Railway Rail Fastening Apparatus Lateral Load Distribution
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Solution Overview
Problem
Railway rail fastening apparatus on concrete slab track faces issues with lateral load transmission, bolt damage due to line contact wear and fatigue, and increased cost and complexity with existing solutions, particularly in urban and underground systems where resilience and vertical height adjustment are critical.
Innovation Solution
The apparatus employs a baseplate with clamping means that overlie the baseplate, featuring a shoulder for load transmission and a screw-threaded fastener for secure anchoring, allowing for flexible clamping and reduced stress on fixing means, along with optional height adjustment using interchangeable clamping parts and shims.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If through-bolts are used to secure the baseplate to the concrete slab, then the baseplate can be anchored to the slab track, but the bolts are subject to high levels of lateral bending loads and can easily fail in fatigue
Solution Approach 1:
The baseplate is divided into multiple segments with individual resilient pads at each bolt location, allowing each bolt to be isolated and independently supported, reducing the transmission of lateral bending loads across the entire baseplate structure
Solution Approach 2:
Resilient pads are introduced as intermediary elements between the bolts and the baseplate, absorbing lateral movements and reducing the bending loads transmitted to the bolts, thereby improving fatigue resistance
2Ease of operation
If the tops of the bolts project above the height of the clips, then the clips can be retained, but the bolt assemblies are liable to damage by track machinery used to install and extract laterally-driven clips
Solution Approach 1:
The fixing mechanism is moved from a vertical projection above the baseplate to a lateral arrangement where L-shaped clips engage with the baseplate edges horizontally, eliminating the height issue while maintaining retention functionality
Solution Approach 2:
Instead of having bolts project upward to retain clips, the invention inverts the approach by having L-shaped clips engage laterally with the baseplate, reversing the traditional retention mechanism and eliminating the conflict with track machinery
3Shape
If a clamp is designed to overhang the edge of the baseplate to hold it down, then the profile is lower and lateral loads can be reacted, but the clamp would itself need to be rigidly bolted down
Solution Approach 1:
The retaining function and the anchoring function are merged into a single L-shaped clip element, where the same component that retains the rail also provides the lateral reaction and anchors to the baseplate, eliminating the need for separate clamp and bolt assemblies
4Strength
If shoulders and clips are provided to hold down the baseplate in addition to those required to hold down the rail, then lateral loads can be better reacted, but the cost and complexity of the apparatus increases
Solution Approach 1:
The L-shaped clips serve multiple functions simultaneously: they retain the rail laterally, anchor the baseplate to the slab, and provide lateral load reaction paths, eliminating the need for separate shoulders and additional clips
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
This configuration effectively distributes lateral loads, reduces the risk of bolt damage, maintains cost-effectiveness, and allows for flexible height adjustments, enhancing the durability and adaptability of the rail fastening system.
Implementation Method 1
a screw-threaded fastener, the shank of which is engaged in a threaded aperture in the rail foundation
Implementation Method 2
a shoulder, the stem of the shoulder being engaged in the rail foundation and the head of the shoulder being configured so as to interlock with and retain the clamping means
Implementation Method 3
clamping means configured such that an overhang part of the clamping means can be arranged so as to overlie part of the baseplate
Data Source
Figure 1A~1D
Figure 2A~2C
Figure 2D~2G
AI summary
Railway rail fastening apparatus comprises a baseplate (20) for receiving a railway rail (10) to be fastened thereto and baseplate securing means (30, 40) for securing the baseplate (20) to a baseplate seat area (2) of a concrete railway foundation (1), the baseplate securing means (30, 40) comprising first and second fastening assemblies (30, 40) configured for location on the concrete rail foundation (1) on opposite sides of the baseplate seat area (2), each fastening assembly (30, 40) comprising clamping means (35, 351-35N, 35A, 35B1-35BN, 45) configured such that a part (36, 361-36N, 46) of the clamping means (35, 351-35N, 35A, 35B1-35BN, 45) can be arranged so as to overlie part (27) of the baseplate (20), when the baseplate (20) is supported by the concrete rail foundation (1) and is located in the baseplate seat area (2) thereof, each of the first and second fastening assemblies (30, 40) further comprising fixing means (31, 41) having a first part (32, 42) configured for retention within the concrete rail foundation (1) and a second part (33, 43) configured for location above the rail foundation (1) and for engaging the said clamping means (35, 351-35N, 35A, 35B1-35BN, 45) Of the fixing means (31, 41) of the first and second fastening assemblies (30, 40), only the fixing means (41) of the second fastening assembly (40) consists of a screw-threaded fastener