Golf shaft

Abstract

A multi-material golf shaft having a butt portion joined to a tip portion and possessing unique relationships, including rigidity relationships, which provide beneficial performance characteristics.

1 .- 20 . (canceled) 
     
     
         21 . A golf club shaft ( 100 ), comprising:
 a shaft distal end ( 110 ), a shaft proximal end ( 120 ), a shaft outer diameter, a shaft length ( 130 ), and a shaft mass, wherein each point along the shaft length ( 130 ) has (i) a shaft flexural rigidity, and (ii) a shaft torsional rigidity;   the shaft ( 100 ) having a butt portion ( 1000 ) joined to a tip portion ( 2000 ) by a coupler ( 3000 );   the butt portion ( 1000 ) having a butt portion distal end ( 1010 ), a butt portion proximal end ( 1020 ), a butt portion length ( 1030 ), a butt portion sidewall ( 1040 ) having a butt portion sidewall thickness ( 1050 ), a butt portion inner diameter ( 1060 ) that varies, and a butt portion outer diameter ( 1070 ) of 0.500″-0.700″;   the tip portion ( 2000 ) having a tip portion distal end ( 2010 ), a tip portion proximal end ( 2020 ), a tip portion length ( 2030 ) that is no more than 65% of the butt portion length ( 1030 ), a tip portion sidewall ( 2040 ) having a tip portion sidewall thickness ( 2050 ), a tip portion inner diameter ( 2060 ), and a tip portion outer diameter ( 2070 ), wherein the tip portion outer diameter ( 2070 ) of a portion of the tip portion ( 2000 ) is at least 25% less than the butt portion outer diameter ( 1070 ) of a portion of the butt portion ( 1000 ), and the butt portion sidewall thickness ( 1050 ) of a portion of the butt portion ( 1000 ) is greater than the tip portion sidewall thickness ( 2050 ) of a portion of the tip portion ( 2000 );   the coupler ( 3000 ) having a coupler distal end ( 3010 ), a coupler proximal end ( 3020 ), a coupler length ( 3030 ), a coupler sidewall ( 3040 ) having a coupler sidewall thickness ( 3050 ), a coupler inner diameter ( 3060 ), and a coupler outer diameter ( 3070 );   the butt portion ( 1000 ) formed of a non-metallic butt portion material having a butt material density, a butt portion mass that is 35-75% of the shaft mass, and each point along the butt portion length ( 1030 ) having a butt portion flexural rigidity, and a butt portion torsional rigidity;   the tip portion ( 2000 ) formed of a metallic tip portion material having a tip material density that is at least 15% greater than the butt material density, and each point along the tip portion length ( 2030 ) having a tip portion flexural rigidity, and a tip portion torsional rigidity, wherein the tip portion flexural rigidity of a portion of the tip portion ( 2000 ) is less than the butt portion flexural rigidity of a portion of the butt portion ( 1000 ), and the tip portion torsional rigidity of a portion of the tip portion ( 2000 ) is less than the butt portion torsional rigidity of a portion of the butt portion ( 1000 );   wherein a reinforced region ( 2500 ) is located between a first point located 5″ from the shaft proximal end ( 120 ) and a second point located 24″ from the shaft proximal end ( 120 ), and:   (a) at a first location in the reinforced region ( 2500 ) the shaft flexural rigidity is at least 50% greater than a minimum tip portion flexural rigidity and the shaft torsional rigidity is at least 50% greater than a minimum tip portion torsional rigidity and less than 100 N*m 2 ; and   (b) at a second location in the reinforced region ( 2500 ) the shaft flexural rigidity is at least 50% greater than a minimum butt portion flexural rigidity and the shaft torsional rigidity is at least 50% greater than a minimum butt portion torsional rigidity.   
     
     
         22 . The shaft ( 100 ) of  claim 21 , wherein a first portion of the shaft ( 100 ) extending ⅔ of the shaft length ( 130 ) from the shaft proximal end ( 120 ) has a first average flexural rigidity and a first average torsional rigidity, a second portion of the shaft ( 100 ) extending ⅓ of the shaft length ( 130 ) from the shaft distal end ( 110 ) has a second average flexural rigidity and a second average torsional rigidity, and the first average flexural rigidity is at least 50% of the second average flexural rigidity. 
     
