Adjustable Pulley Position for Compound Bow Cable Alignment

Solution Overview

Problem

Compound archery bows face misalignment issues due to the lateral deflection of power cables, leading to shooting inaccuracy, poor arrow flight, and accelerated wear, as the power cables' lines of force become misaligned with the shooting plane when deflected laterally.

Innovation Solution

The design allows for adjustable position and alignment of the power cable by fixing the pulley member at multiple transverse positions along its rotation axis, enabling optimization of the bow's performance parameters such as arrow grouping and accuracy by altering the pulley member's position or the power cable's alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the power cable is deflected laterally out of the shooting plane using a cable guard, then the power cable is prevented from interfering with arrow movement, but the lines of force become misaligned with the shooting plane causing shooting inaccuracy and lateral deflection of pulley members

Engineering Contradiction:

Improveinterference with arrow movementVSAvoidshooting accuracy

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The pulley member is made adjustable in its transverse position along the rotation axis, allowing dynamic repositioning to optimize alignment. The adjustment mechanism enables the pulley to be moved to different positions and secured, transforming a static misalignment problem into a dynamically adjustable configuration that can be optimized for both arrow clearance and shooting accuracy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the positional parameter of the pulley member along the rotation axis. By adjusting the transverse position of the pulley member, the alignment of the power cable and its lines of force can be optimized to maintain accuracy while still clearing the arrow path.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the pulley member position is fixed, then the structure is simple and reliable, but the power cable alignment cannot be optimized for different shooting conditions or accuracy requirements

Engineering Contradiction:

Improvealignment optimizationVSAvoidadjustment mechanism

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The pulley member is made adjustable in its transverse position along the rotation axis, allowing dynamic repositioning to optimize alignment. The adjustment mechanism enables the pulley to be moved to different positions and secured, transforming a static misalignment problem into a dynamically adjustable configuration that can be optimized for both arrow clearance and shooting accuracy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes the positional parameter of the pulley member along the rotation axis. By adjusting the transverse position of the pulley member, the alignment of the power cable and its lines of force can be optimized to maintain accuracy while still clearing the arrow path.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If the power cable is kept in a straight path, then the lines of force remain aligned with the shooting plane, but the power cable interferes with arrow movement in the shooting plane

Engineering Contradiction:

Improveshooting accuracyVSAvoidinterference with arrow movement

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The pulley member is made adjustable in its transverse position along the rotation axis, allowing dynamic repositioning to optimize alignment. The adjustment mechanism enables the pulley to be moved to different positions and secured, transforming a static misalignment problem into a dynamically adjustable configuration that can be optimized for both arrow clearance and shooting accuracy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Instead of deflecting the cable in the shooting plane (which causes interference), the invention moves the pulley member in a transverse dimension perpendicular to the shooting plane. This dimensional change allows the power cable to clear the arrow path without creating lateral force components that would affect shooting accuracy.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS9683806B1Compound archery bow with adjustable transverse position of pulley assembly

Publication Date: 2017.06.20 BOWTECH LLC

AI summary

A compound archery bow includes a pulley member that is rotatable on a transverse axle and that takes up a power cable as the bow is drawn. The pulley member is arranged so as to be fixed at any one of multiple transverse positions along its rotation axis relative to the bow limb by one or both of: (i) the transverse axle being retained on the bow limb at any one of multiple axle positions along the rotation axis by engagement of the transverse axle with the bow limb, or (ii) the pulley member being retained on the transverse axle at any one of multiple pulley positions along the transverse axle by engagement of the pulley member with the transverse axle. Performance characteristics of the bow can be optimized with respect to the transverse position of the pulley member along its rotation axis.