Crossbow with pivoting brackets

Abstract

A crossbow may include a stock assembly including a rail with a rail groove, a nock point and a trigger mechanism. A first bracket assembly is pivotally attached to the stock assembly, wherein the first bracket assembly includes a first roller and a first primary cam. A first limb has a rearward end attached to the stock assembly. A first roller engages a forward end of the first limb. A second bracket assembly is pivotally attached to the stock assembly. The second bracket assembly includes a second roller and a second primary cam. The second limb has a rearward end attached to the stock assembly. A second roller engages a forward end of the second limb. The first limb and the second limb extend on opposite lateral sides of the stock assembly. A bowstring extends between the first primary cam and the second primary cam. When the bowstring is pulled along the rail toward the nock point, the bowstring and control cables pull the first primary cam and the second primary cam toward the stock assembly thereby causing the first bracket assembly and the second bracket assembly to pivot toward the stock assembly, wherein during the pivoting the first roller bends the first limb toward the stock assembly to flex and store energy and the second roller bends the second limb toward the stock assembly to flex and store energy.

1 . An archery bow comprising:
 a stock assembly including a rail with a rail groove, a nock point and a trigger mechanism;   a first bracket assembly pivotally attached to the stock assembly, wherein the first bracket assembly includes a first roller and a first primary cam;   a first limb, wherein the first limb has a rearward end attached to the stock assembly, and wherein the first limb has a forward end, wherein the first roller engages the forward end of the first limb;   a second bracket assembly pivotally attached to the stock assembly, wherein the second bracket assembly includes a second roller and a second primary cam;   a second limb, wherein the second limb has a rearward end attached to the stock assembly, and wherein the second limb has a forward end, wherein the second roller engages the forward end of the second limb;   wherein the first limb and the second limb extend on opposite lateral sides of the stock assembly;   a bowstring extending between the first primary cam and the second primary cam; and   wherein when the bowstring is pulled along the rail toward the nock point, the bowstring pulls the first primary cam and the second primary cam toward the stock assembly thereby causing the first bracket assembly and the second bracket assembly to pivot toward the stock assembly, wherein during the pivoting the first roller bends the first limb toward the stock assembly to flex and store energy and the second roller bends the second limb toward the stock assembly to flex and store energy.   
     
     
         2 . The archery bow of  claim 1 , wherein the stock assembly comprises a first riser and a second riser, wherein the first riser and the second riser extend laterally from opposite sides of the stock assembly, wherein the rearward end of the first limb is attached to the first riser and wherein the rearward end of the second limb is attached to the second riser. 
     
     
         3 . The archery bow of  claim 2 , wherein a rearward end of the first bracket assembly is pivotally attached to the first riser and wherein a rearward end of the second bracket assembly is pivotally attached to the second riser. 
     
     
         4 . The archery bow of  claim 3 , wherein the rearward end of the first bracket assembly is pivotally attached to the first riser between the rearward end of the first limb and the rail, and wherein the rearward end of the second bracket assembly is pivotally attached to the second riser between the rearward end of the second limb and the rail. 
     
     
         5 . The archery bow of  claim 1 , wherein the first bracket assembly is pivotally attached to the stock assembly adjacent a forward end of the rail and wherein the second bracket assembly is pivotally attached to the stock assembly adjacent a forward end of the rail. 
     
     
         6 . The archery bow of  claim 1 ,
 wherein the first bracket assembly includes a first top pivot bracket and a first bottom pivot bracket, and a first gap is defined between the first top pivot bracket and the first bottom pivot bracket;   wherein the first roller is positioned within the first gap between the first top pivot bracket and the first bottom pivot bracket;   wherein the forward end of the first limb extends into the first gap to engage the first roller;   wherein the second bracket assembly includes a second top pivot bracket and a second bottom pivot bracket, and a second gap is defined between the second top pivot bracket and the second bottom pivot bracket;   wherein the second roller is positioned within the second gap between the second top pivot bracket and the second bottom pivot bracket; and   wherein the forward end of the second limb extends into the second gap to engage the second roller.   
     
     
         7 . The archery bow of  claim 1 , comprising
 a first secondary cam coaxially arranged and rotationally synchronized with the first primary cam;   a second secondary cam coaxially arranged and rotationally synchronized with the second primary cam; and   a control cable arrangement extending between the first secondary cam and the second secondary cam.   
     
     
         8 . The archery bow of  claim 1 , wherein the first roller rolls along a surface of the forward end of the first limb as the first roller bends the first limb toward the stock assembly, and wherein the second roller rolls along a surface of the forward end of the second limb as the second roller bends the first limb toward the stock assembly. 
     
