Tower Crane Auxiliary Hoist for Lifting Close to the Tower
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Solution Overview
Problem
Tower cranes with luffing or trolley jibs face limitations in lifting components close to the tower, necessitating external devices, especially in confined spaces, due to their limited reach and angled pull.
Innovation Solution
A separate auxiliary lifting rope with a rope deflection device is used, guiding the rope vertically alongside the crane tower, utilizing pulleys and a pivoting or telescopic arm to achieve parallel lifting without angled pull.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a luffing jib or trolley jib is used, then the crane can lift loads over a large area, but the minimum reach is limited and cannot move close enough to the tower
Solution Approach 1:
The hoisting system is segmented into two independent ropes: the main hoist rope for general lifting operations, and an auxiliary hoist rope for lifting components close to the tower. This segmentation allows each rope to be optimized for its specific function, resolving the contradiction between wide lifting area and minimum reach limitation.
Solution Approach 2:
A rope deflection device with pulleys acts as an intermediary mechanism between the auxiliary hoist rope and the load. This intermediary redirects the auxiliary rope's path alongside the tower, enabling the crane to lift components in the minimum reach zone without requiring the jib to extend further.
2Length of moving object
If the hoist rope is moved close to the tower, then components can be lifted near the tower, but the rope must pull at an enormous diagonal angle
Solution Approach 1:
The rope deflection device changes the spatial dimension of the rope's path. Instead of pulling diagonally from the jib end, the auxiliary rope is redirected to run vertically alongside the tower, transforming the pull direction from oblique to vertical and eliminating excessive diagonal forces.
Solution Approach 2:
The rope deflection device with its pulleys serves as a mediator that intercepts the auxiliary hoist rope and redirects its trajectory. This intermediary mechanism ensures the rope pulls vertically alongside the tower rather than at a diagonal angle, reducing unnecessary force components.
3Length of moving object
If external lifting devices are used, then components can be lifted close to the tower, but this is problematic on confined construction sites
Solution Approach 1:
The tower crane is enhanced with multi-functionality by integrating the auxiliary hoist rope and rope deflection device into its existing structure. This allows the single crane to perform both standard lifting operations and confined-space lifting near the tower, eliminating the need for separate external lifting devices.
Solution Approach 2:
The tower crane becomes self-sufficient by equipping itself with the auxiliary hoisting capability. Instead of relying on external lifting devices, the crane uses its own hoist mechanism with the added auxiliary rope and deflection device to lift components in previously inaccessible zones.
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 the tower crane to lift components close to the tower without angled pull, allowing for efficient assembly and disassembly of components like climbing ladders and guy wires, even in confined spaces.
Implementation Method 1
This arm is equipped with at least two pulleys that guide the auxiliary hoist rope from the area of the connection point with the hoist rope of the tower crane towards the crane tower
Implementation Method 2
After deflection, the auxiliary lifting rope can run from the rope deflection device directly alongside the crane tower to the ground
Data Source
Figure 1~3
AI summary
The invention relates to a tower crane with a lufting jib or a trolley jib and with a hoisting cable which is guided via a roller of the lufting jib or the trolley of the trolley jib and which is connected to a crane load hook, wherein the crane load hook can be connected to an auxiliary hoisting cable, and the auxiliary hoisting cable is guided from the connection point to the crane tower via a cable deflecting device and runs from the crane tower to the ground directly adjacently to the crane tower, said auxiliary hoisting cable being provided with a load receiving means at the end face.