Rail Joint Bar with Epoxy Bond for Insulated Lap Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing railroad rail joint assemblies suffer from end batter and deformation, leading to electrical shorting and increased costs due to the use of non-standard rails and joint bars, which compromises the electrical isolation and structural integrity of the rail system.
Innovation Solution
A lap joint assembly is created by machine-tapering and trimming standard railroad rails to conform spatially, using electrically-insulating material between the rails, and attaching them with standard rail joint bars, which are bonded with epoxy to enhance longitudinal strength and resist deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard railroad rails are used in joint assemblies, then costs are reduced and availability is improved, but the rails suffer from end batter and deformation leading to electrical shorting
Solution Approach 1:
The rail ends are pre-machined with tapered surfaces and recesses before assembly. This preliminary machining creates precise geometric features that guide the fit-up of rails and positioning of insulating material, preventing end batter and maintaining electrical isolation while using standard rails
Solution Approach 2:
Electrically-insulating material is introduced as an intermediary component between the rail ends. This insulating material fills the recesses and maintains proper spacing, preventing electrical contact while allowing the use of standard rails that would otherwise deform and short out
2Strength
If non-standard double thick web section rails are used, then Moment of Inertia is increased and deformation is reduced, but the cost increases and standard joint bars cannot be used
Solution Approach 1:
Instead of using heavier rails, the invention applies preliminary machining to create tapered surfaces and recesses in standard rails. This geometric modification distributes impact loads more effectively, providing sufficient strength and deformation resistance without requiring non-standard heavy rails
Solution Approach 2:
The invention changes the geometric parameters of standard rails through machining (creating tapers and recesses) rather than changing the fundamental rail profile. This allows standard rails to achieve the necessary structural performance at lower cost without requiring non-standard double thick web section rails
3Reliability
If rail ends are joined with insulating material, then electrical isolation is achieved, but the rail ends deform and break apart causing contact and shorting
Solution Approach 1:
The rail ends are pre-machined with recesses and tapered surfaces before assembly. This preliminary geometric preparation creates interlocking features that mechanically strengthen the joint while accommodating the insulating material, preventing both electrical shorting and structural failure
Solution Approach 2:
The joint assembly creates a composite structure combining metal rail ends with electrically-insulating material. The machined recesses allow the insulating material to be embedded within the metal structure, creating a composite joint that provides both electrical isolation and structural strength
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 solution effectively eliminates end batter, maintains electrical isolation, and increases the structural strength of the rail joint assembly, allowing it to withstand train impacts while using standard components, thus reducing costs and improving durability.
Implementation Method 1
a rail joint bar used for attaching the railroad rail to one another via fasteners... bonded rail joints and an adhesive such as an epoxy between the adjoining rail end sections thus increasing the longitudinal bond strength
Data Source
AI summary
A rail joint bar for use in an insulated lap joint assembly includes a longitudinal extending body defining a plurality of holes therein for receiving fasteners. The body has a first end and a second end positioned at opposite ends of the body relative to a longitudinal direction of the body. The body is bent forming a first portion adjacent to the first end, a second portion adjacent to the second end and spaced from the first portion in the longitudinal direction, and an intermediate portion defined therebetween and positioned between the first and second ends. The first portion and the second portion are substantially parallel to each other and, and the intermediate portion of the body is configured to accommodate an increase in thickness of a web section at a point where two railroad rails are joined.