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US 12,722,053 B2Granted
Golf club shaft
AssigneeSumitomo Rubber Industries, Ltd.
InventorsHiroshi Hasegawa, Yuma Yamamoto, Kota Maeda
Life of this patent
Estimating the term…
Abstract
Provided is a hollow shaft including a hoop layer. The shaft weight is 50 g or less. The shaft has a flexural rigidity EI (N·m2) and a shaft wall thickness t (mm). In a first region having a distance of 200 mm to 300 mm from the tip end, EI/t is 10 or greater and 40 or less. In a second region having a distance of 800 mm to 900 mm from the tip end, EI/t is 45 or greater and 80 or less. The hoop layer includes a partial hoop layer disposed in a part of an entire length of the shaft. The partial hoop layer includes a specific butt hoop layer that is not present in the first region and that is disposed over an entirety of the second region. The specific butt hoop layer has a thickness of 0.05 mm or greater.
Claims17
A golf club shaft being hollow, formed by a plurality of fiber reinforced resin layers, and comprising a tip end and a butt end,
- wherein the golf club shaft has a weight of less than or equal to 50 g,
- the golf club shaft has a flexural rigidity EI (N·m2) and a shaft wall thickness t (mm) at each position in an axial direction of the golf club shaft,
- in a first region that extends from a position located 200 mm apart from the tip end to a position located 300 mm apart from the tip end, EI/t is greater than or equal to 10 and less than or equal to 40,
- in a second region that extends from a position located 800 mm apart from the tip end to a position located 900 mm apart from the tip end, EI/t is greater than or equal to 45 and less than or equal to 80,
- the fiber reinforced resin layers include straight layers, a bias layer, and hoop layers,
- the straight layers include a full length straight layer that is disposed over an entire length of the golf club shaft and a partial straight layer that is disposed in a part of the entire length of the golf club shaft,
- the hoop layers include a full length hoop layer that is disposed over the entire length of the golf club shaft and a partial hoop layer that is disposed in a part of the entire length of the golf club shaft,
- the partial hoop layer includes a specific butt hoop layer that is not present in the first region and that is disposed over an entirety of the second region,
- the specific butt hoop layer has a thickness of greater than or equal to 0.05 mm,
- the full length straight layer includes low resin content full length straight layers each having a resin content of less than or equal to 20% by weight,
- the specific butt hoop layer has a resin content of greater than 20% by weight, and
- the low resin content full length straight layers include a first low resin content full length straight layer that is in contact with inside of the specific butt hoop layer, and a second low resin content full length straight layer that is in contact with outside of the specific butt hoop layer.
9 more elements
A golf club shaft being hollow, formed by a plurality of fiber reinforced resin layers, and comprising a tip end and a butt end,
- wherein the golf club shaft has a weight of less than or equal to 50 g,
- the golf club shaft has a flexural rigidity EI (N·m2) and a shaft wall thickness t (mm) at each position in an axial direction of the golf club shaft,
- in a first region that extends from a position located 200 mm apart from the tip end to a position located 300 mm apart from the tip end, EI/t is greater than or equal to 10 and less than or equal to 40,
- in a second region that extends from a position located 800 mm apart from the tip end to a position located 900 mm apart from the tip end, EI/t is greater than or equal to 45 and less than or equal to 80,
- the fiber reinforced resin layers include straight layers, a bias layer, and hoop layers,
- the straight layers include a full length straight layer that is disposed over an entire length of the golf club shaft and a partial straight layer that is disposed in a part of the entire length of the golf club shaft,
- the hoop layers include a full length hoop layer that is disposed over the entire length of the golf club shaft and a partial hoop layer that is disposed in a part of the entire length of the golf club shaft,
- the partial hoop layer includes a specific butt hoop layer that is not present in the first region and that is disposed over an entirety of the second region,
- the partial straight layer includes a tip partial straight layer that is disposed in a tip portion of the golf club shaft, and a butt partial straight layer that is disposed in a butt portion of the golf club shaft,
- the butt partial straight layer includes a specific butt straight layer that is disposed on a butt side with respect to the second region and that is not present in the second region, and
- in a graph having a horizontal axis that represents a distance (mm) from the tip end and a vertical axis that represents EI/t (N·m2/mm), a rate of change of each of six regions that each have a length of 50 mm and are obtained by dividing a region that extends from a position located 600 mm apart from the tip end to a position located 900 mm apart from the tip end into six equal parts is less than or equal to 0.20.
8 more elements
A golf club shaft being hollow, formed by a plurality of fiber reinforced resin layers, and comprising a tip end and a butt end,
- wherein the golf club shaft has a weight of less than or equal to 50 g,
- the golf club shaft has a flexural rigidity EI (N·m2) and a shaft wall thickness t (mm) at each position in an axial direction of the golf club shaft,
- in a first region that extends from a position located 200 mm apart from the tip end to a position located 300 mm apart from the tip end, EI/t is greater than or equal to 10 and less than or equal to 40,
- in a second region that extends from a position located 800 mm apart from the tip end to a position located 900 mm apart from the tip end, EI/t is greater than or equal to 45 and less than or equal to 80,
- the fiber reinforced resin layers include straight layers, a bias layer, and hoop layers,
- the straight layers include a full length straight layer that is disposed over an entire length of the golf club shaft and a partial straight layer that is disposed in a part of the entire length of the golf club shaft,
- the hoop layers include a full length hoop layer that is disposed over the entire length of the golf club shaft and a partial hoop layer that is disposed in a part of the entire length of the golf club shaft,
- the partial hoop layer includes a specific butt hoop layer that is not present in the first region and that is disposed over an entirety of the second region,
- the specific butt hoop layer has a thickness greater than a thickness of the full length hoop layer,
- the full length straight layer includes low resin content full length straight layers each having a resin content of less than or equal to 20% by weight,
- the specific butt hoop layer has a resin content of greater than 20% by weight, and
- the low resin content full length straight layers include a first low resin content full length straight layer that is in contact with inside of the specific butt hoop layer, and a second low resin content full length straight layer that is in contact with outside of the specific butt hoop layer.
9 more elements
Dependencies are inferred from the claim text.