Expandable Broadhead Blade Retention for Reliable Impact Deployment
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Solution Overview
Problem
Existing expandable broadheads suffer from mechanical failures that can cause blades to deploy prematurely or fail to deploy upon impact, leading to decreased accuracy and non-reusability.
Innovation Solution
A broadhead design featuring a spring-loaded retaining mechanism that keeps blades in a retracted position during flight and deploys upon impact, with a pin and plunger system allowing for easy reset and re-use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-loaded retaining mechanism is used to keep blades retracted during flight, then reliability of deployment is improved, but device complexity increases
Solution Approach 1:
The broadhead utilizes the kinetic energy from target impact itself to trigger blade deployment through the spring-loaded plunger mechanism, eliminating the need for external activation systems or complex electronic components. The mechanism serves itself by converting the impact force into the deployment action.
Solution Approach 2:
The spring is pre-loaded during assembly to store potential energy, and the plunger is pre-positioned to engage with the blade retention notches. This preliminary preparation ensures that upon target contact, the blades immediately deploy without requiring additional activation steps or complex control systems.
2Stability of the object's composition
If blades are kept in retracted position during flight, then flight stability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The retention system is divided into discrete components: the plunger with its engagement surface, the notches in each blade, and the spring mechanism. This segmentation allows each component to be manufactured and assembled independently, reducing the cumulative precision requirements compared to a monolithic retention system.
Solution Approach 2:
The design employs geometric parameters such as the notch shape, plunger engagement surface angle, and spring compression distance to provide mechanical advantage and self-alignment. These parameter choices create a tolerance-friendly system where minor manufacturing variations are compensated by the mechanical geometry rather than requiring tight tolerances.
3Ease of operation
If a pin and plunger system is used for easy reset, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The pin is designed to be removable from the broadhead body, allowing the plunger and spring assembly to be extracted and replaced independently. This extraction capability enables easy reset or replacement of the retention mechanism without disassembling the entire broadhead, simplifying field maintenance and reset operations.
Solution Approach 2:
The pin serves multiple functions: it anchors the plunger assembly to the body, provides a reference surface for plunger engagement, and acts as a removable interface for reset operations. This multi-functionality reduces the need for additional dedicated components, balancing operational ease with mechanism simplicity.
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 deployment upon target contact and allows for multiple uses by maintaining blades in a retracted state during flight and facilitating easy resetting.
Implementation Method 1
The spring-loaded retaining member is biased to translate in the longitudinal direction towards the target penetrating end
Implementation Method 2
The contact surfaces are configured to be driven by the target as the broadhead plunges into the target such that the blade members are driven to move and rotate along the slot from the retracted positions to the fully deployed positions
Data Source
AI summary
A broadhead includes a body, a blade member, and a plunger. The body defines a target penetrating end. The blade member is positioned partially within an inner volume of the body. The blade member is configured to rotate and translate relative to the body by a pin that is fixedly coupled with the body being received through a slot of the blade member. The blade member is transitionable between a retracted position and a deployed position. The plunger is bias by a spring in a longitudinal direction towards the target penetrating end. The plunger is configured to be received within a recess of the blade member when the blade member is in the retracted position.