Abstract:
A method for manufacturing an insert for a golf club head, the insert having a face plate, is disclosed herein. The method involves forming a metal face insert, co-molding a first polymer insert and then a second polymer insert. The metal face insert has a plurality of flanges that when co-molded with the first polymer insert, secure the metal face insert within the insert.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a method for manufacturing an insert for a golf club head. More specifically, the present invention relates to a method of manufacturing a polymer insert with a face plate for a golf club head.  
         [0003]     2. Description of the Related Art  
         [0004]     Throughout the history of golf, which dates back to as early as 1457, various techniques have been used to enhance the hitting characteristics of golf club heads. Golf club heads having inserts for the striking portion have been used at least as far back as 1880&#39;s when leather face irons were manufactured in Scotland. Golfer&#39;s in the 1890&#39;s were able to purchase putters with faces composed of gutta percha. More recently, inserts composed of various materials and shapes have been put forth by the creative geniuses of the golf industry to provide golfers with better feel and control of the golf ball.  
         [0005]     One example is an ODYSSEY® DUAL FORCE® putter having a STRONOMIC® insert that is disclosed in Magerman et al., U.S. Pat. No. 5,575,472 for a Golf Putter Head Having Face Insert And Method Of Forming The Same. The Magerman, et al. Patent discloses a putter head with a recess into which is poured or inserted a resinous material which cures and is subsequently milled to produce the putter.  
         [0006]     Another example is an ODYSSEY® WHITE HOT® putter having an insert composed of a polyurethane material. The ODYSSEY® WHITE HOT® putter is disclosed in U.S. Pat. No. 6,238,302 for a Golf Club Head With An Insert Having Integral Tabs.  
         [0007]     Another example is Pond, U.S. Pat. No. 5,524,331 for a Method For Manufacturing Golf Club Head With Integral Inserts that discloses a method for casting a graphite-epoxy composite insert within a recess of a face of a metal club head. The golf club head of the Pond Patent is directed at displacing the weight away from the center and increasing the moment of inertia.  
         [0008]     Another example is Schmidt et al., U.S. Pat. No. 5,485,997, for a Golf Putter Head With Face Plate Insert Having Heightened Medial Portion, that discloses a putter head with a face plate composed of a non-metallic material such as an elastomer. The overall construction of the putter head of the Schmidt et al. Patent is directed at enlarging the sweet spot and improving the peripheral weighting.  
         [0009]     Yet another example is found in Baker et al., U.S. Pat. No. 5,931,743 for a Putter Having Club Head With A Golf-Ball Engagement Insert And A Shaft Rearwardly Of The Insert which discloses a putter with a center shaft and an insert composed of a thermoplastic polyurethane. Another example is Jepson et al., U.S. Pat. No. 3,937,474 for a Golf Club With Polyurethane Insert, which discloses a wood having an insert on its striking face that is composed of a polyurethane formed from a tolylene diisocyanate polyether terminated prepolymer and a curing agent. The hardness of this insert varies from 40 to 75 shore D, and a Bashore Resiliometer of 17 or above. The polyurethane insert is claimed to impart additional energy to the golf ball during a golf hit.  
         [0010]     Chen et al., U.S. Pat. No. 5,743,813 for a Golf Club Head discloses a wood composed of stainless steel with a three layer face having a first stainless steel layer, an elastic layer and a second stainless steel layer. The three-layer face does not absorb the hitting force when a golf ball is hit.  
         [0011]     Fisher, U.S. Pat. No. 5,458,332, for a Golf Putter Head With A Cushioning Face, discloses a set of golf putters, each having an insert composed of polyurethane with a hardness in the range of 70 Shore A to about 80 Shore D. The rebound factor of each of the inserts is in the range of 12.5% to 50%, and the inserts are formulated to effect a reproducible direct linear relationship between the rebound factor and the distance of the putt.  
