Patent Publication Number: US-2006014593-A1

Title: Golf club head structure for improving casting fluidity in a slurry shell

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a golf club head structure for improving casting fluidity in a slurry shell. More particularly, the present invention relates to a golf club head structure consisting of two adjacent portions having changes in thickness to improve casting fluidity in a slurry shell and casting quality.  
      2. Description of the Related Art  
      Fe—Mn—Al alloy has highly low density, excellently vibration-absorbable and high degree of hardness. Casting a golf club head with Fe—Mn—Al alloy, the center of gravity of the golf club head may be lowered, and a striking surface area and dimensions of the golf club head may be increased. In slush casting, 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.  
      The present invention intends to provide a golf club head structure for a casting consisting of two adjacent portions having changes in thickness to improve casting fluidity in a slurry shell and casting quality. In slush casting, the ratio of width of the slurry shell allows the fluent passage of molten iron of Fe—Mn—Al alloy to eliminate contraction cavities and slag-eyes in a casting 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 improving casting fluidity in a slurry shell. The golf club head structure consists of two adjacent portions having changes in thickness corresponding to changes in width of the slurry shell to thereby avoid generating contraction cavities and slag-eyes in a casting.  
      The golf club head structure in accordance with the present invention includes a first portion and a second portion adjacent thereto. The first portion and the second portion have a first thickness and a second thickness respectively. The ratio of the first thickness to the second thickness ranges between 0.56 and 1.00 that may enhance casting fluidity of molten iron in a slurry shell to thereby reduce the possibility of generating contraction cavities and slag-eyes in 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 a cross-sectional view of a golf club head structure for improving casting fluidity in a slurry shell in accordance with a first embodiment of the present invention;  
       FIG. 2  is an enlarged cross-sectional view, in  FIG. 1 , of the golf club head structure in accordance with the first embodiment of the present invention;  
       FIG. 3  is a cross-sectional view of the slurry shell for the golf club head structure in accordance with the first embodiment of the present invention;  
       FIG. 4  is an enlarged cross-sectional view, in  FIG. 3 , of the slurry shell for the golf club head structure in accordance with the first embodiment of the present invention;  
       FIG. 5  is a lateral schematic view of a golf club head structure for improving casting fluidity in the slurry shell in accordance with a second embodiment of the present invention;  
       FIG. 6  is an enlarged lateral view, in  FIG. 5 , of the golf club head structure in accordance with the second embodiment of the present invention;  
       FIG. 7  is a cross-sectional view of a golf club head structure for improving casting fluidity in the slurry shell in accordance with a third embodiment of the present invention; and  
       FIG. 8  is enlarged cross-sectional view, in  FIG. 7 , of the golf club head structure in accordance with the third embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring initially to  FIGS. 1 through 4 , a golf club head structure in accordance with a first embodiment of the present invention includes a club head body  10  pertaining to an iron-type club head integrally formed with a single member and made of Fe—Mn—Al alloy. The single member of the club head body  10  includes an annular flange  11 , a flat plate portion  12 , a weight portion  13  and a compartment  14 . In assembling, the compartment  14  is adapted to receive a weight member  15  for adjusting a center of gravity of the club head body  10 . Each of the club head sections has two adjacent portions gradually changing in thickness, a connecting portion of the flat plate portion  12  to the annular flange  11  or the flat plate portion  12  to the weight portion  13  for example.  
      Referring again to  FIG. 3 , a slurry shell  20  can be made by dewaxing a wax pattern (not shown) of the club head body  10 . The construction of the slurry shell  20  has a cavity  21  configured with an inner space corresponding to an outer predetermined shape of the club head body  10 . Consequently, the club head body  10  can be obtained by pouring molten iron of Fe—Mn—Al alloy into the cavity  21  of the slurry shell  20 .  
      Referring back to  FIGS. 2 and 4 , in slush casting, the club head body  10  should avoid generating contraction cavities and slag-eyes in a casting formed in the cavity  21  of the slurry shell  20 . To accomplish this task, the cavity  21  of the slurry shell  20  has two adjacent portions with respect to a reference point (shown at “a”) changing in width. The ratio of the two widths of the any two adjacent portions ranges between 0.56 to 1.00 that may improve casting fluidity in the slurry shell  20 .  
      Referring again to  FIG. 2 , a boundary between the flat plate portion  12  and the annular flange  11  of the club head body  10  has changes in thickness. The flat plate portion  12  has a thickness t 1  (a thinner thickness) while the annular flange  11  having a thickness t 2  (a thicker thickness). As best shown in  FIG. 4 , the cavity  21  of the slurry shell  20  correspondingly includes a first width t 1  (a thinner width) and a second width t 2  (a thicker width). The ratio of the first width t 1  to the second width t 2  of the cavity  21  ranges between 0.56 and 1.00. In slush casting, molten iron of Fe—Mn—Al alloy may fluently pass through any two adjacent portions of the cavity  21  of the slurry shell  20  since the cavity  21  has such changes in width for enhancing casting fluidity of molten iron. Consequently, the structure of the club head body  10  accomplishes to enhance casting fluidity of Fe—Mn—Al alloy that further carries out to avoid generating contraction cavities and slag-eyes in the club head body  10  and to improve casting quality.  
