Dual-Panel Footrest Crank Mechanism to Avoid Floor Interference

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Solution Overview

Problem

Existing footrest devices for armchairs or sofas often cause damage to the padding and floor due to interference during movement between the extracted and retracted positions.

Innovation Solution

A footrest device with a crank mechanism that allows two panels of equal width to move between positions without interfering with the support floor, using a lever mechanism and actuating cylinder to maintain distance from the floor during retraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the second footrest panel is folded beneath the armchair or sofa in a horizontal position during retraction, then the footrest device achieves compact storage space, but the panel interferes with the support floor and causes damage to padding and/or floor

Engineering Contradiction:
Improvestorage spaceVSAvoiddamage to padding and floor
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent changes the retraction path of the second footrest panel from a horizontal folding motion (2D plane) to a vertical lifting motion (3D space). The panel is raised above the support frame during retraction instead of being folded beneath it, thereby avoiding interference with the floor while achieving compact storage through vertical stacking with the first panel.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the crank mechanism moves the footrest panels between extracted and retracted positions, then the footrest functionality is achieved, but the movement path causes the second panel to interfere with the support floor

Engineering Contradiction:
Improvefootrest functionalityVSAvoidinterference with support floor
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the crank mechanism to dynamically adjust the movement path of the second footrest panel. During retraction, the mechanism temporarily lifts the panel vertically above the support frame, then completes the retraction motion. This dynamic path adjustment maintains the ease of operation while avoiding floor interference throughout the movement sequence.

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

Prevents damage to the padding and floor by ensuring the panels do not interfere with the support floor during movement, maintaining a safe distance and preventing damage.

Implementation Method 1

an actuating cylinder interposed between the support frame and the crank mechanism to move the two footrest panels between the extracted operating position and a retracted rest position

Methodology Applied
Scientific EffectHydraulic or pneumatic actuation: Hydraulic Press

Implementation Method 2

the actuating device comprises a crank mechanism interposed between the support frame and the two footrest panels

Methodology Applied
Scientific EffectCrank mechanism: Crankshaft

Implementation Method 3

Each lever mechanism 7 comprises two cranks 9, 10, which are hinged to the respective side member 6 to rotate, with respect to the frame 2, about respective fulcrum axes 11, 12

Methodology Applied
Scientific EffectLever mechanism: Lever

Data Source

PatentEP2957190B1Footrest device for armchairs or sofas
Publication Date: 2016.10.05 CIAR
  • EP2957190B1 patent drawingFigure 1
  • EP2957190B1 patent drawingFigure 2~4
  • EP2957190B1 patent drawingFigure 3~5

AI summary

A footrest device for armchairs or sofas has two footrest panels (3, 4), which have substantially the same width (L1, L2), and are movable under the thrust of a crank mechanism (5) between an extracted operating position, in which the two footrest panels (3, 4) project from the front of a support frame (2), and a retracted rest position, in which the two footrest panels (3, 4) substantially overlap one another.