Lever system for lever bow
An archery bow is disclosed. Bows of the present disclosure comprise lever cams. The lever cam includes a base and an elongated lever arm that extends upwards or downwards, depending on which end of the bow the lever cam is attached to. The lever cams are rotatably secured between the split limbs of the bow. In some embodiments, the bows include an adjustment screw to change the position of an offset axle relative to a lever axle. In other embodiments, the bows include a pair of adjustable bowstring modules attachable to the respective elongated lever arms to alter the draw length of the bowstring.
1 . An archery bow, comprising:
a riser configured as a handle of the archery bow;
an upper limb attached to an upper portion of the riser, wherein the upper limb comprises an upper left limb and an upper right limb;
a lower limb attached to a lower portion of the riser, wherein the lower limb comprises a lower left limb and a lower right limb;
an upper lever cam assembly including an upper lever cam with a base and an elongated lever arm extending upward from the base and a first lever axle, wherein the upper lever cam is rotatably attached between the upper left and upper right limbs via the first lever axle;
a lower lever cam assembly including a lower lever cam with a base and an elongated lever arm extending downward form the base and a second lever axle, wherein the lower lever cam is rotatably attached between the lower left and lower right limbs via the second lever axle;
a first power cable with a first end anchored to the base of the upper lever cam in a take-up position and a second end;
a second power cable with a first end anchored to the base of the lower lever cam in a take-up position and a second end; and
a bowstring with a first end extending up and over a rearward side of the elongated lever arm of the upper lever cam and anchored to the upper lever cam, and a second end extending down and under a rearward side of the elongated lever arm of the lower lever cam and anchored to the lower lever cam;
wherein the upper lever cam assembly includes upper offset axle portions extending from the upper lever cam base parallel to the first lever axle, wherein the second end of the second power cable includes a pair of ends anchored to the upper offset axle portions;
wherein the lower lever cam assembly includes lower offset axle portions extending from the lower lever cam base parallel to the second lever axle, wherein the second end of the first power cable includes a pair of ends anchored to the lower offset axle portions;
wherein the upper offset axle portions are a single piece forming an upper offset axle extending through the upper lever cam, and wherein the lower offset axle portions are a single piece forming a lower offset axle extending through the lower lever cam;
an upper adjustment screw engaged between the upper lever cam base and the upper offset axle, wherein the upper offset axle extends through a slot in the upper lever cam base, and wherein rotation of the upper adjustment screw alters the position of the upper offset axle through the upper lever cam relative to the upper lever axle; and
a lower adjustment screw engaged between the lower lever cam base and the lower offset axle, wherein the lower offset axle extends through a slot in the lower lever cam base, and wherein rotation of the lower adjustment screw alters the position of the lower offset axle through the lower lever cam relative to the lower lever axle.
2 . The archery bow of claim 1 , wherein the upper offset axle portions are a pair of pieces extending from opposing sides of the upper lever cam, and wherein the lower offset axle portions are a pair of pieces extending from opposing sides of the lower lever cam.
3 . The archery bow of claim 1 , wherein rotating the upper adjustment screw rotates the upper lever cam relative to the limbs of the bow.
4 . The archery bow of claim 3 , wherein the upper adjustment screw is rotatable to specific positions to allow an archer to choose a draw length of the bow.
5 . The archery bow of claim 3 , wherein the upper adjustment screw comprises a worm gear perpendicularly extending through the upper offset axle.
6 . The archery bow of claim 4 , wherein the upper adjustment screw and the lower adjustment screw are rotated to a matched position such that the upper lever cam assembly and the lower lever cam assembly are synchronized during draw and release of the bow.
7 . The archery bow of claim 1 , wherein the second ends of the first power cable and the second power cable are attached to power cable anchors at opposing ends of the upper offset axle and the lower offset axle.
8 . An archery bow, comprising:
a riser configured as a handle of the archery bow;
an upper limb attached to an upper portion of the riser, wherein the upper limb comprises an upper left limb and an upper right limb;
a lower limb attached to a lower portion of the riser, wherein the lower limb comprises a lower left limb and a lower right limb;
an upper lever cam assembly including an upper lever cam with a base and an upper elongated lever arm extending upward from the base and a first lever axle, wherein the upper lever cam is rotatably attached between the upper left and upper right limbs via the first lever axle;
a lower lever cam assembly including a lower lever cam with a base and a lower elongated lever arm extending downward form the base and a second lever axle, wherein the lower lever cam is rotatably attached between the lower left and lower right limbs via the second lever axle;
a first power cable with a first end anchored to the base of the upper lever cam in a take-up position and a second end anchored to the lower lever cam assembly;
a second power cable with a first end anchored to the base of the lower lever cam in a take-up position and a second end anchored to the upper lever cam assembly; and
a bowstring with a first end extending up and over a rearward side of the elongated lever arm of the upper lever cam and anchored to the upper lever cam, and a second end extending down and under a rearward side of the elongated lever arm of the lower lever cam and anchored to the lower lever cam; and
a pair of bowstring modules respectively coupled to the upper elongated lever arm and the lower elongated lever arm to receive and route the bowstring.
9 . The archery bow of claim 8 , wherein the upper elongated lever arm and the lower elongated lever arm each include a series of bores to couple the bowstring modules to the elongated lever arms.
10 . The archery bow of claim 9 , wherein the bowstring modules are attachable to different bores of the series of bores to define different draw lengths of the archery bow.
11 . The archery bow of claim 10 , wherein the bowstring modules are coupled to matched sets of bores on the upper elongated lever arm and the lower elongated lever arm to synchronize the lever cams.
12 . The archery bow of claim 8 , wherein the bowstring modules each include a groove guide extending from the module engaging the respective upper elongated lever arm and the lower elongated lever arm to align the bowstring module on the respective upper lever cam and lower lever cam.