Link Unit Segmented Pin for Bicycle Chain Reassembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chain link units are difficult for end-users to reassemble without specialized machinery, and existing solutions compromise chain smoothness and tensile strength during bicycle operation.
Innovation Solution
A link unit design featuring a secure chain pin connection that maintains equal pin length with adjacent links, utilizing a connecting pin and assembling pin with specific hole configurations to facilitate easy assembly and disassembly, ensuring smooth transmission and high tensile strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional chain pins are riveted in the factory, then the chain plates are securely held together, but the chain becomes difficult for end-users to reassemble
Solution Approach 1:
The chain pin is segmented into a body portion and a head portion, where the body passes through the chain plates and the head provides retention. This segmentation allows the pin to be easily inserted and removed by users while maintaining secure connection during operation.
Solution Approach 2:
Instead of using a riveting machine to permanently secure the pin, the invention inverts the approach by designing a pin that can be easily inserted from one side and retained by its head structure, transforming a complex factory process into a simple user action.
2Reliability
If two pins are inserted into elongated holes with protruding ends, then the connection is secured, but the pin length exceeds that of adjoining links, reducing gear change smoothness
Solution Approach 1:
The pin head is designed with a localized enlarged portion that provides retention functionality only where needed, while the body portion maintains a compact length consistent with adjoining links. This local quality differentiation ensures both secure connection and smooth gear operation.
3Ease of manufacture
If pin heads latch into countersinks to finish connection, then the assembly is completed, but gaps appear between link plates, reducing tensile strength
Solution Approach 1:
The invention extracts the countersink feature from the design, eliminating the gap-forming latching mechanism. Instead, the pin head retains the connection through friction and geometric interference fit, removing the source of tensile strength reduction while maintaining assembly simplicity.
4Strength
If conventional riveting is used, then strong connection is achieved, but specialized machinery is required, increasing device complexity
Solution Approach 1:
The pin structure is designed to be self-assembling through its head-body configuration, where the head automatically retains the pin body upon insertion. This self-service mechanism eliminates the need for specialized riveting machinery, allowing end-users to perform assembly with simple tools.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A link unit includes two outer chain plates (2) and an assembling pin (6). Each of the outer chain plates has a first end section, and a second end section spaced apart from the first end section. The first end section of each of the outer chain plates has a through hole (211). The second end section of each of the outer chain plates has a connecting hole (20) that has a first hole portion (201), a second hole portion (202), and a neck portion (203) located between the first and second hole portions. The assembling pin is inserted removably through the connecting hole of each of the outer chain plates, and is capable of being prevented from moving past the neck portion of each of the outer chain plates so as to be positioned in the second hole portion of each of the outer chain plates.