Collapsible Broadhead With Biasing Blades For Bone Penetration
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Solution Overview
Problem
Conventional arrowhead designs often fail to reliably penetrate bone, resulting in wounded animals that may suffer and escape, as they get stuck in bone rather than continuing to penetrate and cause a fatal wound.
Innovation Solution
A collapsible broadhead design with pivotally interconnected blade members and biasing members that allow the blade members to retract during bone penetration and extend on either side to maximize flesh cutting, ensuring clean passage through bone and effective killing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional blade designs are used to penetrate bone, then the arrowhead structure is simple, but the reliability of bone penetration is poor and the arrowhead gets stuck in bone
Solution Approach 1:
The blade members are designed to be movable rather than fixed, capable of pivoting between extended and retracted positions. This dynamic structure allows the blades to automatically adjust their configuration during penetration - extended for cutting flesh and retracted for penetrating bone - thereby resolving the contradiction between penetration reliability and structural complexity
Solution Approach 2:
The blade assembly is segmented into multiple independent blade members that can move relative to each other and the ferrule body. This segmentation allows each blade to independently respond to the penetration medium, improving reliability by ensuring that at least some blades remain effective for cutting while others retract for bone penetration
2Area of moving object
If blade members are extended to maximize flesh cutting, then the cutting surface area is increased, but the arrowhead cannot penetrate bone cleanly
Solution Approach 1:
The blade members dynamically change their effective area by pivoting between extended and retracted positions. When extended, they provide maximum cutting surface area for flesh penetration; when retracted, they minimize the profile for clean bone penetration. This dynamic area adjustment resolves the contradiction between cutting surface area and bone penetration capability
Solution Approach 2:
The blade members undergo periodic extension and retraction during the penetration process, alternating between cutting mode (extended) and penetration mode (retracted). This periodic action allows the arrowhead to effectively perform both functions - maximizing flesh cutting when needed and ensuring clean bone penetration when needed
3Reliability
If blade members are retracted to allow clean bone penetration, then the bone penetration reliability is improved, but the flesh cutting effectiveness is reduced
Solution Approach 1:
The blade members periodically alternate between retracted (for bone penetration) and extended (for flesh cutting) positions during the penetration process. This periodic action ensures that the blades are in the optimal configuration for each type of tissue encountered, resolving the contradiction between bone penetration reliability and flesh cutting effectiveness
Solution Approach 2:
The blade members are designed to dynamically adjust their position based on the resistance encountered. When encountering bone, they retract to ensure clean penetration; when in flesh, they extend to maximize cutting effectiveness. This dynamic adaptation resolves the contradiction between the two opposing requirements
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 design ensures reliable bone penetration and maximizes cutting of soft flesh on either side of the bone, increasing the likelihood of a quick and humane kill by allowing the arrow to pass through bone while expanding the cutting surface post-penetration.
Implementation Method 1
at least one biasing member for biasing the first and second blade members towards the extended positions. The biasing member is the only element operable to hold the blade members in the extended position
Data Source
AI summary
A broadhead for an arrow has a ferrule and a pair of blade members. Each blade member has a first end that is pivotally interconnected with the ferrule body and an opposite second end. The blade members each have a retracted position and an extended position. A biasing member biases the blade members toward the extended positions and is the only element operable to hold the blade members in the extended position.