Bicycle Pedal Leaf Spring Composite Buckling Mechanism

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional automatic bicycle pedals with metallic helical springs face issues such as limited dimensions, stiffness variations, corrosion sensitivity, and fatigue, while elastomer springs are affected by temperature and creep, leading to performance limitations.

Innovation Solution

An automatic bicycle pedal with a rear catch element that uses an extended elastic leaf made of composite material, prestressed in buckling, housed laterally on the pedal body, providing a durable and easy-to-produce elastic return mechanism that maintains the conventional pivoting operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metallic helical springs are used as elastic return means, then the pedal can provide reliable elastic return force, but the springs are sensitive to corrosion and fatigue, have limited dimensions, and require broad production tolerances

Engineering Contradiction:

Improveelastic return reliabilityVSAvoidcorrosion and fatigue sensitivity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces traditional metallic helical springs with a leaf spring made of composite material. This composite leaf spring provides the necessary elastic return force while being resistant to corrosion and fatigue, directly resolving the contradiction between reliability and susceptibility to harmful environmental factors.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the physical form and material properties of the elastic return means from a metallic helical spring to a composite leaf spring. This parameter change includes altering the material composition, structural geometry, and elastic characteristics to achieve both reliable elastic return and resistance to corrosion and fatigue.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If metallic helical springs are used, then elastic return function is achieved, but stiffness variations require broad production tolerances or additional controlling devices

Engineering Contradiction:

Improveelastic return consistencyVSAvoidproduction tolerances

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The composite material used in the leaf spring provides more consistent elastic properties compared to metallic helical springs. This material consistency reduces stiffness variations and allows for tighter production tolerances without requiring additional controlling devices.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

By changing from metallic helical spring geometry to composite leaf spring geometry, the patent achieves more predictable and consistent elastic behavior. The leaf spring's monolithic structure and composite material properties reduce parameter variations that would otherwise require tight tolerances or additional control mechanisms.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If elastomer springs are used to eliminate metallic spring deficiencies, then corrosion and fatigue resistance is improved, but temperature sensitivity and creep limit performance

Engineering Contradiction:

Improvecorrosion and fatigue resistanceVSAvoidtemperature stability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses a composite material for the leaf spring that combines the advantages of different materials. This composite construction provides corrosion and fatigue resistance like elastomers while maintaining temperature stability and reducing creep, thus resolving the contradiction between corrosion resistance and temperature stability.

Inventive Principle:

Principle #40Composite materials

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 solution offers improved resistance to corrosion and fatigue, reduced production tolerances, and enhanced performance stability, ensuring reliable engagement and disengagement of the retaining plate without the limitations of traditional spring systems.

Implementation Method 1

an extended elastic element that extends in a longitudinal plane relative to said pedal body so as to be stressed along its longitudinal axis in buckling by the rear catch element when the latter is pivoted towards the position of release of said retaining plate

Methodology Applied

Scientific EffectBuckling:

Implementation Method 2

an extended elastic element that extends in a longitudinal plane relative to said pedal body so as to be stressed along its longitudinal axis in buckling

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS8516923B2Automatic bicycle pedal with leaf spring

Publication Date: 2013.08.27 LOOK CYCLE INT SA

AI summary

The pedal includes a pedal body (1) rotationally mounted on a pedal shaft. The pedal body (1) includes a fixed front catch element (4) and a movable rear catch element (6) that work with a retaining plate (3) fixed underneath the footwear of the cyclist. The movable rear catch element (6) is mounted to be able to pivot between a retaining position of the plate (3) and a position of release of the plate (3) by the pivoting of the rear catch element (6) in opposition to the action of an elastic return element (10). The elastic return element (10) is composed of an elastic leaf that forms a spring located in a longitudinal housing (11) of the pedal body (10) open to the rear, the leaf (10) being able to be stressed along its longitudinal axis in buckling during pivoting of the rear catch element.