Crossbow

A crossbow comprising;

• first and second flexible limbs attached to a center rail;
• a first string guide mounted to the first flexible limb by a first axle mount and rotatable around a first axis located a fixed distance from the first flexible limb by the first axle mount, the first string guide comprising a first draw string journal having a first plane of rotation perpendicular to the first axis, and first upper and lower power cable journals on opposite sides of the first draw string journal each comprising a path that is not co-planar with the first plane of rotation;
• a second string guide mounted to the second flexible limb by a second axle mount and rotatable around a second axis located a fixed distance from the second flexible limb by the second axle mount, the second string guide comprising a second draw string journal having a second plane of rotation perpendicular to the second axis, and second upper and lower power cable journals on opposite sides of the second draw string journal each comprising a path that is not co-planar with the second plane of rotation;
• a draw string received in the first and second string guide journals, wherein the draw string unwinds from the first and second string guide journals as it translates from the released configuration to a drawn configuration;
• a pair of first power cables having first ends received in the first upper and lower power cable journals and second ends attached to attachment points on the crossbow;
• and
• a pair of second power cables having first ends received in the second upper and lower power cable journals and second ends attached to attachment points on the crossbow,
• wherein the first and second upper and lower power cable journals displace the pairs of power cables along the first and second axes relative to the first and second planes of rotation, respectively, the first and second pairs of power cables wrap onto the respective first and second upper and lower power cable journals, and the first and second axes move continuously toward the center rail as the draw string is moved from the released configuration to the drawn configuration, and the first and second pairs of power cables unwrap from the respective first and second upper and lower power cable journals as the drawstring is moved between the drawn configuration to the released configuration.

A method of operating a crossbow comprising the steps of:

• locating a draw string in first and second draw string journals on first and second cams mounted to first and second flexible limbs by first and second axle mounts, the first and second flexible limbs are attached to a center rail, the first and second draw string journals having first and second planes of rotation that are perpendicular to first and second axes of rotation located fixed distances from the first and second flexible limbs by the first and second axle mounts, respectively, and first and second upper and lower helical power cable take-up journal on opposite sides of the first and second draw string journals comprising paths that are not co-planar with the first and second planes of rotation;
• translating the draw string from the released configuration to a drawn configuration so the draw string unwinds from the draw string journals as the first and second cams rotate around the first and second axes;
• wrapping first and second pairs of power cables onto the first and second upper and lower helical power cable take-up journals and moving the first and second axes continuously toward the center rail as the draw string translates from the released configuration to the drawn configuration, the first and second pairs of power cables having first ends attached to the first and second cams and second ends attached to static attachment points on the crossbow;
• displacing the first and second pairs of power cables along the first and second axes relative the first and second planes of rotation as the bow string is translated from the released configuration to the drawn configuration;
• and
• unwrapping the first and second pairs of power cables from first and second upper and lower helical power cable take-up journals as the draw string translates from the drawn configuration to the released configuration.