Reusable Gas Cartridge for Aircraft Store Ejection
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Solution Overview
Problem
Existing ejector release units using pyrotechnic or hot gas cartridges face issues with maintenance complexity, erosion, and incompatibility with compressed air systems, requiring frequent cleaning and adaptation, and lack reusability.
Innovation Solution
A cartridge with a gas chamber and a release valve, operable by a firing pin, that uses compressed gas to drive a release mechanism, allowing for sympathetic firing and recharging, suitable for existing ejector release units, and compatible with both electric and pressure operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If hot gas cartridges are used to eject stores, then stores can be ejected very quickly, but the cartridges cannot be re-used and combustion products build up requiring frequent cleaning
Solution Approach 1:
The patent applies the opposite approach by designing a reusable cartridge system. The cartridge is filled with inert gas (nitrogen or compressed air) that can be recharged after each use, eliminating the need for disposable cartridges. The gas can be replenished through a refilling mechanism, making the cartridge a long-lasting, reliable component that maintains ejection performance across multiple operations.
Solution Approach 2:
Instead of discarding the cartridge after single use, the patent recovers and recharges the gas in the cartridge. The gas is extracted, replenished, and sealed back into the cartridge for subsequent use. This recovery process eliminates waste and reduces maintenance frequency, directly addressing the reusability issue while maintaining quick ejection capability.
2Speed
If hot gas cartridges are used, then stores can be ejected quickly, but combustion products erode the surfaces of the ejector release unit requiring hard materials
Solution Approach 1:
The patent replaces combustion-based hot gas cartridges with inert gas (nitrogen or compressed air) cartridges. This inert atmosphere eliminates combustion products that cause erosion. The inert gas provides the necessary pressure for ejection without the harmful thermal and chemical effects of combustion, thereby protecting the ejector release unit surfaces from erosion while maintaining ejection speed.
3Reliability
If hot gas cartridges are used, then stores can be ejected, but the ejector release units must be rigid to resist thermal shock and pressure impulse
Solution Approach 1:
The patent changes the physical parameters of the gas from hot combustion gases to cold inert gas. This parameter change eliminates thermal shock concerns. The inert gas operates at ambient or compressed air temperatures, significantly reducing thermal loading on the ejector release unit structure. This allows the use of lighter, less rigid materials while maintaining the ability to withstand pressure impulses during ejection.
4Adaptability or versatility
If specially adapted ejector release units are used for compressed air, then compatibility with aircraft pneumatics system is achieved, but the aircraft must be specifically adapted to provide compressed air
Solution Approach 1:
The patent designs a universal cartridge system that can be used with existing ejector release units without requiring specially adapted aircraft. The standard cartridge interface fits into conventional breeches, and the inert gas or compressed air can be supplied through existing aircraft pneumatic systems or portable fillers. This universality eliminates the need for aircraft-specific adaptations while maintaining compatibility with compressed air systems.
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 provides a reusable, low-maintenance, and efficient means of store ejection, ensuring safe separation and reducing structural damage risks while being adaptable to various aircraft systems.
Implementation Method 1
a gas chamber for containing gas under pressure, an outlet of the gas chamber for releasing the compressed gas to drive a release mechanism
Implementation Method 2
a release valve associated with the outlet and arranged to be operable to open the outlet upon activation of a firing pin
Data Source
AI summary
The present invention relates to the field of store ejection from aircraft. More specifically it relates to cartridges used in ejector release units for stores. The invention aims to provide a cartridge that can be used in existing ejector release units that overcomes some of the problems (such as; only a one-time use, the need for cleaning of ejector units, the erosion of ejector units and the need for a holder to be used) of pyrotechnic or hot gas cartridges but without compromising performance. The present invention provides a cartridge for use in an ejector release unit, the cartridge comprising a gas chamber for containing gas under pressure, an outlet of the gas chamber for releasing the compressed gas to drive a release mechanism in the ejector release unit, and a release valve associated with the outlet and arranged to be operable to open the outlet upon activation of a firing pin of an ejector release unit. An ejector release unit containing such a cartridge or pair of cartridges is also provided.