High-Impact Lighted Nock Assembly with Shaft-Isolating Bushing
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Solution Overview
Problem
Existing lighted arrow nocks fail to withstand the high forces generated by modern bows and crossbows, leading to dry fire events and arrow shaft fractures, while also suffering from unintended light activation and battery drain.
Innovation Solution
A matched weight arrow set with a lighted nock assembly and a non-lighted nock assembly, both constructed from a transparent, high impact strength polymeric material, and a bushing that isolates launch forces within the bushing to prevent arrow shaft fractures, along with a mechanism that activates the light only upon launch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If existing lighted nock products are used, then the arrow can be seen in flight and impact point can be observed, but the nock breaks under high forces from modern bows and crossbows
Solution Approach 1:
The nock is constructed from a blend of polymeric materials including a first polymer and a second polymer with different properties. The first polymer provides flexibility and light transmission, while the second polymer provides structural strength and impact resistance. This composite structure allows the nock to withstand high forces from modern bows and crossbows while maintaining light visibility capabilities.
2Ease of operation
If lighted nock components transfer forces to the arrow shaft, then the light can be activated, but the arrow shaft fractures
Solution Approach 1:
The nock assembly is divided into separate functional components: a nock body that interfaces with the arrow shaft, a light assembly with battery, and a force-distributing structure. The nock body includes a first portion that contacts the arrow shaft and a second portion that houses the light assembly. Force transfer elements are specifically designed to distribute loads across a larger area of the arrow shaft, preventing stress concentration and fractures while still enabling light activation through controlled movement.
3Strength
If the light assembly is made robust to handle high forces, then the nock can withstand launch forces, but the unintended activation during transport increases
Solution Approach 1:
The light activation mechanism uses a dynamic threshold-based design where the force sensitivity is calibrated to distinguish between normal transport vibrations and actual launch forces. The nock includes a force-sensing element that remains in a neutral position during normal handling but is designed to trigger light activation only when subjected to the specific magnitude and direction of forces experienced during bow launch. This dynamic response ensures the nock maintains high strength while preventing unintended activation during transport.
4Illumination intensity
If a transparent polymeric material is used for the nock, then light can pass through for visibility, but the impact strength is insufficient
Solution Approach 1:
The nock utilizes a composite polymeric structure where a transparent or translucent first polymer material provides light transmission properties, while a second polymer material with higher impact strength provides structural reinforcement. The composite blend is engineered to optimize the balance between optical clarity and mechanical strength, allowing the nock to transmit light effectively for arrow visibility while simultaneously withstanding the high impact forces generated by modern bows and crossbows.
Data Source
AI summary
A matched arrow set including a first arrow and a second arrow. The first arrow including: a first shaft, a first bushing coupled to the first shaft, and a first nock received in the first bushing. The second arrow including: a second shaft, a second bushing coupled to the second shaft, and a second nock received in the second bushing. The first shaft and the first bushing define a first weight, the second shaft and the second bushing define a second weight greater than the first weight, and a first arrow weight is substantially the same as a second arrow weight.