Snap-Fit Fastener With Twist-Actuated Detachment Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Snap-fit plastic fasteners are difficult to remove and often require breaking or damaging, especially when high retention force is needed, leading to inconvenience and increased costs in applications like automobile trim reattachment.
Innovation Solution
A snap-fit fastener design with deflectable wings that can be easily inserted and removed using a tool, featuring a pedestal with hinge-connected wings and twisted lead-in extensions, allowing for easy detachment by rotating an implement within a defined slot to spread the extensions and move the wings inward.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the fastener is designed with high retention force to securely hold parts, then the fastener can maintain strong connection, but the fastener becomes difficult to remove and may require breaking or damaging
Solution Approach 1:
The fastener is divided into a body and separate deflectable wings that can be independently manipulated. The wings are connected to the body through hinge regions, allowing them to deflect inward for removal while the body maintains structural integrity and high retention force during normal operation.
Solution Approach 2:
The fastener transitions from a static structure to a dynamic one where the wings can deflect inward when force is applied through the slot. This dynamic behavior allows the fastener to maintain high retention force during normal use but become removable when appropriate force is applied through the defined slot using a tool.
2Productivity
If the fastener is designed as a one-piece snap-fit structure for quick assembly, then assembly time is reduced, but the fastener becomes difficult to remove and reusable fasteners are not available
Solution Approach 1:
The one-piece fastener structure is maintained for quick assembly, but functional segmentation is introduced through the hinge regions that separate the wings from the body. This allows the wings to be independently deflected inward for removal while maintaining the one-piece construction benefits of quick assembly and cost-effectiveness.
Solution Approach 2:
The hinge regions act as intermediaries between the wings and the body, allowing controlled deflection of the wings inward when force is applied through the slot. This intermediary mechanism enables removal of the one-piece fastener without requiring breaking or damaging, while preserving the assembly advantages of one-piece construction.
3Ease of manufacture
If the fastener uses deflectable wings for easy insertion through holes, then assembly is simplified, but the fastener becomes difficult to extract and may require breaking
Solution Approach 1:
The deflectable wings are segmented from the body through hinge regions, allowing them to be deflected inward independently. This segmentation maintains the easy insertion characteristic while enabling extraction by deflecting the wings inward through the slot using a tool, preventing the need for breaking.
Solution Approach 2:
The fastener incorporates dynamic elements where the wings can deflect inward when force is applied through the slot. This dynamic capability maintains the simplified assembly process while enabling easy extraction without breaking, as the wings can be actively deflected inward to release the fastener.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables easy attachment and detachment with high retention force, allowing for reuse without damaging the fastener, reducing costs and manufacturing complexity.
Implementation Method 1
the wings are deflectable and deflect inwardly for insertion of the fastener through a hole and rebound outwardly after passing through the hole
Implementation Method 2
The lead-in extensions are twisted relative to the wings... rotating an implement within a defined slot to spread the extensions and move the wings inward
Data Source
AI summary
A snap-fit fastener having deflectable, diverging wings extending from a distal end of a pedestal is provided with lead-in extensions from the connection of each wing to the pedestal. The extensions define a slot therebetween and are curved relative to the wings. By inserting an implement such as a screwdriver in the slot and twisting the implement, the lead-in extensions are spread relative to each other and the wings are moved toward the pedestal to allow the fastener to be disconnected from an object.