Spring Clutch Arm Assembly With Variable Friction Position Holding

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Solution Overview

Problem

Passenger seat systems in vehicles face challenges in supporting increasing screen sizes and loads of electronic devices while maintaining adjustability and preventing accidental movement, which can lead to damage or injury.

Innovation Solution

A spring clutch arm assembly with a moveable arm and a coil spring mechanism that adjusts friction based on configuration, providing resistance to movement from the deployed to the retracted position to securely hold electronic devices in place.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a moveable arm mechanism is designed to support significant loads of electronic devices, then the load-bearing capacity is improved, but the mechanism becomes more complex and heavier

Engineering Contradiction:
Improveload-bearing capacityVSAvoidmechanism complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The spring mechanism is divided into distinct functional segments: the coil portion wrapped around the fixed shaft provides structural support and friction control, while the moving portion with distal end provides attachment and movement capability. This segmentation allows each part to be optimized for its specific function, reducing overall complexity while maintaining load-bearing capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring portion is designed to dynamically change its friction characteristics based on the configuration of the moveable arm. As the arm moves between deployed and retracted positions, the spring's interaction with the fixed shaft automatically adjusts friction levels, providing adaptive load support without requiring complex control mechanisms.

Inventive Principle:
Principle #15Dynamics

2Reliability

If friction is increased to prevent accidental movement of electronic devices, then safety is improved, but adjustability and ease of movement are reduced

Engineering Contradiction:
ImprovesafetyVSAvoidadjustability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The spring clutch mechanism dynamically adjusts friction based on the arm's configuration. When the moveable arm is in the deployed configuration, the spring portion engages with the fixed shaft to provide high friction and prevent accidental movement. When the arm is in the retracted configuration, the friction is reduced, allowing easy adjustment and positioning. This dynamic friction variation resolves the contradiction between safety and adjustability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The friction parameter is changed based on the operational state of the moveable arm. The spring portion's geometric parameters (such as coil diameter and pitch) are designed to automatically vary the friction force as the arm moves between configurations, enabling the system to provide high friction for safety during use and low friction for ease of adjustment during positioning.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the moveable arm is designed to allow free movement for ergonomic adjustment, then ease of operation is improved, but the ability to hold position securely is reduced

Engineering Contradiction:
Improveergonomic adjustabilityVSAvoidposition holding capability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The spring clutch mechanism provides dynamic position holding. During adjustment, the moveable arm can move freely with minimal resistance. Once positioned, the spring portion automatically engages with the fixed shaft to create friction that securely holds the arm in place. This dynamic transition between free movement and secure holding resolves the contradiction between ergonomic adjustability and position stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring mechanism is designed to automatically provide position holding without external intervention. As the moveable arm is moved to a desired position, the spring portion self-adjusts its engagement with the fixed shaft to provide appropriate friction force, securing the arm in place without requiring additional locking mechanisms or user action.

Inventive Principle:
Principle #25Self-service

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 solution effectively supports significant loads, allows for ergonomic adjustability, and prevents accidental movement of electronic devices, ensuring safety and reducing the risk of damage by varying friction levels based on the arm's configuration.

Implementation Method 1

the coil portion comprises a tension diameter such that friction between the coil portion and the fixed shaft increases

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a spring portion comprising (i) a moving portion with a distal end and (ii) a coil portion wrapped around the fixed shaft

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3814670B1Spring clutch arm assembly
Publication Date: 2022.04.27 ZODIAC SEATS US LLC
  • EP3814670B1 patent drawingFigure 1A
  • EP3814670B1 patent drawingFigure 1B
  • EP3814670B1 patent drawingFigure 2A~2B

AI summary

A spring clutch arm assembly includes a moveable arm comprising a retracted configuration and a deployed configuration, a fixed shaft, and a spring portion comprising a moving portion with a distal end and a coil portion wrapped around the fixed shaft. The moveable arm may include a moveable member. The distal end may be attached to the moveable member. The moveable arm may be held in the deployed configuration by the spring portion.