Bow Energy Storage System Cam Lean Reduction
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Solution Overview
Problem
Conventional reverse-draw bow configurations experience 'cam lean' and wear due to frictional contact between power cables at their intersection, which increases the size of the cam and affects performance.
Innovation Solution
The design incorporates a bow with first and second wheels, each having upper and lower pulleys, a spool, and power cords that minimize cam lean by eliminating spiraling grooves and ensuring the power cords wrap and unwrap efficiently around the pulleys, reducing friction and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If power cables are arranged to cross each other in reverse-draw configuration, then the power stroke is increased, but cam lean and cable wear occur due to frictional contact at the intersection point
Solution Approach 1:
The patent introduces an intermediary component (cable guide or pulley system) at the intersection point of the power cables. This intermediary redirects the cables to prevent direct frictional contact while maintaining the crossing arrangement necessary for reverse-draw configuration, thereby reducing wear and cam lean without sacrificing power stroke length
2Ease of operation
If spiral grooves are added to cams for cable reception, then cable wrapping and unwrapping is enabled, but the cam size increases
Solution Approach 1:
The patent transitions from two-dimensional spiral grooves on the cam surface to a three-dimensional cable management system using separate guide pulleys or blocks. This dimensional change allows cables to wrap and unwrap without requiring enlarged cam grooves, maintaining compact cam size while enabling proper cable reception and guidance
3Length of moving object
If conventional reverse-draw configuration with crossing cables is used, then power stroke is increased, but mechanical stress and friction on components increase
Solution Approach 1:
The patent employs intermediary pulleys or cable guides at strategic positions to redirect the power cables, reducing the angle of intersection and distributing mechanical stress more evenly across the system. This maintains the power stroke advantage of reverse-draw configuration while minimizing friction and stress concentrations on individual components
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
This configuration minimizes 'cam lean' and wear, enhancing the bow's performance by maintaining a consistent power stroke and reducing mechanical stress on components.
Implementation Method 1
the cables are in frictional contact at the point of intersection
Implementation Method 2
first and second wheels, each having upper and lower pulleys
Implementation Method 3
a spool extending between and affixed to the upper and lower pulleys
Data Source
AI summary
An energy storage system for a bow, the system defined at least in part by a riser, a first and second limb each having a first end coupled to the riser, a first and second wheel disposed at a second end of respective first and second limbs, a first and second power cord each having a first end coupled to the riser and a second end coupled to respective first and second wheels, and a string extending between and coupled to the first and second wheels.