Compound archery crossbow

Abstract

The invention is directed to a compound archery crossbow wherein the power cables and the bowstring remain substantially parallel allowing the bowstring to be positioned for increased power and accuracy of an arrow and/or wherein the power stroke has been extended by positioning the bowstring farther from the string catch.

1 . A compound archery crossbow comprising:
 a) a stock with a barrel;   b) at least one right limb and at least one left limb, wherein the at least one right limb and at least one left limb are mounted to the stock by a riser;   c) a first cam and a second cam, wherein the first cam comprises a first let-out groove, a second let-out groove and a take-up groove, and the second cam comprises a first let-out groove, a second let-out groove and a take-up groove;   d) a first power cable extending from the first let-out groove of the first cam to the take-up groove of the second cam;   e) a second power cable extending from the first let-out groove of the second cam to the take-up groove of the first cam;   f) a bowstring extending from the second let-out groove of the first cam to the second let-out groove of the second cam;   g) a first axel assembly that extends through the first cam and the at least one right limb; and   h) a second axel assembly that extends through the second cam and the at least one left limb,   wherein draw of the bowstring from the second let-out groove of the first and second cams rotates the first and second cams about the first and second axel assemblies and lets out portions of the first and second power cables from the first let-out groove on the first and second cams while taking up portions of the first and second power cables in the take up grooves of the first and second cams.   
     
     
         2 . The crossbow of  claim 1 , wherein the bowstring, the first power cable and the second power cable are substantially parallel, wherein the upper pair and the lower pair of limbs are parallel. 
     
     
         3 . The crossbow of  claim 2 , wherein the second let-out groove is positioned between the first let-out groove and the take-up groove in the first and second cam. 
     
     
         4 . The crossbow of  claim 3 , wherein the first let-out groove, the second let-out groove and the take-up groove of the second cam and the first let-out groove, the second let-out groove and the take-up groove of the first cam are inverted with respect to each other. 
     
     
         5 . The crossbow of  claim 4 , wherein the first part of the first axel assembly and first part of the second axel assembly have opposite rotation movement. 
     
     
         6 . The crossbow of  claim 5 , wherein each of the first let-out groove, the second let-out groove and the take-up groove of the first cam and the second cam comprises a base having a periphery on which the bowstring, first power cable and second cable are disposed, wherein the base of the first let-out groove of the first cam and the second cam are of substantially the same dimension, the base of the second let-out groove of the first cam and the second cam are of substantially the same dimension and the base of the take-up groove of the first cam and the second cam are of substantially the same dimension. 
     
     
         7 . The crossbow of  claim 6 , wherein the bowstring is positioned between the riser and the first and second power cables. 
     
     
         8 . The crossbow of  claim 7 , wherein the at least one right limb, the at least one left limb, the first cam, and the second cam extend forward of the riser. 
     
     
         9 . The crossbow of  claim 6 , wherein the first and second power cables are positioned between the riser and the bowstring. 
     
     
         10 . The crossbow of  claim 9 , wherein the at least one right limb, the at least one left limb, the first cam, and the second cam extend forward of the riser. 
     
     
         11 . A compound archery crossbow comprising:
 a) a stock with a barrel;   b) an right pair and a left pair of limbs, wherein the right pair of limbs has a first member comprising a distal end and a proximal end and a second member comprising a distal end and a proximal end and the left pair of limbs has a first member comprising a distal end and a proximal end and a second member comprising a distal end and a proximal end, wherein the right pair and the left pair of limbs are mounted to the stock by a riser, wherein an attachment means attaches the proximal end of the first member and the second member of the right pair of limbs and the proximal end of the first member and the second member of the left pair of limbs to the riser, and wherein the first member and the second member of the right pair of limbs are parallel and the first member and the second member of the left pair of limbs of limbs are parallel;   c) a first cam and a second cam, wherein the first cam comprises a first let-out groove, a second let-out groove and a take-up groove, and the second cam comprises a first let-out groove, a second let-out groove and a take-up groove, wherein the second let-out groove is positioned between the first let-out groove and the take-up groove in the first and second cam, wherein the first let-out groove, the second let-out groove and the take-up groove of the second cam and the first let-out groove, the second let-out groove and the take-up groove of the first cam are inverted with respect to each other;   d) a first power cable extending from the first let-out groove of the first cam to the take-up groove of the second cam;   e) a second power cable extending from the first let-out groove of the second cam to the take-up groove of the first cam;   f) a bowstring extending from the second let-out groove of the first cam to the second let-out groove of the second cam, wherein the bowstring is positioned between the riser and the first and second power cables; and   g) a first axel assembly extending through the first cam and the distal ends of the first member and second member of the right pair of limbs and a second axel assembly extending through the second cam and the distal ends of the first member and second member of the left pair of limbs,   wherein draw of the bowstring away from the riser lets out the bowstring from the second let-out groove of the first and second cam, rotates around the first and second axel assembly and lets out portions of the first and second power cables from the first let-out groove on the first and second cam.   
     
     
         12 . The crossbow of  claim 11 , wherein the bowstring, the first power cable and the second power cable are substantially parallel. 
     
     
         13 . The crossbow of  claim 12 , wherein the first part of the first axel assembly and first part of the second axel assembly have opposite rotation movement. 
     
