Tower Crane Stop Surface Friction Connection
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Solution Overview
Problem
Current tower crane designs lack visibility during the dismantling process of the boom or counter-jib, leading to unpredictable swinging and potential damage due to the absence of a clear connection release mechanism, especially when using auxiliary cranes that may not grip the components at their center of gravity.
Innovation Solution
The connection between the boom or counter-jib and the crane tower is enhanced by using stop surfaces on connecting parts that provide a frictional connection through compressive force, eliminating the need for a separate bolt for force transmission and incorporating a catch element for secure alignment and stabilization during assembly and dismantling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bolt is used to lock connection partners together, then the connection is secure and reliable, but the bolt must be comparatively large or strongly dimensioned, increasing weight and complexity
Solution Approach 1:
The patent extracts the force transmission function from the bolt and relocates it to the stop surfaces. The bolt is reduced to merely a positioning and locking element, while the stop surfaces (concave and convex) bear the primary compressive forces through friction, eliminating the need for a large, complex bolt structure.
Solution Approach 2:
The stop surfaces act as intermediaries between the connecting parts. The concave stop surface on one part and the convex stop surface on the other part create a frictional connection that transmits forces without requiring a large bolt. This intermediary mechanism simplifies the overall connection structure while maintaining reliability.
2Ease of operation
If the connection is made without tools for assembly purposes, then ease of assembly is improved, but visibility of movement during dismantling is lost, leading to unpredictable swinging
Solution Approach 1:
The catch element is positioned in advance during assembly to guide and stabilize the boom or counter-jib. During dismantling, this pre-positioned catch element continues to provide control, allowing the auxiliary crane to safely lower the component without unexpected swinging, thus maintaining reliability during the dismantling process.
3Reliability
If steel safety ropes are used for additional securing, then safety during armament is improved, but the connection point becomes more complex and the ropes add additional components
Solution Approach 1:
The patent merges the safety function into the existing connection structure by integrating the catch element with the stop surfaces. The catch element works in conjunction with the concave and convex stop surfaces to provide both the frictional connection and the safety securing function, eliminating the need for separate steel safety ropes and reducing overall complexity.
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 design allows for tool-free articulation and secure connection/disconnection, preventing uncontrolled swinging of the boom or counter-jib during dismantling by ensuring proper alignment and stabilization, thereby reducing the risk of damage to the crane structure.
Implementation Method 1
During crane operation, these stop surfaces are pressed against each other by an applied compressive force, so that a frictional connection between the boom/counter-jib and the tower top is provided
Data Source
Figure 1a~1b
Figure 2
Figure 3a~3b
AI summary
The invention relates to a tower crane, preferably a rotary tower crane, particularly preferably a top-slewing crane, comprising a jib and a counter-jib. The jib and/or counter-jib is hinged to the tower top and/or rotating platform by means of at least one connection point. A first connection part of the at least one connection point has a concave stop surface, and a second connection part of the connection point comprises a convex counter-stop surface, wherein the counter-stop surface of the second connection part acts on the stop surface of the first connection part by means of a pressure force in order to produce a force-fitting connection between the connection parts.