Patent Publication Number: US-7713140-B2

Title: Golf club head with variable face thickness

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
   The Present Application is a continuation application of U.S. patent application Ser. No. 11/928,318, filed on Oct. 30, 2007, now U.S. Pat. No. 7,448,960 which is a continuation application of U.S. patent application Ser. No. 11/841,384, filed on Aug. 20, 2007, now U.S. Pat. No. 7,422,528, which is a continuation application of U.S. patent application Ser. No. 11/469,742, filed on Sep. 1, 2006, now U.S. Pat. No. 7,258,626, which is a continuation application of U.S. patent application Ser. No. 10/904,332, filed on Nov. 4, 2004, now U.S. Pat. No. 7,101,289, which is a continuation-in-part application of U.S. patent application Ser. No. 10/711,825, filed on Oct. 7, 2004, and now U.S. Pat. No. 7,137,907. 

   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a golf club head with variable face thickness. 
   2. Description of the Related Art 
   Conventional golf club head designs are limited with regard to the maximum face area, both physical and practical limitations. The physical limitation is due to the golf club head having insufficient mass to both increase the length and width of the golf club head and also to increase the face size without exceeding the upper range of the preferred total golf club head mass. Such mass distributions are dependent on minimum wall thickness values required to achieve acceptable in-service durability. 
   Further, the thinning of the face thickness of a large face area golf club head will result in a golf club head that does not conform with the United States Golf Association&#39;s “Pendulum Test” which measures the characteristic time of the golf club head. The characteristic time is the contact time between metal mass attached to a pendulum that strikes the face center of the golf club head at a low speed. The limit is 239 microseconds with a test tolerance of 18 microseconds. The United States Golf Association (“USGA”) states that this characteristic time corresponds to a coefficient of restitution of 0.822 with a test tolerance of 0.008. 
   Uniformly increasing the thickness of the face portion typically requires the addition of large amounts of material to adequately reduce the stress sufficient to prevent impact and/or fatigue cracking. However, the addition of such a large amount of material to a face generally adversely affects the performance of the golf club. 
   One of the first patents to disclose variable face thickness was U.S. Pat. No. 5,318,300 to Schmidt et al., for a Metal Wood Golf Club With Variable Faceplate Thickness which was filed on Nov. 2, 1992. Schmidt et al discloses thickening the faceplate to prevent cracking. 
   A further disclosure of variable face thickness is disclosed in U.S. Pat. No. 5,830,084 to Kosmatka for a Contoured Golf Club Face which was filed on Oct. 23, 1996. Kosmatka addresses contouring the face to thicken certain regions while thinning other regions depending on the stress load experienced by such regions. Kosmatka also discloses a method for designing a face plate according to measured stress levels experienced during impact with a golf ball. Kosmatka, U.S. Pat. No. 5,971,868 for a Contoured Back Surface Of Golf Club Face, filed on Nov. 18, 1997, discloses similar contouring for an iron. 
   A more recent disclosure is Noble et al., U.S. Pat. No. 5,954,596, for a Golf Club Head With Reinforced Front Wall, which was filed on Dec. 4, 1997. Noble et al. discloses a face plate with the thickness portion at the geometric center, and gradually decreasing toward the top and bottom, and the sole and heel. The top and bottom ends along a line through geometric center have the same thickness, and the heel and sole ends along a line through geometric center have the same thickness. 
   Other references make partial disclosure of varying face thickness. One example is FIG. 8 of U.S. Pat. No. 5,505,453 which illustrates an interior surface of a face with a bulging center and decreasing thickness towards the heel and sole ends, similar to Noble et al. Another example is FIGS. 4C and 4D of U.S. Pat. No. 5,346,216 which discloses a bulging center that decreases in thickness toward the heel and sole ends, and the top and bottom end of the face, similar to Noble et al. However, the prior art has failed to design a face or face plate that varies the thickness according to predicted golf ball impact points on the face. 
   What is needed is a light weight face that conforms to the USGA characteristic time test. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is directed at a face with variable thickness that allows for a light-weight face or face insert that conforms to the USGA characteristic time test. The present invention is able to accomplish this by providing a interior surface that has a first thickness section and a second thickness region. 
