Rotatable Fastener Clip for Variable Sheet Metal Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fastener devices for attaching vehicle body panels to chassis fail to provide a low insertion force while maintaining high extraction force, and they do not adequately accommodate varying sheet metal thicknesses and production tolerances, leading to issues like noise, wear, and corrosion due to inadequate engagement and vibration resistance.
Innovation Solution
A fastener clip with laterally offset legs and wings that adapt to continuous variations in slot thickness, allowing for low insertion force and high extraction force, and featuring engagement regions that adjust to different sheet metal thicknesses and environmental conditions, such as vibrations and thermal expansion, ensuring secure attachment and reduced noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional fastener devices are used to attach body panels to chassis, then the fastener provides equal levels of insertion and extraction force, but the insertion force is not low enough for easy assembly and the extraction force is not high enough to maintain secure attachment
Solution Approach 1:
The fastener clip employs a dynamic engagement mechanism where the leg can rotate about the fastener body axis. During insertion, the leg rotates to an engaged position where the engagement feature contacts the slot, providing low insertion force. During extraction, the leg maintains engagement through friction and geometric constraints, providing high extraction force. This dynamic positioning resolves the contradiction between easy insertion and secure attachment.
Solution Approach 2:
The fastener changes the engagement parameter from a fixed rigid connection to a rotatable joint with controlled degrees of freedom. The leg's rotation capability allows the engagement feature to align with and contact the slot during insertion, reducing insertion force. Once engaged, the friction and geometric constraints maintain high extraction force, resolving the force level contradiction.
2Adaptability or versatility
If conventional fastener devices with discrete step positions are used, then the fastener can engage the slot, but it cannot accommodate continuous variations in sheet metal thickness and production tolerances
Solution Approach 1:
The leg's rotatable joint provides continuous adjustment capability rather than discrete step positions. As the leg rotates into engagement, the engagement feature can contact the slot at any position along the rotational arc, accommodating continuous variations in sheet metal thickness and production tolerances. This dynamic engagement resolves the contradiction between adaptability and precision.
Solution Approach 2:
The fastener changes from a fixed-geometry engagement system to one with a variable engagement parameter (rotation angle). This allows the engagement feature to adapt to continuous variations in slot position and thickness while maintaining accurate contact through the rotational degree of freedom, resolving the adaptability-precision contradiction.
3Reliability
If conventional fastener devices with large rise and run steps are used, then the fastener can engage the slot, but movement within the step size range causes wear and generates noise from vibrations
Solution Approach 1:
The rotatable leg provides a continuous engagement mechanism that eliminates large discrete steps. The engagement feature contacts the slot at a precise point during rotation, minimizing movement within the engagement range. This reduces vibration-induced wear and noise while maintaining engagement stability, resolving the contradiction between reliability and harmful factors.
Solution Approach 2:
The fastener design minimizes vibration-induced noise and wear by eliminating large step movements. The continuous rotational engagement allows the fastener to settle into a stable engaged position with minimal play, reducing the amplitude of vibrations during vehicle operation. This resolves the contradiction between engagement stability and vibration-related harmful factors.
4Ease of manufacture
If conventional fastener devices require twisting of wings for engagement are used, then the fastener can engage the slot, but the process is complex and requires multiple discrete engagement points
Solution Approach 1:
The fastener separates the engagement function from the body panel attachment function. The leg with its rotatable joint and engagement feature handles slot engagement independently, while the body panel attaches to the fastener body. This segmentation simplifies the engagement process to a single rotational motion rather than multiple twisting operations, resolving the contradiction between ease of manufacture and device complexity.
Solution Approach 2:
The rotatable leg provides a single-degree-of-freedom engagement mechanism that replaces complex multi-point twisting operations. The leg rotates into engagement, providing both slot contact and structural connection in one motion. This dynamic simplification reduces the number of engagement points required while improving ease of manufacture, resolving the stated contradiction.
Data Source
AI summary
A fastener clip includes a base plate and a first and second pair of laterally offset legs extending from the base plate. At least one first wing extends from the first pair of laterally offset legs. The at least one first wing has an engagement region. At least one second wing extending from the second pair of laterally offset legs. The at least one second wing has an engagement region, such that a distance between the engagement regions and the base plate is operative to vary continuously according to a slot thickness. The fastener clip is operative for insertion into the slot defined in a first engagement structure, such as a vehicle chassis.