Aircraft Door Interlock Assembly for Auto-Disarm Control
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Solution Overview
Problem
Existing aircraft door emergency support systems lack efficient mechanisms to control their active or inactive conditions, leading to potential inefficiencies and risks during emergency evacuations.
Innovation Solution
An interlock assembly is integrated into the aircraft door system, featuring a triggering shaft with interlock and auto-disarm cams, allowing for precise control of the emergency support system's mode selection and prevention of inadvertent actuation during door opening, thereby ensuring the system remains disarmed when the door is open.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an emergency support system is always active, then safety during emergency evacuation is improved, but the risk of inadvertent actuation and mechanical failures increases
Solution Approach 1:
The interlock assembly is configured to automatically disarm the emergency support system when the door transitions to the open position, preventing inadvertent actuation before it can occur. The cam mechanism preliminarily sets the system state based on door position, ensuring safety by default when the door is open.
Solution Approach 2:
The interlock assembly acts as an intermediary mechanism between the door position and the emergency support system activation. It mediates the control signal through cam mechanisms that translate door position into corresponding system states (armed/disarmed), preventing direct and potentially erroneous activation.
2Reliability
If a complex control mechanism is added to prevent inadvertent actuation, then reliability is improved, but device complexity increases
Solution Approach 1:
The interlock assembly merges multiple functions (interlocking, auto-disarming, mode selection) into a single integrated mechanism. The cam mechanisms combine several control actions that would otherwise require separate components, reducing overall system complexity while maintaining reliability.
Solution Approach 2:
The triggering shaft with integrated cam mechanisms serves multiple functions: it detects door position, controls system arming/disarming, and prevents inadvertent actuation. This multi-functional design reduces the number of separate components needed, balancing complexity with reliability.
3Object-affected harmful factors
If the emergency support system is disarmed when the door is open, then inadvertent actuation is prevented, but the system may not be ready for immediate emergency use
Solution Approach 1:
The system dynamically adjusts its state based on door position. When the door closes, the interlock assembly automatically arms the system, ensuring readiness for emergency use. When the door opens, it automatically disarms to prevent inadvertent actuation. This dynamic adaptation resolves the contradiction between safety and readiness.
Solution Approach 2:
The interlock assembly provides feedback control by continuously monitoring door position and automatically adjusting the emergency support system state accordingly. The cam mechanisms detect door position and provide feedback signals that trigger arming or disarming, ensuring the system is always in the appropriate state without manual intervention.
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
An interlock assembly (52) for an aircraft door (28) includes a shaft (54), an interlock first portion (56), and an auto-disarm second portion (58). The shaft (54) is rotatable about a second rotational axis (60) between an armed position and a disarmed position. The shaft (54) includes an interlock cam (64) and an auto-disarm cam (66). In a first interlock position, the interlock first portion (56) permits rotation of the shaft (54) between the armed position and the disarmed position. In a second interlock position, the interlock first portion (56) prevents rotation of the shaft (54) from the disarmed position to the armed position. In a first auto-disarm position, the auto-disarm second portion (58) permits rotation of the shaft (54) between the armed position and the disarmed position. In a second auto-disarm position, the auto-disarm second portion (58) prevents rotation of the shaft (54) from the disarmed position to the armed position.