Art  
      Referring initially to  FIG. 1 , it illustrates a conventional golf club head structure casting in Fe—Mn—Al alloy. The golf club head is integrally formed with a club head body  10  which has a thickness generally greater than 5 mm that may deteriorate casting fluidity in slush casting. A striking plate  11  connects to a face portion of the club head body  10  for striking a golf ball (not shown) while a hosel  12  connecting to a side portion of the club head body  10  for receiving a shaft (not shown). The club head body  10  further includes a compartment  100  to accommodate a weight member  20 . A rear portion of the club head body  10  is recessed an undercut (not labeled) that provides with a space to permit the deformation of the striking plate  11  within the undercut.  
      Fe—Mn—Al alloy has highly low density, high coefficient of elasticity and high degree of hardness that performs excellently vibration-absorbable and highly heterogeneous-weldable characteristic. Hence, when Fe—Mn—Al alloy is employed to cast a golf club head, it can accomplish to lower a center of gravity, to improve striking ability and heterogeneous welding quality, and to enlarge striking surface area.  
      In slush casting, there are several problems of worse casting fluidity in a slurry shell and casting quality for casting in Fe—Mn—Al alloy due to changes in thickness and a complicated three-D structure of the club head body  10 . Inevitably, when Fe—Mn—Al alloy is employed to cast a casting of a golf club head, a finished product of the casting has many casting deficiencies of cold-shot, contraction cavities and slag-eye due to low casting fluidity in a slurry shell. Generally, the improvement of casting technology and cast molding system may eliminate deficiencies of cold-shot and slag bonding. As to the contraction cavity, a finishing and grinding process can eliminate it. However, when the contraction cavities are located in a complicated structure and an unbalanced thickness (such as an opening or an undercut) of the golf club head, it is hard to eliminate the contraction cavities by means of the finishing and grinding process. Consequently, the contraction cavities may be remained on the surface of the golf club head that may result in a decrease in the value of products. Thus, the applied scope of Fe—Mn—Al alloy in the industry is restricted and unsuitable for casting the golf club head. Hence, there is a need for a club head structure which is suitable for using Fe—Mn—Al alloy in slush casting.  
      To adjust a center of gravity of the golf club head, the club head body  10  must reserve the compartment  100  to fittingly accommodate the weight member  20  that the golf club head has a desired weight and a center of gravity. To reduce dimensions of the golf club head, the club head body  10  must be dimensioned as small as possible. Because of this task, it is preferable to size the weight member  20  as small as possible that cannot effectively adjust a center of gravity of the golf club head. However, the compartment  100  may complicate the structure of the club head body  10  that is unsuitable for slush casting. Namely, the structure of the club head body  10  is simplified by eliminating the compartment  100 . Hence, there is also a need for a simplified structure of the golf club head which is suitable for using Fe—Mn—Al alloy in slush casting.  
      The present invention intends to provide a golf club head structure consisting of a striking plate member and a weight member for casting in Fe—Mn—Al alloy. For better casting fluidity in a slurry shell, relative changes in thickness of a casting of the striking plate member are controlled in a particular ratio that aids low casting fluidity of molten iron in the slurry shell for casting in Fe—Mn—Al alloy to eliminate contraction cavities of the casting. Thereby, the golf club head structure for Fe—Mn—Al with excellently vibration-absorbable characteristic can enhance casting quality in such a way to mitigate and overcome the above problem.  
     SUMMARY OF THE INVENTION  
      The primary objective of this invention is to provide a golf club head structure for casting a striking plate member in Fe—Mn—Al alloy. A casting of the striking plate member employs a particular ratio of thickness that aids low casting fluidity of molten iron in a slurry shell for casting in Fe—Mn—Al alloy to eliminate contraction cavities of the casting. Thereby, the golf club head structure for Fe—Mn—Al with excellently vibration-absorbable characteristic can enhance casting quality.  
      The secondary objective of this invention is to provide the golf club head structure for casting a striking plate member in Fe—Mn—Al alloy. The striking plate member directly connects to a weight member to simplify the entire structure of the golf club head that may aids low casting fluidity of molten iron in the slurry shell for casting in Fe—Mn—Al alloy.  
      The golf club head structure in accordance with the present invention includes a striking plate member and a weight member connected thereto. The striking plate member is cast in Fe—Mn—Al alloy and integrally formed with a striking portion and a hosel portion so as to improve casting fluidity in the slurry shell and to eliminate contraction cavities. The weight member is made of high specific gravity material used to adjust a center of gravity of the golf club head.  
      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 an exploded perspective view of a conventional golf club head structure in accordance with the prior art;  
       FIG. 2  is an exploded perspective view of a golf club head structure in accordance with a preferred embodiment of the present invention;  
       FIG. 3  is a rear exploded perspective view of the golf club head structure in accordance with a preferred embodiment of the present invention;  
       FIG. 4  is a combined perspective view of the golf club head structure in a welding process in accordance with a preferred embodiment of the present invention; and  
       FIG. 5  is a perspective view of a finished product of the golf club head structure in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to  FIGS. 2 through 5 , reference numerals of the preferred embodiment of the present invention have applied the identical numerals of the conventional golf club head member, as shown in  FIG. 1 . The construction of the golf club head member in accordance with the preferred embodiment of the present invention has similar configuration and same function as that of the conventional golf club head member and detailed descriptions may be omitted.  
