Spring Nut Crumple-Zone Structure for Axial Load Retention
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Solution Overview
Problem
Existing spring nuts lack sufficient retention strength and ease of installation when attaching threaded objects to structures with reentrant lips, often requiring rotational alignment and struggling to securely hold loads against axial loading.
Innovation Solution
A spring nut design featuring resilient arms with crumple zones and engagement gussets that deform upon loading, inducing a spring force to securely engage with reentrant lips, allowing for non-rotational insertion and enhanced retention strength, while stop tabs prevent over-insertion and facilitate sliding adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If existing spring nuts are used to attach threaded objects to structures with reentrant lips, then the attachment can be made, but the retention strength is insufficient and the threaded object cannot be securely held against axial loading
Solution Approach 1:
The spring nut incorporates resilient arms that can dynamically deflect and deform under axial loading conditions. The arms are designed to flex laterally inward when engaged with the threaded object, allowing them to accommodate load variations while maintaining secure engagement. This dynamic response enables the connection to withstand axial forces that would cause failure in rigid spring nut designs.
Solution Approach 2:
The patent modifies the structural parameters of the spring nut by adding crumple zones with specific curvature radii and thickness variations. These parameter changes allow the arms to undergo controlled deformation and crumpling under axial load, transforming the rigid structure into one that can absorb and distribute axial forces while maintaining retention strength.
2Ease of operation
If existing spring nuts require rotational alignment for installation, then the attachment can be made, but the ease of installation is reduced and assembly time increases
Solution Approach 1:
Instead of requiring the threaded object to rotate into alignment with the spring nut's engagement features, the design inverts the approach by allowing the resilient arms to flex and adapt to the threaded object's position. The arms can deflect laterally to accommodate misalignment, eliminating the need for precise rotational alignment during installation and enabling quick push-on assembly.
Solution Approach 2:
The resilient arms function as flexible structural elements that can bend and deform during installation. This flexibility allows the arms to accommodate various insertion angles and positions of the threaded object, enabling tool-free, non-rotational installation while maintaining secure engagement once installed.
3Strength
If the spring nut uses resilient arms to engage with reentrant lips, then the retention strength can be improved, but the device complexity increases due to crumple zones and engagement gussets
Solution Approach 1:
The patent merges multiple functions into the resilient arms structure. The arms simultaneously provide engagement with reentrant lips, accommodate axial loading through crumpling, and enable lateral deflection for threaded object retention. By combining these functions into a single integrated structure rather than separate components, the design improves retention strength while limiting the increase in overall device complexity.
Solution Approach 2:
The resilient arms are segmented into distinct functional zones including engagement portions, crumple zones with specific curvature radii, and connection portions. This segmentation allows each zone to perform its specific function optimally while maintaining manufacturability. The crumple zones are positioned at specific locations along the arms to provide controlled deformation characteristics without requiring complex overall structural design.
4Strength
If the crumple zones are designed to deform upon loading, then the retention strength against axial loading is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies particular parameter ranges for the crumple zones, including curvature radii and thickness variations, that balance performance requirements with manufacturing capabilities. By defining specific parameter ranges rather than exact dimensions, the design allows for normal manufacturing tolerances while still achieving the desired crumpling behavior and retention strength under axial loading.
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 design provides improved retention strength and ease of installation, securely attaching threaded objects to structures with reentrant lips, resisting axial loading and allowing for quick assembly and sliding adjustment as needed.
Implementation Method 1
a crumple zone that can be configured to deform upon loading of the threaded object in the second direction to decrease a distance between the base and the thread-engagement portion
Implementation Method 2
The first and second arms can be configured to flex laterally inwardly as the first and second arms are urged past the reentrant lips of the structure and then resiliently spring laterally outwardly, so that the structure-engagement portions are disposed to seat against the reentrant lips
Implementation Method 3
The first and second arms can also resiliently spring laterally inwardly to engage the thread-engagement portions with a thread of the threaded object, to secure the threaded object against non-rotational movement of the threaded object opposite the first direction
Implementation Method 4
the legs can be configured to be elastically deformed by a force that urges the base toward the structure, to extend at a second angle from the base that is different from the first angle, so that the engagement features of the structure-engagement portions disengage from the reentrant lips to permit sliding adjustment
Data Source
AI summary
A spring nut for attaching a threaded object to a structure with reentrant lips. The spring nut can include a base, a first arm and a second arm extending from the base in a first direction, and legs extending laterally from the base. The arms can include a support portion, a structure-engagement portion, and a thread-engagement portion that can be configured to secure the threaded object against axial loading in a second direction opposite the first direction. Crumple zones in the support portions can deform upon loading of the threaded object in the second direction to cause the structure-engagement portion to be urged into the reentrant lips. Each of the legs can extend at a first angle from the base, toward the structure-engagement portions, to be disposed to contact an exterior surface of the reentrant lips of the structure when the first and second arms are received in the channel.