         [0012]     Yet another example is McGeeney et al, European Patent Application Number 0891790 for a Multiple Density Golf Club Head And Method Of Manufacturing which discloses a putter with a central segment composed of a thermoplastic elastomer or a thermoset polymer. Possible thermoplastic elastomers include styrene co-polymers, co-polyesters, polyurethanes, polyamides, olefins and vulcanates. Possible thermoset polymers include epoxides, polyimides and polyester resins. The central segment has a minimum durometer hardness of Shore D 50. The central segment is bounded by metallic heel and to portions. However, the use of inserts is restrained in order to maintain the integrity of the game of golf.  
         [0013]     In this regard, the Rules of Golf, established and interpreted by the United States Golf Association (“USGA”) and The Royal and Ancient Golf Club of Saint Andrews, sets forth certain requirements for a golf club head. The requirements for a golf club head are found in Rule 4 and appendix II. A complete description of the Rules of Golf are available on the USGA web page at www.usga.org. Although the Rules of Golf do not expressly state specific parameters for an insert for a putter, the Rules of Golf have been interpreted to establish that an insert for a putter should have a Shore A hardness greater than 87±2%, have a constant thickness, have a thickness of at least 0.125 inches, and not act like a spring.  
         [0014]     Issues with the inserts of the prior art include complex processing, yellowing of polyurethane materials, and deformation under extended high temperatures.  
       BRIEF SUMMARY OF THE INVENTION  
       [0015]     The present invention provides a method for manufacturing an insert for a golf club head. The insert has a metal face with a polymer body. The method involves co-molding a first polymer insert about the metal face insert and then co-molding a second polymer insert about the combined first polymer insert and metal face insert. A plurality of flanges of the metal face insert secure the metal face insert within the polymer body.  
         [0016]     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  
       [0017]      FIG. 1  is a perspective view of one embodiment of a golf club head without an insert in the recess of the club head body.  
         [0018]      FIG. 1A  is a front view of the club head of  FIG. 1  with the insert placed therein.  
         [0019]      FIG. 1B  is a side view of the club head of  FIG. 1 .  
         [0020]      FIG. 1C  is a rear view of the club head of  FIG. 1 .  
         [0021]      FIG. 1D  is a top view of the club head of  FIG. 1 .  
         [0022]      FIG. 2  is a front view of another embodiment of a golf club head with an insert in the recess of the club head body.  
         [0023]      FIG. 2A  is a partial cross-sectional side view of the club head of  FIG. 2 .  
         [0024]      FIG. 2B  is a rear view of the club head of  FIG. 2 .  
         [0025]      FIG. 2C  is a top view of the club head of  FIG. 2 .  
         [0026]      FIG. 2D  is an enlarged view of circle D of  FIG. 2A .  
         [0027]      FIG. 3  is a front view of another embodiment of a golf club head with an insert in the recess of the club head body.  
         [0028]      FIG. 3A  is a side view of the club head of  FIG. 3 .  
         [0029]      FIG. 3B  is a rear view of the club head of  FIG. 3 .  
         [0030]      FIG. 3C  is a top view of the club head of  FIG. 3 .  
         [0031]      FIG. 4  is a front view of another embodiment of the golf club head of the present invention with an insert in the recess of the club head body.  
         [0032]      FIG. 4A  is a side view of the club head of  FIG. 4 .  
         [0033]      FIG. 4B  is a rear view of the club head of  FIG. 4 .  
         [0034]      FIG. 4C  is a top view of the club head of  FIG. 4 .  
         [0035]      FIG. 5  is a top perspective another embodiment of a golf club head with an insert in the recess of the club head body.  
         [0036]      FIG. 6  is a front view of the golf club head of  FIG. 5 .  
         [0037]      FIG. 7  is a side view of the golf club head of  FIG. 5 .  
         [0038]      FIG. 8  is a top view of the golf club head of  FIG. 5 .  
         [0039]      FIG. 9  is a bottom view of the golf club head of  FIG. 5 .  
         [0040]      FIG. 10  is a flow chart of a general method of the present invention.  
         [0041]      FIG. 11  is a flow chart of a specific method of the present invention.  
         [0042]      FIG. 12  is a top plan view of a stamped metal face insert.  
         [0043]      FIG. 12 A  is an end view of the insert of  FIG. 12 .  
         [0044]      FIG. 13  is a top plan view of a machined metal face insert.  
         [0045]      FIG. 13A  is an end view of the machined metal face insert of  FIG. 13 .  
