A base cam/power cam assembly for a compound bow is disclosed, the base cam/power cam assembly comprising: a) a base cam for letting out a draw cable when the assembly rotates as the bow is drawn, the base cam having an oblong shape with a major axis and a minor axis and an eccentric rotation axis substantially perpendicular to the plane of the base cam; b) a power cam for taking up a power cable when the assembly rotates as the bow is drawn, the power cam being secured to the base cam and having an oblong shape with a major axis and a minor axis and an eccentric rotation axis substantially perpendicular to the plane of the base cam and coinciding with the rotation axis of the base cam; and c) an eccentric attachment for securing the end of a let-out/take-up cable to the assembly and for letting out the let-out/take-up cable when the assembly rotates as the bow is drawn. The major axes of the base cam and power cam are angularly displaced from one another, and are arranged so that a draw cable lever arm increases and a power cable lever arm decreases when the assembly rotates as the bow is drawn. Efficiencies of at least 82% and as large as 94% are achieved.
RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 60/046,625, filed May 16, 1997, said provisional application being incorporated by reference as if fully set forth herein.
An archery bow (B) having at least one draw force module (1a or 1b). The module includes a concentric bowstring (3) pathway (12a) and at least one eccentric cable (6a) pathway (7a) with a decreasing radius proportional to the increasing spring rate of the flexing limb so the peak weight remains the same through a portion of the draw force curve and decreases at the end.
A compound bow includes a cam configuration permitting the force line of the harness cable to effectively act through a portion of the axle pin. This permits, in this bow design, 100% let-off. An adjustable bushing or a modular cam portion enables the archer to adjust the let-off in a range of between 85% and 99+%. Single and double cam bows are disclosed.
An archery bow having a substantially constant draw weight having a handle portion, a flexible upper limb supported by the handle portion, and a flexible lower limb supported by the handle portion. The bow also having an upper rotational assembly rotatably mounted upon the upper limb for rotation about a first axle. The upper rotational assembly having at least one upper cable track. a lower rotational assembly rotatably mounted upon the lower limb for rotation about a second axle. The lower rotational assembly having at least a first lower cable track and a second lower cable track. The first lower cable track being a cable payout track, the second lower cable track constructed and arranged to payout a predetermined length of cable and simultaneously take up a second predetermined length of cable when the second cam assembly is rotated.
An eccentric pulley assembly is provided for a compound bow, including an eccentric base cam having a peripheral track for letting out a draw string as the bow is drawn. A power cam secured to the base cam has a cable track for taking up a power cable as the bow is drawn and a shoulder is provided for spacing the track of the base cam from the track of the power cam.
In one aspect, the invention includes an archery bow cam assembly having a first body and a second body discrete from the first body. The first body defines a first portion of a sheave having an eccentric profile and the second body defines a second portion of the sheave. The second body is pivotally supported on the first body and is adjustably oriented relative to the first body for adjusting the eccentric profile. In another aspect, the invention includes an archery bow having a first limb, a second limb and a handle between the limbs. At least one rotating member is rotatably joined to at least one of the limbs, and the rotating member defines a first portion of a sheave having an eccentric profile. A body discrete from the rotating member defines a second portion of the sheave. The body is pivotally supported on the rotating member and is adjustably oriented relative to the rotating member for adjusting the eccentric profile. A string extends between the first and second limbs.
