Golf shaft for controlling passive vibrations
OwnerRaymund S. Cabales, John B. Kosmatka +1inventors
InventorsRaymund S. Cabales, John B. Kosmatka, Frank M. Belknap
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Abstract
In the field of golf equipment, a new shaft design incorporates passive damping to suppress the vibrations excited in the shaft before and after impact. The design comprises a viscoelastic material sandwiched between multiple layers of composite plies which induce large shear strains in the viscoelastic when the shaft is subjected to bending, extension, or twist, thus increasing damping losses over conventional golf shafts. In one embodiment, the sandwiching layers are of opposing orientation. In another embodiment, the layers are oriented in an opposing V-shape laminate.
Claims15
A tubular composite golf shaft forming a part of a golf club having a grip terminating in a butt end and a head attached to a tip opposite said butt end, said golf shaft provided with at least one integral damping device, said golf shaft comprising an inner shaft member and an outer shaft member, said at least one integral passive damping device comprising at least two tubular members whose length defines a damping region, said at least two tubular members disposed one inside the other and separated by at least one layer of viscoelastic material, said tubular members being connected to each other at the ends of the damping region, said integral passive damping device disposed between said inner shaft member and said outer shaft member, wherein each of said tubular members comprise at least one composite ply, wherein each composite ply surrounding said viscoelastic material has an off-axis ply orientation, and wherein said tubular members are non-rigid such that said plies experience relative twist displacements about the central axis of said shaft as a result of shaft bending or extension, which induce shear strains in said viscoelastic material for the purpose of controlling passive vibrations.
Dependencies are inferred from the claim text.