Regulating Valve Anti-rotation Groove for Hydraulic Door Closers

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Solution Overview

Problem

Existing control valves for hydraulic door closers often experience unintentional adjustment due to dynamic loads, leading to unreliable closing behavior and potential self-loosening issues.

Innovation Solution

A control valve design featuring an anti-twist device with a groove and an elastic element that fills the space between the internal thread and the valve thread, preventing rotation and ensuring a secure clamping effect, allowing for manual adjustment while preventing self-loosening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional thread connection is used to attach the regulating valve to the door closer, then the valve can be adjusted manually, but the dynamic loads cause unintentional rotation and self-loosening

Engineering Contradiction:
Improvemanual adjustabilityVSAvoidresistance to unintentional adjustment
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

An elastic element is introduced as an intermediary between the groove in the thread and the external environment. This elastic element fills the groove and creates frictional resistance that prevents unintentional rotation while allowing intentional manual adjustment when force is applied. The elastic element acts as a mediator that provides both locking function and adjustment capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The groove is pre-formed in the thread structure during manufacturing, and the elastic element is pre-positioned within this groove before the valve is installed. This preliminary preparation ensures that the anti-rotation mechanism is already in place and functional before the valve encounters dynamic loads during operation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the elastic element is pressed into the groove to create high surface pressure, then the clamping effect prevents independent rotation, but the assembly process becomes more complex

Engineering Contradiction:
Improveprevention of independent rotationVSAvoidassembly process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The elastic element is designed to be self-retaining within the groove through its elastic properties. When pressed into the groove, it deforms and creates frictional forces that hold it in place without requiring additional locking mechanisms or complex assembly steps. The elastic element serves itself by using its own material properties to maintain its position and provide the clamping effect.

Inventive Principle:
Principle #25Self-service

3Stress or pressure

If the groove is filled completely by the elastic element, then high surface pressure is generated between thread flanks, but the groove design becomes more critical

Engineering Contradiction:
Improvesurface pressure between thread flanksVSAvoidgroove design requirements
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The elastic element's material properties (elastic modulus, Poisson's ratio) and geometric parameters (cross-sectional area, length) are optimized to achieve the desired surface pressure in the groove. By carefully selecting these parameters, the design achieves high clamping force while maintaining a simple groove geometry that is easy to manufacture. The parameters are tuned so that the elastic element fills the groove effectively without requiring complex groove shapes.

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 anti-twist device effectively prevents unintentional adjustment and self-loosening, ensuring reliable door closer operation and maintaining defined closing behavior under dynamic loads.

Implementation Method 1

The anti-rotation device has at least one groove (6a) arranged on the thread (7) and accommodating an elastic element (6b). When the regulating valve (1) is screwed in, the elastic element (6b) is located within the groove (6a) and rests directly against the internal thread (2) of the door closer's bore, creating a clamping effect.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

This generates high surface pressure, especially between the thread flanks of the internal thread and the regulating valve. It has been shown that this arrangement prevents the interlocking threaded parts from rotating independently.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2134992B2Regulating valve
Publication Date: 2019.08.14 DORMA GMBH & CO KG
  • EP2134992B2 patent drawingFigure 1~2
  • EP2134992B2 patent drawingFigure 3~4

AI summary

The invention relates to a regulating valve (1) that can be fixed especially in a borehole (3) of a hydraulic door closer, comprising an internal thread (2), said valve having a base body (4), a regulating region (5), an anti-rotation element, and a thread (7) that can be arranged in the internal thread (2) of the borehole (3). The invention is characterised in that the anti-rotation element comprises at least one groove (6a) which is arranged on the thread (7) and receives an elastic element (6b).