Divisible A-Frame for Mobile Crane Transport Weight Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Mobile cranes, especially caterpillar cranes, face challenges with the weight and complexity of their A-Bock units during transport, which can exceed maximum permissible transport weights and complicate assembly and disassembly.

Innovation Solution

The A-Bock unit is designed to be divisible, with a spar that can be removed for transport and a Klappholm that remains on the upper car, allowing for a reduced transport weight and simplified assembly process without disassembling the pull-out.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the entire A-frame unit is disassembled for transport, then the transport weight is reduced, but the assembly and disassembly process becomes complicated and time-consuming

Engineering Contradiction:
Improvetransport weightVSAvoidassembly complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The A-frame is divided into two separate parts: a beam that can be removed for transport and a folding beam that remains on the superstructure. This segmentation allows the heavy beam to be transported separately, reducing the weight of the moving unit, while the folding beam with integrated fastening means can be quickly assembled without complex disassembly procedures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The beam component is extracted from the complete A-frame assembly for separate transport. This extraction removes the majority of the A-frame's weight from the transport unit, while the essential folding beam with fastening means remains on the superstructure, enabling quick reassembly without handling the entire A-frame unit.

Inventive Principle:
Principle #2Taking out (Extraction)

2Weight of moving object

If the entire A-frame unit is disassembled for transport, then the transport weight is reduced, but the risk of damaging sensitive components increases

Engineering Contradiction:
Improvetransport weightVSAvoidcomponent protection
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The sensitive components of the retraction mechanism are extracted from the disassembly process by leaving them attached to the superstructure with the folding beam. Only the beam is removed for transport, which protects the sensitive components from potential damage during handling and transport operations.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If the A-frame is designed as a complete unit, then the structure is simple, but the transport weight exceeds maximum permissible limits

Engineering Contradiction:
Improvestructure simplicityVSAvoidtransport weight
Core Design Contradiction:
Device complexityVSWeight of moving object

Solution Approach 1:

The A-frame is segmented into a beam and a folding beam, allowing the heavy beam to be separated from the superstructure for transport. This segmentation reduces the transport weight to comply with regulations while maintaining structural simplicity through the straightforward design of the folding beam with integrated fastening means.

Inventive Principle:
Principle #1Segmentation

4Loss of time

If the folding beam is detachably connected to the superstructure, then the assembly time is reduced, but the device complexity increases

Engineering Contradiction:
Improveassembly timeVSAvoidfastening system complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The fastening means are pre-integrated into the folding beam design during manufacturing. This preliminary action allows the folding beam to be quickly attached to the superstructure using pre-positioned fastening elements, significantly reducing assembly time while avoiding complex assembly procedures.

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

This solution reduces the transport weight and complexity of the A-Bock unit, simplifying assembly and reducing the risk of damage during transport, while also adhering to strict transport weight regulations.

Implementation Method 1

the folding beam is pivotably connected to the beam about a horizontal axis (pivot axis) and can be locked to it

Methodology Applied
Scientific EffectPivoting: Hinge

Implementation Method 2

The folding beam and the superstructure each have fastening means by which the folding beam can be detachably mounted to the superstructure, wherein the fastening means of the folding beam and the superstructure can be brought together by pivoting the folding beam about the axis (pivot axis)

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Implementation Method 3

the retraction mechanism comprises a retraction winch 20 arranged on the superstructure 3 with a retraction cable 21, which is guided over a pulley or pulley assembly 24 arranged at the end of the A-frame 10 and a pulley or pulley assembly 22 arranged on the superstructure 3. By retracting/paying out the retraction cable 21 using the retraction winch 20, the distance between the pulleys or pulley assemblies 22 and 24 can be decreased/increased, thereby pivoting the A-frame 10 and the boom 6

Methodology Applied
Scientific EffectPulley: Pulley

Data Source

PatentEP3943438B1Mobile crane with separable a frame
Publication Date: 2025.04.30 LIEBHERR WERK NENZING
  • EP3943438B1 patent drawingFigure 1
  • EP3943438B1 patent drawingFigure 2
  • EP3943438B1 patent drawingFigure 3

AI summary

The invention relates to a mobile crane (1), in particular a crawler crane, comprising an undercarriage (2) with a chassis, a superstructure (3) rotatably mounted on the undercarriage about a vertical axis, a boom (12) pivotally mounted on the superstructure about a horizontal axis (A2), an A-frame (10) pivotally mounted on the superstructure about a horizontal axis and connected to the boom via a bracing element (12), and a retraction mechanism by means of which the A-frame can be pivoted. According to the invention, the A-frame is divisible and comprises a beam (14) pivotally mounted on the superstructure and a folding beam (16) detachably connected to the beam.