Manhole Cover Hinge Retention for Accidental Tilt Prevention

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Solution Overview

Problem

Existing road manholes with large, heavy covers are prone to accidental tilting and falling out of their frames due to external forces, posing a safety risk.

Innovation Solution

An articulation device with a complementary shape between the articulation head and housing, featuring a transverse slot and projecting part, prevents the head from tilting out of the housing by engaging when the cover is upright, ensuring secure locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the crowning element is made large and heavy to ensure durability and coverage, then the structural strength and coverage area are improved, but the stability of the articulation device deteriorates as the element can easily tilt and fall out of the frame

Engineering Contradiction:
Improvestructural strengthVSAvoidstability of articulation device
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The articulation head is divided into two separate parts: a retaining part that fits into the housing and an articulation part that allows pivoting. This segmentation enables the heavy crowning element to be supported stably while maintaining articulation functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining part of the articulation head is nested within the housing of the ear, creating a secure fit that prevents the heavy crowning element from tilting or falling out while allowing controlled articulation movement.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If the articulation head is freely mounted in the housing without additional constraints, then the ease of operation and pivoting movement are improved, but the stability deteriorates allowing accidental tilting

Engineering Contradiction:
Improvepivoting movementVSAvoidstability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The articulation device combines dynamic pivoting capability with static retention. The articulation part allows dynamic movement for opening/closing operations, while the retaining part provides static stability to prevent accidental tilting.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The retaining part has an asymmetric shape that fits specifically into the housing, allowing free pivoting in one direction while preventing tilting in other directions. This asymmetric design enables controlled movement while maintaining stability.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2893087B1Manhole cover
Publication Date: 2025.09.03 EJ EMEA
  • EP2893087B1 patent drawingFigure 1
  • EP2893087B1 patent drawingFigure 2
  • EP2893087B1 patent drawingFigure 3

AI summary

The present invention concerns a manhole having anti-tilt means of a crown member relative to the frame two which it is hinged. According to the invention, the manhole is characterised in that the housing (11) of the lug (12) and the hinge head (9) comprise form-fitting means (18, 19), for example such as a slot (18) of the head (9) and at least one protruding portion (19) secured in the housing (11) of the lug (12) and engaging to prevent the head (9) from tilting out of the housing (11) of the lug (12) when the crown member (5) is in the upright position of same. The invention is applicable in the field of road equipment.