Compact Thermostatic Faucet Valve Layout for Single-Lever Control

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Solution Overview

Problem

Commercially available thermostatic mixing valves are difficult to integrate into compact and visually appealing washbasin faucet designs due to their size and complex water-guiding requirements, limiting the availability of thermostatic washbasin faucets on the market.

Innovation Solution

A mixed water fitting with a thermostatic mixing valve and an adjusting valve arranged one behind the other in a compact housing, allowing for spatial separation and movement, enabled by a screw drive and compressible overload protection, facilitating a compact and user-friendly design with a single-lever operation mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If standard thermostatic mixing valves are used, then temperature regulation function is achieved, but the device size becomes too large for compact faucet design

Engineering Contradiction:
Improvetemperature regulationVSAvoidvalve size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent integrates the thermostatic mixing valve and shut-off valve into a single cartridge assembly where one valve is nested within or alongside the other. The shut-off valve with ceramic discs is positioned upstream, and the thermostatic mixing valve is positioned downstream, sharing a common cartridge housing. This nesting approach allows both valves to occupy overlapping or adjacent spatial volumes, significantly reducing the overall size compared to separate valve installations.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent merges two separate valve functions (shut-off and thermostatic mixing) into a single integrated cartridge assembly. The water flow path is designed so that water flows through the shut-off valve first, then directly into the thermostatic mixing valve within the same cartridge. This combining of functions into one unified component reduces the number of separate parts and overall device volume while maintaining both temperature regulation and flow control capabilities.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If separate shut-off valve and thermostatic mixing valve are used, then each valve can be optimized independently, but the overall device complexity increases

Engineering Contradiction:
Improvevalve performanceVSAvoidcartridge assembly
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The integrated cartridge is segmented into distinct functional zones: an upstream shut-off valve section with ceramic discs for flow control, and a downstream thermostatic mixing section with temperature regulation components. Each segment maintains its independent optimization while being housed within a single cartridge. The segmentation allows each valve to perform its specific function reliably without interference from the other, while the unified housing reduces overall complexity compared to two separate assemblies.

Inventive Principle:
Principle #1Segmentation

3Reliability

If complex water flow elements are used to keep hot and cold water separate, then proper water separation is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improvewater separationVSAvoidgeometric complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the water separation function into dedicated flow channels and sealing elements within the cartridge. The shut-off valve section includes specific geometric features and sealing surfaces that keep hot and cold water streams separate as they flow through the cartridge. By designing these separation features as integral parts of the cartridge geometry rather than separate complex components, the manufacturing process is simplified while maintaining reliable water separation throughout the valve assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

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 enables a visually appealing and compact thermostatic mixing system for washbasin faucets, improving user operability and allowing for easy industrial-scale production, with the ability to integrate different shut-off valves and operating concepts.

Implementation Method 1

a thermostatic mixing valve (3) for regulating the mixed water temperature

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

A mixed water fitting (1) with a thermostatic mixing valve (3) and an adjusting valve (4) arranged one behind the other in a compact housing (2), allowing for spatial separation and movement, enabled by a screw drive

Methodology Applied
Scientific EffectScrew mechanism: Screw

Data Source

PatentEP3859483B1Mixed water fitting with compact thermostatic valve
Publication Date: 2022.12.21 GROHE AG
  • EP3859483B1 patent drawingFigure 1
  • EP3859483B1 patent drawingFigure 2
  • EP3859483B1 patent drawingFigure 3

AI summary

The invention relates to a mixed water fitting (1) with a fitting housing (2), a thermostatic mixing valve (3) for regulating the mixed water temperature, an adjusting valve (4) for adjusting a flow rate through the mixed water fitting (1), and at least one manual actuating element (5) for selective, mechanical actuation of the mixing valve (3) and the adjusting valve (4), wherein the mixing valve (3) and the adjusting valve (4) are arranged one behind the other in the fitting housing (2) and are fluidically connected to each other in such a way that water flowing through the mixed water fitting (1) flows through the mixing valve (3) upstream of the adjusting valve (4) and wherein the mixing valve (3) and the adjusting valve (4) are spatially separated from each other and movable relative to each other.