Crank Set Chain Guard Ring Clamping With Shared Fasteners

Solution Overview

Problem

Crank sets for two-wheeled vehicles require additional fastening elements for attaching a chain guard ring, increasing assembly complexity, weight, and cost.

Innovation Solution

A crank set design where the chain guard ring is clamped in a clamping zone between fastening elements used to attach the chainring to the crank spider, utilizing screw-in and screw-on elements to secure the chainring and chain guard ring together, allowing for a simpler assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional fastening elements are used to attach the chain guard ring, then the chain guard ring can be securely fastened, but the assembly complexity, number of parts, weight, and cost increase

Engineering Contradiction:

Improvesecure fastening of chain guard ringVSAvoidassembly complexity and number of parts

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the chainring fastening function and chain guard ring fastening function into a single integrated fastening element. The fastening element includes a chainring fastening portion that secures the chainring to the crank spider, and a chain guard ring fastening portion that secures the chain guard ring to the crank set, thereby merging two separate fastening operations into one unified component that reduces part count and assembly complexity while maintaining secure fastening of both components

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The fastening element is designed as a multi-functional component that simultaneously performs multiple functions: it fastens the chainring to the crank spider, fastens the chain guard ring to the crank set, and provides structural support for both components. This universal design eliminates the need for separate dedicated fastening elements for each component, thereby reducing overall device complexity while ensuring reliable attachment

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If additional fastening elements are used to attach the chain guard ring, then the chain guard ring can be securely fastened, but the weight and cost of the crank set increase

Engineering Contradiction:

Improvesecure fastening of chain guard ringVSAvoidweight of crank set

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent combines the chainring fastening function and chain guard ring fastening function into a single integrated fastening element. The fastening element includes a chainring fastening portion that secures the chainring to the crank spider, and a chain guard ring fastening portion that secures the chain guard ring to the crank set, thereby merging two separate fastening operations into one unified component that reduces part count and assembly complexity while maintaining secure fastening of both components

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The fastening element is designed as a multi-functional component that simultaneously performs multiple functions: it fastens the chainring to the crank spider, fastens the chain guard ring to the crank set, and provides structural support for both components. This universal design eliminates the need for separate dedicated fastening elements for each component, thereby reducing overall device complexity while ensuring reliable attachment

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Facilitates easier assembly, reduces the number of parts, and maintains a secure connection between the chainring and crank spider while minimizing weight and cost.

Implementation Method 1

fastening elements which press the chainring and the crank spider together along a pressing direction

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

a clamped area (30) of the chain guard ring (22) is clamped in a clamping zone between at least one of the fastening elements with which the chainring (14) is fastened to the crank spider (12) and the crank spider (12) or the chainring (14) and is thereby fastened to the crank set (10)

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentUS12397868B2Crank set with chain guard ring and fastening element

Publication Date: 2025.08.26 MIRANDA & IRMAO LDA

AI summary

A crank set for a two-wheeler, the crank set comprising a crank with a crank spider, a chainring and a chain guard ring, the chainring being fastened to the crank spider by fastening elements, and the fastening elements pressing the chainring and the crank spider against one another along a pressing direction. A clamped area of the chain guard ring is clamped in a clamping zone between at least one of the fasteners by which the chainring is secured to the crank spider and the crank spider or chainring and thereby secured to the crank set.