US 5,919,100 · Granted 1999-07-06
The Liquid-Filled Golf Ball That Defied Traditional Winding
Imagine a golf ball with actual liquid sloshing around inside instead of the wound-up rubber strings you'd normally find. This patent describes a ball made with a fluid center core, wrapped in solid plastic and rubber layers—a completely different way to design a golf ball that changes how it feels and performs on the course.
The plain-English version
What it protects
The claim covers a golf ball construction consisting of a fluid-filled center core surrounded by two specific non-wound layers: a solid inner layer made from non-elastic polymers (plastic, metal, or thermoplastic material) and an outer elastomeric layer made from rubber or thermoplastic elastomer with defined hardness and compression properties. What's protected here is the specific combination of the liquid center, the non-wound solid layers, and their dimensional ranges relative to the overall ball diameter, along with a cover surrounding the whole structure.
Why it matters
This patent matters because it represents a fundamental departure from the century-old wound-ball manufacturing process. Traditional golf balls are made by wrapping hundreds of yards of elastic thread around a core—labor-intensive and difficult to control. A liquid-filled, non-wound design offered manufacturers a potentially simpler, more consistent way to produce golf balls with predictable performance characteristics. For Acushnet, a major golf equipment maker, this patent protected their ability to make balls using this alternative construction method without competitors copying the exact layering scheme and material specifications.
Real-world use
When a golfer tees up one of these liquid-filled balls, they're hitting a ball engineered with a fluid core that shifts slightly on impact, affecting spin and distance in ways a traditional wound ball wouldn't. The liquid center becomes part of the ball's energy response.
Original USPTO abstract
A golf ball having a diameter and comprising a fluid mass at the center of the ball, a first, solid, non-wound layer surrounding the fluid mass comprised of a non-elastic polymer material selected from the group of thermoplastic material, metal, and plastic, and having an inner diameter in the range of 30 to 70% of the ball diameter; a second, solid, non-wound layer surrounding the first mantle layer comprising an elastomeric polymer material selected from the group of thermoset rubber material and thermoplastic clastomeric material having an outer diameter in the range of 80 to 98% of the ball diameter, a hardness of less than about 65 Shore D, and a compression of about 80 or greater; and a cover surrounding the second layer.
Patent details
- Publication number
- US 5,919,100
- Filing date
- 1997-11-03
- Grant date
- 1999-07-06
- Assignee
- Acushnet Company
- Inventor(s)
- BOEHM; HERBERT C., MORGAN; WILLIAM E., REID; WALTER L., PASQUA, JR.; SAMUEL A., CAVALLARO; CHRISTOPHER, HARRIS; KEVIN M.
- CPC class
- B29C43/027
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