Adjustable Pulley Assembly for Compound Archery Bow

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Solution Overview

Problem

Existing pulley assemblies for compound archery bows lack the ability to efficiently adjust draw length, draw weight, stored energy, and draw force curve, limiting customization and performance.

Innovation Solution

An adjustable pulley assembly comprising a draw cable pulley and a power cable pulley, where the mounting member and power cable pulley can be rigidly attached in multiple positions, allowing for adjustments that alter draw length, draw weight, stored energy, and draw force characteristics by changing the relative positions of the pulley components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed pulley assembly is used, then the structure is simple and reliable, but the draw length, draw weight, stored energy, and draw force curve cannot be adjusted

Engineering Contradiction:

Improveadjustability of draw characteristicsVSAvoidpulley assembly structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The pulley assembly transitions from a fixed structure to a dynamic, adjustable structure. The mounting member can be positioned at multiple locations on the draw cable pulley, and the power cable pulley can be rotated to different angular positions, allowing the system to adapt to different draw characteristics while maintaining a relatively simple overall structure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The pulley assembly is divided into separable components: the draw cable pulley, the mounting member, and the power cable pulley. This segmentation allows each component to be independently adjusted (mounting member position on draw cable pulley, power cable pulley rotation) to achieve different draw characteristics without redesigning the entire system.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If multiple adjustment positions are provided, then customization of draw characteristics is enabled, but the device complexity increases

Engineering Contradiction:

Improvecustomization of draw characteristicsVSAvoidnumber of positions and configurations

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mounting member and power cable pulley serve multiple functions: they provide structural support, enable cable routing, and allow adjustment of draw characteristics. By making these components multi-functional, the patent achieves customization capability without proportionally increasing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system achieves adjustment by changing positional parameters (mounting member location on draw cable pulley, angular position of power cable pulley) rather than adding complex mechanical adjustment mechanisms. This parameter-based adjustment approach enables customization while keeping the structural complexity relatively low.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the power cable pulley is fixed relative to the draw cable pulley, then the structure is stable, but the draw force curve and stored energy cannot be optimized

Engineering Contradiction:

Improvestructural stabilityVSAvoidoptimization of draw force curve

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The relationship between the power cable pulley and draw cable pulley is made dynamic rather than fixed. The power cable pulley can be rotated to different angular positions and the mounting member can be repositioned, allowing optimization of the draw force curve and stored energy while maintaining structural stability through rigid attachment at selected positions.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables precise customization of draw characteristics, providing a range of draw lengths, weights, and energy levels, enhancing the performance and adaptability of compound archery bows.

Implementation Method 1

the draw cable pulley is mounted on a first limb of an archery bow to rotate about the first pulley assembly axis

Methodology Applied

Scientific EffectRotation:

Implementation Method 2

the power cable pulley member... takes up the power cable when the bow is drawn and the draw cable pulley rotates about the first pulley assembly axis

Methodology Applied

Scientific EffectRotation:

Data Source

PatentUS9347730B2Adjustable pulley assembly for a compound archery bow

Publication Date: 2016.05.24 BOWTECH LLC

AI summary

A pulley assembly for a compound bow comprises a draw cable pulley rotatable about a first axis, a mounting member attached to the draw cable pulley and adjustable among multiple positions, and a power cable pulley attached to the mounting member and adjustable among multiple positions about a second axis. Movement of the mounting member shifts the second axis relative to the first axis. Movement of one or both of the mounting member or power cable pulley alters one or more of the bow's draw force curve, draw length, draw weight, or stored energy.