Golf club head and method of manufacture

Abstract

The present invention resides in a golf club head having a high COR that is durable and has desirable acoustic qualities. The club head includes a body portion, a striking face and a crown forming a hollow cavity of at least 150 cc in volume. The body portion defines a front opening and an upper opening, and it includes a sole and a side section that extends rearward of the front opening. The striking plate is secured to the body portion, enclosing the front opening. While partially assembled, final weighting and/or other attachment of other members to the inner surface of the club head can be preformed, as desired. The crown is secured to the body portion, enclosing the upper opening. The crown has a maximum thickness no greater than about 2 mm. The density of the crown is less than the density of the body portion. At least one of the striking plate and the crown is attached to the second portion by adhesive bonding, and the golf club head has a maximum coefficient of restitution of at least 0.80.

We claim:  
     
         1 . A golf club head, comprising: 
 a body portion defining an upper opening and a front opening and having a sole and a side section, the side section extending rearward of the front opening and having toe, rear and heel regions, the body portion having a density of at least about 4 g/cc;    a striking plate securely attached to the body portion, enclosing the front opening; and    a crown securely attached to the body portion, enclosing the upper opening, the crown having a density between 1 g/cc and 2 g/cc and having a maximum thickness no greater than about 2 mm, wherein at least one of the striking plate and the crown is attached to the body portion by adhesive bonding, the golf club head having a maximum coefficient of restitution of at least 0.80 and a volume of at least 150 cc.    
     
     
         2 . A golf club head as defined in  claim 1 , wherein the body portion is integrally formed by a metal casting method.  
     
     
         3 . A golf club head as defined in  claim 1 , wherein the striking plate is formed of a metal material and is welded to the body portion.  
     
     
         4 . A golf club head as defined in  claim 3 , wherein a rear surface of the striking plate has an attachment placed thereon after the striking plate is welded to the body portion and before the crown is adhesively bonded to the body portion.  
     
     
         5 . A golf club head as defined in  claim 1 , wherein an inner surface of the sole has an attachment placed thereon after the striking plate is attached to the body portion and before the crown is attached to the body portion.  
     
     
         6 . A golf club head as defined in  claim 1 , wherein the body portion includes a support surrounding the upper opening for adhesive bonding of the crown to the body portion.  
     
     
         7 . A golf club head as defined in  claim 1 , wherein each of the body portion, the striking plate and the crown are formed of different material.  
     
     
         8 . A golf club head as defined in  claim 7 , wherein two of the body portion, the striking plate and the crown are formed of different alloys of the same metal.  
     
     
         9 . A golf club head as defined in  claim 1 , wherein two of the body portion, the striking plate and the crown are formed of composite materials that are attached to the remaining non-composite portion by epoxy adhesive.  
     
     
         10 . A golf club head as defined in  claim 1 , wherein at least one of the body portion, the striking plate and the crown is formed of at least two materials.  
     
     
         11 . A golf club head as defined in  claim 10 , wherein the body portion includes a cast titanium alloy having a higher density weight attached thereto.  
     
     
         12 . A golf club head as defined in  claim 1 , wherein a weight pad substantially equal to the weight savings provided by the crown is provided on the body portion.  
     
     
         13 . A golf club head as defined in  claim 1 , wherein the crown is formed of a graphite-epoxy composite having a 50% to 70% fiber volume ratio and a density of 1.4 to 1.65 g/cc.  
     
     
         14 . A golf club head as defined in  claim 1 , wherein the crown is formed of nylon material having a density ranging between 1 g/cc and 1.7 g/cc.  
     
     
         15 . A golf club head as defined in  claim 1 , wherein the crown is formed of polyphenylene sulfide material having a density ranging between 1.3 g/cc and 2 g/cc.  
     
     
         16 . A golf club head as defined in  claim 1 , wherein the volume is at least 350 cc.  
     
     
         17 . A golf club head, comprising: 
 a body portion defining an upper opening and a front opening and having a sole and a side section, the side section extending rearward of the front opening and having toe, rear and heel regions, the body portion having a density of at least about 4 g/cc;    a striking plate securely attached to the body portion, enclosing the front opening; and    a crown securely attached to the body portion, enclosing the upper opening, the crown being formed of plies of composite material having a fiber area weight of between 20 g/m 2  and 200 g/m 2  and having a maximum thickness no greater than about 2 mm, the weight of the crown being less than the weight of a similar sized piece formed of the material of the body portion; wherein at least one of the striking plate and the crown is attached to the body portion by adhesive bonding, the golf club head having a maximum coefficient of restitution of at least 0.80 and a volume of at least 150 cc.    
     
     
         18 . A golf club head as defined in  claim 17 , wherein the crown is formed of an uppermost fabric ply and at least one layer of four plies of uni-tape standard modulus composite, the plies of uni-tape oriented at 0°, +45°, −45° and 90°.  
     
     
         19 . A golf club head as defined in  claim 17 , wherein the crown is formed of an uppermost ply of uni-tape standard modulus composite oriented at 0° or 90°, the ply of uni-tape being painted along with a top section of the body portion.  
     
     
         20 . A golf club head as defined in  claim 17 , wherein the crown is formed of an uppermost ply of woven graphite cloth oriented at 0° or 90° 
     
     
         21 . A method of manufacturing a hollow golf club head having a volume of at least 150 cc, comprising the steps of: 
 forming a body of a metal material, the body having walls forming a front that defines a front opening, a side section, a sole and a top section that defines an upper opening,    forming a striking plate adapted to be secured to the body and enclose the front opening;    securely attaching the striking plate to the body, enclosing the front opening;    forming a crown of a material having a density less than 2 g/cc, the crown having a maximum thickness no greater than 2 mm, the crown adapted to be secured to the body, enclosing the upper opening; and    securely attaching the crown to the body, enclosing the upper opening; wherein at least one of the crown and the striking plate is attached by adhesive bonding to the opening in the body, the golf club head having a maximum coefficient of restitution of at least 0.80.    
     
     
         22 . A method as defined in  claim 21 , wherein the step of forming the body comprises casting a metal material, the front and upper openings are formed in the casting step.  
     
     
         23 . A method as defined in  claim 21 , wherein the step of forming the striking plate comprises cold-forming a metal material to the desired thickness, shape and size, and the step of attaching the striking plate comprises welding.  
     
     
         24 . A method as defined in  claim 21 , wherein the step of forming the striking plate comprises forming a composite plate, and the step of attaching the striking plate comprises adhesive bonding to a support at the front opening of the body.  
     
     
         25 . A method as defined in  claim 21 , wherein the step of forming the crown comprises forming an uppermost ply and at least one layer of four plies of uni-tape standard modulus graphite.  
     
     
         26 . A method as defined in  claim 21 , further comprising the step of attaching a member to a rear of the striking plate after the striking plate has been attached and before the crown has been attached.  
     
     
         27 . A method as defined in  claim 21 , further comprising the step of attaching a member to an inner surface of the body after the striking plate has been attached and before the crown has been attached.