Self-levelling Manhole Frame with Conical Guide Ring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing manhole cover frames require complex adjustments relative to the road surface and may sink unevenly under vertical forces, compromising their load-bearing capacity and structural integrity.
Innovation Solution
A telescopic manhole cover receptacle with a conical guide ring that allows for easy adjustment and load distribution through the asphalt layer, reducing the burden on the shaft structure and preventing uneven sinking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the manhole cover frame is directly connected to the shaft structure, then vertical forces are transmitted directly to the shaft structure, but this leads to complex adjustment requirements and potential uneven sinking
Solution Approach 1:
The patent introduces an intermediary layer of asphalt concrete between the manhole cover frame and the shaft structure. This asphalt layer acts as a mediator that distributes vertical forces over a larger area, reducing point loads on the shaft structure while eliminating the need for complex adjustment mechanisms. The asphalt layer compensates for minor height differences and provides a self-leveling effect.
Solution Approach 2:
The patent changes the physical state and properties of the connection medium from rigid (direct structural connection) to semi-rigid (asphalt concrete layer). This parameter change allows the connection to accommodate minor misalignments and provides automatic leveling, reducing adjustment complexity while maintaining structural reliability.
2Ease of manufacture
If vertical forces are absorbed only by the roadway surface, then the manhole cover frame can be simply installed, but this leads to uneven lowering and sinking under vehicle loads
Solution Approach 1:
The patent merges two load-bearing systems: the roadway surface (asphalt layer) and the shaft structure. The asphalt layer absorbs distributed loads from the manhole cover frame, while the shaft structure provides underlying support. This combination maintains installation simplicity while preventing uneven sinking through the distributed load path.
Solution Approach 2:
The patent extends the load distribution from a two-dimensional surface contact to a three-dimensional volume by incorporating the asphalt layer as a thickness dimension. This volumetric load distribution prevents point loading and uneven sinking while maintaining simple installation procedures.
3Manufacturing precision
If the manhole cover frame is aligned exactly with the road surface using level holders and grouting mortar, then precise leveling is achieved, but the adjustment process becomes complex and time-consuming
Solution Approach 1:
The patent enables the manhole cover frame to self-level through the deformable asphalt layer. Instead of requiring precise manual alignment with level holders and grouting mortar, the system allows the frame to automatically find its level position as the asphalt conform s to the underlying structure, significantly reducing installation time while maintaining precision.
Solution Approach 2:
The patent transitions from a static alignment process (fixed level holders and rigid grouting) to a dynamic self-adjusting system where the asphalt layer deforms and flows to achieve leveling. This dynamic process occurs during installation and continues to provide adjustment capability under load, reducing both time and 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
The design provides a resilient, easily adjustable manhole cover frame that can withstand extreme loads while maintaining even pressure distribution, ensuring the manhole cover remains level and securely connected to the road surface.
Implementation Method 1
The tapering outer sides, that is to say a conical design of the manhole cover frame, means that forces acting vertically on the manhole cover frame are broken down into vertical and horizontal components. This results in an inclined load transfer, so that a large proportion of the force is diverted into a surrounding road surface
Implementation Method 2
The asphalt layer, which is supported on the conical guide ring, can then transfer the load acting on it to the surrounding layer (base layer, anti-freeze layer) via the guide ring
Data Source
Figure 1~2
AI summary
The frame (1) has a shaft cover holder (3) designed in a telescopic manner and provided in a guiding ring (2). The guiding ring comprises outer sides and a cylindrical inner space, where the outer sides taper from an upper side (4) to a lower side (5). The holder has a flange (11) that points outwards, where the flange and the upper side are arranged parallel to each other. The holder comprises a cast iron, and asphalt is provided between the upper side and the holder. The guiding ring has a cylindrical core (7) for guiding an extension unit (10). An independent claim is also included for a method for insertion of the shaft covering frame.