   One aspect of the present invention is a golf club head including a body and a face. The body has a crown, a sole, and a hollow interior. The face is disposed on the body. The face comprises a perimeter section, a heel vertical section, a toe-vertical section and a central horizontal section connected to each of the heel vertical section and toe vertical section. The face also comprises an upper central region, a lower central region, a heel region and a toe region. Each of the perimeter section, the heel vertical section, the toe-vertical section and the central horizontal section has a first thickness and each of the upper central region, the lower central region, the heel region and the toe region has a second thickness. The first thickness is greater than the second thickness by at least 0.025 inch. 
   Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a plan isolated view of a preferred embodiment of an interior surface of a face of the present invention. 
       FIG. 1A  is a plan isolated view of a preferred embodiment of an interior surface of a face of the present invention. 
       FIG. 2  is a plan isolated view of an alternative embodiment of an interior surface of a face of the present invention. 
       FIG. 2A  is a plan isolated view of an alternative embodiment of an interior surface of a face of the present invention. 
       FIG. 3  is an exploded top perspective view of a golf club head. 
       FIG. 4  is a front view of a golf club head of  FIG. 3 . 
       FIG. 5  is a rear view of a golf club head of  FIG. 3 . 
       FIG. 6  is a front view of the body of a golf club head of  FIG. 3 . 
       FIG. 6A  is a cross-sectional view taken along the line  6 A- 6 A of  FIG. 6 . 
       FIG. 7  is a top plan view of a golf club head illustrating the Y axis and X axis. 
       FIG. 8  is a front view of a golf club head. 
       FIG. 9  is a front plan view of a golf club head of the present invention illustrating the Z axis and Y axis. 
       FIG. 10  is a heel side plan view of a golf club of the present invention illustrating the Z axis and X axis. 
       FIG. 11  is a toe side view of the golf club head of  FIG. 3 . 
       FIG. 12  is a bottom plan view of the golf club head of  FIG. 3 . 
       FIG. 13  is an exploded top perspective of a golf club head of according to the fourth embodiment of the present invention. 
       FIG. 14  is a toe side view of the golf club head of  FIG. 13 . 
       FIG. 15  is a heel side view of the golf club head of  FIG. 13 . 
       FIG. 16  is an exploded top perspective of the golf club head according to the fifth embodiment of the present invention. 
       FIG. 17  is a bottom plan view of the golf club head of  FIG. 16 . 
       FIG. 18  is a top plan view of the golf club head of  FIG. 16 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention is directed at a face for a wood-type golf club head. The face or face insert is generally designated  40 . As shown in  FIG. 1 , a preferred embodiment of the face  40  has a first thickness section  200  in the shape of a cross and a second thickness region  205  defining an interior surface  40   b  of the face  40 . A transition portion  210  is disposed between the first thickness section  200  and the second thickness region  205 . 
   Preferably, the first thickness section  200  has a thickness ranging from 0.100 inch to 0.200 inch, and more preferably from 0.125 inch to 0.165 inch, and most preferably approximately 0.155 inch. The second thickness region  205  preferably has a thickness ranging from 0.030 inch to 0.090 inch, more preferably from 0.050 inch to 0.070 inch, and most preferably 0.060 inch. The transition portion  210  preferably has a thickness that tapers from the thickness of the first thickness section  200  to the thickness of the second thickness region  205  to allow for a smooth contouring interior surface  40   b  as opposed to a surface with ribs. 
   Also in a preferred embodiment, the first thickness section  200  has a thickness that is at least 0.025 inch greater than the thickness of the second thickness region  205 . More preferably, the first thickness section  200  has a thickness that is at least 0.050 inch greater than the thickness of the second thickness region  205 . Even more preferably, the first thickness section  200  has a thickness that is at least 0.075 inch greater than the thickness of the second thickness region  205 . Yet even more preferably, the first thickness section  200  has a thickness that is at least 0.090 inch greater than the thickness of the second thickness region  205 . 
   The thickness within the first thickness section  200  is preferably uniform. However, in an alternative embodiment, the thickness within the first thickness section  200  preferably varies up to 0.020 inch, more preferably up to 0.010 inch, and most preferably up to 0.005 inch. The thickness within the second thickness region  205  is preferably uniform. However, in an alternative embodiment, the thickness within the second thickness region  205  preferably varies up to 0.020 inch, more preferably up to 0.010 inch, and most preferably up to 0.005 inch. 
