Rack-Driven Human Powered Vehicle Propulsion

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Solution Overview

Problem

Existing human-powered vehicles, such as bicycles, rely on chain and gear systems that require a small group of muscles and short strokes, limiting efficiency and user engagement.

Innovation Solution

A rack-driven human-powered vehicle incorporating a rack and pinion system with freewheel sprockets, allowing for efficient propulsion and user control through linear motion conversion into rotational motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a chain and gear system is used for propulsion, then the vehicle can be propelled forward, but the system requires a small group of muscles and utilizes short strokes, limiting efficiency and user engagement

Engineering Contradiction:
Improvepropulsion efficiencyVSAvoiduser engagement
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent replaces the traditional chain and gear system with a rack and pinion system. The rack is directly connected to the wheel axle, and the pinion gear is connected to the pedal axis, creating a more direct mechanical transmission path that improves propulsion efficiency and user engagement

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a rack as an intermediary element between the pinion gear and the wheel. The rack translates the rotational motion of the pinion into linear motion that directly drives the wheel, creating a more efficient power transmission mechanism

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If a rack and pinion system is implemented, then propulsion efficiency is enhanced through direct motion transfer, but the device complexity increases compared to traditional chain systems

Engineering Contradiction:
Improvepropulsion efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the chain from the traditional chain-and-sprocket system, replacing it with a rack and pinion mechanism. This removes the need for chain maintenance and reduces overall system complexity while improving power transmission efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If freewheel sprockets are used to allow unidirectional propulsion, then the wheels can be propelled forward efficiently, but the system requires additional components to control direction

Engineering Contradiction:
Improvepropulsion efficiencyVSAvoidcomponent quantity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs freewheel sprockets that automatically engage and disengage based on the direction of force applied. When the user pushes forward, the sprocket engages to propel the wheel; when pushed backward, it disengages freely, providing automatic directional control without additional complex mechanisms

Inventive Principle:
Principle #25Self-service

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 rack and pinion system enhances propulsion efficiency by directly transferring user energy into wheel rotation, providing a more engaging and efficient mode of transportation compared to traditional chain and gear systems.

Implementation Method 1

The rack and pinion system may transfer the linear motion of the at least one driving rack into rotational motion in the at least one freewheel sprocket

Methodology Applied
Scientific EffectRack and pinion mechanism: Rack and Pinion

Implementation Method 2

The at least one freewheel sprocket may be configured to allow the at least two wheels to be propelled forward when pushed in one direction

Methodology Applied
Scientific EffectFreewheel mechanism: Ratchet

Data Source

PatentEP3960608B1Rack-driven human powered vehicle
Publication Date: 2025.05.21 THOMPKINS TOREK
  • EP3960608B1 patent drawingFigure 1
  • EP3960608B1 patent drawingFigure 2
  • EP3960608B1 patent drawingFigure 3a~3b

AI summary

A rack driven human powered vehicle (100, 200) utilizes a rack and pinion system (13) to provide a more efficient method of propulsion. The rack and pinion system (13) may take the linear momentum of at least one driving rack (6) and may transfer it to rotational momentum for at least one freewheel sprocket (3) which may turn the wheel (12) providing momentum for the vehicle (100, 200).