Spring-Loaded Roller Carrier for Switch Tongue Rail Adjustment

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Solution Overview

Problem

Existing rolling devices for tongue rails in switch systems experience wear and friction issues due to shape changes over time, leading to increased operational costs and site delays, as they require removal and reinstallation for ballast tamping and are not easily convertible without significant work.

Innovation Solution

A spring-loaded roller carrier system is positioned adjacent to the rail base plate, with a piston rod and threaded nut allowing for precise height and horizontal adjustment, ensuring the roller presses against support lugs with a defined spring force, maintaining contact and reducing friction, and can be preassembled, allowing for easy on-site installation without obstructing the tamping area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the roller carrier is mounted on two adjacent switch sleepers via leaf springs and holding elements, then the rolling device provides support and reduces friction, but it protrudes into the tamping area requiring removal and reinstallation

Engineering Contradiction:
Improvesupport functionVSAvoidinstallation convenience
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The roller carrier is extracted from the sleeper-mounted configuration and integrated directly into the rail base plate structure. This removes the protruding element that interfered with tamping operations while maintaining the roller's support function through the base plate's inherent structural support.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The roller carrier is merged with the rail base plate into a single integrated component. The roller carrier is positioned adjacent to the base plate and connected through the piston rod assembly, eliminating the need for separate sleeper mounting hardware and reducing interference with ballast tamping operations.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If the roller carrier is held resiliently in the direction of the stock rail, then the tongue rail rests against the stock rail via the roller reducing movement resistance, but the tongue rail shape changes over time causing wear and friction

Engineering Contradiction:
Improvemovement resistanceVSAvoidwear resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system transitions from a static resilient mounting to a dynamic adjustment system. The piston rod with threaded nut and spring element allows continuous adjustment of the roller's position and contact force, enabling the system to adapt to tongue rail shape changes over time and maintain optimal contact conditions without excessive wear.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The contact parameters between the roller and tongue rail are made adjustable. By modifying the spring force and piston rod extension through the threaded nut mechanism, the system can compensate for wear and shape changes in the tongue rail, maintaining reliable low-friction operation throughout the service life.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the roller carrier is positioned adjacent to the rail base plate, then the arrangement is an integral part of the base plate allowing easy installation, but precise height and horizontal positioning of rollers is required

Engineering Contradiction:
Improveinstallation easeVSAvoidroller positioning precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The roller carrier assembly with piston rod and spring element is pre-configured during manufacturing with adjustable positioning features. The threaded nut and spring preloading allow for fine-tuning of the roller's height and horizontal position relative to the tongue rail, ensuring precise positioning is achieved through simple on-site adjustment rather than complex manufacturing tolerances.

Inventive Principle:
Principle #10Preliminary action

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 provides a durable, easily installable, and adjustable rolling device that minimizes wear and friction, allowing for efficient operation and reducing site work and operational costs by enabling precise positioning and preassembly, while maintaining contact with support lugs and allowing for ballast tamping without obstruction.

Implementation Method 1

a spring element (20) acting on the vertical leg (19) with a permanently applied spring force

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

The switch rail moves over rollers or roller bodies, which cause a significant reduction in the switching forces

Methodology Applied
Scientific EffectRolling friction: Roller

Data Source

PatentEP2402506B1Roller device for a switch tongue
Publication Date: 2016.08.31 SCHWIHAG AG
  • EP2402506B1 patent drawingFigure 1~2
  • EP2402506B1 patent drawingFigure 3~4

AI summary

The invention relates to a roller device (9) for a switch tongue rail (6) associated with a stock rail (4), comprising a roller carrier (13) accommodating at least one roller (17), which is resiliently mounted on a rail support plate (1), designed as a sliding plate or sliding chair plate, wherein the switch tongue rail (6) rests on the roller (17) at least during the adjustment process. With such a roller device, the rollers should be positioned precisely both vertically and horizontally with respect to the switch tongue rail, and existing switches should be able to be retrofitted without significant effort. This is achieved by the roller carrier (13) being resiliently mounted on a retaining plate (10) connected to the rail support plate (1) and pivotably about an axis (12) of the retaining plate (10).