      Referring back to  FIG. 4 , the thickness of the annular flange  11 , the flat plate portion  12 , the weight portion  13  and the compartment  14  preferably ranges from 2 mm to 6 mm and more preferably from 2 mm to 4 mm, excluding the hosel (not labeled). Consequently, such thickness can reduce the possibility of generating contraction cavities and slag-eyes in the club head body  10 .  
      By contrast, the conventional club head body is made of stainless steel having density of 7.8 g/cm 3 . The club head body  10  in accordance with the present invention is suitable for Fe—Mn—Al alloy having lower density of 6.8 g/cm 3  that can reduce 15% of weight and further lower a center of gravity. To adjust a center of gravity, the weight member  15  (density of 10.0 g/cm 3 ) received in the compartment  14  is added for maintaining total weight of the club head body  10 .  
      In consideration of the thickness ranging from 2 mm to 6 mm, the club head body  10  is unsuitable for press-fitting or snap-fitting the weight member  15  into the compartment  14 . To prevent deformation and cracks of the club head body  10 , the weight member  15  preferably connects to the compartment  14  of the club head body  10  by welding. In welding process, the present invention employs a nickel-welding material and a current of a welding torch preferably ranges from 100 A to 150 A that may improve heterogeneous-weldable characteristic.  
      Turning now to  FIGS. 5 and 6 , reference numerals of the second embodiment of the present invention have applied the identical numerals of the first embodiment. The construction of the golf club head member in accordance with the second embodiment of the present invention has similar configuration and same function as that of the first embodiment and detailed descriptions may be omitted.  
      Referring to  FIGS. 5 and 6 , a golf club head structure in accordance with a second embodiment of the present invention includes a club head body  10  pertaining to a pitching wedge or a sand wedge integrally formed with a single member and made of Fe—Mn—Al alloy. In comparison with the first embodiment, the club head body  10  of the second embodiment includes a flat plate portion  12  and a weight portion  13 . A thickness of the club head body  10  preferably ranges from 2 mm to 17 mm, excluding the hosel (not labeled). As best shown in  FIG. 6 , a boundary between the flat plate portion  12  and the weight portion  13  of the club head body  10  has changes in thickness. There exists a reference point (shown at “a”) changing in thickness for enhancing casting fluidity in a slurry shell (not shown). The flat plate portion  12  has a thickness t 1  (a thinner thickness) while the weight portion  13  having a thickness t 2  (a thicker thickness). The ratio of the first thickness t 1  to the second thickness t 2  ranges between 0.56 and 1.00. In slush casting, molten iron of Fe—Mn—Al alloy may fluently pass through any two adjacent portions of the cavity of the slurry shell. Consequently, such thickness can reduce the possibility of generating contraction cavities and slag-eyes in the club head body  10 . In particular, the entire weight portion  13  of the club head body  10  has any two adjacent portions to confine changes in thickness ranging between 0.56 and 1.00.  
      Turning now to  FIGS. 7 and 8 , a golf club head structure in accordance with a third embodiment of the present invention includes a club head body  30  pertaining to a wood-type club head formed with a single member and made of Fe—Mn—Al alloy. In comparison with the first embodiment, the club head body  30  of the third embodiment consists of a main body  31 , a front opening  32  and a stepped portion  33 , and the front opening  32  is adapted to connect to a striking plate (not shown). A thickness of the club head body  30  preferably ranges from 1 mm to 3 mm, excluding the hosel (not labeled). As best shown in  FIG. 8 , a boundary between the main body  31  and the stepped portion  33  of the club head body  30  has changes in thickness. There exists a reference point (shown at “a”) changing in thickness for enhancing casting fluidity in a slurry shell (not shown). The stepped portion  33  has a thickness t 1  (a thinner thickness) while the main body  31  having a thickness t 2  (a thicker thickness). The ratio of the first thickness t 1  to the second thickness t 2  ranges between 0.56 and 1.00. In slush casting, molten iron of Fe—Mn—Al alloy may fluently pass through any two adjacent portions of the cavity of the slurry shell. Consequently, such thickness can reduce the possibility of generating contraction cavities and slag-eyes in the club head body  10 .  
      To prevent deformation and cracks of the club head members, the thiner stepped portion  33  of the club head body  30  connects to an outer periphery of a striking plate by welding instead of press-fitting the striking plate into the front opening  31 .  
      In slush casting, the conventional structure of the club head casting in Fe—Mn—Al alloy results in generating contraction cavities and slag-eyes. However, the golf club head in accordance with the present invention has any two adjacent portions having changes in thickness to improve casting fluidity in a slurry shell and casting quality.  
      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.