Magnetic Model Railroad Coupler Actuation

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Solution Overview

Problem

Model railroad couplers for small scales like N and Z face challenges in being both realistically functional and aesthetically accurate, as existing solutions suffer from issues such as excessive play, 'Slinky' effect, and the use of unreliable plastic springs, which impede smooth operation and appearance.

Innovation Solution

A coupler design featuring pivotable shanks with a coil spring and magnetic actuation, allowing for realistic remote operation without visible external springs, using metallic components to enhance reliability and reduce protrusion, thus addressing the limitations of existing couplers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If biasing compression springs are used to center the shanks and bias them into closed positions, then the coupler can perform coupling/uncoupling operations, but excessive play (0.010-0.020 inches) occurs in the direction of train movement causing delayed motion and Slinky effect

Engineering Contradiction:

Improvecoupling operation reliabilityVSAvoidexcessive play causing delayed motion and Slinky effect

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes the biasing compression springs from the coupler assembly, extracting the source of excessive play. Instead of using springs that allow 0.010-0.020 inches of movement, the invention uses a springless design where the shanks are directly biased into closed position through magnetic forces, eliminating the play and Slinky effect while maintaining coupling reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical spring-based centering and biasing system with a magnetic field-based system. The magnetic forces provide the necessary biasing and centering forces without the mechanical play inherent in spring systems, substituting a magnetic field for a mechanical spring assembly.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If long shanks and mounting box are used to accommodate biasing springs, then the springs can function, but the coupler protrudes excessively from rolling stock reducing realistic appearance

Engineering Contradiction:

Improvespring functionVSAvoidcoupler protrusion affecting appearance

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The patent extracts and removes the biasing compression springs from the coupler assembly. By eliminating the springs, the shanks and mounting box can be shortened to appropriate lengths for realistic appearance without compromising coupling function, as the magnetic field provides the necessary forces without requiring long accommodation spaces.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical spring system with a magnetic field-based system that requires minimal space. The magnetic forces are generated within a compact volume, allowing the coupler components to be shortened to realistic dimensions while maintaining full coupling functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If plastic springs are used in the coupler, then the coupler can be manufactured, but the springs lose resilience over time and deform permanently affecting operation

Engineering Contradiction:

Improvecoupler manufacturingVSAvoidspring resilience and operation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the mechanical plastic spring system with a magnetic field-based system. This substitution eliminates the resilience loss and permanent deformation issues inherent in plastic springs, as magnetic fields do not suffer from material fatigue or permanent deformation, while maintaining ease of manufacture through simple magnetic component integration.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 reliable, realistic, and efficient remote operation with reduced protrusion, eliminating the 'Slinky' effect and the drawbacks of plastic springs, while maintaining a realistic appearance, suitable for N and Z scales.

Implementation Method 1

A magnetic actuating pin mounted on one of the first and second shanks for causing rotation thereof against the biasing force of the spring when a railroad car to which the coupler is mounted is at a location on the track with the actuating pin proximate to a magnetic actuating pad

Methodology Applied

Scientific EffectMagnetic force: Magnetism

Data Source

PatentUS8720710B2Magnetically actuated model railroad coupler

Publication Date: 2014.05.13 LEMERISE JOHN E

AI summary

A model railroad car coupler assembly comprises a coupler with an upper shank having a coupler knuckle at a distal portion and a flat proximal portion, a lower shank having a coupler thumb at a distal portion and a flat proximal portion, and a coil spring terminating in first and second end portions, with a first turn of the coupler spring interlocked with the upper shank and a second turn interlocked with the lower shank. A mounting box has a circular mounting post that accepts circular openings in the shanks permitting them to rotate relative to each other between a closed coupled position and an open uncoupling position. The spring end portions engage the mounting box to bias the shanks into their coupled position. The knuckle carries a ferrous actuating pin that cooperates with a magnetic pad along a track to rotate the upper shank into its open position.