Knee Walker Belt Steering for Stability on Uneven Terrain

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Solution Overview

Problem

Conventional knee walkers face challenges in steering, especially on uneven terrain, and instability, which limits their effectiveness for individuals with ankle or foot injuries.

Innovation Solution

A knee walker design featuring a steering column with a belt linkage system that connects to two pivotable front wheels, allowing simultaneous steering and enhanced frictional contact, along with adjustable belt tension and a compact folding mechanism for ease of use and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single front wheel is used for steering, then the device structure is simpler, but steering effectiveness on uneven terrain deteriorates

Engineering Contradiction:
Improvewheel structureVSAvoidsteering effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single front wheel is divided into two separate front wheels, each capable of independent steering. This segmentation allows each wheel to navigate uneven terrain independently while maintaining overall steering control through the belt linkage system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Two front wheel assemblies are combined and linked together through a belt linkage system connected to a common steering column. This merging allows simultaneous steering of both wheels while maintaining the simplicity of a single steering control mechanism.

Inventive Principle:
Principle #5Merging (Combining)

2Stability of the object's composition

If the steering column is positioned directly over the wheel contact point, then the turning circle is larger, but the structure is more stable

Engineering Contradiction:
Improvestructural stabilityVSAvoidturning circle
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The steering column is positioned asymmetrically forward of the wheel contact point, creating an offset configuration. This asymmetric positioning reduces the turning circle by allowing the wheels to pivot more sharply, while the overall frame structure maintains stability through its geometric design.

Inventive Principle:
Principle #4Asymmetry

3Device complexity

If the belt contacts less than half the pulley circumference, then the linkage is simpler, but steering precision deteriorates

Engineering Contradiction:
Improvelinkage designVSAvoidsteering precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The belt is designed to contact more than half the circumference of each pulley, providing excessive contact area beyond the minimum required for functional operation. This increased contact area enhances frictional engagement and prevents slipping, thereby improving steering precision without significantly complicating the linkage design.

Inventive Principle:
Principle #16Partial or excessive action

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 design enables stable and precise steering on uneven terrain, reduces the turning circle, and allows for easy storage, improving mobility and convenience for users with ankle or foot injuries.

Implementation Method 1

enhancing frictional contact therewith

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentUS9227684B2Knee walker having enhanced steering and stability
Publication Date: 2016.01.05 THE KNEE WALKER COMPANY

AI summary

A knee walker includes a steering column rotatably attached to a forward portion of a frame, wherein the steering column includes a steering pulley rotatable about a vertically disposed axis of rotation. Two wheel assemblies are rotatably carried by the frame and have a pulley for rotating each assembly about a vertical axis. The axis of rotation of each wheel assembly is offset aft the steering column axis. A belt links rotation of the steering column to rotation of the wheel assemblies and in combination with the offset causes the belt to extend around at least half a circumference of each pulley for enhancing frictional contact. A shield guards each pulley. Mating alignment disks for aligning each assembly are provided to permit wheel alignment without affecting the belt tension. A third wheel assembly optionally extends from the column.