Crossbow

Abstract

A crossbow having an energy storage system configured for storing energy when a bowstring is cocked at full-draw and releasing at least a portion of the stored energy when a trigger is pulled releasing the bowstring. The stored energy is defined by an area under a power-curve or draw-curve of the crossbow. The power-curve is defined by the force required to draw the bowstring from an un-cocked position to the cocked position. Between the un-cocked position and an intermediate position, the force required to draw the bowstring is substantially proportional to the draw distance. Between the intermediate position and the cocked position, the force required to draw the bowstring is substantially constant. When the cocked bowstring is released, at least a portion of the stored energy is transferred in the form of kinetic energy of an arrow or bolt nocked on the cocked bowstring.

1 . A crossbow, comprising:
 a bowstring translatable between a cocked position and an un-cocked position;   an intermediate position through which the bowstring passes when the bowstring translates between the cocked position and the un-cocked position; and   a draw force, wherein
 the draw force is substantially proportional to a distance between the un-cocked position and the intermediate position; and 
 the draw force is substantially constant between the intermediate position and the cocked position. 
   
     
     
         2 . The crossbow of  claim 1 , comprising:
 a coefficient of proportionality between 220.0 lb f  per inch of draw and 190.0 lb f  per inch of draw; and   between 220.0 lb f  and 190.0 lb f  of substantially constant draw force.   
     
     
         3 . The crossbow of  claim 1 , comprising:
 a coefficient of proportionality between 210.0 lb f  per inch of draw and 200.0 lb f  per inch of draw; and   between 210.0 lb f  and 200.0 lb f  of substantially constant draw force.   
     
     
         4 . The crossbow of  claim 1 , comprising:
 a coefficient of proportionality approximately 205.55 lb f  per inch of draw; and   approximately 205.55 lb f  of substantially constant draw force.   
     
     
         5 . The crossbow of  claim 1 , comprising between 8.5 inches and 6.5 inches between the un-cocked position and the intermediate position. 
     
     
         6 . The crossbow of  claim 1 , comprising between 8.0 inches and 7.0 inches between the un-cocked position and the intermediate position. 
     
     
         7 . The crossbow of  claim 1 , comprising approximately 7.4 inches between the un-cocked position and the intermediate position. 
     
     
         8 . The crossbow of  claim 1 , comprising between 14.0 inches and 12.0 inches between the cocked position and the un-cocked position. 
     
     
         9 . The crossbow of  claim 1 , comprising between 13.5 inches and 12.5 inches between the cocked position and the un-cocked position. 
     
     
         10 . The crossbow of  claim 1 , comprising approximately 13.125 inches between the cocked position and the un-cocked position. 
     
     
         11 . The crossbow of  claim 1 , comprising between 170.0 ft-lb f  and 150.0 ft-lb f  of stored energy when the bowstring is cocked. 
     
     
         12 . The crossbow of  claim 1 , comprising between 165.0 ft-lb f  and 155.0 ft-lb f  of stored energy when the bowstring is cocked. 
     
     
         13 . The crossbow of  claim 1 , comprising approximately 161.45 ft-lb f  of stored energy when the bowstring is cocked. 
     
     
         14 . The crossbow of  claim 1 , comprising a discharge kinetic energy between 158.0 ft-lb f  and 118.0 ft-lb f  for an arrow weighing approximately 380.8 grains. 
     
     
         15 . The crossbow of  claim 1 , comprising a discharge kinetic energy between 148.0 ft-lb f  and 128.0 ft-lb f  for an arrow weighing approximately 380.8 grains. 
     
     
         16 . The crossbow of  claim 1 , comprising approximately 137.8768 ft-lb f  of discharge kinetic energy for an arrow weighing approximately 380.8 grains. 
     
     
         17 . The crossbow of  claim 1 , comprising an efficiency between 95.0% and 75.0%. 
     
     
         18 . The crossbow of  claim 1 , comprising an efficiency between 90.0% and 80.0%. 
     
     
         19 . The crossbow of  claim 1 , comprising an efficiency of approximately 85.4%. 
     
     
         20 . The crossbow of  claim 1 , comprising a discharge velocity between 415.0 fps and 395.0 fps for an arrow weighing approximately 380.8 grains. 
     
     
         21 - 34 . (canceled)