Mechanical Broadhead With Interlocking Blades
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Solution Overview
Problem
Existing mechanical broadheads face issues with stress and impact energy consumption due to large blade deployment angles, and vulnerability to obstructions causing deflection or damage when blades are locked to the ferrule in the deployed configuration.
Innovation Solution
The mechanical broadhead features L-shaped blades pivoted about a common axis near the bend, with the short leg exposed during flight, levering the longer blade outward upon impact, and locking tabs preventing retraction, allowing blades to pivot freely if an obstruction is encountered, thus avoiding damage and deflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If blades are pivoted rearward of the center to achieve simple deployment mechanism, then deployment simplicity is improved, but stress on blades and hinge increases significantly
Solution Approach 1:
The patent inverts the conventional pivot location from rearward of the center to forward of the center. This reversal changes the deployment characteristics: instead of blades sweeping forward and locking to the ferrule, the blades sweep backward and lock to each other. This inversion resolves the contradiction by maintaining simple deployment mechanics while dramatically reducing stress on the hinge and blades through a more favorable force distribution geometry.
2Stability of the object's composition
If blades are locked to the ferrule in deployed configuration to maintain stability, then trajectory stability is improved, but vulnerability to obstructions increases causing deflection or damage
Solution Approach 1:
The patent segments the locking function from the ferrule by introducing interlocking locking tabs on the blades themselves. Instead of a single rigid lock to the ferrule, the blades lock to each other through their own tabs, creating a distributed, flexible locking system. This segmentation allows the blade assembly to maintain stability while accommodating obstructions through relative blade movement, resolving the contradiction between stability and obstruction vulnerability.
Solution Approach 2:
The patent introduces dynamic flexibility to the deployed configuration by allowing blades to pivot relative to each other while locked. The locking tabs prevent complete disassembly but permit controlled movement when encountering obstructions. This dynamic capability allows the broadhead to adapt to varying conditions, maintaining both stability during normal flight and reliability when encountering resistance.
3Shape
If blades pivot through large angle to achieve deployed configuration, then broadhead expansion is achieved, but impact energy consumption increases
Solution Approach 1:
The patent changes the pivot angle parameter from the conventional large rearward angle to a smaller forward angle. This parameter change reduces the arc through which the blades must travel during deployment, directly reducing the impact energy consumed. The forward pivot location enables effective broadhead expansion with a more energy-efficient motion path, resolving the contradiction between expansion achievement and energy consumption.
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 design reduces stress and impact energy consumption while maintaining penetration and trajectory stability by allowing blades to pivot away from obstructions, preventing damage and deflection, and enabling safe practice mode by locking the blades together rather than to the ferrule.
Implementation Method 1
Upon impact with the target, resistance from the target presses the exposed, short leg of the L backwards. This causes the short leg to lever the longer blade portion outward.
Data Source
AI summary
A mechanical broadhead arrowhead has moveable blades that deploy from a retracted in-flight configuration to an outward deployed configuration as the broadhead strikes the target. Once in the deployed configuration, the blades are locked to each other against the resistance of the target, but freely pivot about the ferrule. Accordingly, if one blade strikes an obstruction such as a solid bone, the blade assembly simply pivots out of the way without damaging the blade, deflecting the trajectory of the arrow, or halting its penetration into the target.