     
         9 . An archery bow comprising:
 a stock assembly including a rail with a rail groove, a nock point and a trigger mechanism;   a first bracket assembly pivotally attached to the stock assembly, wherein the first bracket assembly includes a first primary cam;   a first limb, wherein the first limb has a rearward end attached to the stock assembly, and wherein the first limb has a forward end, wherein the first bracket assembly engages the forward end of the first limb;   a second bracket assembly pivotally attached to the stock assembly, wherein the second bracket assembly includes a second primary cam;   a second limb, wherein the second limb has a rearward end attached to the stock assembly, and wherein the second limb has a forward end, wherein the second bracket assembly engages the forward end of the first limb;   wherein the first limb and the second limb extend on opposite lateral sides of the stock assembly;   a bowstring extending between the first primary cam and the second primary cam; and   wherein when the bowstring is pulled along the rail toward the nock point, the bowstring operably causes the first bracket assembly and the second bracket assembly to pivot toward the stock assembly, wherein during the pivoting the first limb bends toward the stock assembly and the second limb bends toward the stock assembly.   
     
     
         10 . The archery bow of  claim 9 , wherein the stock assembly comprises a first riser and a second riser, wherein the first riser and the second riser extend laterally from opposite sides of the stock assembly, wherein the rearward end of the first limb is attached to the first riser and wherein the rearward end of the second limb is attached to the second riser. 
     
     
         11 . The archery bow of  claim 10 , wherein a rearward end of the first bracket assembly is pivotally attached to the first riser and wherein a rearward end of the second bracket assembly is pivotally attached to the second riser. 
     
     
         12 . The archery bow of  claim 11 , wherein the rearward end of the first bracket assembly is pivotally attached to the first riser between the rearward end of the first limb and the rail, and wherein the rearward end of the second bracket assembly is pivotally attached to the second riser between the rearward end of the second limb and the rail. 
     
     
         13 . The archery bow of  claim 9 , wherein the first bracket assembly is pivotally attached to the stock assembly adjacent a forward end of the rail and wherein the second bracket assembly is pivotally attached to the stock assembly adjacent a forward end of the rail. 
     
     
         14 . The archery bow of  claim 9 ,
 wherein the first bracket assembly includes a first top pivot bracket and a first bottom pivot bracket, and a first gap is defined between the first top pivot bracket and the first bottom pivot bracket;   wherein a first roller is positioned within the first gap between the first top pivot bracket and the first bottom pivot bracket;   wherein the forward end of the first limb extends into the first gap to engage the first roller;   wherein the second bracket assembly includes a second top pivot bracket and a second bottom pivot bracket, and a second gap is defined between the second top pivot bracket and the second bottom pivot bracket;   wherein a second roller is positioned within the second gap between the second top pivot bracket and the second bottom pivot bracket; and   wherein the forward end of the second limb extends into the second gap to engage the second roller.   
     
     
         15 . The archery bow of  claim 9 , comprising
 a first secondary cam coaxially arranged and rotationally synchronized with the first primary cam;   a second secondary cam coaxially arranged and rotationally synchronized with the second primary cam; and   a control cable arrangement extending between the first secondary cam and the second secondary cam.   
     
     
         16 . The archery bow of  claim 9 , wherein a first roller rolls along a surface of the forward end of the first limb as the first roller bends the first limb toward the stock assembly, and wherein a second roller rolls along a surface of the forward end of the second limb as the second roller bends the first limb toward the stock assembly. 
     
     
         17 . A method comprising:
 pulling a bowstring rearwardly along a rail of a crossbow stock assembly toward a nock point;   pivoting a first bracket assembly mounted to the stock assembly toward the stock assembly and pivoting a second bracket assembly mounted to the stock assembly toward the stock assembly;   wherein pivoting the first bracket assembly rolls a first roller along a surface of a first limb thereby bending the first limb toward the stock assembly;   wherein pivoting the second bracket assembly rolls a second roller along a surface of a second limb thereby bending the second limb toward the stock assembly;   holding the bowstring at a nock point; and   pulling a trigger of a trigger mechanism of the crossbow and releasing the bowstring from the nock point of the crossbow, wherein energy stored in the first limb and the second limb is released and the first limb and the second limb flex outward when the bowstring is released from the nock point, causing the bowstring to move forward along the rail.   
     
     
         18 . The method of  claim 17 ,
 wherein the first bracket assembly includes a first top pivot bracket and a first bottom pivot bracket, and a first gap is defined between the first top pivot bracket and the first bottom pivot bracket;   wherein the first roller is positioned within the first gap;   wherein a forward end of the first limb extends into the first gap to engage the first roller;   wherein the second bracket assembly includes a second top pivot bracket and a second bottom pivot bracket, and a second gap is defined between the second top pivot bracket and the second bottom pivot bracket;   wherein the second roller is positioned within the second gap; and   wherein a forward end of the second limb extends into the second gap to engage the second roller.   
     
     
         19 . The method of  claim 17 , wherein the first roller is arranged adjacent a forward end of the first bracket assembly and wherein the second roller is arranged adjacent a forward end of the second bracket assembly. 
     
     
         20 . The method of  claim 17 , wherein the first roller is arranged adjacent a rearward end of the first bracket assembly and wherein the second roller is arranged adjacent a rearward end of the second bracket assembly.