Offset Axle Roller Device for Patient Transport Shock Reduction

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Solution Overview

Problem

Roller devices used in patient transport systems experience shocks when rolling over corrugated aluminum plates or grid elements, which compromises patient comfort due to the immersion of wheels in the corrugations or grid openings, leading to discomfort and potential harm.

Innovation Solution

A roller device design featuring a wheel holder that allows the impeller and support wheel to be arranged with parallel and offset axles, reducing or eliminating immersion in corrugations or grid openings, thereby minimizing shocks and enhancing comfort by maintaining a constant position relative to the patient holder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single running wheel is used in the roller device, then the device complexity is reduced, but the wheel immerses into corrugations or grid openings causing shocks and reducing patient comfort

Engineering Contradiction:
Improveroller device structureVSAvoidshocks to patient
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The single running wheel is segmented into two separate running wheels arranged side by side. This segmentation allows the wheels to be positioned such that they do not simultaneously immerse into adjacent corrugations or grid openings, thereby reducing shocks while maintaining a relatively simple device structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A support wheel is introduced as an intermediary element between the wheel mount and the running wheels. This support wheel provides additional support and helps stabilize the roller device, preventing the running wheels from plunging into gaps while distributing the load more evenly.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the running wheel axis is positioned to avoid immersion in corrugations, then patient comfort is improved, but the wheel mount complexity increases due to additional positioning requirements

Engineering Contradiction:
Improveshock transmissionVSAvoidwheel mount structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The functions of support and running wheel mounting are merged into a single integrated wheel mount structure. This consolidation achieves the required axle positioning to prevent immersion while avoiding the complexity of separate positioning mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The wheel mount is designed to maintain a constant distance between the patient support and the running wheel axles, creating an equipotential positioning system. This ensures consistent spacing that prevents immersion into corrugations without requiring complex active positioning controls.

Inventive Principle:
Principle #12Equipotentiality

3Object-affected harmful factors

If the running wheel diameter is increased to bridge over corrugations, then shock reduction is achieved, but the device dimensions and potential entrapment risks increase

Engineering Contradiction:
Improveshocks during rollingVSAvoidwheel diameter
Core Design Contradiction:
Object-affected harmful factorsVSLength of moving object

Solution Approach 1:

Instead of using a single large-diameter wheel, the system segments the rolling function into two smaller running wheels. These smaller wheels are positioned to roll along the crests of adjacent corrugations or across grid elements, effectively bridging gaps without requiring excessive wheel diameter that would create entrapment risks.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4445888A1Roller device, patient transport device and roller system
Publication Date: 2024.10.16 STARMED GMBH
  • EP4445888A1 patent drawingFigure 1
  • EP4445888A1 patent drawingFigure 2
  • EP4445888A1 patent drawingFigure 3

AI summary

Roller device (10) for a patient transport device with a patient holder for rolling the patient transport device over a surface (350). The roller device (10) has a wheel bracket (12) which is rotatable about a pivot axis (22) or fixedly connected to the patient holder, a running wheel (14) which is rotatably held by the wheel bracket (12) about a running wheel axis (18), and a support wheel (16) which is rotatably held by the wheel bracket (12) about a support wheel axis (20). The running wheel axis (18) and the support wheel axis (20) are arranged parallel and offset from each other.