Throttle Lever Cam Lockout for Reverse Thrust Control
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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, potentially leading 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
1Reliability
If a traditional throttle control lever is used without additional protective mechanisms, then the device complexity is low and ease of operation is high, but the reliability is poor due to risk of unintentional reverse thrust
Solution Approach 1:
The patent combines the protective function into the existing throttle control lever structure by integrating a cam mechanism with a slot and stop portion directly into the lever body. The cam lever, biasing means, and trigger mechanism are merged with the grip assembly, creating a unified structure that prevents unintentional reverse thrust without requiring separate independent safety devices.
Solution Approach 2:
The cam mechanism acts as an intermediary between the user's direct manipulation of the lever and the engine thrust control. The slot engagement element, biased by the biasing means, mediates the movement by providing mechanical resistance through the cam slot geometry, requiring deliberate trigger activation to overcome this intermediate protective barrier before reverse thrust can be engaged.
2Reliability
If a cam mechanism with biasing means is added to prevent unintentional reverse thrust, then the reliability improves, but the ease of operation deteriorates due to additional user action required
Solution Approach 1:
The biasing means is pre-configured to maintain the slot engagement element in a position that blocks unintentional reverse thrust movement. The cam mechanism is preliminarily set up with the slot geometry and biasing force ready to engage, so that normal forward thrust operation proceeds smoothly while reverse thrust requires the preliminary action of deliberately actuating the trigger to overcome the pre-established protective barrier.
3Reliability
If the slot engagement element is biased to resist movement, then the reliability of preventing accidental reverse thrust increases, but the force required to operate the lever increases
Solution Approach 1:
The biasing force is applied locally only in the specific region where reverse thrust protection is needed, rather than uniformly across the entire lever. The cam slot geometry is designed so that the slot engagement element experiences biased resistance only when attempting to move into the reverse thrust zone, while forward thrust movement and idle position adjustments require minimal force. The trigger mechanism concentrates the force requirement locally at the trigger activation point.
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 user control and reduces the risk of unintentional reverse thrust, thereby minimizing engine damage by requiring deliberate action to initiate reverse thrust.
Implementation Method 1
a biasing means biases the cam lever to rotate in a first direction around the cam lever pivot
Data Source
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AI summary
A throttle control lever (2) suitable for controlling the magnitude and direction of thrust of one or more aircraft engines is described. The throttle control lever (2) comprises a frame (4), a trigger mechanism (6), a connection element (8), a cam engagement mechanism (10), a biasing means (12), a cam (14), and a grip (52) suitable for gripping by a user when the throttle control lever (2) is in use, The cam (14) comprises a slot (16) having first and second slot portions (18, 20) and a stop portion (22). The stop portion (22) extends between and connects the first and second slot portions (18, 20). The cam engagement mechanism (10) comprises a cam lever (34) and a slot engagement element (36), the cam lever (34) is pivotally attached to the frame (4) via a cam lever pivot (38), and the slot engagement element (36) is attached to the cam lever (34). The trigger mechanism (6) comprises a trigger lever (46) and a trigger (48), the trigger lever (46) is pivotally attached to the frame (4) via a trigger pivot (50). The trigger (48) extends through the grip (52). The connection element (8) is attached to the trigger lever (46) and the cam lever (34). The biasing means (12) biases the cam lever (34) to rotate in a first direction around the cam lever pivot (38).