Chain Locking Link With Conical Pin And Countersink
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Solution Overview
Problem
Existing chain connecting links for bicycles with derailleur gears face issues with increased sprocket count, as they result in undesirable lateral mobility and shifting behavior due to bolt head overhang and groove width, and lack secure dismantling safety.
Innovation Solution
The design incorporates a shorter bolt head with increased countersink depth, chamfered edges for reduced lateral mobility, and a disassembly safeguard through a narrowing elongated hole at the countersink, ensuring secure anchoring of the chain pin within the outer plate without tool-assisted disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional chain connecting link with a groove on the chain pin is used, then the chain can be assembled without tools, but the bolt head protrudes beyond the outer plate contour resulting in increased chain width and lateral mobility
Solution Approach 1:
The patent changes the geometric parameters of the chain pin end and outer plate recess. Specifically, the chain pin is designed with a conical end instead of a groove, and the outer plate is given a conical recess. This parameter change allows the chain pin to be inserted and locked without a protruding bolt head, thereby reducing chain width while maintaining tool-free assembly capability.
Solution Approach 2:
Instead of using a groove on the chain pin that requires the bolt head to protrude for assembly, the patent inverts the approach by using a conical end on the chain pin that fits into a conical recess in the outer plate. This inversion eliminates the need for bolt head protrusion while preserving the tool-free assembly advantage.
2Ease of operation
If a groove on the chain pin is used for tool-free assembly, then assembly is simplified, but lateral mobility of the chain in the connecting link area increases impairing shifting behavior
Solution Approach 1:
The patent changes the geometric form from a cylindrical groove to a conical recess in the outer plate and a corresponding conical end on the chain pin. This parameter change provides lateral stability through the conical geometry that prevents side movement, while still allowing tool-free assembly through the tapered fit.
Solution Approach 2:
The patent inverts the conventional groove design by using a conical recess and conical pin end instead. This inversion eliminates lateral play and improves shifting behavior while maintaining the simplicity of tool-free assembly through the conical interface.
3Ease of manufacture
If the chain pin is simply inserted into the outer plate, then assembly is simple, but dismantling safety is lacking allowing unintentional release
Solution Approach 1:
The patent changes the end geometry of the chain pin to a conical shape and provides a corresponding conical recess in the outer plate. The conical geometry creates a self-locking effect that prevents unintentional release during operation, while still allowing simple insertion and controlled removal when needed.
Solution Approach 2:
The conical recess and conical pin end create a preliminary anti-action by designing the interface to resist unintended removal forces. The conical geometry provides mechanical interference that prevents accidental release, while allowing deliberate dismantling when maintenance is required.
Data Source
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AI summary
A chain case for a motorcycle drive chain comprises two parts (2) with an external plate (3) connected to a fixed chain bolt (4). The plate has a long hole with ends having large and small diameters (7,8). The bolt has a head (14), groove (15) and a foot (16) with an axial recess, with the foot forming a form-fitting connection with the through hole. The small diameter hole (8) takes the bolt groove and there is a recess (13) to receive the head which is smaller than the large hole diameter. The hole edges between the diameters has a ledge that is less thick than that of the recess.