One-Way Locking Fastener Assembly With Asymmetrical Washer
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Solution Overview
Problem
Existing nut systems require manipulation of multiple objects during assembly, are tedious to assemble, and cannot be automatically assembled or dismantled, with the washer being difficult to remove once in place, limiting their application in automated machinery.
Innovation Solution
A fixing assembly with an asymmetrical washer that allows rotation of a threaded member in only one direction, enabling easy assembly and disassembly using two objects, and incorporating a rotational locking mechanism to secure the washer in place, allowing for automatic locking and easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If symmetrical grooves are used in the washer, then locking in both directions is achieved, but the threaded member cannot be screwed onto the nut after washer insertion
Solution Approach 1:
The patent applies asymmetry by providing grooves in the washer with different profiles on opposite sides. Specifically, one side has a groove with a first profile while the opposite side has a groove with a second profile that is different from the first. This asymmetrical design allows the threaded member to be screwed onto the nut in one direction while providing locking capability, resolving the contradiction between reliable locking and ease of assembly operation.
2Reliability
If multiple objects (threaded member, nut, washer with snap ring) are used, then locking functionality is achieved, but assembly becomes tedious and time-consuming
Solution Approach 1:
The patent merges the washer and snap ring into a single integrated washer component. The snap ring functionality is incorporated directly into the washer structure through the asymmetrical groove design, eliminating the need for a separate snap ring component. This reduction from three separate objects (threaded member, nut, washer with snap ring) to two objects (threaded member, nut with integrated washer) simplifies assembly and reduces assembly time while maintaining locking functionality.
3Reliability
If the washer is secured in place, then locking is achieved, but the system becomes non-removable
Solution Approach 1:
The patent applies dynamics by designing the asymmetrical grooves to allow directional movement. The groove profiles are configured to permit the washer to be inserted and locked in one direction while allowing removal in the opposite direction. This dynamic design enables the system to transition between locked and removable states, providing both locking stability and adaptability for removal when needed.
4Ease of operation
If both ends of the nut are accessible, then assembly is possible, but automatic machine assembly is not feasible
Solution Approach 1:
The patent segments the assembly process into distinct functional zones within the nut structure. The asymmetrical grooves are positioned and configured to allow the threaded member to be inserted from one end and screwed onto the nut while the washer remains accessible. This segmentation enables automatic machines to perform the assembly operation in a single direction without requiring access to both ends of the nut, making automatic assembly feasible.
Data Source
Figure 1~6
Figure 7~11
AI summary
The present invention relates to an attachment system comprising a threaded member (1) and an attachment assembly for receiving the threaded member (1). The attachment assembly comprises a nut (2) and a washer (3). The nut (2) comprises a hollow and threaded body (21) and a skirt (22) arranged to receive the washer (3). The washer (3) and the threaded member (1) comprise asymmetrical flutes (11, 4) enabling the threaded member (1) to rotate in only one direction (101) with respect to the washer (3), and therefore to the attachment assembly.