Folding Shelf with Multi-Panel Segmentation for Wheelchair Accessibility

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Solution Overview

Problem

Existing folding tables in railway vehicles, particularly those for persons with reduced mobility, face challenges in longitudinal extension and mechanical stability, as they are either too short for wheelchairs or require excessive effort to manipulate, and existing solutions either compromise on extension or mechanical strength.

Innovation Solution

A folding shelf assembly with a body fixed to the wall, featuring a first panel rotatably mounted on a body about a first axis and a second panel rotatably mounted on the first panel about a second axis, allowing for a longitudinal extension greater than 500 mm in the unfolded configuration while maintaining mechanical stability through hinges and friction couplings, and accommodating various wheelchair sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the longitudinal extension of the tablet panels is increased to accommodate wheelchair users, then the suitability for wheelchair users is improved, but mechanical stability deteriorates due to excessive overhang

Engineering Contradiction:
Improvesuitability for wheelchair usersVSAvoidmechanical stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The tablet is divided into multiple panels (first panel, second panel, and additional panels) that can be folded or extended independently. This segmentation allows the tablet to achieve sufficient longitudinal extension for wheelchair users while maintaining mechanical stability through the modular structure, as each panel supports itself rather than creating excessive overhang.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tablet employs a dynamic folding mechanism with panels that can be adjusted between folded and unfolded configurations. This dynamic structure allows the tablet to adapt its longitudinal extension based on user needs while maintaining mechanical stability through proper hinge design and friction couplings that control panel movement.

Inventive Principle:
Principle #15Dynamics

2Strength

If a table leg is used to support the panel, then structural support is provided, but it becomes an inconvenience for wheelchair users due to large turning radius requirements

Engineering Contradiction:
Improvestructural supportVSAvoidaccessibility for wheelchair users
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The traditional table leg supporting structure is removed and replaced with a wall-mounted folding panel system. This extraction eliminates the obstacle that interfered with wheelchair access while maintaining structural support through the wall-mounted body and hinge mechanism that provides necessary strength without requiring clearance for leg movement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of having a leg extend upward from the floor to support the panel, the support structure is inverted to be mounted on the wall, with panels folding downward. This inversion allows wheelchair users to approach the tablet from the front without obstruction, as the support mechanism is positioned above rather than below the panel.

Inventive Principle:
Principle #13The other way round (Inversion)

3Length of moving object

If retractable shelves are used to extend the panel, then longitudinal extension is achieved, but the effort required to operate them is significant and difficult for wheelchair users

Engineering Contradiction:
Improvelongitudinal extensionVSAvoideffort required for operation
Core Design Contradiction:
Length of moving objectVSEase of operation

Solution Approach 1:

The folding panels incorporate friction couplings that provide controlled resistance during operation, allowing the panels to be extended or folded with moderate effort while maintaining position when stationary. This dynamic friction mechanism reduces the significant effort required by traditional retractable shelves while still achieving the necessary longitudinal extension for wheelchair accessibility.

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 solution provides a folding table with sufficient longitudinal extension suitable for persons in wheelchairs, ensuring mechanical stability and ease of use, while minimizing overhang and effort required for operation.

Implementation Method 1

a first panel (22A) rotatably mounted on the body (20) about a first axis of rotation (R1) substantially parallel to the transverse direction (T), and at least a second panel (22B) rotatably mounted on the first panel (22A) about a second axis of rotation (R2)

Methodology Applied
Scientific EffectRotation:

Implementation Method 2

the tablet (18) being mobile between: an unfolded, mechanically stable configuration... and a folded, mechanically stable configuration

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3875339B1Folding shelf with large longitudinal extension and vehicle including such a shelf
Publication Date: 2023.01.11 SPEEDINNOV
  • EP3875339B1 patent drawingFigure 1
  • EP3875339B1 patent drawingFigure 2
  • EP3875339B1 patent drawingFigure 3

AI summary

An assembly (12) comprising a wall (14) and a folding shelf (18) having a body (20) fixed to the wall and extending in a transverse direction (T), and a plurality of panels (22) comprising at least one first panel (22A) mounted on the body about a first axis of rotation (R1), and at least one second panel (22B) mounted on the first panel about a second axis of rotation (R2). The shelf is movable between a mechanically stable unfolded configuration in a longitudinal direction (L) and a mechanically stable folded configuration in which the first and second panels form an acute angle with each other about the second axis of rotation. In the unfolded position, the panels together have a longitudinal extension (L1) greater than 500 mm, and at least one of the panels rests on a support surface defined by the wall.