Thrust Reverser Lock Unlocking Mechanism
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Solution Overview
Problem
Existing locks for thrust reverser cowls require oversized actuating cylinders and lengthy unlocking cycles, particularly delaying the activation of the reverse thrust function in critical situations like aborted landings or take-offs.
Innovation Solution
The lock design allows the hook to be disengaged from the striker without moving the cowl to an over-closed position, reducing unlocking time and eliminating the need for actuating cylinders to unlock the lock, using a connecting rod/crank assembly or hydraulic jack mechanism to minimize friction and component size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the hood is brought to the over-closed position to release the latch hook, then the lock can be unlocked, but the unlocking cycle time is lengthened and actuating cylinders must be oversized
Solution Approach 1:
The invention separates the locking function from the hood positioning function. The lock mechanism is divided into independent components: a fixed support, a movable hook for locking, and a dedicated unlocking device that operates independently of the hood's actuating cylinders. This segmentation allows the hook to be unlocked directly without requiring the hood to move to the over-closed position, thereby reducing unlocking time and allowing for smaller actuating cylinders.
Solution Approach 2:
The invention introduces a dedicated unlocking device as an intermediary mechanism between the control system and the hook. This unlocking device, which may include a motor-driven toothed wheel and worm gear or a hydraulic cylinder, directly actuates the hook to release it from the strike plate. This intermediary mechanism eliminates the need to use the oversized actuating cylinders for unlocking, resolving the contradiction between unlocking speed and cylinder size.
2Loss of time
If the hook is released without moving the hood to the over-closed position, then the unlocking time is reduced, but a new unlocking mechanism is required
Solution Approach 1:
The unlocking device is designed to be self-contained and self-actuating. Once activated, the unlocking mechanism automatically performs the hook release function through its own power source (motor or hydraulic cylinder), without requiring external assistance from the hood's actuating system. The mechanism includes built-in components such as a toothed wheel, worm gear, and cam that work together autonomously to tilt and release the hook, minimizing the need for additional complex systems.
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
This design significantly reduces the unlocking time and allows for smaller actuating cylinders, enabling faster activation of the thrust reverser function.
Implementation Method 1
the hook's pivoting is ensured by a cam fixed to the locking/unlocking member
Implementation Method 2
the locking/unlocking device comprises a toothed wheel associated with a worm gear driven by a motor fixed to said support fixed to the nacelle
Implementation Method 3
the locking/unlocking device is connected to a hydraulic cylinder
Data Source
Figure 1~5
Figure 2~4
AI summary
The lock for a cowl (1) of a thrust reverser borne by a nacelle (4) comprises: a catch (16) fixed on the cowl; and a hook (12) that is configured to engage in the catch and is elastically returned (15) towards engagement with the catch; a support (6) fixed on the nacelle (4) and supporting a locking/unlocking component (7, 9; 17, 19) interposed between the hook and said support fixed on the nacelle, said locking/unlocking component being configured to allow, on the one hand, the hook to move in relation to said support (6) fixed on the nacelle between a position, called locking position, in which the hook is engaged in the catch and exerts a pressure thereon, and a position, called unlocking position, in which the hook is disengaged from the catch or is simply in contact therewith, and to allow, on the other hand, the hook to tilt in order to disengage it from the catch or engage it therein.