Tower Crane Folding Structure Cable Tension Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tower cranes face issues with traction cable tension variations during configuration changes, leading to potential damage, increased power requirements, and winding problems, which can affect safety and longevity.
Innovation Solution
A collapsible structure with a movable second cable guide member and a return member, along with a sensor, that adjusts the traction cable's length and tension to compensate for configuration changes, ensuring controlled variation and minimizing wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the traction cable is made taut in the unfolded configuration, then the structural elements can be properly supported, but the cable becomes overtensioned during folding which may damage the cable or components
Solution Approach 1:
The patent makes the cable guide member movable rather than fixed, allowing it to dynamically adjust its position between extended and retracted states. This dynamic adjustment enables the system to accommodate cable length changes during folding/unfolding operations, preventing overtension while maintaining structural support capability.
Solution Approach 2:
The patent changes the positional parameter of the cable guide member along the traction cable's path. By moving the cable guide member between extended and retracted positions, the system alters the effective cable length and tension characteristics, resolving the contradiction between maintaining support and preventing damage.
2Ease of operation
If the traction cable is not taut enough in the unfolded configuration, then folding is easier, but the cable winding on the drum is altered increasing snagging risk and reducing cable life
Solution Approach 1:
The movable cable guide member dynamically adjusts to maintain appropriate cable tension during both folding and unfolding operations. This ensures the cable remains sufficiently taut to prevent winding problems while still allowing folding operations to proceed without excessive force.
Solution Approach 2:
The system provides feedback through the mechanical position of the cable guide member, which automatically adjusts to maintain optimal cable tension. The guide member's position serves as an indicator of cable tension state, enabling the system to self-regulate and prevent both overtension and insufficient tension conditions.
3Productivity
If the telescoping movement is stopped too early, then the traction cable becomes too tight which is dangerous during working phases, but stopping too late causes the cable to be unwound too much and wound incorrectly
Solution Approach 1:
The cable guide member acts as an intermediary element between the telescoping mechanism and the traction cable. It mediates the tension transmission, allowing the system to stop telescoping at the correct position by controlling when the cable guide member reaches its extended position, thus preventing both overtension and incorrect winding.
Solution Approach 2:
The system uses the position of the cable guide member as a preliminary indicator to control the telescoping stop point. Before the telescoping completes, the cable guide member's position provides advance warning of the correct stop point, allowing the operator to halt at the optimal moment to prevent tension problems.
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 controlled length variation of the traction cable, reduces wear, and provides a stop signal for operator alert or automated positioning, enhancing safety and operational efficiency.
Implementation Method 1
a return member (14) configured to exert a return force (F14) from the second cable guide member (12) towards the extended position (figure 5)
Data Source
Figure 1~9
Figure 3~4
Figure 5~8
AI summary
This foldable structure (1) comprises: two structural elements (2.1, 2.2), and a hinge (4) to enable the structural elements (2.1, 2.2) to move between unfolded and folded configurations. The foldable structure (1) further comprises first (10) and second (12) cable guide members (10) to guide first (6.1) and second (6.2) sections of a traction cable (6). The traction cable (6) has an intermediate section (6.3) between the first (10) and second (12) cable guide members (10). The second cable guide member (12) is movable relative to the first cable guide member (10) between extended and shortened positions. The intermediate section (6.3) is longer in the extended position than in the shortened position. A return element (14) returns the second cable guide element (12) to the extended position.