Expansion Joint Cover Assembly with Spring Centering
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Solution Overview
Problem
Existing expansion joint cover assemblies face issues with corrosion, lack of pretensioned spring force, difficulty in installation, and inability to accommodate slab differential movements, leading to misalignment and damage from traffic and environmental factors.
Innovation Solution
A protective cover assembly featuring base members with channels for bearings, a cover plate with pivotably engaged swing arms, and a fastener system that includes a conical inner surface and locking member, made from materials like polymers or metals, providing a spring force and easy installation, while allowing for movement accommodation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal plates are placed in an end-to-end relationship to protect the expansion joint, then the expansion joint is protected from damage due to pedestrian and vehicular traffic, but the metal plates become deformed and do not form a uniform seated engagement with concrete structures, particularly where the traffic bearing upper surfaces are irregular or undulating
Solution Approach 1:
The invention changes the physical state of the support mechanism by introducing a compressible material layer between the metal plates and the concrete structures. This compressible layer can be compressed to accommodate irregularities in the concrete surfaces, allowing the metal plates to maintain uniform contact and engagement even when the underlying surfaces are undulating or irregular.
Solution Approach 2:
The invention uses a composite structure consisting of metal plates combined with a compressible material layer. This composite approach allows the rigid metal plates to provide structural strength and protection while the compressible material provides adaptability to surface irregularities, resolving the contradiction between needing rigid protection and achieving uniform engagement.
2Stability of the object's composition
If spacing mechanisms are added to stabilize the cover plates in a centered position, then the cover plates are stabilized against misalignment, but the device complexity increases due to additional mass and members
Solution Approach 1:
The invention employs a spring mechanism that automatically exerts a centering force on the cover plate when it becomes misaligned. The spring is pre-loaded to provide a restoring force that pushes the cover plate back toward its centered position, eliminating the need for complex active control systems or heavy stabilization members. The system self-corrects alignment issues through this passive elastic mechanism.
3Stability of the object's composition
If the swing arm equidistance system is made rigid to prevent excessive cover plate bouncing and misalignment, then the cover plate stability is improved, but the system becomes more difficult to install and replace
Solution Approach 1:
The invention divides the swing arm equidistance system into separate, modular components including the swing arms, springs, and mounting elements. This segmentation allows each component to be manufactured independently using standard fabrication processes, and enables the system to be assembled and disassembled easily during installation and replacement, while still providing the rigid structural support needed to prevent cover plate bouncing and misalignment.
Data Source
AI summary
An expansion joint system for bridging an expansion joint gap between two spaced-apart, underlying building or roadway structures. The expansion joint system includes a cover plate, at least one swing arm, sliding bearings engaged with the swing arms, and fasteners for engaging the swing arms to the cover plate. The swing arms include a receiving well configured for receiving a mechanical fastener to fasten the swing arms to the cover plate. The expansion joint system permits movement in response to a seismic or thermal event that causes expansion or contraction of the gap between structural members while maintaining coverage of the gap, and following a seismic or thermal event, the maintains a substantially-centered position of the cover plate.