Diaphragm Valve End Stop Geometry for Lower Breakaway Torque

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing diaphragm valves require significant force to actuate and loosen, leading to potential mechanical overload and incorrect direction turning, which reduces stability and increases the risk of damage.

Innovation Solution

A diaphragm valve design featuring a radially outward stop on the threaded spindle and a radially inward counter-stop on the spindle nut, with inclined stop surfaces and tangential surface normals, reduces breakaway force and torque, and includes an overload protection mechanism with asymmetrical axial gearing to ensure safe and easy handling and high stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the end stop is formed by two opposing stop surfaces on the threaded spindle and spindle nut, then the valve element is protected from damage and stability is increased, but a considerable force is required to release the stop surfaces which reduces ease of handling

Engineering Contradiction:
ImprovestabilityVSAvoidease of handling
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The stop mechanism is segmented into two distinct components: a radially outward-pointing stop on the threaded spindle and a radially inward-pointing counter-stop on the spindle nut. This segmentation allows the stop surfaces to be separated in the radial direction, creating a gap that reduces the contact area and consequently the breakaway force required to actuate the valve.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stop surfaces are oriented radially rather than axially. By transitioning from an axial stop configuration to a radial stop configuration, the patent creates a dimensional change that allows the stop surfaces to be offset in the radial direction. This radial offset reduces the mechanical interlocking effect and lowers the breakaway torque required to overcome the end stop.

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

2Reliability

If a considerable force is required to actuate the valve from its end position, then the valve element is securely stopped, but the user may turn it in the wrong direction leading to mechanical overload and reduced stability

Engineering Contradiction:
ImprovestabilityVSAvoidrisk of mechanical overload
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The segmented radial stop configuration reduces the contact pressure between the stop surfaces by distributing the stopping force over a larger radial offset distance. This segmentation prevents concentration of stress at a single point, thereby reducing the risk of mechanical overload and tooth damage while maintaining effective stroke limitation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the geometric parameters of the stop mechanism by introducing a radial offset between the stop surfaces. This parameter change reduces the normal force required to maintain the stop position, thereby lowering the breakaway torque and preventing users from applying excessive force that could cause mechanical overload.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the stop surfaces are designed to provide a robust mechanical stop, then the valve element is protected, but the breakaway force or breakaway torque increases making handling difficult

Engineering Contradiction:
Improveprotection of valve elementVSAvoidbreakaway force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

By transitioning from axial stop surfaces to radial stop surfaces with a radial offset, the patent changes the dimensional orientation of the stopping mechanism. This radial configuration allows the stop surfaces to engage at a point offset from the spindle axis, creating a lever arm effect that reduces the breakaway torque required while maintaining effective stopping protection.

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

The design facilitates easy and correct actuation of the valve, reduces the risk of mechanical overload, and enhances the stability and service life by providing consistent handling conditions and preventing damage to the valve components.

Implementation Method 1

a first gear unit with a threaded spindle, a spindle nut

Methodology Applied
Scientific EffectThreading: Screw

Implementation Method 2

at least one spring element. This spring element presses the first, axially displaceable gear wheel against the second gear wheel

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3763969B1Valve
Publication Date: 2023.08.23 PRAHER KUNST GMBH

AI summary

A valve (1), in particular a diaphragm valve, is shown, comprising a valve element (2) and an actuating device (3) connected to the valve element (2) for its actuation. The actuating device (3) has a drive (4), in particular a manual drive (4.1), and a first gear unit (5) connected to the drive (4). This first gear unit (5) comprises a threaded spindle (6), a spindle nut (7), and an end stop (8), which end stop (8) is formed by at least two opposing stop surfaces (8.1, 8.2) of the threaded spindle (6) and the spindle nut (7). To ensure safe handling and a long service life, it is proposed that the threaded spindle (6) forms a radially outwardly projecting stop (6.1) with the first stop surface (8.1), and that the spindle nut (7) forms a radially inwardly projecting counter-stop (7.2) with the second stop surface (8.2), wherein, in the case of overlapping stop surfaces (8.1, 8.2),2) in the end stop (8) the opposing end faces (6.2, 7.2) of threaded spindle (6) and spindle nut (7) are relative to each other without contact.