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US 11,896,880 B2Granted
Ultra high stiffness putter shaft
AssigneeKarsten Manufacturing Corporation
InventorsJohn E. Oldenburg, David S. Kultala
Life of this patent
Estimating the term…
Abstract
A golf club shaft used with putter type club heads for making a putting stroke on the green of a golf course is made from high-modulus fibers which results in an ultra-high stiffness putter shaft with high frequency, low tip deflection, and high torsional and bending rigidity. The ultra-high stiffness putter shaft prevents unwanted face twisting during the impact of a golf ball during a putting stroke, allowing for greater putt accuracy.
Claims19
A putter shaft comprising:
- a tubular body comprising:
- a torque core formed of bias plies;
- wherein:
- the torque core bias plies comprise a graphite composite with a modulus greater than 60 msi,
- an outer portion formed of longitudinal plies;
- wherein:
- the outer portion longitudinal plies comprise a graphite composite with a modulus value between 54 msi and 56 msi,
- a tip end;
- and
- a butt end;
- wherein:
- the putter shaft has a length, measured between the tip end and the butt end, that is inclusively between 32 inches and 38 inches;
- the putter shaft has a shaft mass inclusively between 115 grams and 135 grams;
- the torque core comprises four full-length bias plies and two partial-length bias plies;
- the outer portion comprises four full-length longitudinal plies;
- each bias ply and each longitudinal ply wrap around twice to form two layers within the tubular body;
- and
- the putter shaft comprises an ultra-high stiffness as evidenced by:
- a frequency value of greater than 650 cycles per minute (cpm);
- a tip deflection of less than 1.0 inch (2.54 cm);
- and
- a torsional stiffness of less than 1.5 degrees;
- wherein the frequency value is the number of oscillations that the tip end undergoes per minute when a first 6 inches of the butt end is clamped, a 205 gram weight is attached onto the tip end, and the tip end has been displaced and released;
- wherein the frequency value is measured within the first 2 to 10 oscillation cycles;
- wherein the tip deflection is the perpendicular displacement of the tip end of the putter shaft from an at-rest position of the putter shaft when a first 6 inches of the butt end is clamped and a 3.9 lb load is applied perpendicularly to the putter shaft at 1 inch inward from the tip end;
- and
- wherein the torsional stiffness is an angle of twist when a first 6 inches of the butt end is clamped, a first 1 inch of the tip end is clamped, and a torque load of 1 ft*lb is applied to the clamped tip end.
24 more elements
A putter shaft comprising:
- a tubular body comprising:
- a plurality of bias plies and a plurality of longitudinal plies;
- wherein:
- the plurality of bais plies comprise a graphite composite with a modulus greater than 60 msi and the plurality of longitudinal plies comprise a graphite composite with a modulus value between 54 msi and 56 msi,
- a tip end;
- and
- a butt end;
- wherein:
- the putter shaft has a length, measured between the tip end and the butt end, that is inclusively between 32 inches and 38 inches;
- the putter shaft has a shaft mass inclusively between 115 grams and 135 grams;
- the putter shaft comprises at least 6 full length plies;
- at least 4 of the full length plies comprise a modulus value of at least 60 msi;
- and
- the putter shaft comprises an ultra-high stiffness as evidenced by:
- a frequency value of greater than 650 cpm;
- a tip deflection of less than 1.0 inch (2.54 cm);
- and
- a torsional stiffness of less than 1.5 degrees;
- wherein the frequency value is the number of oscillations that the tip end undergoes per minute when a first 6 inches of the butt end is clamped, a 205 gram weight is attached onto the tip end, and the tip end has been displaced and released;
- wherein the frequency value is measured within the first 2 to 10 oscillation cycles;
- wherein the tip deflection is the perpendicular displacement of the tip end of the putter shaft from an at-rest position of the putter shaft when a first 6 inches of the butt end is clamped and a 3.9 lb load is applied perpendicularly to the putter shaft at 1 inch inward from the tip end;
- and
- wherein the torsional stiffness is an angle of twist when the putter shaft a first 6 inches of the butt end is clamped, a first 1 inch of the tip end is clamped, and a torque load of 1 ft*lb is applied to the clamped tip end.
20 more elements
A putter shaft comprising:
- a tubular body comprising:
- a plurality of bias plies and a plurality of longitudinal plies;
- wherein:
- the plurality of bais plies comprise a graphite composite with a modulus greater than 60 msi and the plurality of longitudinal plies comprise a graphite composite with a modulus value between 54 msi and 56 msi;
- a tip end;
- and
- a butt end;
- wherein:
- the putter shaft has a length, measured between the tip end and the butt end, that is inclusively between 32 inches and 38 inches;
- the putter shaft is hollow and comprises a wall thickness defined by an inner diameter (ID) and an outer diameter (OD);
- the putter shaft further comprises a tip ID and a tip OD;
- the tip ID and the tip OD are measured at the furthest portion of the tip end;
- the putter shaft comprises an ultra-high stiffness as evidenced by a frequency value of greater than 650 cpm and a frequency ratio (RF) between 5.5 and 8;
- the frequency value of the putter shaft is the number of oscillations that the tip end undergoes per minute when a first 6 inches of the butt end is clamped, a 205 gram weight is attached onto the tip end, and the tip end has been displaced and released;
- wherein the frequency value is measured within the first 2 to 10 oscillation cycles;
- and
- the frequency ratio is calculated by the following equation:
- R
- F
- =
- Frequency
- 10
-
- ,
-
- 0
-
- 0
-
- 0
- ×
- (
- Tip
-
-
- OD
- )
- +
- Shaft
-
-
- Mass
- .
40 more elements
Dependencies are inferred from the claim text.