     
         23 . The shaft ( 100 ) of  claim 22 , wherein the tip portion length ( 2030 ) is no more than 55% of the butt portion length ( 1030 ), the tip material density is at least twice the butt material density, the minimum tip portion flexural rigidity is at least 25% less than the minimum butt portion flexural rigidity, and the minimum tip portion torsional rigidity is at least 25% less than the minimum butt portion torsional rigidity. 
     
     
         24 . The shaft ( 100 ) of  claim 23 , wherein the coupler ( 3000 ) has a coupler mass that is no more than 15% of the shaft mass, the butt portion mass that is 40-70% of the shaft mass, and the tip portion ( 2000 ) has a tip portion mass that is 35-85% of the butt portion mass. 
     
     
         25 . The shaft ( 100 ) of  claim 24 , wherein the coupler ( 3000 ) is formed of a coupler material having a coupler material density, a coupler mass, and each point along the coupler length ( 3030 ) has (i) a coupler flexural rigidity, and (ii) a coupler torsional rigidity, wherein at least a portion of the coupler ( 3000 ) has a coupler flexural rigidity that is greater than the tip portion flexural rigidity of a portion of the tip portion ( 2000 ), and at least a portion of the coupler ( 3000 ) has a coupler torsional rigidity that is greater than the tip portion torsional rigidity of a portion of the tip portion ( 2000 ). 
     
     
         26 . The shaft ( 100 ) of  claim 25 , wherein the coupler flexural rigidity of at least a portion of the coupler ( 3000 ) is greater than the butt portion flexural rigidity of a portion of the butt portion ( 1000 ), and at least a portion of the coupler ( 3000 ) has a coupler torsional rigidity that is greater than the butt portion torsional rigidity of a portion of the butt portion ( 1000 ). 
     
     
         27 . The shaft ( 100 ) of  claim 26 , wherein at least a portion of the coupler ( 3000 ) has a coupler flexural rigidity that is 100-500% greater than the tip portion flexural rigidity of a portion of the tip portion ( 2000 ), and at least a portion of the coupler ( 3000 ) has a coupler torsional rigidity that is 100-500% greater than the tip portion torsional rigidity of a portion of the tip portion ( 2000 ). 
     
     
         28 . The shaft ( 100 ) of  claim 24 , wherein the shaft length ( 130 ) is no more than 38″, and the shaft mass is at least 100 grams. 
     
     
         29 . The shaft ( 100 ) of  claim 24 , wherein a third portion of the shaft ( 100 ) extending ⅓ of the shaft length ( 130 ) from the shaft proximal end ( 120 ) has a third average flexural rigidity and a third average torsional rigidity, a fourth portion of the shaft ( 100 ) extending ⅔ of the shaft length ( 130 ) from the shaft distal end ( 110 ) has a fourth average flexural rigidity and a fourth average torsional rigidity, and the third average torsional rigidity is at least 50% of the fourth average torsional rigidity. 
     
     
         30 . The shaft ( 100 ) of  claim 24 , wherein the shaft flexural rigidity is constant throughout at least 10% of the shaft length ( 130 ), the shaft torsional rigidity is constant throughout at least 10% of the shaft length ( 130 ), and the first average torsional rigidity is at least 50% of the second average torsional rigidity. 
     
