Nesting Toggle Latch for Aircraft Panel Weight Reduction
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Solution Overview
Problem
Aircraft latches are typically large and heavy, which contradicts the goal of reducing weight in aircraft components, and their design can lead to accidental damage to surrounding structures due to weight distribution issues, where the latch's hook may obstruct panel closure.
Innovation Solution
A compact cinch latch with a unique nesting toggle linkage and a keeper detector that minimizes overall volume and weight, featuring U-shaped links that fold together when closed and a mechanism to prevent accidental closure if the keeper is not engaged.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional aircraft latches are used, then secure panel closure is achieved, but the latch becomes large and heavy
Solution Approach 1:
The latch mechanism employs a nested toggle linkage where the latch arm nests within the toggle linkage structure. The U-shaped links are positioned such that one link nests within another, minimizing the overall volume and weight of the latch while maintaining its structural integrity and locking capability
Solution Approach 2:
The latch uses a dynamic toggle linkage mechanism that rotates around a mounting pin to produce the latch reach. The linkage can dynamically adjust its configuration between open and closed positions, allowing the hook to extend and retract as needed while maintaining secure closure when engaged
2Stability of the object's composition
If the latch center of gravity is behind the pivot point, then the hook hangs downward, but the hook may obstruct panel closure and cause damage
Solution Approach 1:
The latch includes a keeper detector that performs a preliminary check to determine whether the keeper is properly engaged by the hook. This preliminary detection prevents the panel from being closed if the keeper is not captured, thereby preventing the hook from obstructing panel closure and causing damage
Solution Approach 2:
The keeper detector provides feedback about the engagement status of the keeper to the control system. This feedback mechanism allows the system to recognize when the latch is properly engaged and when it is not, enabling appropriate actions to be taken to prevent panel damage
3Object-affected harmful factors
If dead weight is added to the hook end, then the hook hangs downward away from the load plane, but the latch weight increases
Solution Approach 1:
The latch arm serves multiple functions: it provides the structural connection between the toggle linkage and the hook, acts as a lever to amplify the closing force, and functions as a detector arm to sense keeper engagement. This multi-functionality eliminates the need for separate dead weight components while achieving the desired hook orientation and protection
Data Source
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AI summary
A latch with a unique nesting toggle linkage that extends and retracts a hook via movement of an actuation handle. The linkage links have U-shaped lateral cross sections with a central channel into which the respective links nest when the latch is closed to minimize the overall volume of the latch. The links fold toward each other while closing to reduce the latch's overall length when fully closed. The components of the latch are arranged so that the center of gravity of the latch is positioned in front of a mounting pin; therefore, in applications where the latch swings in the vertical plane, the hook will necessarily hang downwardly away from the keeper when the latch is open. Optionally, a keeper detector prevents the actuation handle from closing if the keeper has not been first captured in the mouth of the hook. A rod-and-cylinder slide mechanism may be employed between the hook body and the mounting pin.