Door Closer Overload Valve Geometry for Leak-Resistant Sealing

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Solution Overview

Problem

Existing door closers with overload valves often have complex designs that lead to potential malfunctions due to leaks, as simplified designs may not ensure reliable operation and sealing.

Innovation Solution

A door closer with structurally simple yet reliable overload valves featuring a locking body with an n-angular cross section (n ≥ 3) that allows precise positioning and movement within the valve channel, preventing 'Halo' issues and ensuring a reliable seal, using spherical or cylindrical locking bodies that can roll along the channel axis without lateral play, and a sealing seat design that maximizes outflow openings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the overload valve design is simplified, then the device complexity is reduced, but the reliability deteriorates due to potential malfunctions and leaks

Engineering Contradiction:
Improveoverload valve design complexityVSAvoidoverload valve reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The locking body is designed as a spherical element that rolls within the valve channel during operation. This spherical geometry enables reliable sealing through rolling contact while maintaining a simple overall structure. The curvature of the sphere allows it to conform to the sealing seat and maintain consistent contact pressure, resolving the contradiction between simplicity and reliability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The overload valve employs a dynamic rolling mechanism where the spherical locking body moves along the valve channel in response to pressure changes. This dynamic behavior allows the valve to automatically open under overload conditions and close under normal conditions, achieving reliable automatic protection without complex control systems.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If the locking body is designed to roll along the channel axis, then the positioning precision is improved, but the device complexity increases due to the n-cornered cross-section requirement

Engineering Contradiction:
Improvelocking body positioning precisionVSAvoidvalve channel cross-section complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The valve channel features an n-cornered cross-section (where n ≥ 3) that creates asymmetric contact surfaces. This asymmetric geometry provides multiple defined contact points for the spherical locking body, enabling precise positioning and rolling motion while preventing lateral play. The specific angular configuration of the corners creates natural alignment features that improve positioning precision.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The solution transitions from a simple circular cross-section to an n-cornered cross-section, adding geometric complexity in the transverse dimension. This dimensional change creates multiple contact surfaces that constrain the spherical locking body's motion, enabling precise positioning and rolling while maintaining a relatively simple overall valve structure.

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

3Reliability

If the locking body is dimensioned for orthogonal guidance without lateral play, then the sealing reliability is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvesealing reliabilityVSAvoidlocking body dimensional precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The spherical locking body's curved geometry naturally accommodates small manufacturing variations while maintaining consistent contact with the n-cornered valve channel walls. The sphere's ability to roll and conform to the contact surfaces provides self-alignment, reducing the impact of manufacturing tolerances on sealing reliability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The spherical locking body automatically centers itself within the n-cornered valve channel through rolling contact. This self-centering mechanism compensates for manufacturing variations, as the sphere naturally finds its equilibrium position where it contacts all relevant surfaces, ensuring reliable sealing without requiring extremely tight manufacturing tolerances.

Inventive Principle:
Principle #25Self-service

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 solution provides a reliable and leak-resistant operation of the door closer, ensuring efficient fluid flow and preventing damage from overload situations by maintaining a centered locking body on the sealing seat, thus enhancing the door closer's functionality and longevity.

Implementation Method 1

The locking body is particularly adapted to the locking body receiving section in such a way that the locking body can move in the valve channel along the locking body section, in particular, can roll along the channel axis

Methodology Applied
Scientific EffectRolling: Roller

Implementation Method 2

The locking body is received in a locking body receiving section in the valve channel and, when the overload valve is closed, rests against the sealing seat, in particular in a sealing manner

Methodology Applied
Scientific EffectMechanical sealing: Valve

Implementation Method 3

The door closer comprises a closer shaft and a cam disk connected to the closer shaft in a rotationally fixed manner. The cam disk interacts, in particular via a drive contour, with a drive device comprising a drive piston and, in particular via a damping contour, with a damping device comprising a damping piston

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP4180608B1Door closer
Publication Date: 2024.03.13 GRETSCH UNITAS GMBH BAUBESCHLAGFABRIK
  • EP4180608B1 patent drawingFigure 1
  • EP4180608B1 patent drawingFigure 2a~2d
  • EP4180608B1 patent drawingFigure 3a~3d

AI summary

The invention relates to a door closer (10) for actuating a leaf of a door, window or the like, with a closer shaft (20) and a cam disk (26) connected to the closer shaft (20) in a rotationally fixed manner, wherein the cam disk (26) interacts with a drive unit (38) with a drive piston (40) and with a damping unit (60) with a damping piston (62), wherein the drive piston (40) and/or the damping piston (62) each have an overload valve (84, 116) respectively.The overload valve (84, 116) has a valve channel (88, 120) extending along a channel axis (86, 118), a locking element (90, 122) and a sealing seat (91, 124), wherein the locking element (90, 122) is received in a locking element receiving section (92, 128) in the valve channel (88, 120) and bears against the sealing seat (91, 124) when the overload valve (84, 116) is closed, wherein the valve channel (88, 120) has an n-sided cross-section with n ≥ 3 at least in the locking element receiving section (92, 128), preferably along the entire valve channel (88, 120), and wherein the locking element (90, 122) is spherical or cylindrical.