Thermostatic Mixing Cartridge Layout for Reduced Installation Height

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Solution Overview

Problem

Mixer tap cartridges with thermostatic elements have a large overall height, making them difficult to assemble and operate in tight spaces, and are not visually appealing, due to the constant depth of the compensating space in the axially adjustable stop.

Innovation Solution

The design includes a compensating space within the adjustment space for the stop, which decreases with rising temperature, allowing the stop to move relative to both the housing and temperature setting member, with an internal thread in the housing and a non-rotatably adjustable stop, and a two-part stop braced by a compression spring to absorb length fluctuations of the thermostatic element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the compensating space is located in the axially adjustable stop with constant depth, then the thermostatic element is protected from damage during temperature fluctuations, but the overall height of the cartridge increases

Engineering Contradiction:
Improveprotection of thermostatic elementVSAvoidoverall height of cartridge
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent relocates the compensating space from the axially adjustable stop to the receiving space of the thermostatic element itself. The compensating space is formed within the receiving space by a stop that defines a compensation chamber, allowing the thermostatic element to expand and contract axially within this chamber. This nesting approach eliminates the need for additional axial space in the stop, thereby reducing the overall cartridge height while maintaining protection functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention changes the spatial arrangement by moving the compensating space from a separate axial location in the stop to an integrated location within the receiving space. The stop is positioned such that its compensation chamber is axially aligned with the thermostatic element's path, allowing compensation to occur within the existing axial envelope rather than adding to it.

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

2Adaptability or versatility

If the stop is axially adjustable to control mixing ratio, then temperature control is achieved, but the device complexity increases

Engineering Contradiction:
Improvetemperature controlVSAvoidstructure of stop and adjusting element
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the compensation function and the height-adjustment function into a single integrated stop structure. The stop serves dual purposes: it defines the compensation chamber for thermostatic element movement and simultaneously acts as the height-adjustable component controlled by the adjusting element. This merging eliminates the need for separate compensation mechanisms and simplifies the overall structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stop is designed as a multi-functional component that simultaneously provides mechanical support, defines the compensation chamber volume, and serves as the adjustment reference for the thermostatic element. The receiving space is also multi-functional, serving both as the mounting location for the thermostatic element and as the container for the compensating space.

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

This configuration reduces the overall height of the mixer tap cartridge, allowing easier assembly and operation in confined spaces while maintaining temperature control, as the thermostatic element's length variations are compensated within the adjustment space, ensuring efficient mixing ratio adjustments.

Implementation Method 1

the thermostatic element only undergoes changes in length due to temperature changes, and therefore, upon contact with hot water, reaches the end of its maximum expansion length at a specific temperature

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the stop comprises two movable parts that are tensioned against each other by a compression spring

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3722915B1Mixing battery cartridge
Publication Date: 2022.06.15 GUSTAV SCHMIEDL ARMATURENFAB GES & KOMMANDITGES
  • EP3722915B1 patent drawingFigure 1
  • EP3722915B1 patent drawingFigure 2
  • EP3722915B1 patent drawingFigure 3

AI summary

A mixing valve cartridge with a housing (1) in which a length-variable thermostatic element (10) is provided, with a rotatable adjusting element (21) for the temperature of the outgoing mixed water, wherein the rotation of the adjusting element (21) axially adjusts a stop (13) to adapt the receiving space of the thermostatic element (10) to the length corresponding to the selected temperature of the mixed water, wherein the axially adjustable stop (13) is rotatably arranged with the adjusting element (21).