Direct Fixation Rail Fastener With Spatial Elasticity and Uplift Restraint
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rail fasteners are often specific to concrete or wooden ties, are made from expensive and complicated parts, and fail to adequately manage dimensional changes and vibrations due to temperature and load variations, necessitating frequent inspection and replacement.
Innovation Solution
A direct fixation fastener with a track plate, end restraints, and a non-metallic jacket that provides uplift limitation and spatial elasticity, allowing for attachment to various substrates and managing load-induced deflections through uplift-limiting protrusions and a resilient jacket.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a direct fixation fastener is designed with rigid components for concrete or wooden ties, then structural strength is improved, but adaptability to different substrates deteriorates
Solution Approach 1:
The patent employs a non-metallic resilient jacket as a flexible element that can adapt to different substrate surfaces while maintaining structural integrity. The jacket acts as a compliant interface between the rigid fastener components and various substrates (concrete, wood, poured slab), allowing the same fastener design to work across multiple substrate types without compromising strength.
Solution Approach 2:
The resilient jacket introduces parameter changes in terms of material compliance and deformation characteristics. By using a material that can elastically deform and recover, the fastener system can accommodate variations in substrate rigidity, surface irregularities, and installation conditions, thereby achieving both strength and adaptability.
2Force
If end restraints with uplift-limiting protrusions are added to the track plate, then resistance to uplift forces is improved, but device complexity increases
Solution Approach 1:
The uplift-limiting protrusions are integrated directly into the end restraints, which are themselves part of the track plate assembly. This merging of functions (uplift resistance and lateral restraint) into single components avoids adding separate dedicated uplift resistance mechanisms, thereby limiting the increase in device complexity while still achieving improved uplift force resistance.
Solution Approach 2:
The track plate is segmented into functional zones: the main body for lateral support and the end restraints with protrusions for uplift resistance. This segmentation allows each component to be optimized for its specific function while maintaining overall system simplicity.
3Reliability
If a non-metallic jacket is used to attenuate vibrations and provide electrical insulation, then protection against vibrations and electrical grounding is improved, but manufacturing complexity increases
Solution Approach 1:
The non-metallic jacket is made from a composite or resinous material that combines multiple functions: vibration attenuation, electrical insulation, and structural bonding. By using a multi-functional material, the patent achieves improved reliability without requiring separate components for each function, thereby limiting the increase in manufacturing complexity.
Solution Approach 2:
The resilient jacket serves multiple purposes simultaneously: it acts as a vibration damper, an electrical insulator, a structural adhesive, and a protective coating. This multi-functionality reduces the total number of components needed and simplifies the manufacturing process compared to using separate dedicated components for each function.
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 system offers flexible attachment options, enhances structural integrity by limiting uplift displacement, and provides electrical insulation while managing load-induced vibrations, reducing the need for frequent maintenance.
Implementation Method 1
a non-metallic molded covering or jacket extends between the two parts, attenuating vibrations
Implementation Method 2
electrically insulating the respective parts and the rail itself from the underlying substrate
Implementation Method 3
A direct fixation fastener flexible with regard to substrate attachment and having end restraints configured for limiting uplift displacement of a track plate
Data Source
AI summary
A direct fixation fastener in a track fixation system includes a track plate forming cutouts in opposite ends thereof, a first end restraint positioned in a first of the cutouts and a second end restraint positioned in a second of the cutouts. Each of the end restraints includes at least one fastener hole therein, such as an elongated fastener hole for lateral adjustment, and an uplift-limiting protrusion including a hook portion extending over the track plate. The fastener further includes a jacket including a non-metallic jacket material attaching the track plate to each of the first end restraint and the second end restraint and extending therebetween.