Single-cam compound archery bow

Abstract

A single-cam compound archery bow that includes a bow handle from which bow limbs project, a control wheel rotatably mounted on one end of one limb and a power <DEL-S DATE="20020212" ID="DEL-S-00001">can<DEL-E ID="DEL-S-00001"> <INS-S DATE="20020212" ID="INS-S-00001">cam <INS-E ID="INS-S-00001">rotatably mounted at an opposing end of the other limb. A power cable segment is anchored at one end to the one limb and at a second end to the power <DEL-S DATE="20020212" ID="DEL-S-00002">can<DEL-E ID="DEL-S-00002"> <INS-S DATE="20020212" ID="INS-S-00002">cam <INS-E ID="INS-S-00002">at a position to wrap into and unwrap from a power cable groove on the power cam. A bow string cable segment is anchored to the control wheel and to the power cam at positions to wrap into and unwrap from first and second bow string take-up grooves on the control wheel and power cam respectively. The bow string cable segment has a nock point disposed between the spaced limb ends. A control cable segment is anchored at one end to the control wheel at a position to wrap into and unwrap from a control groove on the control wheel, and is anchored at an opposing end to the power cam. As the bow string cable segment is drawn away from the handle, the bow string cable segment unwraps equally from the control wheel and power cam, wraps the power cable segment into the power cable groove on the power cam so as to draw the bow limb ends together up to a power let-off point at the power cable groove, and wraps the control cable segment into the control groove on the control wheel. Length of the power cable groove on the power cam, and position of the power let-off point on the power cam, are adjustable while maintaining a fixed separation between the power let-off point and the control cable anchor on the power cam, so that the nock point travels in a straight line as the bow string cable section is drawn and released independent of adjusted length of the power cable groove and position of the power let-off point.

Description

The present invention is directed to compound archery bows, and more particularly to a so-called single-cam compound archery bow having a power let-off cam mounted on the end of only one of the bow limbs.BACKGROUND AND OBJECTS OF THE INVENTIONCompound archery bows typically are of the so-called dual-cam design, originated in U.S. Pat. No. 3,486,495. Bows of this type typically comprise a bow handle having limbs mounted on and extending from opposed ends of the handle. Power let-off cams are rotatably mounted on the free ends of the bow limbs and are interconnected by one or more cable sections including a draw string section. As the bow draw string is drawn away from the handle, draw force initially increases as the limbs are drawn together and the cams rotate to a power let-off point, and thereafter the leverage increases and the draw force decreases as the cams rotate further but with little additional limb flexure. This so-called compound action allows full bow draw to be maintai...

AI Technical Summary

Benefits of technology

It is therefore a general object of the present invention to provide a compound bow that obtains the benefits of single-cam compound bow designs as compared with dual-cam designs--i.e., obtains uniform stressing of the bow limbs and straight-line (or substantially straight-line) nock travel--for a range of draw lengths. That is, an object of the present invention is to provide a single-cam compound bow in which the bow string draw length can be adjusted without deleteriously affecting other salutary operating characteristics of the bow. A more specific object of the present invention is to provide a single-cam compound bow of the described character in which bow string draw length can be adjusted by adjusting and / or replacing draw length modules on the bow power cam. A further and related object of the present invention is to provide a single-cam compound bow of the described character that obtains the foregoing objectives while employing standard cable lengths for economy of manufacture and service. Yet another object of the present invention is to provide a single-cam compound bow that has a positive bow string draw stop, which is deemed particularly desirable by archery enthusiasts, that automatically adjusts with draw length. A further object of the invention is to provide a single-cam compound bow in which torque applied to the power-cam limb, as the bow is drawn and released, is reduced or eliminated.

Problems solved by technology

A problem inherent in dual-cam bows of this type lies in the fact that the cams must be closely matched and synchronized with each other in order to insure straight-line (or substantially straight-line) travel of the nock point on the bow string, and the limbs must be closely balanced and evenly stressed as the string is drawn.

Damage to or mismatching of the cams, mismatch or incorrect adjustment of the limbs, or stretching of the cable sections can cause loss of synchronization between the cams and uneven stressing of the limbs, resulting in less than optimum performance of the bow.

In particular, the noted application does not disclose any means or technique for adjusting draw length of the bow.

However, since the cams and wheels are optimized for only a single draw length, changing the bow string anchor point inherently changes the path of nock travel as the bow is drawn and released, and consequently affects accuracy of the bow.

Another problem in single-cam compound bows heretofore proposed lies in the creation of a torque or twisting force on the bow limb that carries the power let-off cam, which varies as the bowstring is drawn and released.

This problem is exacerbated when a cable guard is employed on the bow because the cable guard offsets the control and power cable segments from the bow limb centerline.

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