Single-Lever Thermostatic Mixing Valve With Cold-Water Priority

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Solution Overview

Problem

Current thermostatic mixing valves require two control levers for adjusting water flow and temperature, limiting the minimum temperature of delivered water, making it unsuitable for drinking, and existing single-lever designs do not prioritize cold water opening.

Innovation Solution

A single-control thermostatic mixing valve with a single rotary lever that prioritizes cold water opening, featuring a control rod with axial splines, a radial screw, and an insulating jacket to regulate temperature, allowing gradual heating to a predetermined temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a single-control thermostatic mixer is used, then the ease of operation is improved, but the ability to prioritize cold water opening and control temperature progression is worsened

Engineering Contradiction:
Improveease of operationVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The valve carrier is divided into two functional sides: a first side with a first valve for cold water and a second side with a second valve for hot water. This segmentation allows the single control rod to independently regulate each water supply, enabling cold water priority opening while maintaining simple single-lever operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control rod is designed to initially open the cold water valve before hot water flow is activated. This preliminary action ensures cold water priority, and as the user continues rotating the lever, hot water gradually mixes in to achieve the desired temperature progression.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If conventional mixer taps with two handles are used, then the temperature control precision is improved, but the device complexity and ease of operation are worsened

Engineering Contradiction:
Improvetemperature control precisionVSAvoidease of operation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent merges the functions of two separate control handles into a single control rod that actuates both the cold water valve and hot water valve simultaneously. This integration maintains precise temperature control through the thermostatic element while simplifying user interaction to a single lever operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A thermostatic element senses the mixed water temperature and automatically adjusts the valve positions to maintain the desired temperature. This feedback mechanism ensures precise temperature control without requiring the user to manually coordinate two handles.

Inventive Principle:
Principle #23Feedback

3Productivity

If simultaneous hot and cold water supply is used, then the productivity is improved, but the minimum temperature of delivered water is worsened

Engineering Contradiction:
ImproveproductivityVSAvoidminimum temperature of delivered water
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The control rod is designed to initially open the cold water valve before hot water flow is activated. This preliminary action ensures cold water priority opening, allowing the user to receive cold water immediately when turning on the tap, and then progressively heat it by continuing to rotate the lever.

Inventive Principle:
Principle #10Preliminary action

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

Enables safe and efficient temperature control with a single lever, ensuring the water starts as cold and heats progressively, reducing the risk of burns and providing a suitable drinking temperature.

Implementation Method 1

an insulating sleeve can be placed inside the body between the inner bottom of the body and a shoulder provided in the middle part of the cartridge casing, just above the hot water inlet passage, in this way the contact of the hot water with the tap body will be considerably reduced

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Implementation Method 2

a sensitive element (27) which acts on the main valve (20) in order to regulate the temperature of the mixed water

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2557340B1Thermostatic one handle mixing valve for prioritary aperture of cold water and then for the distribution of mixed water to a given temperature
Publication Date: 2023.07.19 DELABIE
  • EP2557340B1 patent drawingFigure 1
  • EP2557340B1 patent drawingFigure 2
  • EP2557340B1 patent drawingFigure 3~3B

AI summary

The valve has a body (1) provided with a cold water supply (2), a hot water supply (3), and a water outlet (4). A control lever (5) cooperates with a control rod (6) arranged axially in a head body (9), where a spacer (18) is placed between a lower face of the head body and an upper face of a seat (17). A plug (20) stops flow of mixed water through the spacer, where mixed water is obtained by opening a cold water inlet (17a) with the support of a spring, and progressively opening a hot water inlet (17b).