Retainer Ring Spring Beam Radial Expansion Bolt Captivation
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Solution Overview
Problem
Existing retainer rings fail to effectively captivate bolts while maintaining the bolt head away from the structure, lacking a reliable mechanism to secure the bolt in a hold-out position.
Innovation Solution
A retainer ring with spring beam elements that expand radially to accommodate the bolt, then spring back to captivate it, utilizing an annular groove mechanism to secure the bolt in a hold-out position, allowing for radial displacement and contraction without permanent deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the retainer ring uses a rigid structure to captivate the bolt, then the bolt is securely retained, but the bolt head cannot be held away from the structure
Solution Approach 1:
The retainer ring incorporates spring beam elements that are dynamically flexible rather than rigid. These spring beams can deflect radially outward to allow bolt insertion and axial movement, then spring back to captivate the bolt and hold the bolt head away from the structure, resolving the contradiction between secure retention and hold-out capability
2Ease of operation
If the retainer ring uses spring beam elements to allow bolt movement, then the bolt can be held in hold-out position, but the captivation reliability decreases
Solution Approach 1:
The spring beam elements are designed with specific material properties and geometric parameters (thickness, length, curvature) that allow them to deflect within controlled limits. The beams have sufficient stiffness to provide reliable captivation force while maintaining enough flexibility to allow bolt insertion and hold-out positioning, balancing reliability and operability
3Ease of operation
If the spring beam elements expand radially to accommodate the bolt, then the bolt can be inserted, but the structure complexity increases
Solution Approach 1:
The retainer ring is segmented into multiple spring beam elements rather than using a single complex mechanism. Each spring beam is a simple, identical component that independently provides the expansion and contraction function, simplifying manufacturing and assembly while achieving the required functionality
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 retainer ring effectively captivates bolts, maintaining them in a hold-out position with resistance to removal forces, ensuring secure fastening while allowing easy axial movement, suitable for various applications including captive panel fasteners.
Implementation Method 1
the at least one spring beam element is displaced and expands radially from a free position to an expanded position in order to enable the bolt to travel through the aperture
Implementation Method 2
when the retainer ring engages and aligns with the annular groove of the bolt, the at least one spring beam element springs back to its free position in order to captivate the bolt
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A retainer ring (20) including an outer ring (76) having an exterior surface (78), an interior surface (80), and a plurality of spring beam elements (82) extending inwardly from the interior surface (80), and a central aperture (96). Each of the spring beam elements (82) includes an elongated arm (84) having a first end (86) attached to the interior surface (80) of the outer ring (76) and a second, free end (88) opposite the first end (86). Each of free ends (88) of the arms (84) includes a tab portion (92) and a pressure pad (94) that extends from the tab portion (92). The retainer ring (20) captivates pin members (12), such as bolts, onto work pieces (114), such that the pressure pads (94) engage and align with an annular groove (40) of the bolt (12). When the bolt (12) engages the retainer ring (20), each of the spring beam elements (82) is displaced and expands radially from a free position to an expanded position in order to enable the bolt (12) to travel through the aperture (96). The retainer ring (20) captivates the bolt (12) onto the work piece (114), while providing a postive hold out of the bolt (12).