Expandable Sealing Disk for Building Wall Cable Bushings

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Solution Overview

Problem

Conventional methods for sealing cable bushings in building walls are complex, involve long drying times, and suffer from shrinkage issues, while also requiring access to the building wall opening which is often restricted.

Innovation Solution

A cable bushing with a sealing disk that can reduce its external dimensions to pass through the wall opening and expand for sealing contact on the other side, using a free-flowing filling substance that hardens to secure the bushing and a flexible elastomeric shell that expands to ensure a permanent seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional mortar sealing is used, then sealing effectiveness is achieved, but the process becomes complex and requires long drying times

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddrying time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the physical state of the filling material from liquid mortar requiring drying to expandable foam that cures through chemical reaction. The foam transitions from a liquid state during injection to a solid expanded state, eliminating the need for long drying times while maintaining sealing effectiveness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical drying process of mortar with a chemical curing process of expandable foam. Instead of relying on evaporation and drying, the foam expands and cures through chemical reaction, significantly reducing the time required for the sealing process.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If conventional mortar sealing is used, then sealing is achieved, but the process requires formwork and becomes complex

Engineering Contradiction:
Improvesealing effectivenessVSAvoidformwork requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a flexible elastomeric bushing that can be inserted into the passage opening without formwork. The bushing's flexible nature allows it to conform to the opening and provide sealing, eliminating the need for complex formwork structures required by conventional mortar sealing.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent replaces the mechanical formwork system with a flexible elastomeric bushing that can be directly inserted and expanded. This substitution eliminates the complexity of assembling and removing formwork while achieving the same sealing effect.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If mortar is used for sealing, then sealing is achieved, but the mortar shrinks during drying causing imperfections

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddimensional stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the material from mortar that shrinks during drying to expandable foam that expands during curing. This parameter change in volume behavior prevents the shrinkage imperfections associated with mortar while maintaining or improving sealing effectiveness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent compensates for potential volume loss by using material that expands during curing. The expandable foam预先 compensates for any shrinkage by expanding to fill the space, ensuring dimensional stability and preventing gaps or imperfections in the sealing.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Reliability

If the sealing disk is enlarged for sealing contact, then sealing effectiveness is improved, but it cannot be passed through the wall opening from the accessible side

Engineering Contradiction:
Improvesealing effectivenessVSAvoidinstallation accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent makes the sealing disk dynamic by enabling it to change size. The sealing disk can be compressed to a smaller size for insertion through the wall opening from the accessible side, then expanded to its full size to provide effective sealing contact on the distal side. This dynamic size change resolves the contradiction between sealing effectiveness and installation accessibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses a nested structure where the sealing disk is contained within the bushing during insertion. The sealing disk is compressed and nested within the bushing's interior space, allowing it to pass through the wall opening. Once in position, the sealing disk expands outward to provide sealing contact, effectively nesting the sealing function within the installation pathway.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

This solution provides a permanent and effective seal with reduced complexity, accommodating restricted access and ensuring moisture prevention, even in porous or rough surfaces, by using a flexible material that expands to fit the passage opening and hardens for secure fastening.

Implementation Method 1

the Shell is made of an elastomeric material and is designed to be pressurized by the filler substance and thereby expanded

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2249070B1Lead through duct for a building wall
Publication Date: 2011.12.07 HAUFF TECHNIK GMBH & CO KG
  • EP2249070B1 patent drawingFigure 1
  • EP2249070B1 patent drawingFigure 2
  • EP2249070B1 patent drawingFigure 3

AI summary

The duct (14) has a pipe unit (19) provided for carrying a sealing disk (16) through an opening (4) in a building wall (1) from a proximal side to a distal side. Feed through sleeves e.g. pipe section (15), sealing disk, out cover (17) and end cap (18), are provided for surrounding a line (8). The sleeves are arranged in an inner side of the opening in the building wall, and are fixed proximal to the sealing disk. The sleeves are fastened in the opening, and a filling substance is strengthened through filling and non- filling of fluid in inner of the sleeves. An independent claim is also included for a method for fastening of a lead through duct.