Manhole Structure with Extendable Riser Pipe

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Solution Overview

Problem

Existing methods for adjusting the height of manhole structures during road resurfacing are time-consuming, prone to debris and water ingress, and require extensive excavation and disassembly, which can lead to damage and breakage of the riser pipe.

Innovation Solution

A manhole structure featuring a longitudinally extendable and retractable riser pipe with a gasket or adhesive seal between the skirt and the riser pipe, allowing for height adjustment without disassembly, while accommodating ground movements and loads, and preventing debris and water ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If spacers or extension rings are placed between the end of the riser pipe and the frame to adjust the level, then the height of the manhole frame can be adjusted to accommodate resurfaced road, but the process requires extensive excavation, disassembly, repositioning and reassembly which is time-consuming and risks surrounding earth or debris entering the manhole

Engineering Contradiction:
Improveheight adjustment capabilityVSAvoidtime for adjustment process
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The riser pipe is designed to be longitudinally extendable and retractable, allowing dynamic adjustment of the manhole frame height. The pipe can be extended by pulling it upward relative to the frame and retracted by pushing it downward, enabling quick adaptation to different road levels without disassembly or excavation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system allows the manhole structure to self-adjust to road level changes through simple vertical movement of the riser pipe. The gasket automatically seals the joint between the pipe and frame at any position, eliminating the need for manual intervention, excavation, or specialized adjustment procedures.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If the manhole frame is disassembled and reassembled to adjust height, then the frame can be repositioned to the new road level, but there is a risk of surrounding earth or debris entering the manhole

Engineering Contradiction:
Improveheight adjustment capabilityVSAvoiddebris ingress risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The gasket maintains a continuous seal between the riser pipe and frame throughout the entire adjustment process. As the pipe is extended or retracted, the gasket continuously conforms to the joint, preventing any interruption in the seal and thus preventing debris ingress during height adjustment.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The gasket is a flexible sealing element that adapts to the joint between the riser pipe and frame. Its flexibility allows it to maintain an effective seal during vertical movement of the pipe, preventing earth and debris from entering the manhole while accommodating height adjustments.

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If the riser pipe is rigid and fixed length, then the structure is simple, but it cannot accommodate ground movements and loads from traffic without risk of damage or breakage

Engineering Contradiction:
Improvestructure simplicityVSAvoidresistance to ground movement and traffic loads
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The riser pipe transitions from a rigid fixed-length component to a dynamic extendable and retractable element. This allows the structure to accommodate ground movements and traffic-induced loads by adjusting the pipe length, thereby maintaining reliability without significantly increasing structural complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The length parameter of the riser pipe is made variable rather than fixed. The pipe can be extended or retracted to change its length in response to ground movements and traffic loads, enhancing the reliability of the manhole structure while maintaining relative simplicity of the overall design.

Inventive Principle:
Principle #35Parameter changes

4Strength

If traditional mounting methods are used to attach the frame to the riser pipe, then the connection is secure, but adjusting the height requires disassembly and reassembly which is time-consuming

Engineering Contradiction:
Improveconnection securityVSAvoidtime for adjustment process
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The gasket serves as a flexible sealing element that simultaneously provides a secure connection between the riser pipe and frame while allowing vertical movement. The flexibility of the gasket enables height adjustment without disassembly, eliminating the time-consuming processes of traditional rigid connection methods.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The gasket maintains a continuous sealing connection between the riser pipe and frame throughout the entire range of motion. This continuous connection allows the frame to be securely attached while enabling smooth vertical adjustment of the pipe length without requiring disassembly or reassembly operations.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2325399B1Manhole structure
Publication Date: 2012.04.18 FURNES HAMJERN NCC
  • EP2325399B1 patent drawingFigure 1a
  • EP2325399B1 patent drawingFigure 1b
  • EP2325399B1 patent drawingFigure 1c

AI summary

By the invention a manhole structure (10) is provided comprising a frame (12) having a skirt (16), a riser pipe (100) at least partly inserted into the skirt (16), and a gasket (50) being placed between the skirt (16) and the riser pipe (100), wherein the gasket (50) is adapted to retain the riser pipe (100), and wherein the riser pipe (100) is longitudinally extendable Moreover, the invention provides a method for adjusting the height of a frame (12) in the manhole structure (10) from a first level to a second level, comprising specific steps of adjusting the height of the frame (12) from the first level to the second level, and supporting the frame (12) at the second level, wherein the distance between the first and the second level is accommodated by the riser pipe (100).