Aircraft seat assembly having a quick change preloading track lock assembly
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Solution Overview
Problem
Aircraft seat assemblies experience loose fit issues between the pin and locking feature of the longitudinal track, leading to play or movement detected by occupants, which compromises the secure locking mechanism.
Innovation Solution
The track lock assembly incorporates a clamping shaft, locking collar, compression cap, biasing member, and latching lever to provide an over-center latching feature, ensuring a secure detent feel by clamping the foot assembly into the track assembly, preventing fore and aft motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pin and locking feature mechanism is used to lock the aircraft seat, then the seat can be secured to the track assembly, but the loose fit between the pin and locking feature results in play or movement within the joint
Solution Approach 1:
The patent changes the geometric parameters of the locking mechanism by introducing a cam surface with specific angular geometry (approximately 45 degrees) that transforms the locking action from a simple pin-fit relationship to a cam-driven rotational movement. This parameter change enables the locking collar to engage the cam surface and rotate, creating a mechanical advantage that eliminates play while maintaining secure locking
Solution Approach 2:
The patent introduces dynamic elements to the locking mechanism, including a biasing member that applies continuous force to maintain engagement between the cam surface and locking collar, and a latching lever that transitions between locked and unlocked positions. This dynamic system ensures the joint remains stable during normal operation while allowing controlled movement for locking and unlocking operations
2Device complexity
If a traditional pin locking mechanism is used, then the structure remains simple, but the loose fit causes detectable movement and reduces security
Solution Approach 1:
The patent segments the locking mechanism into distinct functional components: a cam surface integrated with the track assembly, a locking collar with internal cam engagement surfaces, a biasing member for maintaining engagement force, and a latching lever for operation. This segmentation allows each component to be optimized for its specific function while working together to provide secure locking with minimal detectable movement
Solution Approach 2:
The patent introduces a cam surface as an intermediary element between the track assembly and the locking collar. This cam surface acts as a mediator that transforms the locking action into a rotational movement of the locking collar, providing mechanical advantage and eliminating the loose fit problem inherent in direct pin-to-hole engagement while adding only moderate complexity to the overall structure
Data Source
AI summary
An aircraft seat assembly includes a foot assembly, a seat, and a track lock assembly. The foot assembly is received within a track assembly disposed on an aircraft floor. The seat is connected to the foot assembly. The track lock assembly moves between a lock position and an unlock position. The track lock assembly includes a clamping shaft having a base member and a shaft. The base member is received within the track assembly. The shaft extends from the base member and extends through the foot assembly.