Rotating Blade Broadhead Reduces Axial Forces
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Solution Overview
Problem
Existing broadhead arrow tips with rotating blades face issues such as decreased arrow speed due to high axial forces, increased deployment time, and reduced cutting effectiveness due to sweeping motion and band-related complications.
Innovation Solution
A broadhead design with rotating blades that deploy radially about an axis parallel to the arrow shaft, minimizing axial forces and maintaining consistent velocity, using a reusable magnetic attachment member and beveled blade surfaces to induce rotation and maximize cutting area without shrinking post-impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If rotating blades are configured with axis perpendicular to arrow shaft, then blade deployment is achieved, but axial forces increase and arrow speed decreases
Solution Approach 1:
The patent inverts the conventional blade axis orientation from perpendicular to the arrow shaft to parallel with the arrow shaft. This inversion changes the deployment mechanics so that blades rotate in a plane perpendicular to the arrow shaft rather than parallel to it, thereby reducing axial forces and maintaining arrow speed.
Solution Approach 2:
The patent changes the critical parameter of blade axis orientation from perpendicular to parallel with the arrow shaft. This parameter change fundamentally alters the force dynamics during deployment, reducing axial forces while maintaining the blade's cutting function.
2Productivity
If blades rotate perpendicular to arrow shaft, then deployment motion is achieved, but deployment time increases and cutting effectiveness decreases
Solution Approach 1:
By inverting the rotation plane from parallel to perpendicular to the arrow shaft, the blades achieve a more direct cutting path. This reduces the arc length traveled during deployment, decreasing deployment time and increasing relative blade speed to the target for improved cutting effectiveness.
3Reliability
If blades are secured with bands, then blade retraction is achieved, but bands wear out or are lost after impact
Solution Approach 1:
The patent replaces the mechanical band system with a magnetic field-based retention system. Magnets embedded in the broadhead body attract and hold the blade assemblies during flight, eliminating the need for physical bands that wear out or can be lost upon impact.
Solution Approach 2:
The magnetic field serves as an intermediary force between the broadhead body and blade assemblies, providing retention without direct mechanical contact. This eliminates wear and loss issues associated with physical bands while maintaining reliable blade security during flight.
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 consistent relative velocity and maximized cutting area during impact, reducing axial forces and deployment time, while the reusable attachment member eliminates band-related issues.
Implementation Method 1
an attachment member configured to selectively restrict movement of the blade assembly... These bands are held in slots around the body of the tip and become dislodged when impact occurs
Implementation Method 2
beveled blade surfaces to induce rotation and maximize cutting area
Data Source
AI summary
A broadhead assembly for use with an arrow shaft includes a main body, a blade assembly, and an attachment member. The main body has a central axis and a mating surface for coupling to the arrow shaft. The blade assembly rotatably couples to the main body, and is oriented so as to rotate radially to the central axis. The blade assembly has a blade axis of rotation. The attachment member is coupled to the main body and configured to secure the blade assembly in a closed orientation. Rotation of the blades within the blade assembly is such that they rotate about the blade axis and the blade axis is parallel to the central axis.