Illuminated Nock With Bowstring-Actuated LED Switch
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Solution Overview
Problem
Existing illuminated nocks for arrows and crossbow bolts require manual activation, which can alert the target and reduce the hunter's chances of taking a shot, and prior attempts to automate activation have compromised the accuracy and performance of the arrow or bolt during launch.
Innovation Solution
A nock assembly with a light-emitting diode that automatically turns on when the bowstring is released, utilizing spherical caps to retain the bowstring and only allow activation once sufficient force is applied during launch, ensuring the light is turned on at the right moment without affecting the arrow's flight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the LED is manually turned on before shooting, then the arrow's flight path is visible, but the target animal may be alerted and the hunter loses the opportunity to take a shot
Solution Approach 1:
The nock is pre-configured with the LED and battery in an off state during storage. The preliminary action is set up so that upon release from the bowstring, the nock automatically transitions to the on state without requiring manual activation, thus maintaining hunting effectiveness while enabling illumination when needed
2Extent of automation
If the LED is automatically turned on when the bowstring is released, then the arrow's flight path is visible without manual activation, but the accuracy and speed of the arrow may be compromised
Solution Approach 1:
A mechanical intermediary mechanism consisting of a cam and follower is introduced between the bowstring release and the LED activation. This intermediary converts the rotational motion of the cam (driven by the nock's rotation during launch) into linear motion that pushes the LED on/off switch, enabling automatic activation without directly interfering with the arrow's aerodynamic properties or launch accuracy
Solution Approach 2:
The nock incorporates a rotating cam mechanism that dynamically changes position during the arrow's launch. The cam rotates as the nock spins on the bowstring, and this dynamic motion automatically actuates the LED switch at the appropriate moment, providing automation without compromising the arrow's flight characteristics
3Ease of operation
If the LED remains on during storage to ensure readiness, then no manual activation is needed, but the battery becomes depleted
Solution Approach 1:
The LED operates in a periodic manner - remaining off during storage to conserve battery energy, and automatically turning on only during the brief period when the arrow is in flight and illumination is needed. This periodic operation pattern eliminates continuous energy consumption while ensuring the system is ready when required
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 solution allows for automatic illumination of the nock without compromising the accuracy or speed of the arrow, enhancing visibility during flight and improving the hunter's chances of a successful shot while maintaining the arrow's performance.
Implementation Method 1
a light-emitting diode (LED) or other light-emitting device such as a small incandescent bulb
Data Source
AI summary
A nock assembly for use with a crossbow bolt includes a nock body defining a notch into which the bowstring of a crossbow is insertable. A light assembly includes a switch member at one end of the notch. First and second spherical caps protrude into the notch and define a first gap therebetween. Third and fourth spherical caps protrude into the notch and define a second gap therebetween. The bowstring is positionable between the spherical caps such that the first and second spherical caps resist movement of the bowstring out of the notch, and the third and fourth spherical caps resist movement of the bowstring toward the switch member. Release of the bowstring from its cocked or drawn position causes the bowstring to pass through the second gap and contact the switch member to turn on the light assembly.