Asymmetric Steering Arm Folding for Compact Traction Device Transport

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Solution Overview

Problem

Existing traction devices for mobile seat units, such as hospital elevators and wheelchairs, are difficult to transport due to their size and require additional storage space, necessitating a flexible and compact design.

Innovation Solution

A drive arrangement with a handlebar support and steering arm that can pivot asymmetrically around a pivot axis, allowing the steering arm to fold closely to the drive wheel, combined with a modular design incorporating a motor and torque transmission unit, enabling the device to be compactly folded for transport while maintaining operational flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the steering arm is designed symmetrically to the central plane of the drive wheel, then the structural design is simpler and more balanced, but the packing size during transport is larger and cannot be folded compactly

Engineering Contradiction:
Improvepacking sizeVSAvoidstructural design
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The steering arm is designed asymmetrically with respect to the central plane of the drive wheel, allowing it to pivot completely to the side of the drive wheel during folding. This asymmetric configuration enables the steering arm to overlap with the drive wheel when folded, significantly reducing the packing size and volume of the traction device for transport.

Inventive Principle:
Principle #4Asymmetry

2Volume of moving object

If the steering arm pivots completely to the side of the drive wheel, then the packing size is reduced for easier transport, but the risk of collision between steering arm parts and drive wheel parts increases

Engineering Contradiction:
Improvepacking sizeVSAvoidcollision risk
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The steering arm is divided into multiple segments or parts that can pivot independently. This segmentation allows the steering arm to fold in a controlled manner, with each part moving sequentially to avoid collision with the drive wheel while still achieving complete pivoting to the side for compact packing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The asymmetric design pre-positions the steering arm parts relative to the drive wheel, creating clearances and pathways that prevent collision during the folding process. The geometry is specifically designed so that as the steering arm pivots, its parts naturally clear the drive wheel before reaching the folded position.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the steering arm is designed to fold completely to the side, then the transportability is improved, but the manufacturing complexity and cost increase

Engineering Contradiction:
ImprovetransportabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The asymmetric design of the steering arm, while enabling complete folding to the side for improved transportability, requires custom manufacturing processes and higher precision machining to achieve the specific geometric relationships and clearances needed, thereby increasing manufacturing complexity and cost.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3738570B1Drive arrangement for a traction device and traction device for a mobile seat unit
Publication Date: 2023.09.20 J & A SATTELE
  • EP3738570B1 patent drawingFigure 1~2
  • EP3738570B1 patent drawingFigure 3~4
  • EP3738570B1 patent drawingFigure 5~6

AI summary

The invention relates to a drive arrangement (12) for a traction device (10) for a mobile seating unit, comprising a handlebar support (14) with a steering arm (16) and a fork section (18), wherein a handlebar (20) is arranged on the steering arm (16) and a drive wheel (22) is arranged on the fork section (18), and wherein the steering arm (16) is pivotably mounted on the fork section (18) about a pivot axis (S). It is characterized in that the handlebar support (14), in particular the steering arm (16), is designed and/or arranged asymmetrically to the central plane (M) of the drive wheel (22) such that the steering arm (16) can pivot completely or at least partially on a pivot side (X) of the drive wheel (22) up to the side of the drive wheel (22).