Damper Seal Structure for Controlled Overload Pressure Relief

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Solution Overview

Problem

Existing dampers for furniture fittings suffer from limited application range due to issues with sealing element material properties and manufacturing tolerances, leading to premature or delayed opening of overload ports and potential damper rupture under excessive pressure.

Innovation Solution

A damper design featuring a sealing element with a movable, pivotable, and radially expandable second section that opens an overload channel above a predetermined pressure threshold, allowing controlled fluid flow to relieve pressure and prevent rupture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sealing element material is made softer to ensure sufficient contact with the inner wall, then sealing reliability is improved, but the overload port opens too quickly causing premature pressure release

Engineering Contradiction:
Improvesealing reliabilityVSAvoidpressure release timing
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The sealing element is divided into a first section for sealing contact and a second section for overload port control. This segmentation allows each section to be optimized independently: the first section maintains reliable sealing contact while the second section's geometry controls the precise timing of overload port opening based on pressure thresholds.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the sealing element have different functional properties. The first section has properties optimized for sealing (softer material or specific geometry for contact), while the second section has properties optimized for controlled deformation at specific pressure points to open the overload port at the correct timing.

Inventive Principle:
Principle #3Local quality

2Stress or pressure

If the sealing element material is made harder to delay overload port opening, then pressure maintenance is improved, but sealing contact becomes insufficient reducing reliability

Engineering Contradiction:
Improvepressure maintenanceVSAvoidsealing reliability
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The sealing element is divided into a first section for sealing contact and a second section for overload port control. This segmentation allows each section to be optimized independently: the first section maintains reliable sealing contact while the second section's geometry controls the precise timing of overload port opening based on pressure thresholds.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The geometry and material properties of different sections are independently optimized. The first section uses parameters optimized for sealing contact, while the second section uses parameters optimized for deformation at specific pressure thresholds, allowing pressure maintenance without compromising sealing reliability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the sealing element is designed for a specific application, then performance for that application is optimized, but the damper's range of applications is limited

Engineering Contradiction:
Improveapplication-specific performanceVSAvoidrange of applications
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The two-section sealing element design provides a universal solution that can adapt to different applications. By adjusting the geometry, material properties, and dimensions of the first and second sections, the same basic design principle can be optimized for various pressure thresholds, flow rates, and sealing requirements across multiple applications.

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

Solution Approach 2:

The sealing element incorporates dynamic deformation characteristics where the second section responds to pressure changes by deforming to open the overload port. This dynamic behavior allows the same design to adapt to different operating conditions and applications by modifying geometric parameters rather than requiring fundamentally different designs.

Inventive Principle:
Principle #15Dynamics

4Manufacturing precision

If manufacturing tolerances are reduced to improve precision, then overload port timing is more accurate, but manufacturing cost and complexity increase

Engineering Contradiction:
Improveoverload port timing accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The design uses geometric parameters of the second section (such as thickness, curvature, or positioning) that can be adjusted to compensate for manufacturing tolerances in other components. This allows accurate overload port timing to be achieved through parameter optimization rather than requiring extremely tight tolerances across all manufactured parts.

Inventive Principle:
Principle #35Parameter changes

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

The design effectively manages excessive pressure by allowing controlled fluid flow, preventing damper rupture and ensuring smooth operation across a wider range of applications.

Implementation Method 1

The damping effect of a damper is generated by the flow resistance of a damping fluid located in a damper housing. When pressurized, the piston is moved within the fluid chamber, whereby the damping fluid flows from the high-pressure side to the low-pressure side through piston openings and/or through a gap formed between the piston and an inner wall of the fluid chamber

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 2

As the pressure increases, the sealing element expands radially, reducing the annular gap and thus increasing the flow resistance for the piston

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

If the piston is subjected to excessive pressure, for example due to misuse, a phenomenon known as damper bounce can occur. In such an overload situation, the damping fluid can no longer flow sufficiently through or around the piston. The increased pressure can then no longer be relieved by the damper, causing the piston and the attached piston rod to stop abruptly or rebound

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP4448907B1Damper for a fitting for the movable mounting of a pivoting element or a pull-out element
Publication Date: 2026.04.08 JULIUS BLUM GMBH
  • EP4448907B1 patent drawingFigure 1
  • EP4448907B1 patent drawingFigure 2a~2b
  • EP4448907B1 patent drawingFigure 3a~3c

AI summary

The invention relates to a damper (9) for a fitting (4) for movably mounting a pivoting element (3) or a pull-out element, in particular for movably mounting a furniture part (3a), a window, or a door, relative to a stationary support (2), comprising: a damper housing (10), at least one fluid chamber (25) which is arranged in the damper housing (10), a damping fluid which is arranged in the fluid chamber (25), at least one piston (17) which is movably mounted in the fluid chamber (25), and at least one seal element (18), preferably an annular seal element, which has at least one first section (18a) that rests or can rest against an inner wall (10a) of the fluid chamber (25), said at least one seal element (18) having at least one second section (18b), preferably a substantially annular second section, which is arranged at a distance to the inner wall (10a) of the fluid chamber (25) and which can be moved, preferably pivoted, tilted, and/or radially extended, relative to the first section (18a) that rests or can rest against the inner wall (10a) of the fluid chamber (25) when a damping stroke is carried out above a specified threshold of a pressure applied to the piston (17).