   The face or face insert  40  has a perimeter  240  with a top perimeter line  240   a  and a bottom perimeter line  240   b . As shown in  FIG. 1 , the face  40  preferably has a width, “Wf”, that preferably ranges from 3.50 inches to 5.00 inches, and a height, “Hf”, that preferably ranges from 1.80 inches to 2.50 inches. The center of the face  40  is generally designated point  300 . The face preferably has a mass ranging from 25 grams to 40 grams and most preferably 29 grams. 
   An alternative embodiment wherein the first thickness section  200  has a “X” shape is shown in  FIG. 2 . In this embodiment of the face  40 , the first thickness section  200 , the second thickness region  205  and the transition portion  210  have the same dimensions as discussed above in reference to the embodiment shown in  FIG. 1 . 
   As shown in  FIG. 1A , the first thickness section  200  preferably includes upper extension section  350   a , lower extension section  350   b , heel extension section  350   c , toe extension section  350   d  and central section  350   e . The second thickness region  205  preferably includes an upper toe region  330 , an upper heel region  332 , a lower heel region  334  and a lower toe region  236 . The first thickness section also preferably includes upper heel perimeter section  352   a , lower heel perimeter section  352   b , upper toe perimeter section  352   c  and lower toe section  352   d . Each of the perimeter sections  352   a - d  defines the perimeter of the face  40  and also partially define each of the second thickness regions  330 ,  332 ,  334  and  336 . 
   As shown in  FIG. 1A , the transition portion  210  preferably includes a transition upper toe portion  360 , a transition upper heel portion  361 , a transition lower heel portion  362  and a transition lower toe portion  363 . Each of the transition portions  210  has a width from 0.05 inch to 0.15 inch, more preferably from 0.07 inch to 0.11 inch, and most preferably 0.09 inch. 
   As shown in  FIG. 2A , the first thickness section  200  preferably includes a toe vertical section  220 , a heel vertical section  222  and a central horizontal section  224 . The heel vertical section  220  and the toe vertical section  222  preferable extend from the top perimeter  240   a  of the face  40  to the bottom perimeter  240   b  of the face  40 . The central horizontal section  224  extends between the toe vertical section  220  and the heel vertical section  222 , preferably about the face center  300 . In a preferred embodiment, each of the toe vertical section  220  and the heel vertical section  222  has a top end  250   a  and  250   b  and bottom end  252   a  and  252   b . The width of each of the toe vertical section  220  and the heel vertical section  222 . “Wv”, as shown in  FIG. 2A , preferably ranges from 0.15 inch to 0.50 inch, more preferably from 0.20 inch to 0.35 inch, and most preferably 0.275 inch. The first thickness section  200  also preferably includes heel perimeter section  270   a , upper perimeter section  270   b , toe perimeter section  270   c  and lower perimeter section  270   d . Each of the perimeter sections  270   a - d  defines the perimeter of the face  40  and also partially define each of the second thickness regions  230 ,  232 ,  234  and  236 . 
   As shown in  FIG. 2A , the second thickness region  205  preferably includes an upper central region  230 , a lower central region  232 , a toe region  234  and a heel region  236 . 
   Each of the upper central region  230  and the lower central region are larger in area than each of the toe region  234  and the heel region  236 . 
   As shown in  FIG. 2A , the transition portion  210  preferably includes a transition toe portion  260 , a transition heel portion  261 , a transition lower portion  262  and a transition upper portion  263 . Each of the transition portions  210  has a width from 0.05 inch to 0.15 inch, more preferably from 0.07 inch to 0.11 inch, and most preferably 0.09 inch. 
   The face or face insert  40  is used with various golf club heads. A preferred embodiment of a golf club head is illustrated in  FIGS. 3-10 . Alternative embodiments of golf club heads are illustrated in  FIGS. 11-18 . Although three embodiments are illustrated, those skilled in the pertinent art will recognize from this disclosure that other embodiments of the golf club head using a face or face insert of the present invention are possible without departing from the scope and spirit of the present invention. 
   A golf club head is generally designated  20 . The golf club head  20  has a body  22 , which includes a crown  24 , a sole  26 , a ribbon  28 , a front wall  30  and a hollow interior  34 . The golf club head  20  has a heel end  36 , a toe end  38 , and an aft end  37 . 
   The golf club head  20 , when designed as a driver, preferably has a volume from 200 cubic centimeters to 600 cubic centimeters, more preferably from 300 cubic centimeters to 500 cubic centimeters, and most preferably from 385 cubic centimeters to 475 cubic centimeters. The golf club head  20  preferably has a mass no more than 250 grams, and most preferably a mass of 170 to 250 grams. 
