Self-Threaded Fastener Omitting Washers
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Solution Overview
Problem
The existing fastening systems in electronic apparatuses, which use multiple screws and washers, are cumbersome and prone to mismanagement, leading to concerns of lost or forgotten parts, and require complex attachment processes.
Innovation Solution
A fastening system comprising a first member with a smaller screw hole and a second member with a larger screw hole threaded in the opposite direction, along with a fastener having a first screw section, a second screw section, a neck, and a head, where the second screw section is located between the members and the neck is partially in the second screw hole, preventing the fastener from coming off and maintaining the fastening state without washers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If washers are used to prevent fastening looseness, then the fitting of two members is maintained, but the number of parts increases and management becomes cumbersome
Solution Approach 1:
The invention merges the washer function into the fastener by adding a second screw section with opposite threading to the fastener body. This integration eliminates the need for separate washers while maintaining the prevention of fastening looseness through the differential threading mechanism that converts rotational force into axial clamping force.
Solution Approach 2:
The fastener is designed to perform multiple functions: it provides the primary fastening through the first screw section, prevents loosening through the second screw section with opposite threading, and eliminates the need for separate washers. This multi-functionality reduces part count while maintaining reliability.
2Strength
If multiple screws and washers are used for mounting, then the fastening strength is sufficient, but the attachment process becomes complex and time-consuming
Solution Approach 1:
By combining the fastener and washer functions into a single integrated component, the attachment process requires only one fastening operation instead of coordinating multiple parts. This reduces assembly time and complexity while maintaining the same fastening strength through the differential threading mechanism.
Solution Approach 2:
The fastener is segmented into functional sections (first screw section for fastening, second screw section for preventing loosening) that work together in a single integrated component, allowing the complex function to be achieved through modular design within one part rather than multiple separate parts.
3Device complexity
If washers are omitted to reduce part count, then management becomes easier, but the fastening reliability may be compromised
Solution Approach 1:
The second screw section with opposite threading acts as an intermediary mechanism that converts rotational motion into axial clamping force, mediating between the fastener and the second member to maintain fastening reliability without requiring a separate washer component.
Solution Approach 2:
The fastener is designed to be self-sufficient by incorporating the anti-loosening function directly into its structure through the second screw section. This self-service design eliminates the need for external washers while maintaining fastening reliability through its own integrated mechanism.
4Device complexity
If a single fastener is used without washers, then the number of parts is reduced, but the fastener may rotate and come off the members
Solution Approach 1:
Instead of using a washer to prevent rotation, the invention inverts the approach by using a second screw section with opposite threading that actively engages with the second member. This inverted mechanism converts any rotational force into axial clamping, making the fastener self-retaining without external washers.
Solution Approach 2:
The second screw section with opposite threading provides preliminary anti-action against rotational loosening by engaging with the second member before any loosening can occur. This pre-established counter-threading mechanism prevents the fastener from rotating off the members.
Data Source
AI summary
The present invention provides a structure for omitting washers to reduce the number of parts, and keeping the fitting of two members fastened together even when the washers are omitted. The structure includes: a first member having a first screw hole; a second member facing the first member, having a second screw hole larger than the first screw hole, and threaded in a direction opposite to the first screw hole; and a fastener. The fastener includes, along a longitudinal direction: a first screw section having a diameter corresponding to the first screw hole; a second screw section between the first member and the second member, having a diameter corresponding to the second screw hole, and threaded in a direction opposite to the first screw section; a neck at least partially located in the second screw hole; and a head larger in the longitudinal direction than the second screw hole.