     
         31 . A golf club shaft ( 100 ), comprising:
 a shaft distal end ( 110 ), a shaft proximal end ( 120 ), a shaft outer diameter, a shaft length ( 130 ), and a shaft mass, wherein each point along the shaft length ( 130 ) has (i) a shaft flexural rigidity, and (ii) a shaft torsional rigidity;   the shaft ( 100 ) having a butt portion ( 1000 ) joined to a tip portion ( 2000 ) by a coupler ( 3000 );   the butt portion ( 1000 ) having a butt portion distal end ( 1010 ), a butt portion proximal end ( 1020 ), a butt portion length ( 1030 ), a butt portion sidewall ( 1040 ) having a butt portion sidewall thickness ( 1050 ), a butt portion inner diameter ( 1060 ) that varies, and a butt portion outer diameter ( 1070 ) of 0.500″-0.700″;   the tip portion ( 2000 ) having a tip portion distal end ( 2010 ), a tip portion proximal end ( 2020 ), a tip portion length ( 2030 ) that is no more than 65% of the butt portion length ( 1030 ), a tip portion sidewall ( 2040 ) having a tip portion sidewall thickness ( 2050 ), a tip portion inner diameter ( 2060 ), and a tip portion outer diameter ( 2070 ), wherein the tip portion outer diameter ( 2070 ) of a portion of the tip portion ( 2000 ) is at least 25% less than the butt portion outer diameter ( 1070 ) of a portion of the butt portion ( 1000 ), and the butt portion sidewall thickness ( 1050 ) of a portion of the butt portion ( 1000 ) is greater than the tip portion sidewall thickness ( 2050 ) of a portion of the tip portion ( 2000 );   the coupler ( 3000 ) having a coupler distal end ( 3010 ), a coupler proximal end ( 3020 ), a coupler length ( 3030 ), a coupler sidewall ( 3040 ) having a coupler sidewall thickness ( 3050 ), a coupler inner diameter ( 3060 ), and a coupler outer diameter ( 3070 );   the butt portion ( 1000 ) formed of a non-metallic butt portion material having a butt material density, a butt portion mass that is 35-75% of the shaft mass, and each point along the butt portion length ( 1030 ) having a butt portion flexural rigidity, and a butt portion torsional rigidity;   the tip portion ( 2000 ) formed of a metallic tip portion material having a tip material density that is at least 15% greater than the butt material density, and each point along the tip portion length ( 2030 ) having a tip portion flexural rigidity and a tip portion torsional rigidity, wherein the tip portion flexural rigidity of a portion of the tip portion ( 2000 ) is less than the butt portion flexural rigidity of a portion of the butt portion ( 1000 ), and the tip portion torsional rigidity of a portion of the tip portion ( 2000 ) is less than the butt portion torsional rigidity of a portion of the butt portion ( 1000 ); and   wherein a first portion of the shaft ( 100 ) extending ⅓ of the shaft length ( 130 ) from the shaft proximal end ( 120 ) has a first average flexural rigidity and a first average torsional rigidity, a second portion of the shaft ( 100 ) extending ⅔ of the shaft length ( 130 ) from the shaft distal end ( 110 ) has a second average flexural rigidity and a second average torsional rigidity, and the first average torsional rigidity is at least 50% of the second average torsional rigidity.   
     
     
         32 . The shaft ( 100 ) of  claim 31 , wherein a third portion of the shaft ( 100 ) extending ⅔ of the shaft length ( 130 ) from the shaft proximal end ( 120 ) has a third average flexural rigidity and a third average torsional rigidity, a fourth portion of the shaft ( 100 ) extending ⅓ of the shaft length ( 130 ) from the shaft distal end ( 110 ) has a fourth average flexural rigidity and a fourth average torsional rigidity, and the third average flexural rigidity is at least 50% of the fourth average flexural rigidity. 
     
     
         33 . The shaft ( 100 ) of  claim 32 , wherein the tip portion ( 2000 ) has a minimum tip portion flexural rigidity and a minimum tip portion torsional rigidity, the butt portion ( 1000 ) has a minimum butt portion flexural rigidity and a minimum butt portion torsional rigidity, the tip portion length ( 2030 ) is no more than 55% of the butt portion length ( 1030 ), the tip material density is at least twice the butt material density, the minimum tip portion flexural rigidity is at least 25% less than the minimum butt portion flexural rigidity, and the minimum tip portion torsional rigidity is at least 25% less than the minimum butt portion torsional rigidity. 
     
     
         34 . The shaft ( 100 ) of  claim 33 , wherein the coupler ( 3000 ) has a coupler mass that is no more than 15% of the shaft mass, the butt portion mass that is 40-70% of the shaft mass, and the tip portion ( 2000 ) has a tip portion mass that is 35-85% of the butt portion mass. 
     
     
         35 . The shaft ( 100 ) of  claim 34 , wherein the coupler ( 3000 ) is formed of a coupler material having a coupler material density, a coupler mass, and each point along the coupler length ( 3030 ) has (i) a coupler flexural rigidity, and (ii) a coupler torsional rigidity, wherein at least a portion of the coupler ( 3000 ) has a coupler flexural rigidity that is greater than the tip portion flexural rigidity of a portion of the tip portion ( 2000 ), and at least a portion of the coupler ( 3000 ) has a coupler torsional rigidity that is greater than the tip portion torsional rigidity of a portion of the tip portion ( 2000 ). 
     
     
         36 . The shaft ( 100 ) of  claim 35 , wherein the coupler flexural rigidity of at least a portion of the coupler ( 3000 ) is greater than the butt portion flexural rigidity of a portion of the butt portion ( 1000 ), and at least a portion of the coupler ( 3000 ) has a coupler torsional rigidity that is greater than the butt portion torsional rigidity of a portion of the butt portion ( 1000 ). 
     