   As shown in  FIGS. 3-10 , in one embodiment of the golf club head  20 , the front wall  30  has an opening  32  and preferably a recessed portion  33 . The face insert  40  is disposed within the opening  32 . The ribbon  28  of the body  22  has an aft-recess  52  located opposite of the face insert  40 , and a rear weighting member  50  is disposed within the aft-recess  52 . The body  22  is preferably composed of a non-metal material, preferably a composite material such as a continuous fiber pre-preg material (including thermosetting materials or a thermoplastic materials for the resin). Other materials for the body  22  include thermosetting materials or thermoplastic materials such as injectable plastics. The body  22  is preferably manufactured through bladder-molding, resin transfer molding, resin infusion, injection molding, compression molding, or a similar process. Alternatively, the body  22  may be composed of a lightweight metallic material, such as magnesium alloys, aluminum alloys, magnesium, aluminum, titanium, titanium alloys, or other low density metals. The body  22  may also be composed of a steel such as stainless steel or other steel alloys. 
   The face insert  40  is attached to the body  22  over the opening  32  of the front wall  30 . Preferably the face insert  40  is positioned over and attached to the recessed portion  33  of the front wall  30 . 
   The face insert  40  is preferably composed of a formed metal material. However, the face insert  40  may also be composed of a machined metal material, a forged metal material, a cast metal material or the like. The face insert  40  preferably is composed of a titanium or steel material. Titanium materials suitable for the face insert  40  include pure titanium and titanium alloys. Other metals for the face insert  40  include high strength steel alloy metals and amorphous metals. The exterior surface  40   a  of the face insert  40  typically has a plurality of scorelines thereon, not shown. 
   The face insert  40  is preferably co-molded with the body  22  or press-fitted into the opening  32  subsequent to fabrication of the body  22 . In another attachment process, the body  22  is first bladder molded and then the face insert  40  is bonded to the recessed portion  33  of the front wall  30  using an adhesive. The adhesive is placed on the exterior surface of the recessed portion  33 . Such adhesives include thermosetting adhesives in a liquid or a film medium. In yet another attachment process, the body  22  is first bladder molded and then the face insert  40  is mechanically secured to the body  22 . Those skilled in the pertinent art will recognize that other methods for attachment of the face insert  40  to the body  22  may be composed without departing from the scope and spirit of the present invention. 
   As mentioned above, the non-metallic body  22  is preferably composed of a plurality of plies of pre-preg, typically six or seven plies (preferably ranging from three plies to twenty plies) such as disclosed in U.S. Pat. No. 6,248,025, entitled Composite Golf Head And Method Of Manufacturing, which is hereby incorporated by reference in its entirety. In such an embodiment, the crown  24 , the sole  26  and the ribbon  28  preferably range in thickness from 0.010 inch to 0.100 inch, more preferably from 0.025 inch to 0.070 inch, even more preferably from 0.028 inch to 0.040 inch, and most preferably have a thickness of 0.033 inch. The front wall  30  preferably has a thickness greater than the thickness of the crown  24 , sole  26  or ribbon  28 . The thickness of the front wall preferably ranges from 0.030 to 0.150 inch, more preferably from 0.050 inch to 0.100 inch, even more preferably from 0.070 inch to 0.090 inch, and most preferably the front wall  30  has a thickness of 0.080 inch. 
     FIGS. 6 and 6A  best illustrate the hollow interior  34  of the club head  20 . As shown in  FIGS. 6 and 6A , the recessed portion  33  of the front wall  30  encompasses the opening  32  forming a support for placement and attachment of the face insert  40  thereon. The front wall  30  has a shoulder  75  that preferably engages a perimeter  77  of the face insert  40 . A portion of the interior surface of the face insert  40  will engage the exterior surface of the recessed portion  33  of the front wall  30 . The thickness of the recessed portion  33  of the front wall  30  is preferably thicker than the crown  24 , the sole  26  or the ribbon  28 . 
