Ship Crane Erection Stand with Foldable Tension Rod

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Solution Overview

Problem

Crane installations, particularly on ships, face challenges with height limitations when passing under obstacles like bridges or power lines due to the elevated state of the erection stand, necessitating detours and increased wind exposure during transport.

Innovation Solution

A crane design featuring a tension rod with a swivel joint that allows the erection stand to be folded, reducing overall height, combined with a hydraulic locking mechanism for stability and a deflection roller for rope guidance, enabling the crane to lower its center of gravity and reduce wind exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the erection stand is kept in an upright position to maintain crane functionality, then the crane can perform lifting operations, but the overall height of the crane increases, preventing passage under height-restricting obstacles

Engineering Contradiction:
Improvecrane operational capabilityVSAvoidoverall height
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The erection stand is designed with a swivel joint at its base, allowing it to dynamically change position between upright (operational) and folded (transport) configurations. This dynamic capability enables the crane to adapt its height based on operational needs versus transport requirements, resolving the contradiction between maintaining functionality and reducing height for obstacle passage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The erection stand is divided into separable components that can be folded relative to each other through the swivel joint. By segmenting the structure, the stand can be collapsed into a compact configuration during transport, reducing the overall height while maintaining full functionality when deployed in the upright position.

Inventive Principle:
Principle #1Segmentation

2Length of stationary object

If the erection stand is folded down to reduce height for passing under obstacles, then the crane can traverse previously impassable obstacles, but the center of gravity increases and stability decreases

Engineering Contradiction:
Improveoverall heightVSAvoidcenter of gravity
Core Design Contradiction:
Length of stationary objectVSStability of the object's composition

Solution Approach 1:

The design incorporates a counterweight mechanism that compensates for the increased height and reduced stability when the erection stand is folded. By adding a counterbalancing element, the system maintains adequate stability even in the folded configuration, allowing the crane to pass under obstacles without excessive instability.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Object-affected harmful factors

If the erection stand is folded down to reduce wind resistance during transport, then the crane experiences reduced wind exposure, but the structural complexity increases due to the swivel joint and locking mechanism

Engineering Contradiction:
Improvewind resistanceVSAvoidswivel joint and locking mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

A hydraulic cylinder is integrated with the swivel joint to provide automated locking and unlocking functionality. This hydraulic actuation system simplifies the overall mechanism by replacing complex mechanical locking arrangements with a more reliable and easier-to-control hydraulic system, reducing the operational complexity while maintaining the foldable structure for reduced wind resistance.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 passage under previously impassable obstacles without detours, lowers the center of gravity for improved stability, and reduces wind exposure during transport by minimizing the crane's height and area exposed to wind.

Implementation Method 1

The swivel joint of the drawbar is further provided to be lockable in order to fix the lifting stand in its upright position, with the locking of the swivel joint being effected by a hydraulic cylinder

Methodology Applied
Scientific EffectHydraulic force: Hydraulic Press

Implementation Method 2

The weight of the lifting stand is supported by the lowered boom, which can be lowered thanks to the foldable or swiveling drawbar

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3825274B1Crane with gantry
Publication Date: 2024.08.07 LIEBHERR MCCTEC ROSTOCK GMBH
  • EP3825274B1 patent drawingFigure 1
  • EP3825274B1 patent drawingFigure 2
  • EP3825274B1 patent drawingFigure 3

AI summary

The present invention relates to a crane, in particular a ship crane, comprising a boom (2) that can be raised in height about a pivot axis, and an erection stand (4) for redirecting a rope of a hoisting mechanism (6) to raise the boom (2). The invention is characterized in that the erection stand (4) can be raised in height, and the erection stand (4) comprises a tension rod (7) having a pivot joint (8) for rotating a first section (9) of the tension rod (7) relative to a second section (10) of the tension rod (7).