Power Assist System for Compound Bow Draw
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Compound bows require increasing archer strength to draw and return the string to an at-rest position, especially for hunters, which can lead to uncontrolled movement and scare off targets, particularly in camouflaged or elevated positions.
Innovation Solution
A power assist system for compound bows that pre-stores energy before drawing the string, allowing the energy to be added to the limbs at the let-off region, reducing the force required to draw and return the bow, and enabling faster arrow propulsion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If compound bow strength is increased to achieve higher arrow velocity, then arrow speed improves, but the strength required by the archer to draw and return the string increases
Solution Approach 1:
The patent applies preliminary action by using a powered loading mechanism (such as a motor-driven winch or hydraulic system) to pre-draw the bow string to the desired position before the archer releases it. This eliminates the need for the archer to manually draw heavy compound bows, reducing the force requirement while maintaining high arrow velocity through pre-stored energy in the drawn limbs.
Solution Approach 2:
The patent replaces the manual mechanical drawing action with an automated powered system. Instead of relying on archer strength to overcome the high draw weight of stiff compound bow limbs, an electric motor, hydraulic actuator, or other powered mechanism performs the drawing function, substituting mechanical human effort with automated mechanical assistance.
2Measurement precision
If compound bow draw weight is increased to improve arrow performance, then arrow accuracy and range improve, but the ease of operation deteriorates due to difficulty in drawing and returning the string
Solution Approach 1:
The patent applies self-service by designing a system where the powered loading mechanism automatically draws and can automatically return the bow string to the at-rest position without requiring manual effort from the archer. The system serves itself by using stored energy (such as a spring-loaded winch or reversible motor) to perform both the drawing and returning functions, eliminating the operational difficulty of handling high draw-weight bows.
3Speed
If archer strength is increased to manually manage high-draw-weight bows, then arrow velocity improves, but uncontrolled movement of the bow is reduced
Solution Approach 1:
The patent applies feedback by incorporating sensors and control systems that monitor the bow's position and the powered loading mechanism's operation. The system provides real-time feedback to adjust the drawing and returning speed, ensuring controlled movement and stability. This prevents uncontrolled bow movement during the return to at-rest position while maintaining the high energy storage needed for arrow velocity.
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
The power assist system enables archers to achieve higher arrow velocities and accuracy, allowing for a more humane and efficient hunt by reducing the strength needed to manage the bow, thus minimizing movement and maintaining stealth.
Implementation Method 1
a resilient auxiliary member disposed between the at least one limb and the loading mechanism. The resilient auxiliary member may be pre-loaded with energy and/or may store energy when displaced from an initial position
Implementation Method 2
the compound bow has one or more pulleys or cams which have other cables attached to the opposite limbs. When the string is drawn back, the string causes the pulleys or cams to turn. As force is applied, and as this draw continues, an archer has a reduced mechanical advantage, but during the draw as the pulley or cams rotate, and the archer gains mechanical advantage over the bending limbs, more energy is stored in the limbs
Data Source
AI summary
A compound bow may feature the ability to pre-store energy before the drawing back of the draw string. Various embodiments contemplate that this may allow an archer to draw back the draw string or cable, and upon reaching the let off region of the compound bow's draw profile, cause the pre-stored energy to be transferred to the energy being stored by the bow. Various embodiments contemplate that this addition of pre-stored energy may give the archer more energy, held in the draw string or cable, to transfer to an arrow upon release, propelling it at greater speeds than would have been achieved with a compound bow of equal draw weight that does not feature an energy storage mechanism. Various embodiments contemplate that a system may provide for a return position of the draw.