Pendulum Latch Inertia Lock for Aircraft Seats

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Solution Overview

Problem

Existing aircraft seating systems face challenges in preventing moveable seat substructures from becoming disconnected from the fixed base substructure during dynamic events like rapid deceleration, as known inertia latch mechanisms may suffer from bounce-back or vibration, leading to disengagement.

Innovation Solution

The inertia lock apparatus features a pendulum latch with a mass portion and catch portion that pivots to catch a striker bar during deceleration, combined with a lock mechanism that prevents reverse rotation, ensuring irreversible securing of the seat substructure to the base substructure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pendulum latch mechanism is used to prevent forward seat movement during rapid deceleration, then the seat substructure is secured to the base substructure, but the latch may suffer from bounce-back or vibration and become disengaged

Engineering Contradiction:

Improvelatch engagement reliabilityVSAvoidbounce-back and vibration

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The latch mechanism is divided into two independent functional components: the pendulum latch (with mass portion and catch portion) that responds to deceleration, and the lock mechanism (with pawl member and lock surface) that provides positive locking. This segmentation allows each component to perform its specialized function without interfering with the other, resolving the contradiction between responsiveness and stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lock mechanism is pre-configured with the pawl member and lock surface positioned to engage automatically once the pendulum latch reaches the latching orientation. This preliminary positioning ensures that as soon as the latch engages, the lock mechanism immediately secures it in place, preventing any subsequent bounce-back or vibration from causing disengagement.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a lock mechanism is added to prevent reverse rotation of the pendulum latch, then positive locking is achieved, but the device complexity increases

Engineering Contradiction:

Improvepositive lockingVSAvoidlatch structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The lock mechanism is integrated with the pendulum latch by positioning the pawl member to engage with the lock surface on the pendulum latch body itself. This merging of functions into a compact arrangement achieves positive locking without requiring a separate, complex locking system, thus minimizing the increase in device complexity while ensuring reliable positive locking.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the catch portion is positioned to catch the striker bar during deceleration, then the seat substructure is secured, but the striker bar may not be caught during normal operation

Engineering Contradiction:

Improvedynamic event securingVSAvoidnormal operation freedom

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The pendulum latch is designed to be dynamically responsive to deceleration forces through its mass portion and pivot point configuration. During normal operation, the latch remains in the normal orientation allowing free movement. During rapid deceleration, the mass portion pivots the catch portion into the latching orientation to catch the striker bar. This dynamic behavior automatically provides securing only when needed, maintaining ease of operation during normal use.

Inventive Principle:

Principle #15Dynamics

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 apparatus effectively prevents the seat substructure from becoming uncoupled from the base substructure during dynamic events, providing a secure and stable seating system by resisting bounce-back and ensuring positive latching.

Implementation Method 1

a mass portion configured to pivot about a pivot point relative to a predetermined deceleration

Methodology Applied

Scientific EffectInertia: Inertia

Implementation Method 2

a lock mechanism configured to prevent the pendulum latch from moving from the latching orientation to the normal orientation

Methodology Applied

Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentUS7607729B1Inertia lock apparatus

Publication Date: 2009.10.27 BE AEROSPACE INC

AI summary

An apparatus is provided for securing a moveable seat substructure of a vehicle seating system to a stationary base substructure of the vehicle seating system during a dynamic event such as, for example, rapid vehicle deceleration. In one aspect, an inertia lock apparatus is provided for a vehicle seating system and includes: a striker bar; a pendulum latch pivotally moveable between a normal orientation and a latching orientation, wherein the pendulum latch includes a first end with a mass portion configured to pivot about a pivot point relative to a predetermined deceleration, a second end with a catch portion configured to catch the striker bar in the latching orientation and a cam slot intermediate the first end and the second end; and a lock mechanism configured to prevent the pendulum latch from moving from the latching orientation to the normal orientation. In another aspect, a vehicle seating system including the inertia lock apparatus is provided.