   Also shown in  FIG. 6A  is the hosel  57 , which is disposed within the hollow interior  34 , and is located near the heel end  36 . The hosel  57  is preferably composed of an aluminum material, and preferably has a mass ranging from 3 to 10 grams, more preferably from 4 to 8 grams, and most preferably has a mass of 6 grams. Alternatively, the hosel  57  may be composed of a strong polymer material such as a urethane or ABS material. A shaft, not shown, is disposed within the hosel  57  through a bore  55  in the crown  24 . A hosel insert, not shown, is preferably used to interface between the shaft and the hosel  57 . Such a hosel insert is described in U.S. Pat. No. 6,352,482, entitled Golf Club With Hosel Liner, which pertinent parts are hereby incorporated by reference. The hosel  57  is preferably positioned in a hosel base  59  and extends from the sole  26  to the crown  24 . However, those skilled within the pertinent art will recognize that the hosel need not extend all the way to the side  26  and may also extend outside of the body  22  without departing from the scope and spirit of the present invention. 
   Also shown in  FIGS. 6 and 6   a  are the walls of the aft recess  52 . The aft recess  52  preferably extends into the hollow interior  34  forming an aft recess projection  52   a . The aft recess  52  is preferably defined by upper recess wall  54 , main recess wall  56  and lower recess wall  58 . The rear weighting member  50  is positioned within the aft recess  52 , as best shown in  FIG. 3 . 
   The rear weighting member  50  is preferably composed of a metal material such as steel, steel alloys, brass, tungsten, tungsten alloys, or other high density materials. The rear weighting member  50  is preferably co-molded with a body  22  or press-fitted within the aft recess  52  subsequent to fabrication of the body  22 . In another attachment process, the body  22  is first bladder molded and then the rear weighting member  50  is bonded within the aft recess  52  using an adhesive. 
   A second embodiment of the golf club head  20  is shown in  FIGS. 13-15 , such as disclosed in U.S. Pat. No. 6,565,452, for a Multiple Material Golf Club Head with Face Insert, filed on Feb. 28, 2002, and is hereby incorporated by reference in its entirety. In this embodiment, the golf club head  20 , a face component  60  and an aft-body  61 . The face component  60  has a face cup and has a separate face insert  40 , which is placed within an opening  45  of a face cup  74 . The aft-body  61  has a crown portion  62  and a sole portion  64 . 
   The face cup  74  has a return portion  63  that extends laterally rearward from the perimeter  73  of the front wall. The face insert  40  is joined to the face cup  74  of the face component  60  in a manufacturing process discussed in co-pending U.S. application Ser. No. 10/710,143, entitled Method for Processing a Golf Club Head with Cup Shaped Face Component, filed on Jun. 22, 2004, and hereby incorporated by reference in its entirety. 
   The return portion  63  of the face cup preferably includes an upper lateral section  76 , a lower lateral section  78 , a heel lateral section  80  and a toe lateral section  82 . Thus, the return portion  63  preferably encircles the face insert  40  a full 360 degrees. However, those skilled in the pertinent art will recognize that the return portion  63  may only encompass a partial section of the face insert  40 , such as 270 degrees or 180 degrees, and may also be discontinuous. 
   The upper lateral section  76  extends rearward, towards the aft-body  61 , a predetermined distance, d, to engage the crown  62 . In a preferred embodiment, the predetermined distance ranges from 0.2 inch to 1.0 inch, more preferably 0.40 inch to 0.75 inch, and most preferably 0.68 inch, as measured from the perimeter  73  of the face insert  40  to the rearward edge of the upper lateral section  76 . In a preferred embodiment, the upper lateral section  76  has a general curvature from the heel end  36  to the toe end  38 . The upper lateral section  76  has a length from the perimeter  73  of the face insert  40  that is preferably a minimal length near the center of the face insert  40 , and increases toward the toe end  38  and the heel end  36 . However, those skilled in the relevant art will recognize that the minimal length may be at the heel end  36  or the toe end  38 . 
   The face component  60  engages the crown portion  62  of the aft-body  61  along a substantially horizontal plane. The crown portion  62  has a crown undercut portion  62   a , which is placed under the return portion  63 . Such an engagement enhances the flexibility of the face insert  40  allowing for a greater coefficient of restitution. The crown portion  62  of the aft-body  61  and the upper lateral section  76  of the face component  60  are attached to each other as further explained below. 
   The heel lateral section  80  is substantially perpendicular to the face insert  40 , and the heel lateral section  80  covers the hosel  57  before engaging an optional ribbon section  90  and a bottom section  91  of the sole portion  64  of the aft-body  61 . The heel lateral section  80  is attached to the sole portion  64 , both the ribbon  28  and the bottom section  91 , as explained in greater detail below. The heel lateral section  80  extends inward a distance, d′″, from the perimeter  73  a distance of 0.250 inch to 1.50 inches, more preferably 0.50 inch to 1.0 inch, and most preferably 0.950 inch. The heel lateral section  80  preferably has a general curvature at its edge. 
