Aircraft Emergency Lever With Profiled Cowl For Reduced Cabin Intrusion
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Solution Overview
Problem
Existing aircraft door emergency opening levers have limited maneuverability and aerodynamic constraints, leading to increased intrusion into the cabin and higher production and maintenance costs due to complex mechanical coupling with internal opening mechanisms.
Innovation Solution
An aircraft door design featuring a pivotable emergency opening lever with a profiled cowl and driving/return abutments, allowing for a large angular deflection without significant intrusion, and enabling a rigid coupling with internal opening mechanisms by eliminating gear reduction mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the emergency opening lever is positioned on the external wall with aerodynamic surfaces for retraction, then the aerodynamic qualities are maintained, but the maneuverability of the lever is limited and the angular deflection is constrained
Solution Approach 1:
The lever system is divided into two independent rotational movements: the main arm rotates relative to the door structure, and the profiled cowl rotates relative to the main arm. This segmentation allows each component to be optimized independently - the main arm for maneuverability and the cowl for aerodynamics.
Solution Approach 2:
The profiled cowl is made dynamically movable relative to the main arm through the driving abutment mechanism. When the main arm moves from retracted to deployed position, the driving abutment automatically rotates the cowl from concealing to swung-out position, adapting the aerodynamic surface orientation to the lever's operational state.
2Ease of operation
If the lever is allowed to have large angular deflection for improved maneuverability, then the ease of operation is enhanced, but the intrusion into the cabin and door thickness increases
Solution Approach 1:
The lever system utilizes two rotational dimensions instead of one. The main arm provides the primary angular deflection for maneuverability, while the profiled cowl rotates in a second dimension to compensate for space usage, allowing large angular deflection without proportional increase in cabin intrusion.
Solution Approach 2:
The profiled cowl is nested on the main arm, allowing it to rotate independently. This nested configuration enables the cowl to swing out and fold in a direction that minimizes intrusion into the cabin while the main arm achieves the necessary angular deflection for operation.
3Adaptability or versatility
If complex mechanical coupling mechanisms are used to connect the emergency opening lever with internal opening mechanisms, then the functional coupling is achieved, but the device complexity and production costs increase
Solution Approach 1:
The gear reduction mechanisms are extracted and eliminated from the coupling system. The invention achieves the necessary functional coupling between the emergency opening lever and internal opening mechanisms through direct mechanical linkage, removing unnecessary complexity while maintaining adaptability.
Solution Approach 2:
Instead of using complex gear reduction to reduce force requirements, the invention inverts the approach by using the lever arm geometry and rotational mechanics to achieve force multiplication, eliminating the need for gear mechanisms while maintaining functional coupling.
4Ease of manufacture
If the profiled cowl remains in the concealing position during lever deployment, then the aerodynamic surface continuity is maintained, but the main arm's angular deflection is constrained by the cowl's position
Solution Approach 1:
The profiled cowl transitions from a static concealing component to a dynamic element that automatically rotates with the main arm's movement. The driving abutment mechanism ensures the cowl rotates from concealing to swung-out position as the main arm deploys, maintaining aerodynamic continuity in both states.
Solution Approach 2:
The driving abutment is pre-positioned on the main arm to engage with the profiled cowl before the main arm reaches its deployed position. This preliminary engagement ensures the cowl begins rotating in advance, maintaining aerodynamic surface continuity throughout the transition and preventing disruption during the angular deflection.
Data Source
AI summary
The invention concerns an aircraft door having a lever (3) for emergency opening from outside, disposed in a lever window. The lever (3) for emergency opening from outside includes: a main arm (7) having a first aerodynamic surface (9); a profiled cowling (8) with a second aerodynamic surface (10); a driving stop (18) capable of rotating the profiled cowling (8) from its concealing position to its separated position when the main arm (7) passes from its retracted position to its deployed position.