Archery Arrow Shaft Concentricity via Insert Machining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional archery arrows and bolts exhibit non-concentricity between the outer and inner diameters of their shafts, leading to imperfect alignment of inserts and nocks, which compromises weight distribution and arrow spin, affecting accuracy and precision.
Innovation Solution
The solution involves manufacturing arrows with inserts that are secured to the shafts in a manner that ensures concentricity with the outer diameter, while maintaining alignment with the inner diameter, using methods such as centerless grinding and precise machining to create a balanced shaft structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If centerless grinding is used to form the outer diameter of the shaft, then manufacturing efficiency is improved, but concentricity between outer and inner diameters deteriorates
Solution Approach 1:
The patent applies preliminary action by forming the inner diameter of the shaft before the outer diameter through a two-step machining process. The inner diameter is precisely machined first to establish a reference axis, then the outer diameter is formed relative to this pre-established inner diameter axis, ensuring concentricity before final assembly operations
Solution Approach 2:
The patent replaces conventional centerless grinding with a controlled machining process that uses the inner diameter as a mechanical reference. Instead of grinding the outer diameter independently without reference to the inner diameter, the system uses the inner diameter surface as a datum for positioning and controlling the outer diameter formation, substituting the independent mechanical grinding process with a referenced machining approach
2Ease of manufacture
If inserts and nocks are positioned using the inner diameter of the shaft, then installation is simplified, but alignment with the outer diameter deteriorates
Solution Approach 1:
The patent introduces the inner diameter surface as an intermediary reference element that mediates between the insert positioning and the outer diameter alignment. By establishing the outer diameter relative to the inner diameter through controlled machining, the inner diameter becomes a mediator that ensures both easy insert installation (using inner diameter as reference) and proper outer diameter alignment simultaneously
Solution Approach 2:
The patent changes the reference parameter relationship by making the outer diameter dependent on the inner diameter through controlled machining tolerances and offsets. Instead of treating outer and inner diameters as independent parameters, the system establishes a controlled parameter relationship where the outer diameter is machined with specific dimensional and angular tolerances relative to the inner diameter, ensuring proper alignment
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 approach enhances arrow flight consistency and accuracy by ensuring that broadheads and other components are centered relative to the outer surface, improving overall arrow performance.
Implementation Method 1
The insert can be adhered to the shaft and later machined to define the hole
Implementation Method 2
the exterior of the arrow is centerless ground with a machine to form a consistent, cylindrical outer surface
Data Source
AI summary
An archery arrow is provided to include a shaft that is tubular and includes an exterior surface and an opposing interior surface, with an insert secured to the shaft. The insert can define a hole configured to join a component, for example, a broadhead with the arrow. The hole can be round and concentric with the exterior surface of the shaft, and in some cases non-concentric with the interior surface. The insert can be adhered to the shaft and later machined to define the hole to provide the concentricity of the hole and the shaft exterior or an associated outer diameter. When a component such as a broadhead is joined with the arrow via installation in the hole, the component can be centered relative to the shaft exterior. A related method of manufacturing an arrow is provided.