Wheel Rim Nipple Interface With Self-Locking Alignment Washers
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Solution Overview
Problem
In spoked bicycle wheels, misalignment between spokes and nipples during tensioning leads to anomalous stress distribution, necessitating oversized components to prevent yielding, especially in high-performance bicycles.
Innovation Solution
An abutment interface using two washers with limited abutment tracks allows initial freedom of movement and subsequent locking, ensuring alignment between the nipple and spoke, even when the spoke is not in a radial direction, by using conical or spherical surfaces and narrow abutment tracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the nipple is fastened to a non-radial spoke, then the spoke can be arranged tangentially to the hub flange, but misalignment occurs during tensioning causing anomalous stress distribution
Solution Approach 1:
The head of the nipple and the abutment surface of the bridge are shaped according to spherical surfaces, allowing the nipple to self-align radially during tensioning while accommodating non-radial spoke orientations. The curved surfaces enable rotational adjustment to achieve proper alignment.
Solution Approach 2:
The abutment interface transitions from a static fixed position to a dynamic self-aligning mechanism. The spherical surfaces allow the nipple to rotate and adjust its orientation dynamically during the tensioning process, automatically achieving radial alignment regardless of the initial spoke orientation.
2Strength
If oversized components are used to prevent yielding under anomalous stress, then component strength increases, but wheel weight increases
Solution Approach 1:
By shaping the abutment interface with spherical surfaces, the patent enables proper stress distribution through correct alignment, eliminating the need for oversized components. The curved surfaces concentrate forces along the radial direction, allowing use of optimally sized rather than oversized components.
3Manufacturing precision
If the nipple abuts on the bridge with the stem in the radial direction, then proper alignment is achieved, but the head presses more on one side of the bridge causing misalignment
Solution Approach 1:
The spherical abutment surfaces create a self-centering mechanism where the nipple naturally aligns radially during tensioning. The curved contact surfaces distribute pressure evenly around the radial axis, preventing one-sided pressing and maintaining stable radial alignment throughout the tensioning process.
Data Source
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AI summary
This bicycle wheel comprises a rim (11) connected to a hub (12) by a plurality of spokes (13), wherein at least one of the spokes (13) is anchored to the rim (11) through a nipple (20) having a stem (21) inserted in a hole (17) in a bridge (16) of the rim (11) and facing towards the hub (12) and an enlarged head (22) hooked to the bridge (16). An abutment interface (30) between the head (22) of the nipple (20) and the bridge (16) of the rim (11) comprises: - a first washer (31), with a radially inner first face (32) abutting on the bridge (16) and a radially outer second face (33), - a second washer (41), with a radially inner first face (42) abutting on the second face (33) of the first washer (31) and a radially outer second face (43) abutting on the head (22) of the nipple (20). The faces (32, 33, 42, 43) of the washers (31, 41) are shaped so as to allow the washers (31, 41) to make adjustment movements both with respect to each other and with respect to the nipple (20), during an initial step of the fixing operation of the spoke (13) to the rim (11), and vice-versa so as to prevent the washers (31, 41) from making any adjustment movement both with respect to one another and with respect to the nipple (20), during a subsequent fixing step of the spoke (13) to the rim (11) in which the nipple (20) has tension applied to it through the spoke (13).