Armrest Motor-Spring Drive Design to Prevent Jamming and Injury

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Solution Overview

Problem

Existing armrest designs for vehicle seats face difficulties in easily transitioning between stowed and use positions, with a risk of jamming and potential injury from limb pinching, often requiring complex sensors and overload protection.

Innovation Solution

An armrest with a guide device that allows movement parallel to the pivot axis and rotational movement about the axis, utilizing a motor-driven linear drive and spring mechanism for smooth transition, along with a damping system to prevent jamming and injury, and a space-saving telescopic guide structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the armrest uses a motor-driven linear drive with spring mechanism for movement, then the ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improveease of movement between positionsVSAvoidcomplexity of drive mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The spring mechanism is configured to automatically tension during the armrest's movement from stowed to use position, providing self-powered assistance that reduces motor load and simplifies control requirements. The spring tensions as the armrest pivots and translates, creating a self-regulating system that aids movement without requiring complex active control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The spring mechanism is pre-configured to provide cushioning force during the armrest movement, absorbing shocks and preventing jamming before they occur. The spring tensions in advance during the movement sequence, providing protective cushioning that prevents harmful effects from occurring in the first place.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If the armrest includes damping device and spring mechanism, then the reliability is improved by preventing jamming, but the device complexity increases

Engineering Contradiction:
Improverisk of jammingVSAvoidcomplexity of protection system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring mechanism converts the potential harmful effect of sudden movements and impacts into beneficial cushioning force. The spring tensions during normal operation to store energy, then releases this energy to cushion against jamming and prevent limb pinching, transforming what could be harmful mechanical shocks into protective cushioning.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The damping device and spring mechanism are configured to provide protective cushioning before harmful effects can occur. The spring tensions in advance during the armrest's movement sequence, and the damping device is positioned to absorb shocks before they can cause jamming or injury, preventing problems rather than reacting to them.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Volume of moving object

If the armrest uses telescopic guide structure, then the volume in non-use position is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvespace in non-use positionVSAvoidprecision of guide structure
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The guide structure employs a telescopic configuration where the armrest assembly nests within the base structure when in the non-use position. The armrest translates axially to extend or retract from the base, creating a compact nested arrangement that minimizes the volume occupied when the armrest is stowed, similar to a nested doll configuration.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Facilitates easy and safe movement between stowed and use positions, reducing the risk of jamming and injury without the need for complex sensors, while maintaining a compact design.

Implementation Method 1

utilizing a motor-driven linear drive and spring mechanism for smooth transition

Methodology Applied
Scientific EffectSpring mechanism: Spring

Implementation Method 2

along with a damping system to prevent jamming and injury

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3680130B1Armrest
Publication Date: 2021.04.14 GRAMMER AG
  • EP3680130B1 patent drawingFigure 1
  • EP3680130B1 patent drawingFigure 2
  • EP3680130B1 patent drawingFigure 3

AI summary

Armrest (10) with a base (19) and an armrest (13) movable between at least one use position and a non-use position by means of a guide device (17), wherein the armrest (13) is movable parallel to a pivot axis (a) between a proximal and a distal position by means of the guide device (17) and pivotable about the pivot axis (a) between a primary position and a secondary position, wherein the armrest (10) has a drive device (30) comprising a motor drive with a drive part (29) which is movable between a first and a second position in order to move the armrest (13) at least partially in a first direction (y1) between the non-use position and the use position, wherein the drive device (30) comprises at least one spring (21) which can be tensioned when the drive part (29) or an additional drive part of the drive device (30) is moved.wherein the armrest (13) can be moved axially in a second direction (y2) by means of the spring (21), which is directed opposite to the first direction (y1).