   At the other end of the face component  60  is the toe lateral section  82 . The toe lateral section  82  is attached to the sole portion  64 , both the ribbon  28  and the bottom section  91 , as explained in greater detail below. The toe lateral section  82  extends inward a distance, d″, from the perimeter  73  a distance of 0.250 inch to 1.50 inches, more preferably 0.75 inch to 1.30 inch, and most preferably 1.20 inch. The toe lateral section  82  preferably has a general curvature at its edge. 
   The lower lateral section  78  of the face component  60  extends inward, toward the aft-body  61 , a predetermined distance to engage the sole portion  64 . In a preferred embodiment, the predetermined distance ranges from 0.2 inch to 1.25 inches, more preferably 0.50 inch to 1.10 inch, and most preferably 0.9 inch, as measured from the perimeter  73  of the face insert  40  to the edge of the lower lateral section  78 . In a preferred embodiment, the lower lateral section  78  has a general curvature from the heel end  36  to the toe end  38 . The lower lateral section  78  has a length from the perimeter  73  of the face section  72  that is preferably a minimal length near the center of the face section  40 , and increases toward the toe end  38  and the heel end  36 . 
   The sole portion  64  has a sole undercut  64   a  for placement under the return portion  63 . The sole  64  and the lower lateral section  78 , the heel lateral section  80  and the toe lateral section  82  are attached to each other as explained in greater detail below. 
   The aft-body  61  is preferably composed of a non-metal material, preferably a composite material such as continuous fiber pre-preg material (including thermosetting materials or a thermoplastic materials for the resin). Other materials for the aft-body  61  include other thermosetting materials or other thermoplastic materials such as injectable plastics. The aft-body  61  is preferably manufactured through bladder-molding, resin transfer molding, resin infusion, injection molding, compression molding, or a similar process. Alternatively, the aft-body may be composed of a metallic material such as magnesium, titanium, stainless steel, or any other steel or titanium alloy. 
   The crown portion  62  of the aft-body  61  is generally convex toward the sole portion  64 , and engages the ribbon section  90  of sole portion  64  outside of the engagement with the face member  60 . Those skilled in the pertinent art will recognize that the sole portion  64  may not have a ribbon section  90 . The crown portion  62  preferably has a thickness in the range of 0.010 to 0.100 inch, more preferably in the range of 0.025 inch to 0.070 inch, even more preferably in the range of 0.028 inch to 0.040 inch, and most preferably has a thickness of 0.033 inch. The sole portion  64 , including the bottom section  91  and the optional ribbon section  90  which is substantially perpendicular to the bottom section  91 , preferably has a thickness in the range of 0.010 to 0.100 inch, more preferably in the range of 0.025 inch to 0.070 inch, even more preferably in the range of 0.028 inch to 0.040 inch, and most preferably has a thickness of 0.033 inch. 
   The assembled face component  60  may then be attached to the aft body  61 . The face component  60 , with an adhesive on the interior surface of the return portion  63 , is placed within a mold with a preform of the aft-body  61  for bladder molding. The return portion  63  is placed and fitted into the undercut portions  62   a  and  64   a . Also, the adhesive may be placed on the undercut portions  62   a  and  64   a . Such adhesives include thermosetting adhesives in a liquid or a film medium. During this attachment process, a bladder is placed within the hollow interior of the preform and face component  60 , and is pressurized within the mold, which is also subject to heating. The co-molding process secures the aft-body  61  to the face component  60 . In another attachment process, the aft-body  61  is first bladder molded and then is bonded to the face component  60  using an adhesive, or mechanically secured to the return portion  63 . 
   A third embodiment of the golf club head  20  is shown in  FIGS. 16-18 . In this embodiment, the golf club head  20  includes a body  22 , a face  40  a weighting frame  42 , and an optional support gasket  44 . A more thorough description of such a golf club head  20  is set forth in U.S. Pat. No. 6,672,975, for a Golf Club Head, and assigned to the assignee of the present application, and which is hereby incorporated by reference in its entirety. 
