Bicycle Arm Drive Using Universal Joint for Stability

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Solution Overview

Problem

Conventional leg-powered bicycles do not effectively utilize the arms for propulsion, leading to undertrained upper body muscles and stability issues when attempting to integrate arm-driven systems, as previous solutions either compromise stability or require significant redesign and additional weight.

Innovation Solution

A structurally simple arm drive unit is integrated below the steering head bearing, using a connecting shaft with a universal joint and deflection gear to transmit power from the handlebars to the pedal crank without altering existing components, allowing for synchronous arm and leg movement and easy retrofitting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If arm drive mechanisms are integrated into conventional bicycles, then upper body muscle engagement and propulsion capability are improved, but bicycle stability deteriorates

Engineering Contradiction:
Improvepropulsion capabilityVSAvoidbicycle stability
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

A connecting shaft with universal joints is introduced as an intermediary component between the handlebars and the drive system. This mediator transmits arm movements to the drive chain while isolating the steering mechanism from direct drive forces, thereby maintaining stability while enabling arm propulsion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The drive system is segmented into independent functional components: handlebars for steering, connecting shaft with universal joints for movement transmission, and a separate drive chain mechanism. This segmentation allows each component to perform its specific function without interfering with others, particularly keeping steering independent from drive forces to maintain stability.

Inventive Principle:
Principle #1Segmentation

2Productivity

If arm drive systems are added to existing bicycles, then propulsion efficiency is improved, but device complexity increases

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

Solution Approach 1:

The connecting shaft with universal joints serves multiple functions simultaneously: it transmits rotational movement from handlebars, accommodates steering movements, and connects to the drive chain system. This multi-functionality reduces the need for additional specialized components, thereby limiting complexity increase while maintaining propulsion efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The universal joints in the connecting shaft provide dynamic adaptability, allowing the mechanism to accommodate varying angles and movements during both steering and pedaling operations. This dynamic design enables a single mechanism to handle multiple motion types without requiring complex fixed-geometry components.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If conventional leg-powered bicycles are used, then structural simplicity is maintained, but upper body muscle engagement is insufficient

Engineering Contradiction:
Improvestructural simplicityVSAvoidupper body muscle engagement
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The invention merges the steering function (handlebars) with the arm drive function by connecting them through the universal joint mechanism. This combination allows the same component (handlebars) to serve both steering and propulsion purposes, thereby adding upper body engagement while maintaining relatively simple structure.

Inventive Principle:
Principle #5Merging (Combining)

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

This solution enables effective arm support during cycling, enhancing upper body muscle engagement, stability, and comfort while maintaining the integrity of the bicycle frame, allowing for efficient and cost-effective integration into existing bicycle systems.

Implementation Method 1

whose rotary movement can drive a deflection gear that is attached to the bicycle frame

Methodology Applied
Scientific EffectUniversal joint mechanism: Gimbal

Implementation Method 2

a connecting shaft with a universal joint and deflection gear to transmit power from the handlebars to the pedal crank

Methodology Applied
Scientific EffectMechanical power transmission: Axle

Implementation Method 3

the power transmission from the handlebars to the pedal crank (or a corresponding leg drive element)

Methodology Applied
Scientific EffectGear mechanism: Gear

Data Source

PatentEP2113455B1Bicycle with arm drive
Publication Date: 2012.10.31 BERGER JOACHIM
  • EP2113455B1 patent drawingFigure 1
  • EP2113455B1 patent drawingFigure 2
  • EP2113455B1 patent drawingFigure 3

AI summary

The bicycle has an arm drive, a bicycle frame (28), a steering device with a handlebar (1) and a steering fork fastened on the handlebar. The steering fork has a head tube (20), a cross bar (22) fastened on the head tube and fork arms (24a,24b) fastened on the cross bar as bracket of a wheel (26). The fork arms are fastened on a side of the cross bar turned away from the head tube. An arm drive unit is provided for supporting locomotion of the bicycle by movement of the handlebar with arms.