Archery Broadhead Spring Mechanism for Reliable Blade Deployment
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Solution Overview
Problem
Current mechanical broadheads face issues with accuracy due to aerodynamic differences from fixed blade designs, energy loss during blade opening, unreliability in opening at impact, and potential premature opening during flight, leading to inefficiencies and regulatory restrictions.
Innovation Solution
The design employs an internal spring to maintain blades in a closed position during flight and automatically open them upon impact using stored potential energy, ensuring consistent and reliable deployment without relying on target interaction for opening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If mechanical broadheads use forward momentum or kinetic energy of the flying arrow to open blades upon impact, then the blades can be deployed automatically, but the energy loss significantly diminishes the effectiveness of the arrow for penetrating the target
Solution Approach 1:
The spring is pre-compressed during assembly to store potential energy before flight. This preliminary action ensures that when the arrow impacts the target, the stored energy is immediately released to open the blades, eliminating the need to convert kinetic energy during impact and thus preventing energy loss.
2Extent of automation
If mechanical broadheads rely on target interaction to open blades, then automatic deployment is achieved, but the opening may be unreliable due to insufficient kinetic energy or incorrect angle of incidence
Solution Approach 1:
The spring mechanism is self-actuating and does not depend on external conditions such as target material, angle of incidence, or remaining kinetic energy. Upon impact, the spring automatically releases stored energy to open the blades, ensuring reliable and consistent operation under all hunting conditions.
3Measurement precision
If mechanical broadheads use moving blades that remain retracted during flight, then aerodynamics are improved and accuracy is maintained, but the blades may open prematurely during arrow flight
Solution Approach 1:
The spring is pre-compressed and held in a locked position during assembly and flight. This preliminary preparation ensures the blades remain securely closed during the entire flight, maintaining optimal aerodynamics and accuracy, while being ready to open immediately upon impact.
4Device complexity
If fixed blade broadheads are used, then structural simplicity is maintained, but the aerodynamics differ significantly from target points requiring re-adjustment of equipment settings
Solution Approach 1:
The broadhead uses movable blades that dynamically change position based on flight phase: closed during flight to match target point aerodynamics and maintain accuracy, and open upon impact to provide cutting effectiveness. This dynamic adaptation eliminates the need for equipment re-adjustment.
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 solution maintains arrow kinetic energy for effective penetration, enhances accuracy and reliability, and allows for use as either a mechanical or fixed blade broadhead, addressing the limitations of existing mechanical broadheads.
Implementation Method 1
A spring is provided having a first end exerting a force against the second cam follower... the spring exerting biasing force to secure the cutting blades in the closed position
Implementation Method 2
The first angled cam is configured to pivot the cutting blade to an intermediate position between the closed position and the open position responsive to rearward movement of the first cam follower
Implementation Method 3
When the cutting blades are in the intermediate position, the second cam follower exerts a force against the second cam surface to urge the cutting blades to the open position
Data Source
AI summary
Archery broadheads include one or more cutting blades which are folded in when shot from a bow. The blades deploy automatically using stored potential energy upon impact with minimal interaction with the target. The blades are attached to the main body of the broadhead and pivot near the leading or forward edge. The deployment is caused by a plunger tip cam releasing the stored potential energy of an internal spring mechanism and uses only minimal kinetic energy of the arrow to actuate. According to one exemplary embodiment, once actuated, the internal spring slides along a cam shaped part of the blades forcing them open. According to another exemplary embodiment, once actuated, the internal spring operates a slide connecting a toggle-link to the blades forcing them open. In both embodiments, the spring-slide mechanism holds the blades closed during flight, deploys the blades on contact and locks the blades open.