     
         37 . The shaft ( 100 ) of  claim 36 , wherein at least a portion of the coupler ( 3000 ) has a coupler flexural rigidity that is 100-500% greater than the tip portion flexural rigidity of a portion of the tip portion ( 2000 ), and at least a portion of the coupler ( 3000 ) has a coupler torsional rigidity that is 100-500% greater than the tip portion torsional rigidity of a portion of the tip portion ( 2000 ). 
     
     
         38 . The shaft ( 100 ) of  claim 34 , wherein the shaft length ( 130 ) is no more than 38″, and the shaft mass is at least 100 grams. 
     
     
         39 . The shaft ( 100 ) of  claim 34 , wherein the shaft flexural rigidity is constant throughout at least 10% of the shaft length ( 130 ), the shaft torsional rigidity is constant throughout at least 10% of the shaft length ( 130 ), and the third average torsional rigidity is at least 50% of the fourth average torsional rigidity. 
     
     
         40 . A golf club shaft ( 100 ), comprising:
 a shaft distal end ( 110 ), a shaft proximal end ( 120 ), a shaft outer diameter, a shaft length ( 130 ), and a shaft mass, wherein each point along the shaft length ( 130 ) has (i) a shaft flexural rigidity, and (ii) a shaft torsional rigidity;   the shaft ( 100 ) having a butt portion ( 1000 ) joined to a tip portion ( 2000 );   the butt portion ( 1000 ) having a butt portion distal end ( 1010 ), a butt portion proximal end ( 1020 ), a butt portion length ( 1030 ), a butt portion sidewall ( 1040 ) having a butt portion sidewall thickness ( 1050 ), a butt portion inner diameter ( 1060 ) that varies, and a butt portion outer diameter ( 1070 ) of 0.500″-0.700″;   the tip portion ( 2000 ) having a tip portion distal end ( 2010 ), a tip portion proximal end ( 2020 ), a tip portion length ( 2030 ) that is no more than 65% of the butt portion length ( 1030 ), a tip portion sidewall ( 2040 ) having a tip portion sidewall thickness ( 2050 ), a tip portion inner diameter ( 2060 ), and a tip portion outer diameter ( 2070 ), wherein the tip portion outer diameter ( 2070 ) of a portion of the tip portion ( 2000 ) is at least 25% less than the butt portion outer diameter ( 1070 ) of a portion of the butt portion ( 1000 ), and the butt portion sidewall thickness ( 1050 ) of a portion of the butt portion ( 1000 ) is greater than the tip portion sidewall thickness ( 2050 ) of a portion of the tip portion ( 2000 );   the butt portion ( 1000 ) formed of a non-metallic butt portion material having a butt material density, a butt portion mass that is 35-75% of the shaft mass, and each point along the butt portion length ( 1030 ) having a butt portion flexural rigidity, and a butt portion torsional rigidity;   the tip portion ( 2000 ) formed of a metallic tip portion material having a tip material density that is at least 15% greater than the butt material density, and each point along the tip portion length ( 2030 ) having a tip portion flexural rigidity, and a tip portion torsional rigidity, wherein the tip portion flexural rigidity of a portion of the tip portion ( 2000 ) is less than the butt portion flexural rigidity of a portion of the butt portion ( 1000 ), and the tip portion torsional rigidity of a portion of the tip portion ( 2000 ) is less than the butt portion torsional rigidity of a portion of the butt portion ( 1000 );   wherein a first portion of the shaft ( 100 ) extending ⅔ of the shaft length ( 130 ) from the shaft proximal end ( 120 ) has a first average flexural rigidity and a first average torsional rigidity, a second portion of the shaft ( 100 ) extending ⅓ of the shaft length ( 130 ) from the shaft distal end ( 110 ) has a second average flexural rigidity and a second average torsional rigidity, the first average flexural rigidity is at least 50% of the second average flexural rigidity, and the first average torsional rigidity is at least 50% of the second average torsional rigidity; and   wherein a third portion of the shaft ( 100 ) extending ⅓ of the shaft length ( 130 ) from the shaft proximal end ( 120 ) has a third average flexural rigidity and a third average torsional rigidity, a fourth portion of the shaft ( 100 ) extending ⅔ of the shaft length ( 130 ) from the shaft distal end ( 110 ) has a fourth average flexural rigidity and a fourth average torsional rigidity, and the third average torsional rigidity is at least 50% of the fourth average torsional rigidity.