Coupling Unit for Bicycle Tire Rim Attachment

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Solution Overview

Problem

The existing coupling units for solid tires on bicycle rims are prone to separation during external impacts, leading to safety accidents, as they lack effective mechanisms to securely fasten the tire to the rim.

Innovation Solution

A coupling unit with an upper surface, lower surface, and side surfaces, where the maximum length is greater than the distance between rim hooks, allowing easy insertion and ensuring surface contact with hooks to prevent separation, satisfying specific geometric equations to ensure secure attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the coupling unit is made longer to ensure secure attachment to the rim, then the reliability improves, but the ease of operation deteriorates due to difficult insertion

Engineering Contradiction:
Improvesecure attachmentVSAvoidinsertion difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The coupling unit incorporates curved side surfaces that conform to the shape of the rim hooks, enabling smooth insertion while maintaining secure engagement. The curvature allows the coupling unit to navigate the hook geometry without requiring excessive force, thus resolving the contradiction between secure attachment and ease of insertion.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The coupling unit is designed with flexible characteristics that allow it to deform during insertion and then maintain a stable engaged position. This dynamic behavior enables easy insertion through temporary deformation while ensuring reliable attachment in the final position, addressing both requirements simultaneously.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the coupling unit height is increased to improve contact with hooks, then the reliability improves, but the device complexity increases

Engineering Contradiction:
Improvecontact stabilityVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coupling unit features localized contact areas on its upper surface that are specifically designed to engage with the hook geometry. Rather than increasing overall height uniformly, the design concentrates the necessary contact features in specific local regions, maintaining reliability while minimizing overall structural complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The coupling unit's upper surface is designed to perform multiple functions: providing contact stability with hooks, maintaining appropriate height clearance, and ensuring proper positioning. This multi-functional design achieves reliable contact without requiring additional complex structural elements.

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

3Reliability

If the coupling unit length is increased to ensure complete insertion between hooks, then the reliability improves, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveinsertion completenessVSAvoiddimensional tolerance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The coupling unit employs asymmetric side surface profiles that are optimized for the specific insertion path between hooks. This asymmetric design provides built-in guidance that compensates for manufacturing variations, ensuring complete insertion and reliable engagement without requiring extremely tight dimensional tolerances.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The design incorporates specific geometric parameters and dimensional relationships that are optimized to ensure proper engagement. By carefully selecting and coordinating multiple dimensional parameters rather than relying on a single critical dimension, the design achieves reliable complete insertion while maintaining reasonable manufacturing precision requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3431306B1Coupling unit
Publication Date: 2020.10.21 TANNUS CO LTD
  • EP3431306B1 patent drawingFigure 1
  • EP3431306B1 patent drawingFigure 2A~2A(b)
  • EP3431306B1 patent drawingFigure 2B~2B(e)

AI summary

The present disclosure relates to a Coupling unit for coupling a tire to a rim, the Coupling unit including an upper surface, a lower surface, and side surfaces, in which a maximum length of the Coupling unit is larger than a distance between both hooks of the rim, the side surfaces include sliding areas that are slidable with respect to the hooks of the rim such that the Coupling unit is easily inserted into the rim while the Coupling unit is being inserted into the rim, and in a state in which the Coupling unit is completely inserted into the rim, at least a part of the upper surface is in surface contact with lower surfaces of the hooks to prevent the Coupling unit from being separated from the rim.