Tower Crane Boom Folding via Rotary Joints
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Solution Overview
Problem
Existing rotating tower cranes face challenges in efficiently changing boom lengths during work tasks and maintenance, as existing solutions either restrict boom length adjustments when retracted or complicate maintenance with hydraulic actuators, hindering operator access and increasing complexity.
Innovation Solution
An automated collapsible tower crane with a telescoping mast and articulated boom sections, utilizing a combination of cable and pulley systems for mast extension and hydraulic actuators for boom folding, allowing independent operation and enhanced maintenance access through a bracing sling and rotary joints, enabling flexible boom length adjustments and simplified maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the boom is driven by means of a cable mechanism, then the crane can be retracted for transport, but the length of the boom can only be changed when the tower is retracted, hindering work tasks and maintenance access
Solution Approach 1:
The patent applies the dynamics principle by enabling the boom to change its configuration dynamically between folded and unfolded states while the tower remains extended. The boom sections can be folded relative to each other through rotary joints, allowing length adjustment during active work tasks rather than requiring tower retraction. This dynamic adaptability resolves the contradiction by making boom length changes independent of tower position.
2Adaptability or versatility
If hydraulic actuators are used to drive the folding of the boom, then changes in boom lengths are allowed with the tower fully unfolded, but the folding and telescoping of the mast by means of hydraulic actuators increases the complexity and maintenance requirements
Solution Approach 1:
The patent extracts the hydraulic actuation system from the mast telescoping function and applies it only to the boom folding mechanism. The mast telescoping is driven by a cable mechanism instead, reducing the number of hydraulic actuators needed. This selective application of hydraulic actuation to only where needed (boom folding) maintains adaptability while reducing overall system complexity and maintenance requirements.
3Adaptability or versatility
If the crane is in an upright working position with hydraulic actuators for mast telescoping, then boom length changes are possible, but access by operators to the boom for repairs is impeded without auxiliary mobile cranes
Solution Approach 1:
The patent applies segmentation by dividing the boom into multiple articulated sections connected by rotary joints. This segmentation allows individual boom sections to be folded and maneuvered independently, enabling operators to access specific areas of the boom for maintenance without requiring the entire structure to be reconfigured or auxiliary cranes. The modular segmented design facilitates easier maintenance access while preserving boom length adjustability.
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 allows for efficient boom length changes and maintenance without auxiliary cranes, improving safety, maintenance, and operational efficiency by enabling independent boom folding and unfolding, and facilitating operator access for repairs.
Implementation Method 1
a telescoping system of the mast to telescopically extend and retract the mast between a retracted vertical position in which the mast is in its non-extended vertical position and an extended vertical position in which the mast extends upwards, the telescoping system comprising a combination of cable and pulleys driven by a winch
Implementation Method 2
a boom folding system for unfolding and folding the boom by the rotary joints between a folded position and at least one linearly unfolded working position along a substantially horizontal plane
Data Source
AI summary
An automated collapsible tower crane comprising a mast with telescopic portions, a boom with boom sections articulated with each other by respective rotary joints, a boom folding system to unfold and fold the boom by the rotary joints wherein each proximal and distal rotary joint is associated with at least one hydraulic actuator to unfold and fold boom sections, a mast folding system to fold the mast down, wherein in the transport position the boom sections are folded down one on top of the other and on the mast, and the boom folding and unfolding system acts independently of the folding and telescoping system of the mast, and comprises hydraulic actuators to fold and unfold the boom sections.