Pivoting Blade Broadhead Retention Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional mechanical broadheads struggle to maintain blades in a closed position during the launch and flight of an archery arrow, leading to premature opening and reduced cutting efficiency.
Innovation Solution
The use of a spring element, wave washer, or O-ring to pivotally mount blades, ensuring they remain in a retracted position until impact, combined with an interference fit and a shaft to prevent linear movement, allowing blades to pivot radially and open only upon encountering a target, thereby enhancing cutting diameter and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If blades are held in closed position by retaining members during flight, then blade stability is improved, but device complexity increases
Solution Approach 1:
The blade assembly is segmented into multiple independent blades that can be individually retained and controlled. Each blade has its own retaining member (spring element, O-ring, or wave washer) that independently maintains the closed position, allowing the system to manage complexity through modular segmentation while ensuring overall stability.
Solution Approach 2:
The retaining members are designed to automatically perform their function of holding blades in the closed position during flight without external intervention. The spring elements, O-rings, or wave washers self-generate the necessary retaining force through their elastic properties, eliminating the need for additional control mechanisms or external actuation systems.
2Area of moving object
If blades pivot radially upon impact, then cutting diameter is improved, but reliability of closed position maintenance deteriorates
Solution Approach 1:
The blade assembly transitions from a static closed position during flight to a dynamic expanded position upon impact. The blades are designed to pivot radially outward when impact forces exceed the retaining force of the spring elements, O-rings, or wave washers. This dynamic behavior allows the system to maintain reliable closed position during flight while achieving maximum cutting diameter when needed.
Solution Approach 2:
The system changes the physical state and position parameters of the blades based on operational conditions. During flight, the blades maintain a closed position parameter for stability; upon impact, the position parameter changes to an expanded radial configuration for cutting. The spring elements, O-rings, or wave washers are selected with specific force parameters that allow this parameter transition at the appropriate moment.
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 effectively keeps blades closed during flight, ensuring maximum cutting efficiency upon impact by overcoming the resistance bias force, resulting in improved cutting performance and expanded cutting diameter.
Implementation Method 1
a spring element and/or another suitable holding element, such as a wave washer, a rubber band or an O-ring is used to hold a pivotably mounted blade in an in-flight or retracted position
Implementation Method 2
an interference fit between a blade and a ferrule body
Data Source
AI summary
A mechanical arrowhead or broadhead with pivoting blades that each pivot between an in-flight position and an impact position. One or more blades is each mounted within an opening of a body so that each blade pivots or otherwise moves with respect to the body. A stop element is secured directly to or with respect to the body. In the impact position, each blade contacts the stop element. In the in-flight position, each blade does not contact but rather is arranged or positioned away from the stop element.