Rotary Toggle Link Mechanism for Compact Inertial Ignition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inertial igniters for thermal batteries in munitions fail to provide safe initiation and small size, particularly for drops from high heights (up to 40 feet) and high spin rates, while maintaining reliability and low volume, due to impractical striker travel and energy requirements.
Innovation Solution
Development of novel rotary and rotary-toggle type mechanical mechanisms with tuned safety systems and pyrotechnic designs for inertial igniters and G-switches that initiate only at specified acceleration profiles, eliminating the need for external power sources and reducing volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional inertial igniters are designed to withstand high drop heights (up to 40 feet) and high spin rates, then safety and reliability are improved, but device volume and complexity increase due to impractical striker travel and energy requirements
Solution Approach 1:
The patent applies dynamics by making the striker travel distance variable based on the acceleration profile. The striker is constrained to travel only the minimum necessary distance to initiate the pyrotechnic composition, rather than requiring fixed long travel distances. This dynamic adjustment allows the igniter to maintain reliability for high acceleration events while reducing the volume required for striker accommodation.
Solution Approach 2:
The invention changes the parameter of striker travel distance from a fixed value to a variable value that adapts to different acceleration profiles. By adjusting the striker travel distance parameter based on the specific acceleration event (drop height or spin rate), the device achieves both safety for high-G events and compact volume for low-G events, resolving the contradiction between reliability and volume.
2Reliability
If striker travel distance is increased to provide sufficient energy for initiation under high acceleration, then initiation reliability is improved, but device complexity and volume increase
Solution Approach 1:
The patent applies partial action by providing the striker with only the minimum necessary travel distance and energy required for reliable initiation under the specific acceleration profile. Rather than designing for excessive striker travel that would guarantee initiation under all conditions, the mechanism is tuned to provide just sufficient energy, thereby reducing complexity while maintaining adequate reliability.
Solution Approach 2:
The dynamic constraint mechanism allows the striker travel distance to be optimized for each specific application's acceleration profile. This dynamic adjustment eliminates the need for complex over-engineered mechanisms that would provide excessive travel distance for all conditions, thereby reducing overall device complexity while maintaining initiation reliability.
3Object-affected harmful factors
If the igniter is designed for high spin rates and high drop heights, then safety performance is improved, but the device occupies more space and becomes less suitable for miniaturized thermal batteries
Solution Approach 1:
The invention changes key parameters including striker mass, striker travel distance, spring constant, and pyrotechnic composition to match the specific acceleration profile of the application. By optimizing these parameters rather than using fixed conservative values, the igniter achieves adequate protection against accidental initiation while minimizing volume for miniaturized thermal battery applications.
Solution Approach 2:
The patent applies local quality by customizing the igniter parameters specifically for the intended acceleration environment. Rather than designing a universal igniter with maximum protection capabilities, the mechanism is locally optimized for the specific drop height or spin rate conditions, achieving sufficient safety performance with minimal volume.
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 mechanisms ensure safe initiation at high acceleration levels and spin rates, occupying minimal space and maintaining reliability for up to 20 years of shelf life, suitable for miniaturized thermal batteries and smart munitions.
Implementation Method 1
Method for rotating a toggle link upon an acceleration event greater than a predetermined threshold
Data Source
AI summary
A mechanism including: a toggle rotatably connected to a base structure; a stop fixed to the base for limiting a rotational travel of the toggle, the stop being fixed to the base such that there is no relative movement between the stop and the base; a biasing element having a first end attached to the base and a second end attached to the toggle to bias the toggle towards the stop when the toggle is positioned on a first side of a singular position and the toggle is biased towards an opposite direction from the stop when the toggle is positioned on a second side of the singular position; and an inertial element movably disposed relative to the base and the toggle to move the toggle from the first side to the second side of the singular position when the base undergoes an acceleration event greater than a predetermined threshold.