Inertial Seat Lock Assembly Using Conical Binding During Deceleration

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Solution Overview

Problem

Seating assemblies in aircraft and other vehicles experience undesirable movement during rapid dynamic events due to inertial forces, posing safety risks to passengers.

Innovation Solution

An inertial lock assembly is designed with a housing containing a biasing member and binding members, including ball bearings, which are configured to bias and lock the seat frame in place by sliding along a tracking rod, utilizing conical sections and collars to secure the seat during deceleration events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a sliding mechanism is provided to allow seat assembly to translate fore and aft for adjusting leg room and facilitating reclining, then ease of operation is improved, but stability during rapid dynamic events deteriorates due to undesirable movement under inertial forces

Engineering Contradiction:
Improveease of operationVSAvoidstability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The inertial lock assembly utilizes dynamic principles by allowing the seat assembly to move freely during normal operation through a sliding mechanism, then automatically transitioning to a locked state during rapid dynamic events. The conical surface and binding member create a dynamic locking mechanism that engages only when inertial forces exceed a threshold, providing both ease of operation and stability as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the friction parameter between the binding member and conical surface based on operational conditions. During normal operation, low friction allows easy sliding. During rapid deceleration, increased normal force on the conical surface increases friction and mechanical interlocking, preventing unwanted movement. This parameter change enables the system to provide both ease of operation and stability.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If an inertial lock assembly with binding members and conical sections is used to prevent movement during rapid deceleration, then stability is improved, but device complexity increases

Engineering Contradiction:
ImprovestabilityVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The inertial lock assembly is a self-activating device that requires no external control systems, sensors, or power sources. The conical surface and binding member automatically engage when inertial forces during rapid deceleration push the seat assembly forward, causing the binding member to ride up the conical surface and lock. This passive, self-service mechanism provides stability without adding significant complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts only the essential locking function from complex active locking systems. By using a simple conical surface and binding member arrangement that relies on inertial forces alone, the design achieves stability without requiring motors, sensors, control electronics, or multiple actuating mechanisms, thereby minimizing device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If ball bearings are used in the binding member to facilitate sliding motion, then ease of operation is improved, but friction increases during locking due to ball bearing engagement with the conical surface

Engineering Contradiction:
Improveease of operationVSAvoidfriction
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The ball bearings dynamically transition between two functional states: during normal operation, they facilitate low-friction sliding motion for ease of operation; during rapid deceleration, the increased normal force on the conical surface causes the ball bearings to be pressed against the cone, converting their motion to a locking action where friction becomes beneficial for maintaining the locked position.

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 inertial lock assembly effectively prevents the seat assembly from further movement during rapid deceleration, ensuring passenger safety by securely locking the seat to the floor, even in the presence of inertial forces.

Implementation Method 1

a biasing member disposed within the housing and configured to bias the first binding member in a first direction opposite the apex

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

the first binding member comprises a first plurality of ball bearings

Methodology Applied
Scientific EffectBall bearing: Ball Bearing

Implementation Method 3

the first portion defines a first conical section extending from the apex to the first end... configured to bind the first sliding member to the rod in response to rapid deceleration of the seat assembly

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3604030B1Linear inertial lock
Publication Date: 2023.12.06 GOODRICH CORP
  • EP3604030B1 patent drawingFigure 1
  • EP3604030B1 patent drawingFigure 2A~2C
  • EP3604030B1 patent drawingFigure 3

AI summary

An inertial lock assembly (250, 350, 450) is disclosed. In various embodiments, the inertial lock assembly includes a tracking rod (222, 322, 422) oriented with respect to a longitudinal axis, a housing (260, 360, 460) slidably disposed about the tracking rod (222, 322, 422), the housing (260, 360, 460) including an inner surface having a first portion extending from an apex to a first end spaced longitudinally from the apex (266, 366), a first sliding member slidably disposed about the tracking rod (222, 322, 422) and within the housing (260, 360, 460) proximate the first portion of the inner surface and a first binding member slidably disposed about the tracking rod and within the housing (260, 360, 460), the first binding member positioned between the apex (266, 366) and the first sliding member.