         [0046]      FIG. 13 B  is a front side view of the machined metal face insert of  FIG. 13 .  
         [0047]      FIG. 14  is a front plan view of a first polymer insert co-molded about a machined metal face insert.  
         [0048]      FIG. 14A  is a front side view of the  FIG. 14 .  
         [0049]      FIG. 15  is a front plan view of a second polymer insert co-molded about the first polymer insert and a machined metal face insert.  
         [0050]      FIG. 15A  is a front side view of the  FIG. 14 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0051]     As shown in  FIGS. 1 through 1 D, a putter is generally designated  50 . The putter  50  includes a club head  52  having a body  54  with a front face  56  with a recess  58  therein. The club head  52  also includes an insert  60  disposed within the recess  56 . The insert  60  extends along most of the face  56  from a heel  62  of the club head  52  to a toe  64  of the club head  52 , and from a sole  66  of the club head  52  to a crown  68  of the club head  52 . A face plate  75  is co-molded with insert as discussed below. The club head  52  also has a hosel  70  for connection to a shaft  72 . Opposite of the front face  56  of the club head  52  is a rear  74  of the club head  52 .  
         [0052]     The body  54  of the club head  52  is preferably composed of a metallic material such as stainless steel. Other metallic materials include titanium, aluminum, tungsten, zinc, magnesium, and alloys of stainless steel and tungsten. However, those skilled in the pertinent art will recognize that the body  54  may be composed of other materials without departing from the scope and spirit of the present invention. Further, the non-insert portion of the face  56  may be smooth or textured to provide a consistent or non-consistent surface with the exterior surface of the insert. Additionally, the body  54  may be specifically weighted to provide a specific center of gravity and inertial properties for the putter  50 .  
         [0053]      FIGS. 2-4C  illustrate various embodiments of putters  50 . Each of the putters  50  of  FIGS. 2-4C  has a club head  52  with a body  54 , an insert  60  disposed within a recess  58  of the body  54 , and a face plate  75 . The putters  50  illustrated in  FIGS. 1-4C  are flanged blade, mallet and semi-mallet putters, however, those skilled in the art will recognize that other similar putter designs may be utilized without departing from the scope and spirit of the present invention. In a preferred embodiment, each of the club heads  52  weigh approximately 328 grams±7 grams. Further, in a preferred embodiment, the recess  58  of each of the club heads  52  has a depth of approximately 0.205 inches±0.010 inches.  
         [0054]     Referring specifically to  FIG. 1 , the recess  58  of the body  54  is defined by a recess face wall  80  which is substantially parallel with the insert  60 , and a recess edge wall  82  which is substantially perpendicular to the recess face wall  80 . The recess face wall  80  defines the depth of the recess  58  that will determine the thickness of the polymer insert  60 . The recess edge wall  82 , as shown in  FIG. 1 , is composed of a bottom recess edge wall  82   a , a heel recess edge wall  82   b , a top recess edge wall  82   c  and a toe recess edge wall  82   d . The recess edge wall  82  defines the shape of the recess  58 , and the length of the recess edge wall  82  is determined by the depth of the recess  58 . In a preferred embodiment, the insert  60  will engage the recess edge wall  82  as described below.  
         [0055]     The putter  50  of  FIGS. 1-1D  is a flanged blade style putter. The rear  74  of the club head  52  has a rear wall  75  and a flanged portion  77 . The insert  60  of this embodiment occupies approximately 67.90% of the face area of the club head  52 . The insert  60  also occupies approximately 20.71% of the volume of the club head  52 . Yet further, the insert  60  of this embodiment is approximately 3.95% of the weight of the club head  52 .  
         [0056]     The putter  50  of  FIGS. 2-2C  is also a blade style putter, however, it has an offset hosel  70 , and an insert  60  with a panhandle portion  60   a . The insert  60  is one-piece, including the panhandle portion  60   a . It is apparent from  FIG. 2  that this putter  50  has a larger area of the non-insert portion of the face  56  than the embodiment shown in  FIG. 1A . The insert  60  of this embodiment occupies approximately 69.22% of the face area of the club head  52 . The insert  60  also occupies approximately 20.33% of the volume of the club head  52 . Yet further, the insert  60  of this embodiment is approximately 3.86% of the weight of the club head  52 .  FIG. 2D  illustrates a enlarged view of a cross-section of the putter  50 .  
