Beveled Arrow Ends Manage Radial Forces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Arrows, bolts, and projectiles for bows and crossbows often fracture or crack due to radial forces acting on the inserts and arrowheads, reducing their lifespan.
Innovation Solution
The design incorporates a tubular shaft with beveled ends, a nock with a tapered annular flange, and an insert with a second tapered annular flange, which redistribute and dissipate radial forces, reducing the likelihood of cracking or fracture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If flat ends perpendicular to the shaft are used, then the arrow is simple to manufacture, but the radial forces cause fracture or cracking of the shaft
Solution Approach 1:
The patent applies curvature by replacing the flat ends with beveled surfaces that form angled interfaces. The beveled surfaces create a tapered configuration that distributes radial forces more evenly across the shaft end, preventing stress concentration that leads to fracture. This geometric modification maintains manufacturability while significantly improving structural reliability under radial loading.
Solution Approach 2:
The beveled surfaces are strategically positioned at the critical interface between the shaft and the insert/nock to locally enhance force distribution. By concentrating the beveling at these specific locations rather than modifying the entire shaft, the design achieves improved fracture resistance at the stress-prone areas while keeping the rest of the shaft structure simple and easy to manufacture.
2Reliability
If beveled ends are used to reduce radial forces, then the shaft fracture resistance improves, but the manufacturing complexity increases
Solution Approach 1:
The beveled surface is segmented into distinct angular regions that can be independently controlled. The first and second beveled surfaces are positioned at specific angles relative to the shaft axis, creating discrete zones of force distribution. This segmentation allows for optimized force management while keeping each individual bevel region relatively simple to manufacture using standard machining operations.
Solution Approach 2:
The design utilizes parameter changes by varying the angles and dimensions of the beveled surfaces to optimize the balance between fracture resistance and manufacturing complexity. By adjusting parameters such as the bevel angle, bevel width, and surface depth, the design achieves adequate fracture protection with minimal added complexity, allowing manufacturers to select appropriate parameters based on their capabilities and performance requirements.
Data Source
AI summary
Example nocks, arrowheads and/or arrowhead inserts include a tapered annular flange axially engaging a correspondingly tapered edge on a tubular arrow shaft. The tapered flange and edge help prevent the end of tubular arrow shaft from deforming radially outward when substantial axial force is applied to the nock, arrowhead and/or arrowhead insert.