Aircraft Throttle Lever Trigger Mechanism for Reverse Thrust Lockout
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Solution Overview
Problem
Existing throttle control levers for aircraft engines lack mechanisms to prevent unintentional movement from idle or forward thrust to reverse thrust positions, which can lead to engine damage.
Innovation Solution
A throttle control lever design featuring a cam with a slot and stop portion, a biasing mechanism, and a trigger mechanism that requires user action to overcome biasing force for reverse thrust initiation, reducing the likelihood of unintentional reverse thrust.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple throttle control lever design is used, then the device complexity is reduced and ease of manufacture is improved, but the reliability is worsened due to lack of protection against unintentional reverse thrust
Solution Approach 1:
The patent applies preliminary anti-action by incorporating a trigger mechanism that must be deliberately actuated to enable movement into the reverse thrust zone. This preliminary protective action prevents unintentional reverse thrust by requiring a conscious, two-step operation (moving the lever to the reverse zone AND pulling the trigger), thereby counteracting the risk of accidental activation before it can occur.
2Reliability
If a trigger mechanism with biasing means is added to prevent unintentional reverse thrust, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The biasing means (spring) provides self-service by automatically returning the throttle control lever to the neutral or forward thrust position when the reverse thrust zone is selected, and by requiring the pilot to deliberately overcome this bias through trigger actuation. This self-service mechanism reduces the need for additional complex control systems while maintaining reliability.
3Ease of operation
If the trigger is positioned to be operated by fourth and fifth fingers while gripping the grip, then the ease of operation is improved, but the device complexity increases due to additional constraint mechanisms
Solution Approach 1:
The patent applies dimensionality change by positioning the trigger in a location that allows operation from a different spatial dimension - specifically, the trigger is arranged to be actuated by the fourth and fifth fingers while the hand grips the handle, utilizing the lateral dimension of finger placement rather than requiring separate hand positioning. This ergonomic arrangement improves ease of operation without significantly increasing mechanical complexity.
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 design enhances control over throttle lever movement, decreases the risk of unintentional reverse thrust, and simplifies maintenance with a compact, mechanically straightforward structure.
Implementation Method 1
a biasing means configured to bias the cam lever to rotate in a first direction around the cam lever pivot
Data Source
AI summary
A throttle control lever suitable for controlling the magnitude and direction of thrust of one or more aircraft engines is described. The throttle control lever comprises a frame, a trigger mechanism, a connection element, a cam engagement mechanism, a biasing means, a cam, and a grip suitable for gripping by a user when the throttle control lever is in use, The cam comprises a slot having first and second slot portions and a stop portion. The stop portion extends between and connects the first and second slot portions. The cam engagement mechanism comprises a cam lever and a slot engagement element, the cam lever is pivotally attached to the frame via a cam lever pivot, and the slot engagement element is attached to the cam lever. The trigger mechanism comprises a trigger lever and a trigger, the trigger lever is pivotally attached to the frame via a trigger pivot.