   The body  22  is preferably composed of a light weight or low-density material, preferably a non-metal material or a low-density (less than 4.5 grams per cubic centimeter) metal material, such as a polycarbonate material. Other materials for the body  22  include a composite material such as a continuous fiber pre-preg material (including thermosetting materials or a thermoplastic material for the resin), other thermosetting materials such as thermosetting polyurethane, or other thermoplastic materials such as polyamides, polyimides, polycarbonates, PBT (Polybutlene Terephthalate), blends of polycarbonate and polyurethane, and the like. The body  22  is preferably manufactured through injection molding, bladder-molding, resin transfer molding, resin infusion, compression molding, or a similar process. A preferred metal material for the body  22  is aluminum, tin or magnesium. The face  40  is attached to the frame  42  and over the opening  32 . Preferably the face  40  is positioned over and attached to the support gasket  44 . 
   The face  40  is preferably composed of a formed metal material, however, the face  40  may also be composed of a machined metal material, a forged metal material, a cast metal material or the like. The face  40  preferably is composed of a formed titanium or steel material. Titanium materials useful for the face  40  include pure titanium and titanium alloys. Other metals for the face  40  include other high strength steel alloy metals and amorphous metals. The exterior surface of the face  40  typically has a plurality of scorelines thereon, not shown. 
   The face  40  preferably has an elliptical shape or a trapezoidal shape. The face  40  preferably has a plurality of holes  46   a - d  for insertion of the bolts  88   a - d  there through. 
   The weighting frame  42  is preferably composed of a metal material such as stainless steel, titanium alloy, aluminum, magnesium and other like metal materials. In an alternative embodiment, the weighting frame  42  is composed of a thermoplastic material. The frame  42  is preferably composed of four arms  86   a - d  and a central body  84 . In the preferred embodiment, each of the arms  86   a - d  are positioned within a corresponding groove  40   a - d  of the body  22 . Each of the grooves  40   a - d  are generally shaped to receive an arm  86   a - d . Each arm  86   a - d  has a length sufficient to extend from the aft end  37  of the body  22  to the opening  32 . In a preferred embodiment, each arm  86   a - d  is tubular with a threaded aperture at the forward end (opposite the central body  84 ) to receive a bolt for attachment of the face  40  thereto. The frame  42  preferably engages the face  40  at each of the corners (upper heel, lower heel, upper toe and lower toe) of the face  40 . The frame  42  also increases the moment of inertia of the golf club head  20  since mass is positioned at the outer extremes of the golf club head  20 . 
   Further, the attachment of the face  40  to the frame  42  provides the ability to use an amorphous metal for the face  40  and a different material for the frame  42  and the body  22  thereby eliminating problems associated with bonding amorphous metals to other metals. Although attachment through the use of bolts is preferred, other joining means may be utilized such as riveting, self taping screws, localized friction or welding, spot welding, local bonding, melt or solvent bonding, and the like. 
   Preferably, the frame  42  has a mass ranging from 30 grams to 90 grams, more preferably from 40 grams to 70 grams. The hosel  57  preferably has a mass ranging from 3 to 10 grams, more preferably from 4 to 8 grams, and most preferably has a mass of 6 grams. Additionally, epoxy, or other like flowable materials, in an amount ranging from 0.5 grams to 5 grams, may be injected into the hollow interior  50  of the golf club head  20  for selective weighting thereof. 
   As shown in  FIGS. 17 and 18 , the depth, D, of the club head  20  from the face  40  to the after end  37  of the crown  24  preferably-ranges from 3.0 inches to 4.5 inches, and is most preferably 3.74 inches. The height of the club head  20 , as measured while in address position from the sole  26  to the crown  24 , preferably ranges from 2.0 inches to 3.5 inches, and is most preferably 2.62 inches. The width, W, of the club head  20  from the toe end  38  to the heel end  36  preferably ranges from 4.0 inches to 5.5 inches, and more preferably 4.57 inches. The height of the face  40 , preferably ranges from 1.8 inches to 2.5 inches, and is most preferably 2.08 inches. The width, w, of the face insert from the toe end to the heel end preferably ranges from 3.0 inches to 5.0 inches, and more preferably 3.52 inches. 
   The golf club head  20  preferably has a high coefficient of restitution for greater distance of a golf ball hit with the golf club head of the present invention. The coefficient of restitution (also referred to herein as “COR”) is determined by the following equation: 
           e   =         v   2     -     v   1           U   1     -     U   2               
wherein U 1  is the club head velocity prior to impact; U 2  is the golf ball velocity prior to impact which is zero; ν 1  is the club head velocity just after separation of the golf ball from the face of the club head; ν 2  is the golf ball velocity just after separation of the golf ball from the face of the club head; and e is the coefficient of restitution between the golf ball and the club face.
 
