Railway Frog Point Reprofiling With Six-Axis Tool Positioning

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Solution Overview

Problem

Current methods for repairing and reprofiling worn or damaged frog points in railway track switches are time-consuming, imprecise, and require frequent rework due to the difficulty in achieving precise frog geometry restoration under time pressure, leading to reduced service life.

Innovation Solution

A portable device with a base frame and mounting frame that supports a milling or grinding machine, allowing precise reprofiling of frog points by enabling adjustable positioning in six directions, including pivoting and sliding mechanisms, and optionally laser control for enhanced accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual grinding is used for reprofiling frog points, then the method is simple and requires minimal equipment, but the manufacturing precision and compliance with tight tolerances cannot be achieved

Engineering Contradiction:
Improvefrog point geometry precisionVSAvoidcomplexity of reprofiling device
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The device is divided into a base frame for positioning and a separate support frame for holding the milling/grinding machine. The support frame can be independently adjusted and positioned, allowing precise control of the cutting tool relative to the frog point while keeping the base frame simple for stable mounting on the turnout assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support frame is designed with adjustable and displaceable components that allow dynamic positioning in multiple directions. The milling or grinding machine can be moved along the support frame and tilted at various angles, enabling adaptation to different frog geometries and precise machining requirements while maintaining a relatively simple overall device structure.

Inventive Principle:
Principle #15Dynamics

2Productivity

If manual grinding with constant checking is used, then the equipment requirement is low, but the time consumption increases and productivity decreases

Engineering Contradiction:
Improverepair speedVSAvoidtime for measurement and reprofiling
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The device allows preliminary positioning and alignment of the milling or grinding machine before actual machining begins. The support frame can be pre-adjusted to the correct orientation and position relative to the frog point, and the cutting tool can be pre-positioned at the required depth and angle, eliminating the need for frequent interruptions to check and adjust during the machining process.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If laser scanning and measurement are performed before and during manual reprofiling, then measurement accuracy improves, but the process becomes more time-consuming and complex

Engineering Contradiction:
Improvefrog geometry measurement accuracyVSAvoidtime for laser scanning and checking
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The device replaces complex laser scanning and measurement systems with a mechanically precise positioning system. The support frame's adjustable mechanisms provide inherent geometric reference and positioning accuracy through mechanical means such as guided rails, adjustable arms, and precision mounting interfaces, eliminating the need for time-consuming laser measurements while maintaining high precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Duration of action of stationary object

If repeated repairs are performed due to imprecise work, then the service life of the frog is reduced, but the initial repair simplicity is maintained

Engineering Contradiction:
Improveservice life of frogVSAvoidcomplexity of reprofiling device
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The device incorporates inherent geometric feedback through its mechanically precise positioning system. The support frame's adjustment mechanisms are designed to maintain consistent reference geometries relative to the base frame, providing automatic feedback that ensures the milling or grinding machine operates at the correct position and angle throughout the machining process, thereby achieving high precision without requiring complex external measurement and adjustment systems.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4298280B1Device and method for material machining of the frog point of a points arrangement
Publication Date: 2026.04.22 LIND-RUEDT ANDREA
  • EP4298280B1 patent drawingFigure 1A~1B
  • EP4298280B1 patent drawingFigure 2
  • EP4298280B1 patent drawingFigure 3

AI summary

The invention relates to a device (1) and a method for material machining of the frog point (102) of a frog (101) of a points arrangement (100) of a track system, in particular for reprofiling the geometry of the wheel transfer region of a frog point (102). The device (1) according to the invention comprises a base frame (2) and a holding frame (3), and a milling or grinding machine (4) which is held by the holding frame (3). The device (1) can be fastened by way of the base frame (2) to the points arrangement in the region of the frog (101). The milling or grinding head (41) of the milling or grinding machine (4) can be oriented flexibly and precisely for reprofiling of the frog point (102) by way of a combination of setting possibilities of the position of the holding frame (3) with respect to the base frame (2) and of the milling or grinding machine (4) within the holding frame (3).