Self-Closing Sanitary Fitting with Ceramic Valve Discs

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Solution Overview

Problem

Self-closing sanitary fittings with ceramic valve disks face issues of high maintenance requirements, short service life, and hygiene problems due to stagnant water in counter-pressure chambers, which are not compatible with the conventional operation principle of self-closing fittings.

Innovation Solution

A self-closing sanitary fitting with a valve assembly featuring ceramic valve disks, a mechanically coupled linearly displaceable damper element, and a restoring element, which reduces frictional forces and pressure between the disks, and includes a pressure compensation surface to maintain constant forces independently of position and line pressure, along with a hydraulic damper for efficient closing and improved hygiene.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a self-closing fitting uses a counter-pressure chamber with elastic seal, then the valve can close automatically, but stagnant water in the chamber forms germs and causes hygiene problems

Engineering Contradiction:
Improveautomatic closing functionVSAvoidhygiene problems from stagnant water
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes the counter-pressure chamber entirely from the system. Instead of using a chamber that traps stagnant water, the invention employs a different mechanism (spring-loaded piston with ceramic disks) that achieves automatic closing without requiring a water-filled pressure chamber, thereby eliminating the hygiene problem while maintaining the self-closing function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a spring-loaded piston mechanism with ceramic sealing disks that operate through mechanical force rather than hydraulic pressure from stagnant water. The restoring force from the spring replaces the need for counter-pressure water, eliminating the hygiene issue while maintaining automatic closing capability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Reliability

If a self-closing fitting uses ceramic sealing disks with high pressing forces, then the valve ensures long service life and maintenance-free operation, but resetting the operating lever requires high restoring force and large user effort

Engineering Contradiction:
Improveservice life and maintenance-free operationVSAvoiduser effort to open and reset the fitting
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces a piston with variable pressing force against the ceramic disks. The pressing force is not constant but varies dynamically based on the piston position and spring compression. This allows the valve to maintain high sealing force when closed while requiring less force to open, as the piston can be pushed past the point of maximum spring resistance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses a spring-loaded piston that can be pushed beyond the point where the spring force is maximum. By applying slightly excessive force momentarily to overcome the spring compression, the valve opens easily, and then the spring provides continuous restoring force to close it automatically without requiring sustained high user effort.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If a single-lever mixer uses a hollow body actuating lever with self-closing device, then automatic closing is achieved, but the device complexity increases and compatibility with conventional self-closing fitting operation principle is lost

Engineering Contradiction:
Improveautomatic closing functionVSAvoidstructure complexity and operational compatibility
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the valve mechanism to work with a simple external actuator that can be operated in the conventional manner (pushing down to open). The complex spring-piston-ceramic disk mechanism is contained within the valve body itself, allowing the external interface to remain simple and compatible with standard self-closing fitting operation while achieving automatic closing through the internal mechanism.

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

4Ease of operation

If ceramic valve disks are used with smooth surfaces, then frictional forces are reduced, but the pressing forces required to keep the valve tight must be compensated

Engineering Contradiction:
Improvereduced frictional forcesVSAvoidpressing forces between valve disks
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The patent employs a spring-loaded piston that provides dynamic pressing force against the ceramic disks. The spring ensures continuous contact force to maintain sealing, while the smooth ceramic surfaces minimize friction. The system balances these by using the elastic recovery of the spring to maintain pressure without requiring excessive force, as the smooth surfaces reduce the friction component that would otherwise require even higher pressing forces.

Inventive Principle:
Principle #15Dynamics

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 reduces frictional forces and wear, allows for lower actuating forces, and enhances hygiene by eliminating stagnant water, resulting in a durable, reliable, and cost-effective self-closing fitting that meets higher hygiene standards.

Implementation Method 1

a self-closing device which consists of a damper filled with hydraulic oil and a return spring

Methodology Applied
Scientific EffectHydraulic damping: Viscous Damping

Implementation Method 2

a return spring, which automatically moves the mixer lever from an open position back to a closed position

Methodology Applied
Scientific EffectElastic restoring force: Elasticity

Implementation Method 3

Due to the smooth surfaces of ceramic components, the frictional forces acting between them are reduced

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2998623B1Self closing sanitary fitting with ceramic valve discs
Publication Date: 2018.04.11 KWC AQUAROTTER GMBH
  • EP2998623B1 patent drawingFigure 1
  • EP2998623B1 patent drawingFigure 2a~2d
  • EP2998623B1 patent drawingFigure 2e~3b

AI summary

A self-closing sanitary fitting is proposed, comprising a valve arrangement with ceramic valve discs. This arrangement includes a movable valve disc (23) that is axially displaceable and at least one static valve disc (21, 22). The movable valve disc is mechanically coupled to a linearly displaceable damper element of a damper via an axially acting actuating element (17). When the damper element is deflected from a starting position to an end position to open the sanitary fitting, and the valve disc is moved into an open position via the actuating element, the damper element automatically moves back to its starting position against the resistance of the damper due to the restoring force exerted by a return element, thereby returning the movable valve disc to the closed position via the actuating element.