Deformable Collar Fastener for Thin Sheet Push-Out Resistance
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Solution Overview
Problem
Existing fastening systems, such as clinch and rivet technologies, face challenges in providing effective push-out and torque-out resistance on very thin sheets without increasing assembly thickness or distorting the material, particularly in the electronics industry where thin panels are common.
Innovation Solution
A fastener design featuring a deformable shank collar with an undercut and cross-cut slots in the mating panel, allowing for snap-in engagement and subsequent deformation to provide enhanced attachment forces, ensuring the fastener remains flush on one side while resisting push-out and torque-out forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional clinch fasteners are used to provide push-out and torque-out resistance, then attachment strength is improved, but sheet thickness requirement increases
Solution Approach 1:
The patent combines push-out resistance and torque-out resistance functions into a single integrated collar structure. The collar simultaneously provides both resistance mechanisms through its deformation characteristics, eliminating the need for separate displacer and knurl features required by traditional clinch fasteners.
Solution Approach 2:
The collar is designed with specific material properties and geometric parameters (diameter ratios, thickness) that allow it to deform under controlled conditions. The deformation parameter changes enable the collar to expand and engage with the panel, providing both push-out and torque-out resistance while working with thin sheet material.
2Length of stationary object
If rivet nuts are used to reduce sheet thickness requirement, then assembly thickness is reduced, but material distortion occurs
Solution Approach 1:
The collar is pre-formed with a specific geometry that anticipates the deformation needed during installation. The preliminary shaping allows the collar to expand controllably when engaged with the panel, achieving the necessary grip without causing excessive material distortion.
3Reliability
If clinch fasteners with independent push-out and torque-out features are used, then attachment reliability is improved, but device complexity increases
Solution Approach 1:
The collar integrates both push-out resistance (through radial expansion) and torque-out resistance (through circumferential engagement) into a single structural element. This merging of functions reduces the number of separate features needed compared to traditional clinch fasteners that require distinct displacer and knurl elements.
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
The fastener achieves improved push-out and torque-out resistance on panels as thin as 0.1mm without adding thickness, offering superior attachment characteristics compared to traditional clinch and rivet systems, particularly in thin and hard panel applications.
Implementation Method 1
a deformable collar on the shank of greater diameter than the shank includes an undercut in the shank having a inner wall of lesser diameter than the shank
Data Source
Figure 1A~1B
Figure 2~4
Figure 5
AI summary
A fastener for thin panels has a shank with a deformable collar which works in conjunction with a configured mating panel to produce enhanced attachment forces, especially in the case of very thin panels. The mating panel is prepared with a round mounting hole with cross-cut openings or slots. The panel is stamped into a conical section in a preparatory step before installation to provide the fastener with snap-in engagement prior to final pressing. The fastener shank has an undercut located immediately below the collar which is snapped into the prepared hole. Once snapped in, a punch and flat anvil are used to press the deformable band of the fastener tightly against the prepared panel, capturing the panel rigidly between the deformable band and a base of the fastener. During pressing, the material of the fastener collar will also flow into the slots of the panel to prevent rotation.