US 5,624,331 · Granted 1997-04-29
The Metal-and-Composite Golf Club Head That Stopped Faces From Caving In
Golf club designers found a way to make wood-style club heads stronger by mixing metal with composite materials. They added a stainless-steel bar inside the club head that acts like an internal brace, keeping the hitting face from flexing and warping when you whack a ball at 100+ mph—kind of like adding an internal skeleton to a hollow helmet.
The plain-English version
What it protects
The claim covers a golf club head design where a metal casing has cutouts in the crown (top), and composite material fills those gaps. A metal bar-like stiffener runs from the front face to the back of the club, perpendicular to the face. Behind the hitting surface sits a thicker composite core. What's protected is this specific sandwich-like structure: the rigid metal reinforcement working together with the composite covers to resist face deformation during ball impact.
Why it matters
In the mid-1990s, metal wood-style clubs were replacing wooden clubs in golf bags, but designers struggled with face flexure—the face would bend and twist on impact, leading to inconsistent shots and durability issues. This patent offered a structural solution: use a metal stiffener to brace the face while composite covers handled weight distribution and dampening. The design addresses a real engineering constraint in club manufacturing and gives Pro-Kennex a locked-in way to build stronger heads.
Real-world use
When a golfer swings a driver and the club face connects with the ball at impact, the metal bar inside this club head keeps the face rigid and prevents the elastic 'trampoline effect' that causes mis-hits and reduces control.
Original USPTO abstract
A composite-metal wood-style golf club head having a metal casing with at least two openings in the crown in which composite covers are disposed. The portion of the metal casing between the covers defines a bar-like stiffener that extends between the face and the back in a direction generally perpendicular to the face. The metal stiffener braces and reinforces the face against flexure during impact with the ball, while the composite covers optimize weight distribution and provide other advantages. The club head may include a composite core with a relative thick portion behind the hitting face to further reinforce the hitting face against flexure.
Patent details
- Publication number
- US 5,624,331
- Filing date
- 1995-10-30
- Grant date
- 1997-04-29
- Assignee
- Pro-Kennex, Inc.
- Inventor(s)
- LO; KUN-NAN, CHUNG; WU-HSIANG, LIAO; HSUEH-CHENG
- CPC class
- A63B53/0466
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