Tower Crane Hoist Rope Auxiliary Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tower cranes with hoist ropes longer than required for normal operation face damage and inefficiency, especially in multi-layer windings, due to the inability to completely unwind lower rope layers, particularly in high-rise constructions and rental cranes that need flexible hook height adjustments.
Innovation Solution
The method involves using an auxiliary deflection to unwind and rewind the excess hoist rope length without slack, allowing the rope to be stored on an auxiliary deflection device that can be adjusted with the crane structure, enabling the use of longer ropes without damage by pretensioning the unwound layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a hoist rope longer than required for normal operation is used, then the crane can operate at maximum hook height, but the lower rope layers cannot be completely unwound and damage occurs to the rope
Solution Approach 1:
The patent introduces an auxiliary deflection that can be selectively deployed to change the rope path dynamically. When the auxiliary deflection is in use, it creates an additional unwrap path that allows the rope to be completely unwound even when a longer rope is installed. This dynamic adjustment of the rope path resolves the contradiction by enabling full unwinding of longer ropes without causing damage to lower layers.
Solution Approach 2:
The auxiliary deflection acts as an intermediary element between the hoist drum and the load. By introducing this intermediate deflection point, the system creates an extended unwrap path that allows the rope to be fully utilized. This intermediary structure enables the rope to wrap around additional components, effectively increasing the usable rope length and preventing damage to lower layers.
2Reliability
If the rope length is adapted to the increasing height of the hook, then damage to the rope is prevented, but considerable effort is required to change ropes of different lengths
Solution Approach 1:
The auxiliary deflection structure serves multiple functions: it enables full unwinding of longer ropes, prevents rope damage, and allows the crane to operate at maximum hook height. By making this single structural element multi-functional, the system eliminates the need to manage multiple ropes of different lengths, thereby reducing operational complexity while maintaining rope integrity.
Solution Approach 2:
The patent changes the geometric parameters of the rope path by introducing the auxiliary deflection. This parameter change extends the effective unwrap path without requiring physical changes to the rope itself. By modifying the path geometry rather than the rope properties, the system achieves universal compatibility with longer ropes while maintaining simplicity in rope management.
3Ease of operation
If a rope length sufficient for usual hook heights is chosen, then normal operation is possible, but the maximum hook height cannot be used effectively
Solution Approach 1:
The auxiliary deflection provides a dynamic solution that adapts the rope path based on operational requirements. When maximum hook height is needed, the auxiliary deflection enables the extended rope to be fully utilized. This dynamic adaptation allows the same rope to serve both normal operations and maximum height operations effectively.
4Adaptability or versatility
If rental cranes are equipped with flexible cable for different applications, then adaptability is improved, but the cable becomes too long for the existing use
Solution Approach 1:
The auxiliary deflection structure provides a universal solution that works across different crane applications and rope lengths. By making the deflection system multi-functional, rental cranes can use a single standardized cable for various applications without suffering from cable damage, thereby achieving both adaptability and reliability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a method for operating a tower crane on whose hoist winch (10) a hoist rope (11) is wound, the length of which is greater than the length required for normal operation. The hoist rope is guided over an auxiliary deflection (8, 9, 12) in order to unwind the portion of the hoist rope that is not unwound during normal operation.