     
         14 . The crossbow of  claim 13 , wherein each of the first let-out groove, the second let-out groove and the take-up groove of the first cam and the second cam comprises a base having a periphery on which the bowstring, first power cable and second cable are disposed, wherein the base of the first let-out groove of the first cam and the second cam are of substantially the same dimension, the base of the second let-out groove of the first cam and the second cam are of substantially the same dimension and the base of the take-up groove of the first cam and the second cam are of substantially the same dimension. 
     
     
         15 . The crossbow of  claim 14 , wherein at least one base of the first let-out groove, the second let-out groove and the take-up groove of the first cam and the second cam includes a post mounted thereto. 
     
     
         16 . The crossbow of  claim 14 , wherein the base of the take-up groove on the first and second cam includes a draw stop. 
     
     
         17 . The crossbow of  claim 14 , wherein the attachment is limb caps. 
     
     
         18 . The crossbow of  claim 14 , wherein the crossbow further comprises a receiver attached to the barrel, wherein the receiver comprises a bowstring catch, safety and trigger linkage. 
     
     
         19 . The crossbow of  claim 14 , wherein the stock includes a trigger attached to the trigger linkage, to release the bowstring form a string catch in the receiver in the loaded position. 
     
     
         20 . The crossbow of  claim 14 , wherein a groove on the barrel is positioned to hold an arrow, wherein vanes of an arrow would not contact the first or second power cable when traversed by an arrow. 
     
     
         21 . The crossbow of  claim 14 , wherein at least one base of the first let-out groove, the second let-out groove and the take-up groove of the first cam and the second cam is circular. 
     
     
         22 . The crossbow of  claim 14 , wherein at least one base of the first let-out groove, the second let-out groove and the take-up groove of the first cam and the second cam is non-circular. 
     
     
         23 . A compound archery crossbow comprising:
 a) a stock with a barrel;   b) limbs mounted to the stock by a riser;   c) a first cam and a second cam, wherein the first cam comprises at least a first let-out groove and a take-up groove, and the second cam comprises at least a first let-out groove and a take-up groove;   d) a first axel assembly extending through the first cam and the limbs;   e) a second axel assembly extending through the second cam and the limbs;   f) at least one independent groove traversed by the first axel assembly and at least one independent groove traversed by the second axel assembly;   g) a first power cable extending from an anchor at the at least one independent groove traversed by the first axel assembly to the take-up groove of the second cam;   h) a second power cable extending from an anchor at the at least one independent groove traversed by the second axel assembly to the take-up groove of the first cam;   i) a bowstring extending from the first let-out groove of the first cam to the at least first let-out groove of the second cam;   wherein draw of the bowstring from the at least first let-out groove of the first cam and the at least first let-out groove of the second cam rotates the first cam around the first axle assembly and the second cam around the second axle assembly such that the a portion of the first power cable is pulled into the take-up groove on the first cam and a portion of the second power cable is pulled into the take-up groove on the second cam.   
     
     
         24 . The crossbow of  claim 23 , wherein the first axel assembly and the second axel assembly have opposite rotational movement. 
     
     
         25 . The crossbow of  claim 24 , wherein the bowstring is positioned between the riser and the first and second power cables. 
     
     
         26 . The crossbow of  claim 25 , wherein the limbs, the first cam, and the second cam extend forward of the riser. 
     
     
         27 . The crossbow of  claim 25 , wherein the bowstring, the first power cable, and the second power cable are substantially parallel. 
     
     
         28 . The crossbow of  claim 27 , wherein the at least first let-out groove of the first cam is positioned between the anchor at the at least one independent groove traversed by the first axle assembly and the take-up groove on the first cam and the at least first let-out groove of the second cam is positioned between the anchor at-the at least one independent groove traversed by the second axle assembly and the take-up groove on the second cam. 
     
     
         29 . The crossbow of  claim 28 , wherein the at least one let-out groove and the take-up groove traversed by the first axel assembly are inverted in position with respect to the at least one let-out groove and the take-up groove traversed by the second axel assembly. 
     
     
         30 . The crossbow of  claim 29 , wherein the at least one independent groove traversed by the first axel assembly is disposed below the at least first let-out groove of the first cam and the at least one independent let-out groove traversed by the second axel assemble is disposed above the at least first let-out groove of the second cam. 
     
     
         31 . The crossbow of  claim 30 , wherein the first and second power cables are positioned between the riser and the bowstring. 
     
     
         32 . The crossbow of  claim 31 , wherein the limbs, the first cam, and the second cam extend forward of the riser. 
     
     
         33 . The crossbow of  claim 25 , wherein a second let-out groove is provided with the take-up groove as a hybrid groove on the first cam and replaces the independent groove traversed by the first axle assembly, and a second let-out groove is provided with the take-up groove as a hybrid groove on the second cam and replaces the independent groove traversed by the second axel assembly. 
     
     
         34 . The crossbow of  claim 33 , wherein the stock has a forked portion that is traversed by the first and second power cable, wherein means is positioned within the forked portion to guide the first and second power cables. 
     
     
         35 . The crossbow of  claim 33 , wherein the limbs and first came and second cam extend forward of the riser.