Tugger Trailer Lifting Rails With Horizontal Retraction

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Solution Overview

Problem

Existing tugger train trailers with purely vertical lifting rails cannot accommodate load carriers with rollers flush with the support frame due to interference during insertion, limiting their universality for different load carriers.

Innovation Solution

A lifting device with support rails that are adjustable in height and movable horizontally between retracted and extended positions, using a coupling device to convert vertical movements of a lifting actuator into horizontal and vertical movements of the rails, allowing for interference-free insertion and lifting of various load carriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If purely vertical lifting rails are used, then the lifting device is simple in structure, but it cannot accommodate load carriers with rollers flush with the support frame due to interference during insertion

Engineering Contradiction:
Improveaccommodation of different load carriersVSAvoidstructure of lifting device
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The support rail is made dynamically movable in the horizontal direction between retracted and extended positions. During insertion, the rail retracts horizontally to clear the path for load carriers with flush rollers. After insertion, the rail extends to engage the load carrier for vertical lifting. This dynamic repositioning resolves the contradiction by adapting the rail position to different operational phases.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The lifting device transitions from purely vertical movement to two-dimensional movement by adding horizontal adjustability to the support rail. The rail can now move both horizontally (to avoid interference during insertion) and vertically (to perform lifting), enabling accommodation of diverse load carrier designs without compromising lifting functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If support rails are extended to engage load carriers, then lifting function is achieved, but interference occurs during insertion of load carriers with flush rollers

Engineering Contradiction:
Improvelifting functionVSAvoidinsertion of load carrier
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Before the load carrier is inserted, the support rail is preliminarily retracted horizontally to create clearance. This preliminary retraction action prevents interference during insertion. After successful insertion, the rail is extended to engage the load carrier for lifting, ensuring both smooth insertion and reliable lifting function.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The support rail dynamically adjusts its horizontal position based on the operational phase: retracted during insertion to facilitate ease of operation, and extended during lifting to ensure reliable engagement. This dynamic adaptation eliminates interference while maintaining lifting reliability.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If horizontal movement of support rail is added, then universality for different load carriers is achieved, but complexity of lifting device increases

Engineering Contradiction:
Improveuniversality for different load carriersVSAvoidlifting device structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The coupling device merges the vertical lifting motion with the horizontal retraction/extension motion of the support rail into a single integrated mechanism. This combining of movements reduces the need for separate actuators and control systems, thereby limiting the increase in device complexity while achieving universality for different load carriers.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coupling device acts as an intermediary mechanism that translates the vertical movement of the lifting actuator into coordinated horizontal and vertical movements of the support rail. This intermediary mechanism enables the complex two-dimensional rail movement to be controlled through a simple vertical actuator, minimizing the increase in overall device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If support rails are made movable in horizontal direction, then interference-free insertion is enabled, but additional mechanisms are required

Engineering Contradiction:
Improveinsertion of load carrierVSAvoidmechanisms of lifting device
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The coupling device combines the functions of vertical lifting and horizontal retraction/extension into a single integrated mechanism. This merging reduces the total number of separate mechanisms required, as one coupling device performs multiple functions that would otherwise require separate systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coupling device serves as an intermediary that simplifies the control of horizontal rail movement by translating vertical actuator motion into coordinated horizontal and vertical rail movement. This intermediary mechanism reduces operational complexity by providing a single control point for multiple movements.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables the tugger train trailer to universally transport different load carriers, including floor rollers, by ensuring the support rails move out of the way during insertion and then engage the load carrier, reducing construction effort and enhancing adaptability.

Implementation Method 1

the coupling device is designed to convert a vertical lifting movement of the lifting actuator into a horizontal movement and into the subsequent vertical movement of the support rail

Methodology Applied
Scientific EffectMechanical movement conversion:

Data Source

PatentEP4001205B1Lifting device of a tugger train trailer and tugger train trailer having a lifting device
Publication Date: 2026.02.25 LR INTRALOGISTIK GMBH
  • EP4001205B1 patent drawingFigure 1
  • EP4001205B1 patent drawingFigure 2
  • EP4001205B1 patent drawingFigure 3

AI summary

The invention relates to a lifting device (20) of a tugger train trailer (1) for raising and lowering a load carrier carried in the tugger train trailer (1), wherein the lifting device (20) for raising and lowering the load carrier has at least one support rail (11, 12; 13, 14) that is height-adjustable in the vertical direction (V) and is designed to engage the load carrier. The support rail (11, 12; 13, 14) is additionally movable in the horizontal direction (L) between a retracted position and an extended position.