Safety Arming Unit for Underwater Charges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing underwater ordnance disposal systems face risks of accidental arming and firing due to lack of robust safety features, particularly when dealing with unsweepable ordnance and the need for remote operation, which is not adequately addressed by current safety and arming units.
Innovation Solution
A safety and arming unit with multiple interlocks and electrical switches arranged in series, triggered by independent events, and a resilient biasing mechanism that requires external water pressure to arm the detonator, ensuring safe handling and remote initiation while preventing unintentional arming and firing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple interlocks and electrical switches are arranged in series with independent triggering events, then the safety against accidental arming is improved, but the device complexity increases
Solution Approach 1:
The safety and arming unit is divided into multiple independent interlock mechanisms (first and second interlocks) and series-connected electrical switches, each controlled by independent events. This segmentation ensures that a single failure or accidental trigger cannot compromise the entire system, as each segment must be independently activated to reach the armed state.
Solution Approach 2:
The system requires preliminary actions to be completed before arming can occur. The interlocks must be sequentially engaged, and electrical switches must be in the correct state before the detonator can be armed. This preliminary preparation ensures that all safety conditions are met before the system becomes operational.
2Reliability
If external water pressure is required to trigger the arming mechanism, then the safety during handling is improved, but the ease of operation is reduced
Solution Approach 1:
The arming mechanism is designed to arm itself automatically when subjected to external water pressure. The pressure differential between the internal and external environments of the housing causes the interrupter to move to the armed position without requiring manual intervention, thus maintaining safety while enabling operation.
Solution Approach 2:
External water pressure is utilized as the triggering mechanism for arming. The hydraulic pressure from the surrounding water environment acts on the interrupter or piston to move it from the safe to the armed position, converting environmental pressure into a functional arming action.
3Reliability
If the interrupter is locked in the first position by interlocks, then the prevention of unintentional firing is improved, but the productivity is reduced due to additional safety steps
Solution Approach 1:
The interrupter is designed to transition dynamically from a locked safe position to an armed position based on environmental conditions. The interlocks provide static protection during transport and deployment, but allow dynamic arming when the charge is in its operational underwater environment, thus balancing safety with operational efficiency.
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 significantly reduces the risk of accidental arming and firing by providing a robust safety mechanism that ensures the detonator is only armed under controlled conditions, enhancing the safety and reliability of underwater ordnance disposal operations.
Implementation Method 1
a resilient member, for example a spring, biased towards the first position
Implementation Method 2
the interrupter is slidable from the first position to the second position upon being subjected to an external water pressure greater than a threshold value
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The present invention relates to a safety and arming unit for initiation of underwater charges, comprising: a housing; a detonator; an interrupter slidable within the housing from a first position in which a firing chain from the detonator to a charge is interrupted, to a second position, in which the firing chain is complete; a first member configured to cooperate with the housing and the interrupter to form a first interlock, wherein, upon the first member being in a first position, said interlock locks said interrupter in said first position, and upon the first member being in a second position, said interrupter is free to slide relative to said first member; a second member configured to cooperate with the housing and the interrupter to form a second interlock, mechanically independent of said first interlock, wherein, upon the second member being in a first position, the interlock locks said interrupter in said first position, and upon the second member being in a second position, said interrupter is free to slide relative to said second member; and a plurality of electrical switches arranged in series, switchable from a first configuration in which the detonator is electrically isolated from a remote initiation firing system, to a second configuration in which the detonator is in electrical communication with a remote initiation firing system; wherein, upon the first member being in the second position, and the second member being in the second position, the interrupter is slidable from the first position to the second position upon being subjected to an external water pressure of at least a predefined threshold value. Upon the interrupter being in the second position, the interrupter acts on the plurality of electrical switches to switch said plurality of switches to said second configuration.