Double Point Derail Switch Inversion for Track Bump Elimination

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Solution Overview

Problem

Existing double point derail switches cause bumps and require frequent maintenance due to their normally closed configuration, which is impractical and costly to deploy, especially since they are often not activated for derailing purposes.

Innovation Solution

A derailer design with an outside switch rail and an inside switch rail, where the outside switch point overlays the mainline rail and the inside switch rail lies adjacent to the second mainline rail, allowing for derailing without the need for a switch in the mainline track, thus avoiding bumps and reducing maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a normally closed double point derail switch is used to derail trains, then the train can be diverted to a short truncated section, but the switch causes bumps and crosslevel conditions when trains traverse it during normal operation

Engineering Contradiction:

Improvederailing functionVSAvoidbumps and crosslevel conditions

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the normal operation state of the derail switch from normally closed to normally open. The switch points are positioned away from the main track during normal operation, eliminating bumps and crosslevel conditions. When derailing is required, the switch is activated to close the points onto the main track, lifting the wheel flange to derail the train.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If a normally closed double point derail switch is placed in the mainline track path, then it can derail trains when activated, but it requires routine maintenance even when never activated for derailing purposes

Engineering Contradiction:

Improvederailing functionVSAvoidmaintenance requirements

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the derailing function from the mainline track path by positioning the switch points adjacent to but not on the main track during normal operation. The switch points are only brought into contact with the main track when derailing is required, reducing wear and maintenance needs while preserving the derailing function.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If a switch rail is constructed to lift train car wheels over the active track as described in the '727 patent, then derailing can be achieved, but the construction is impractical to produce and too costly to deploy

Engineering Contradiction:

Improvederailing functionVSAvoidproduction practicality and cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the geometric parameters of the switch points, specifically incorporating a shelf portion with a horizontal top surface that contacts the wheel flange at a controlled height. This geometric modification enables effective derailing while using standard switch rail construction methods, making the solution practical to produce and cost-effective to deploy.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9932054B2Double point derail switch

Publication Date: 2018.04.03 PROGRESS RAIL SERVICES CORP

AI summary

A derailer for use in a railroad system, has an outside switch point that selectively overlays a running surface of a first mainline track and rises above the running surface of the first mainline track and an outside switch rail mechanically fastened to the outside switch point. The derailer also includes an inside switch rail including a second switch point that selectively lies adjacent a head of a second mainline track and terminates between the first and second mainline tracks.