   The values of e are limited between zero and 1.0 for systems with no energy addition. The coefficient of restitution, e, for a material such as a soft clay or putty would be near zero, while for a perfectly elastic material, where no energy is lost as a result of deformation, the value of e would be 1.0. The golf club head  20  preferably has a coefficient of restitution ranging from 0.80 to 0.94, as measured under conventional test conditions. 
   The coefficient of restitution of the club head  20  of the present invention under standard USGA test conditions with a given ball preferably ranges from approximately 0.80 to 0.94, more preferably ranges from 0.82 to 0.89 and is most preferably 0.86. However, the face center  300  preferably has a COR no greater than 0.83, and the golf club head  20  preferably conforms to the USGA characteristic time test. 
     FIGS. 9 and 10  illustrate the axes of inertia through the center of gravity of the golf club head. The axes of inertia are designated X, Y and Z. The X axis extends from the face insert  40  through the center of gravity, CG, and to the rear of the golf club head  20 . The Y axis extends from the toe end  38  of the golf club head  20  through the center of gravity, CG, and to the heel end  36  of the golf club head  20 . The Z axis extends from the crown  24  through the center of gravity, CG, and to the sole  26 . 
   As defined in  Golf Club Design, Fitting, Alteration  &amp;  Repair,  4 th  Edition, by Ralph Maltby, the center of gravity, or center of mass, of the golf club head is a point inside of the club head determined by the vertical intersection of two or more points where the club head balances when suspended. A more thorough explanation of this definition of the center of gravity is provided in  Golf Club Design, Fitting, Alteration  &amp;  Repair.    
   The center of gravity and the moment of inertia of a golf club head  20  are preferably measured using a test frame (X T , Y T , Z T ), and then transformed to a head frame (X H , Y H , Z H ). The center of gravity of a golf club head may be obtained using a center of gravity table having two weight scales thereon, as disclosed in U.S. Pat. No. 6,607,452, entitled High Moment Of Inertia Composite Golf Club, and hereby incorporated by reference in its entirety. If a shaft is present, it is removed and replaced with a hosel cube that has a multitude of faces normal to the axes of the golf club head. Given the weight of the golf club head, the scales allow one to determine the weight distribution of the golf club head when the golf club head is placed on both scales simultaneously and weighed along a particular direction, the X, Y or Z direction. 
   In general, the moment of inertia, Izz, about the Z axis for the golf club head  20  is preferably greater than 3000 g-cm 2 , and more preferably greater than 3500 g-cm 2 . The moment of inertia, Iyy, about the Y axis for the golf club head  20  is preferably in the range from 2000 g-cm 2  to 4000 g-cm 2 , more preferably from 2300 g-cm 2  to 3800 g-cm 2 . The moment of inertia, Ixx, about the X axis for the golf club head  20  is preferably in the range from 1500 g-cm 2  to 3800 g-cm 2 , more preferably from 1600 g-cm 2  to 3100 g-cm 2 . 
   Table One illustrates a comparison of a golf club head with a face insert ( 40 ) of the present invention as compared to a golf club head with a face insert having a uniform thickness. Both golf club head conform to the USGA regulations for characteristic time. The golf club head  20  with the face insert ( 40 ) having a H-shaped first thickness section  200  has a mass that is more than 25% lighter than the uniform thickness face of the comparison golf club head while having similar CORs and characteristic times. 
   
     
       
         
             
             
             
             
             
           
             
                 
             
             
               Face 
               Mass 
               Characteristic 
                 
               Thickness 
             
             
               Design 
               (grams) 
               Time (μs) 
               COR 
               (inches) 
             
             
                 
             
           
          
             
               Uniform 
               42.7 
               240 
               0.828 
               0.120 
             
             
               H-shaped 
               29.0 
               240 
               0.829 
               variable 
             
             
                 
             
          
         
       
     
   
   From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.