Billiard cue shaft for reducing deflection

Abstract

A billiard cue shaft includes a shaft body having first and second ends, a longitudinal axis and a first length. The shaft body includes a wooden rod and an outer layer of fiber reinforced plastic (FRP) wrapped around the surface of the wooden rod. The shaft body further includes a straight section with a first outer diameter and a second length, and a tapered section. The wooden rod has a bore with a predetermined inner diameter and a predetermined depth. The predetermined depth of the bore of the wooden rod is about 15% to 55% of the first length of the shaft body. The predetermined inner diameter of the bore of the wooden rod is about 51% to 81% of the first outer diameter of the straight section of the shaft body. The billiard cue shaft thereby has the advantage of natural wood and can decrease the deflection.

What is claimed is: 
     
         1 . A billiard cue shaft comprising:
 a shaft body having a first end, a second end, a longitudinal axis and a first length extending from the first end along the longitudinal axis to the second end;   the shaft body including a wooden rod and an outer layer of fiber reinforced plastic (FRP) wrapped around the surface of the wooden rod;   the shaft body further including a straight section with a first outer diameter and a second length extending from the first end thereof toward the second end, and a tapered section extending from an end of the straight section to the second end of the shaft body;   the wooden rod having a bore with a predetermined inner diameter and a predetermined depth extending from the first end along the longitudinal axis to the second end;   the predetermined depth of the bore of the wooden rod being about 15% to 55% of the first length of the shaft body; and   the predetermined inner diameter of the bore of the wooden rod being about 51% to 81% of the first outer diameter of the straight section of the shaft body.   
     
     
         2 . The billiard cue shaft of  claim 1 , wherein the outer layer comprises fiberglass impregnated with epoxy resin. 
     
     
         3 . The billiard cue shaft of  claim 1 , wherein the predetermined depth of the bore is equal to or less than the second length of the straight section of the shaft body. 
     
     
         4 . The billiard cue shaft of  claim 1 , wherein the second length of the straight section of the shaft body is about 31% to 54% of the first length of the shaft body. 
     
     
         5 . The billiard cue shaft of  claim 4 , wherein the first length of the shaft body is about 711 mm to 813 mm. 
     
     
         6 . The billiard cue shaft of  claim 5 , wherein the first length of the shaft body is about 737 mm. 
     
     
         7 . The billiard cue shaft of  claim 6 , wherein the second length of the straight section of the shaft body is about 394 mm. 
     
     
         8 . The billiard cue shaft of  claim 7 , wherein the predetermined depth of the bore of the wooden rod is about 370 mm. 
     
     
         9 . The billiard cue shaft of  claim 5 , wherein the first outer diameter of the straight section of the shaft body is about 10.5 mm to 13.5 mm. 
     
     
         10 . The billiard cue shaft of  claim 9 , wherein the inner diameter of the bore  32  is about 5.36 mm to 10.94 mm. 
     
     
         11 . The billiard cue shaft of  claim 9 , wherein the first outer diameter of the straight section of the shaft body is about 12.75 mm. 
     
     
         12 . The billiard cue shaft of  claim 11 , wherein the predetermined inner diameter of the bore of the wooden rod is about 8.50 mm. 
     
     
         13 . The billiard cue shaft of  claim 9 , wherein the thickness of the outer layer is about 3.6% to 5.8% of the first outer diameter of the straight section of the shaft body. 
     
     
         14 . The billiard cue shaft of  claim 13 , wherein the thickness of the outer layer is about 0.74 mm. 
     
     
         15 . The billiard cue shaft of  claim 5 , wherein the weight of the shaft is about 96 grams to 120 grams. 
     
     
         16 . The billiard cue shaft of  claim 15 , wherein the weight of the shaft is about 106 grams.