Shadow Gap Guide Element for Door Rain Drainage

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Solution Overview

Problem

Existing external doors face challenges in maintaining impermeability to driving rain due to the shadow gap between the frame and the door leaf, especially with zero barrier designs, where water accumulation and capillary action lead to sealing failures, and the use of additional components like weatherboards and drainage systems results in soiling and reduced effectiveness over time.

Innovation Solution

A guide element is positioned at the lower end of the outer rebate seal in the shadow gap to direct water flow away from the door sill and into a drainage system, enhancing water drainage and reducing the risk of water penetration through the seal, which can be retrofitted to existing doors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a shadow gap is formed between the frame and door leaf, then accessibility and modern design are improved, but water penetration and sealing reliability deteriorate

Engineering Contradiction:
ImproveaccessibilityVSAvoidsealing reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The sealing system is divided into multiple independent sealing levels (first, second, and third sealing levels) positioned at different heights within the shadow gap. Each sealing level contains separate seals that can independently prevent water penetration, so if one seal fails or is overwhelmed, others remain effective. This segmentation transforms a single-point-of-failure system into a redundant multi-layer defense system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing approach transitions from a single horizontal sealing plane to a three-dimensional multi-level sealing structure. Seals are positioned at different vertical heights (first sealing level at top, second at middle, third at bottom of shadow gap), creating vertical dimensionality. This allows water to be blocked at multiple heights, preventing channeling effects that would compromise a single-level seal.

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

2Reliability

If additional sealing components like weatherboards and drainage systems are added, then water protection is improved, but device complexity and maintenance requirements increase

Engineering Contradiction:
Improvewater protectionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple sealing functions are merged into a single integrated shadow gap structure. The first, second, and third sealing levels are all positioned within the same shadow gap space between frame and door leaf, combining what would traditionally require separate weatherboards, thresholds, and drainage components into one unified system. This reduces overall device complexity while maintaining comprehensive water protection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The shadow gap structure serves multiple functions simultaneously: it provides the aesthetic and accessible gap space, contains three levels of water sealing, and integrates drainage pathways. The same structural space that enables modern design also houses the complete sealing system, eliminating the need for separate dedicated sealing components and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If a threshold is used to achieve driving rain tightness, then sealing performance is improved, but accessibility and zero barrier design are compromised

Engineering Contradiction:
Improvedriving rain tightnessVSAvoidaccessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sealing function is segmented across three vertical levels within the shadow gap rather than concentrated in a single threshold structure. The first sealing level at the top, second level in the middle, and third level at the bottom create distributed sealing points that prevent water channeling without requiring a physical threshold barrier, maintaining zero barrier accessibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing system transitions from a horizontal threshold barrier to a vertical multi-level sealing arrangement within the shadow gap. By positioning seals at different heights (vertical dimension) rather than relying on a horizontal threshold elevation, the system achieves driving rain tightness while maintaining floor-level accessibility and zero barrier design.

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

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 effectively minimizes water accumulation on the door sill, enhances the impermeability to driving rain, and reduces the risk of sealing failures, particularly in outward-opening doors with butt hinges, by ensuring controlled drainage and reducing the burden on the sill seal.

Implementation Method 1

A guide element is positioned at the lower end of the outer rebate seal in the shadow gap to direct water flow away from the door sill and into a drainage system

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

inner and outer stop seals made of elastic material being arranged between window frame profile and window frame profile

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3173568B1Door having improved shadow joint drainage
Publication Date: 2018.06.27 HEROAL JOHANN HENKENJOHANN GMBH & CO KG
  • EP3173568B1 patent drawingFigure 1
  • EP3173568B1 patent drawingFigure 2
  • EP3173568B1 patent drawingFigure 3A

AI summary

A door or window, particularly one with aluminum profiles, is shown and described, comprising a frame (1, 1') composed of individual frame profiles (2, 22) and a door leaf (3, 3') hinged to it, consisting of a continuous sash frame profile (4, 24). Inner and outer stop seals (9i, 9a) made of elastic material are arranged between the frame profile (2, 22) and the sash frame profile (4, 24), and a shadow gap (SF) is formed between the frame (1, 1') and the door leaf (3, 3'). To enable controlled drainage of surface water accumulating in the shadow gap (SF) and thus improve resistance to driving rain, at least one guide element (19A and 19B) acting as a sealing termination is arranged in the shadow gap (SF) at the respective lower end of the outer stop seal (9a).