Mixer Tap Mixing Unit Using Shape-Memory Alloy Shutter Actuation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing mixing units for mixer taps require complex manufacturing processes and know-how for thermostatic modules, making them difficult to produce and maintain effectively.

Innovation Solution

A simplified mixing unit design featuring a shape memory alloy actuating element that adjusts the shutter position based on temperature, allowing for reliable and durable operation without the need for complex thermostatic modules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thermostatic module with a cup containing thermodilatable wax is used to automatically limit the temperature of the mixed flow, then the temperature control reliability is improved, but the manufacturing complexity and expertise required increase

Engineering Contradiction:
Improvetemperature control reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the essential thermostatic function from the complex cup-wax-plunger-shutter mechanism and implements it through a simplified actuating element that directly responds to temperature changes. This removes unnecessary intermediate components while preserving the core temperature limitation function, thereby maintaining reliability while reducing manufacturing complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical thermostatic system (cup, wax, plunger, shutter) with a different mechanical approach using an actuating element that directly couples temperature sensing with flow control. This substitution eliminates the need for complex mechanical transformations while achieving the same temperature control objective with simpler manufacturing requirements

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a separate additional housing with thermostatic module is attached to the cartridge, then the temperature control function is improved, but the device assembly complexity increases

Engineering Contradiction:
Improvetemperature control functionVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the thermostatic temperature control function directly into the cartridge structure, eliminating the need for a separate additional housing. The actuating element is integrated within the cartridge, combining the mixing and temperature control functions into a single unified component, thereby reducing assembly complexity while maintaining temperature control reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cartridge is designed to perform multiple functions: mixing hot and cold water flows and simultaneously controlling the temperature of the mixed flow. The actuating element provides thermostatic control as an integral part of the mixing unit, making the cartridge a multi-functional component that eliminates the need for separate temperature control modules

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

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 provides a reliable and efficient mixing unit that is easy to manufacture and maintain, ensuring consistent temperature control of the mixed water flow while reducing production complexity.

Implementation Method 1

The actuating element is made of a shape memory alloy and is configured to change its shape under the combined effect of the spring and of the temperature to which the actuating element is subjected

Methodology Applied
Scientific EffectShape memory alloy: Shape Memory Alloy

Data Source

PatentEP3715996B1Mixing unit and mixer tap comprising such a mixing unit
Publication Date: 2021.12.29 VERNET SA
  • EP3715996B1 patent drawingFigure 1
  • EP3715996B1 patent drawingFigure 2~3
  • EP3715996B1 patent drawingFigure 4

AI summary

This mixing unit for a mixer tap comprises a first inlet for a first incoming flow of fluid, a second inlet (50) for a second incoming flow (C1) of fluid having a temperature (Tc) higher than that of the first incoming flow, means for mixing the incoming flows to form an outgoing flow (M1) having an outlet temperature (Tm), an outlet (52) for the outgoing flow, a shutter (72) that is movable between an open position of the second inlet and a closed position of the second inlet, and an actuating element (106) for the shutter, which is disposed at least partially at the outlet so as to deform, depending on the outlet temperature, between a first shape, to move the shutter to the open position, and a second shape, to move the shutter to the closed position. According to the invention, the actuating element is made of a shape-memory alloy.