Self-locking Concrete Paving Bloc Asymmetrical Spacer Design

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Solution Overview

Problem

Existing concrete paving stones lack effective long-term locking against tearing or sagging due to spacer wear and migration of grouting sand, and they fail to provide sufficient resistance against vertical forces and aesthetic compatibility with linear joint continuity.

Innovation Solution

The self-locking concrete paving stone features asymmetrical spacer means with a teardrop or aircraft wing-shaped profile, forming a vertical channel for interlocking, which ensures both vertical and horizontal blocking through continuous force distribution and sand placement, maintaining aesthetic linear continuity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional vertical spacers with point contact are used, then the structure is simple and easy to manufacture, but the locking reliability deteriorates due to spacer wear and sand migration over time

Engineering Contradiction:
Improvelocking reliabilityVSAvoidspacer structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spacer is designed with an asymmetric profile featuring a vertical portion and an inclined portion, rather than a symmetric shape. This asymmetric geometry creates a self-locking mechanism where the inclined surface prevents reverse movement and the vertical surface provides stable contact, thereby improving locking reliability without requiring complex additional components

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention transitions from point contact to line contact by extending the spacer contact surface along the height of the adjacent paving stone edge. This dimensional change from a point to a vertical line contact area distributes wear over a longer path and prevents sand migration, significantly enhancing long-term locking reliability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If spacers with decreasing cross-section are used, then the spacers can interlock, but the joint cannot close at the bedding level allowing sand to spill into the bedding layer

Engineering Contradiction:
Improveinterlocking effectivenessVSAvoidsand spillage into bedding
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The spacer profile combines a vertical portion and an inclined portion asymmetrically arranged, where the vertical portion maintains joint closure at the bedding level while the inclined portion provides the interlocking action. This asymmetric design simultaneously achieves both joint sealing and effective interlocking without sand spillage

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Instead of using a spacer that decreases in cross-section from base to top (which creates gaps), the invention uses a spacer with a vertical portion that maintains constant width, ensuring the joint remains closed at the bedding level while the inclined portion provides the locking mechanism in the upper section

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If spacers with line contact over entire height are used, then locking is improved, but resistance to vertical tearing and sagging remains insufficient

Engineering Contradiction:
Improveblocking effectivenessVSAvoidresistance to vertical forces
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The asymmetric spacer profile with its inclined portion creates a mechanical interlock that resists vertical tearing forces. The inclined surface acts as a wedge that converts vertical pull-out forces into lateral compression forces against the adjacent paving stone, significantly enhancing resistance to vertical tearing and sagging

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The inclined portion of the spacer creates a curved contact surface that distributes vertical loads more effectively compared to a purely vertical spacer. This curved geometry provides better load bearing capacity and resistance to vertical forces while maintaining the self-locking mechanism

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Reliability

If vertical recesses are provided for spacer interlocking, then self-locking is achieved, but aesthetic appearance deteriorates due to visible joints

Engineering Contradiction:
Improveself-locking capabilityVSAvoidjoint continuity aesthetics
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The invention eliminates the need for visible vertical recesses by integrating the locking mechanism into the spacer projection itself. The asymmetric spacer with its inclined portion creates the self-locking action without requiring corresponding recesses in the paving stone, thereby maintaining continuous linear joint appearance while achieving reliable self-locking

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3957794B1Self-locking concrete paving bloc
Publication Date: 2024.02.21 ETABLISSEMENTS HEINRICH BOCK ET CIE SPAS
  • EP3957794B1 patent drawingFigure 1~2
  • EP3957794B1 patent drawingFigure 3~4
  • EP3957794B1 patent drawingFigure 5~6

AI summary

The present invention relates to a self-locking concrete paving stone (1), provided on its longitudinal (2) and transverse (3) edges with spacers (4, 4') and spacers (5) arranged between the spacers (4, 4') and cooperating, by shape, with said spacers (4, 4') of the neighboring paving stones, during the interpenetration of the paving stones in the laying position. The said paving stone (1) is characterized in that the spacers (4, 4') are each made up of an asymmetrical section and mounted in pairs with vertical tabs with a polygonal base or in the shape of a half-teardrop, projecting from the edge of the paving stone (1) and whose apex is in the shape of a truncated pyramid or a portion of a truncated cone, and in that the said vertical tabs delimit between them a vertical recess of specific section and of reception of a corresponding spacer (5) projecting from the edge of the neighboring paving stone.