      Referring to  FIGS. 2 and 3 , a golf club head structure in accordance with a preferred embodiment of the present invention includes a striking plate member  10   a  and a weight member  10   b  to constitute a club head body  10 ′. Preferably, the striking plate member  10   a  is substantially shaped a spatula-like member while the weight member  10   b  being substantially shaped an irregular ring member.  
      The construction of the striking plate member  10   a  shall be described in detail. The striking plate member  10   a  is a front portion of the club head body  10 ′ integrally formed with a striking portion  11 ′ and a hosel portion  12 ′. In manufacture, the structure of the striking plate member  10   a  is suitable for Fe—Mn—Al alloy in slush casting. Preferably, the striking portion  11 ′ of the striking plate member  10   a  has a thickness smaller than 5 mm that may enhance casting fluidity in slush casting. A connection portion of the striking portion  11 ′ to the hosel portion  12 ′ has changes in thickness to improve casting fluidity in the slurry shell and casting quality. The combined member of the striking portion  11 ′ with the hosel portion  12 ′ has a minimum thickness and a maximum thickness respectively. Preferably, the ratio of the minimum thickness to the maximum thickness ranges between 0.56 and 1.00. When the striking plate member  10   a  is cast in a slurry shell (not shown) in Fe—Mn—Al alloy, the slurry shell has a cavity preformed a predetermined width that changes for corresponding to the ratio of the minimum thickness to the maximum thickness of the striking plate member  10   a.  Accordingly, pouring worse casting fluidity of molten iron of Fe—Mn—Al alloy into the slurry shell, the molten iron of Fe—Mn—Al alloy is able to pass through each width of the slurry shell without generating contraction cavities and slag-eye in a casting. Namely, since the changes in width of the slurry shell is confined, the worse casting fluidity of molten iron of Fe—Mn—Al alloy can reduce the possibility of remaining as less contraction cavities and slag-eye as possible in the striking plate member  10   a.  Thereby, low specific gravity of Fe—Mn—Al alloy is suitable for manufacturing the striking plate member  10   a  that may improve casting quality and products. Consequently, the striking plate member  10   a  performs low specific gravity (6.8 g/cm 3 ), excellently vibration-absorbable and highly heterogeneous-weldable characteristic, high coefficient of elasticity, and high degree of hardness.  
      Referring again to  FIGS. 2 and 3 , the construction of the weight member  10   b  shall be described in detail. The weight member  10   b  is a rear portion of the club head body  10 ′ formed an opening  13  that is adapted to permit the deformation of the striking portion  11 ′ of the striking plate member  10   a  therein while striking a golf ball. The weight member  10   b  is made of metal material with high specific gravity (about 10.0 g/cm 3 ). Preferably, the metal material for the weight member  10   b  is tungsten alloy or W—Fe—Ni alloy. The total weight of the weight member  10   b  is greater than that of the striking plate member  10   a.  The construction of the weight member  10   b  consists of a top portion and a bottom portion greater than the top portion that considerably lowers a center of gravity of the club head body  10 ′ to thereby improve striking ability and distance. To accomplish various design choices, the desired weight member  10   b  is made of various specific weights for metal or alloy material selected from a group consisting of stainless steel, low-carbon steel, alloy steel or other steel.  
      Turning now to  FIGS. 4 and 5 , it illustrates a combined club head body in accordance with the preferred embodiment of the present invention. To prevent deformation and cracks of the club head members, the club head body  10 ′ is formed by welding the striking plate member  10   a  to the weight member  10   b  instead of press-fitting the striking plate member  10   a  in the weight member  10   b.  In welding process, the present invention employs a nickel-welding rod and a current of a welding torch preferably ranges from 100 A to 150 A that may improve heterogeneous-weldable characteristic. Further, welding process can be selected from a group consisting of gas tungsten arc welding, brazing, laser beam welding, plasma arc welding and ion beam welding. After welding, a rear surface of the striking plate member  10   a  securely connects to the weight member  10   b  and a welding line  14  is remained therebetween. Subsequently, precision finishing on the welding line  14  and the surface of the club head body  10 ′ can obtain a finished product of the club head body  10 ′. Alternatively, each of the striking plate member  10   a  and the weight member  10   b  provides with a predetermined processing area for precision finishing.  
      Referring back to  FIG. 1 , the conventional club head structure results in generating contraction cavities and slag-eye remained in a casting. However, as best shown in  FIG. 2 , the present invention employs a single member of the striking plate member  10   a  made of Fe—Mn—Al alloy so that it can avoid generating contraction cavities and slag-eye in the striking plate member  10   a,  and perform excellently vibration-absorbable characteristic of Fe—Mn—Al alloy. Consequently, the club head structure in accordance with the present invention accomplishes casting quality of the club head body  10 ′.  
      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.