         [0057]     The putter  50  of  FIGS. 3-3C  is a half-mallet style putter with an offset hosel  70 . The insert  60  has a trapezoidal shape with parallel sides and a curved bottom portion. It is apparent from  FIG. 3  that the toe end and heel end of the face  56  of this putter  50  has a large area of the non-insert portion. The insert  60  of this embodiment occupies approximately 68.27% of the face area of the club head  52 . The insert  60  also occupies approximately 17.15% of the volume of the club head  52 . Yet further, the insert  60  of this embodiment is approximately 3.08% of the weight of the club head  52 .  
         [0058]     The putter of  FIGS. 4-4C  is a mallet style putter, however, it does not have an offset hosel  70 . The insert  60  of this embodiment occupies the largest amount of the face area of the club head  52 , approximately 70.38%. However, the insert  60  occupies the smallest volume of the club head  52 , approximately 16.24%. Yet further, the insert  60  of this embodiment is the lightest, weighing approximately 2.46% of the club head  52 .  
         [0059]      FIGS. 5-9  illustrate an extended mallet type putter-type golf club head  20  with an alignment system such as disclosed in U.S. Pat. No. 6,471,600, issued on Oct. 22, 2002, which relevant parts are hereby incorporated by reference.  
         [0060]     In a preferred embodiment, the insert  60  is composed of a thermoplastic polyurethane material, preferably an injection moldable thermoplastic polyurethane. A preferred thermoplastic polyurethane is available from Bayer under the tradename Desmopan KU2-88956.  
         [0061]     The Shore D hardness of the thermoplastic polyurethane material for the insert  60  preferably ranges from 40 to 70 Shore D, more preferably from 50 to 65 Shore D, and is most preferably approximately 60 Shore D.  
         [0062]     The thickness of the insert  60  may vary depending on its application. A preferred thickness for a putter  50  is in the range of 0.125 to 0.500 inch. A preferred range of thickness is 0.188 inch to 0.200 inch. A preferred thickness is 0.198 inch. The thickness of the insert  60  is increased or decreased to influence the feel to the golfer during impact with a golf ball.  
         [0063]     The face plate  75  is preferably composed of a metal material. Such metal materials include stainless steel, steel, other steel alloys, titanium, titanium alloys, amorphous metals, aluminum, aluminum alloys, magnesium, magnesium alloys, bronze, and other like metal materials. The face plate  75  preferably has a thickness ranging from 0.020 inch to 0.075 inch, and more preferably ranging from 0.035 inch to 0.045 inch, and most preferably having a thickness of 0.040 inch. The face plate  75  preferably has a height, Hf, that ranges from 0.30 inch to 0.80 inch, more preferably from 0.50 inch to 0.70 inch, and most preferably 0.60 inch. The face plate  75  preferably has a trapezoidal shape with a bottom width, Wf, ranging from 1.0 inch to 2.0 inches, more preferably from 1.20 inches to 1.75 inches, and most preferably 1.27 inches. The top width, W′f, of the face plate  75  preferably has a length ranging from 0.50 inch to 1.5 inches, more preferably from 0.70 inch to 1.25 inches, and most preferably 0.88 inch.  
         [0064]     The face plate  75  preferably is positioned at the center of the face of the putter  20 . The face plate  75  preferably covers less than 90% of the exterior surface of the insert  60 , and more preferably less than 60% of the exterior surface of the insert, and most preferably covers between 25% to 50% of the exterior surface of the insert  60 .  
         [0065]     The insert  60  has a plurality of tabs spaced substantially equidistant apart. In a preferred embodiment, the distance “d” is 0.41 inches. However, those skilled in the pertinent art will recognize that the value of d may be adjusted for various embodiments. The plurality of tabs lie on a perimeter of the insert  60 . The perimeter defines the thickness of the insert  60 . A most preferred thickness is 0.198 inches, however the thickness may preferably range from 0.125 to 0.50 inches. The insert  60  has an interior surface and an exterior surface. The interior surface faces the recess face wall  80  while the exterior surface forms a portion of the face  56  of the club head  52 .  
