Spring-Shaped Bicycle Rim Joining Element

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Solution Overview

Problem

Existing joining elements for bicycle rims are rigid, difficult to insert due to machining tolerances, overly long, and heavy, often interfering with spoke holes and increasing weight, particularly in lightweight competition bicycles.

Innovation Solution

A joining element made in two separate plastic parts joined by elastically deformable transverse connecting elements, with a rectilinear shape and spring configuration, allowing easy insertion and adaptation to rim dimensions, reducing length and weight, and auto-blocking within the rim.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid joining element is used, then structural integrity is maintained, but insertion difficulty increases due to machining tolerances

Engineering Contradiction:

Improvestructural integrityVSAvoidinsertion difficulty

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The joining element transitions from a rigid state during insertion to a locked rigid state after insertion. The elastic deformable connecting elements allow the joining element to flex during insertion to accommodate machining tolerances, then lock into a fixed position to provide structural integrity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The joining element changes its physical parameters (flexibility/rigidity) based on the insertion state. During insertion, the elastic deformable connecting elements allow flexibility to accommodate dimensional variations. After insertion, the element locks into position to provide the necessary rigidity for structural strength.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a curved joining element reproducing the inner cavity profile is used, then rim closure is achieved, but the element becomes overly long and heavy

Engineering Contradiction:

Improverim closureVSAvoidjoining element weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The joining element is divided into multiple straight segments connected by elastic deformable connecting elements. This segmentation allows the element to achieve the necessary curvature for rim closure while using shorter straight sections, reducing overall length and weight compared to a fully curved design.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The elastic deformable connecting elements act as flexible connections between straight segments, allowing the joining element to adapt to the curved inner cavity profile without requiring a fully curved rigid structure. This reduces material usage and weight while maintaining functionality.

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If a long joining element is used to ensure rim closure, then reliability is improved, but interference with spoke holes increases

Engineering Contradiction:

Improverim closureVSAvoidinterference with spoke holes

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By segmenting the joining element into straight sections connected by flexible joints, the overall length is reduced while maintaining the ability to achieve rim closure. The segmented structure allows the element to fit within the available space without extending into the spoke hole region.

Inventive Principle:

Principle #1Segmentation

4Ease of manufacture

If a rigid joining element is used, then manufacturing simplicity is maintained, but adaptability to machining tolerances decreases

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidadaptability to machining tolerances

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The joining element incorporates elastic deformable connecting elements that provide adaptability during insertion while maintaining structural integrity after locking. This dynamic characteristic allows the element to accommodate machining tolerances without requiring complex manufacturing processes.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The joining element's physical parameters (flexibility/rigidity) change based on the insertion state. The elastic deformable connecting elements provide flexibility during insertion to accommodate dimensional variations, then lock into a rigid configuration to ensure structural strength.

Inventive Principle:

Principle #35Parameter changes

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

Ensures reliable closure, adapts to inner dimensions, reduces interference with spoke holes, and minimizes weight while maintaining structural integrity.

Implementation Method 1

i which are joined by two elastically deformable transverse connecting elements (13)

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The spring configuration of the joining element allows an easy insertion of the same in one of the ends (2) of the rim (1) before closure, compensating possible machining tolerances

Methodology Applied

Scientific EffectSpring mechanism: Spring

Data Source

PatentEP3476621B1Joining element for bicycle rims, bicycle rim incorporating such a joining element and method for producing a respective rim

Publication Date: 2020.02.26 AMBROSIO WHEELS SRL

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AI summary

Joining element (10) for tubular profile bicycle rims (1) suitable for being inserted in the ends (2) of the rim to allow the joining thereof following the application of a closing force, made in two separate parts (12), joined by elastically deformable transverse connecting elements (13), such as to give the joining element (10) a spring shape.