Tower Crane Punch Folding via Lifting Cable Tension
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Solution Overview
Problem
Existing tower cranes face challenges in automatically and reliably folding and unfolding their punches, especially when they do not have a telescopic mast, leading to complex systems that are prone to errors and damage due to the need for additional components like gas cylinders, which are unreliable in harsh conditions.
Innovation Solution
A tower crane design that uses the lifting cable and a return system to automatically move the punch between working and transport positions, leveraging the tension force from the lifting cable to fold and unfold the punch, allowing for precise control of the folding and unfolding speed and maintaining the crane's compactness without requiring additional complex components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If gas springs or hydraulic cylinders are used to fold the punch, then the punch can be folded automatically, but the system becomes more complex and less reliable in harsh conditions
Solution Approach 1:
The invention extracts and eliminates the complex pneumatic or hydraulic folding systems from the tower crane design. Instead of using gas springs or hydraulic cylinders, the punch folding function is integrated into the existing lifting cable system, removing the need for separate folding mechanisms and their associated complexity.
Solution Approach 2:
The lifting cable system is given a dual function: it performs both the load-lifting operation and the punch folding operation. By making the lifting cable multi-functional, the invention eliminates the need for dedicated folding actuators, thereby reducing system complexity while maintaining automatic folding capability.
2Extent of automation
If gas springs are used to fold the punch, then the punch can be folded automatically, but the system becomes more expensive and requires more space inside the boom
Solution Approach 1:
The lifting cable system is given a dual function: it performs both the load-lifting operation and the punch folding operation. By making the lifting cable multi-functional, the invention eliminates the need for dedicated folding actuators, thereby reducing system complexity.
Solution Approach 2:
The invention extracts and eliminates the complex pneumatic or hydraulic folding systems from the tower crane design. Instead of using gas springs or hydraulic cylinders, the punch folding function is integrated into the existing lifting cable system, removing the need for separate folding mechanisms and their associated complexity.
3Device complexity
If the punch is folded using its own weight by inclining the boom, then the system remains simple, but it requires preliminary boom unfolding and only works with significant punch extension
Solution Approach 1:
The invention enables continuous and direct punch folding action through the lifting cable system, eliminating the need for preliminary boom unfolding steps. The lifting cable can fold the punch at any stage of the tower crane operation, providing continuous folding capability without requiring specific preliminary configurations.
Solution Approach 2:
The lifting cable acts as an intermediary mechanism that directly controls punch folding. Instead of relying on the punch's own weight and complex boom positioning, the lifting cable serves as a mediating element that can fold the punch reliably under various operating conditions, including when the punch has minimal extension.
4Extent of automation
If telescopic mast is used to enable punch folding by gravity, then the punch can be folded automatically, but the solution is limited to telescopic masts only
Solution Approach 1:
The lifting cable system is given a dual function: it performs both the load-lifting operation and the punch folding operation. By making the lifting cable multi-functional, the invention eliminates the need for dedicated folding actuators, thereby reducing system complexity.
Solution Approach 2:
The lifting cable acts as an intermediary mechanism that directly controls punch folding. Instead of relying on the punch's own weight and complex boom positioning, the lifting cable serves as a mediating element that can fold the punch reliably under various operating conditions, including when the punch has minimal extension.
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 simple, reliable, and precise automatic folding and unfolding of the punch, ensuring the crane's compactness and reliability across various types and capacities, including those without telescopic masts, while maintaining the lifting cable's load-lifting function and minimizing the need for additional components.
Implementation Method 1
a lifting cable (5) connected to a winding device (53) designed to exert a tension force (T) on said lifting cable (5)
Implementation Method 2
causing a displacement of said punch from its working position to its transport position
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Tower crane (1), of the type that can be folded and unfolded between a working configuration and a transport configuration, having a boom (2) articulated in rotation relative to a mast (3) around a main axis of rotation, said tower crane having a rear restraint fixed to a frame (4) supporting said mast and to a punch (6), extending said boom to the rear of said main axis of rotation and movable relative to said boom (2) between a working position and a transport position, said tower crane being characterized in that it has a lifting cable (5) provided to be connected to a winding device exerting on said lifting cable (5) a tension force (T) applied on said punch by means of a return system (8) designed to cooperate with said lifting cable, so as to cause a displacement of said punch from its working position to its transport position.