         [0066]     The face plate  75  is preferably co-molded with a first insert and second insert portion to form the final insert  60 . As illustrated in  FIG. 10 , a general method for co-molding the insert  60  is designated  200 . At block  202 , a metal face insert  75   a  is formed from a sheet of metal and machined to become a machine face insert  75   b  as shown in  FIG. 13-13B . The metal face insert  75   b  is generally formed into a trapezoidal shape. At block  204 , a first polymer insert  95  is co-molded about the metal face insert  75   b , as shown in  FIGS. 14 and 14 A. At block  206 , the second polymer insert  99  is co-molded about the first polymer insert body  95  and the metal face insert  75   b  to form the final insert  60 .  
         [0067]     A more specific method  300  is illustrated in  FIG. 11 . At block  302 , a metal face insert  75   a  is stamped from a sheet of metal, preferably stainless steel. The metal face insert  75   a  is as shown in  FIGS. 12 and 12 A. The metal face insert  75   a  preferably has a thickness of approximately 3.2 millimeters, a length of approximately 55 millimeters and a height of approximately 18 millimeters.  
         [0068]     At block  304 , the metal face insert  75   a  is machined and an exterior surface  173  is textured to form the machined metal face insert  75   b . As shown in  FIGS. 13, 13A  and  13 B, a toe flange  170   a  and a heel flange  170   b  are formed during the machining of the metal face insert  75   a . A body  165  of the machined metal face insert  75   b  extends above the toe flange  170   a  and the heel flange  170   b . The machined metal face insert  75   b  preferably has a thickness of approximately 3.2 millimeters, a length of approximately 41 millimeters and a height of approximately 14 millimeters. Each of the toe flange  170   a  and the heel flange  170   b  has a thickness of approximately 0.8 millimeters. The toe flange  170   a  and the heel flange  170   b  provide a locking mechanism for securing the face insert  75  within the polymer insert  60 .  
         [0069]     At block  306 , the metal face insert is sand blasted for providing better adhesion of the metal the polymer. At block  308 , an interior surface  171  of the machined metal face insert  75   b  is coated with an adhesive material, preferably CHEMLOCK 213.  
         [0070]     At block  310 , a first polymer insert body  95  is co-molded about the machined metal face insert  75   b  to form a combined metal face insert/first polymer insert body  93 . The first polymer insert body  95  is preferably composed of a thermoplastic polyurethane such as Bayer DESMOPAN KU2-88956. As shown in  FIGS. 14 and 14 A, the first polymer insert body  95  is co-molded around the interior surface  173  of the machined metal face insert  75   b  and around the toe flange  170   a  and the heel flange  170   b  thereby securing the machined metal face insert  75   b  within the first polymer insert body  95 . The body  165  of the machined metal face insert  75   b  extends above a front surface of the first polymer insert body  95 .  
         [0071]     At block  312 , the combined metal face insert/first polymer insert body  93  is heat treated, preferably by baking the combined metal face insert/first polymer insert body  93  in an oven at an oven temperature ranging from 100 to 150 degrees Celsius, and most preferably 120 degrees Celsius, for a time period ranging from one to two hours, most preferably one and a half hours. At block  314 , the second polymer insert body  99  is co-molded about the combined metal face insert/first polymer insert body  93  to form the final insert  60 . As shown in  FIGS. 15 and 15 A, the second polymer insert body  99  is preferably co-molded about the first polymer insert body  95 . An exterior surface of the second polymer insert body  99  is preferably flush with the exterior surface  173  of the machined metal face insert  75   b . The second polymer insert body  99  preferably is co-molded against the side walls of the body  165  of the machined metal face insert  75   b . The co-molding preferably includes forming a plurality of tabs  100  on the perimeter of the insert  60 .  
         [0072]     At block  316 , the final front insert  60  is finished, preferably by painting or coating the exterior surface with a durable top coat. At block  318 , the insert  60  is attached within the recess of the golf club head.  
         [0073]     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.