Coffee Grounds Metering Using Volume Feedback for Grind Control

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Solution Overview

Problem

Fully automatic coffee machines face challenges in maintaining consistent brewing quality over their service life due to gradual deviations in coffee powder quantity and grinding quality, leading to potential machine damage or clogging, and variations in coffee taste caused by changes in grinding behavior with different coffee types.

Innovation Solution

The method involves determining the actual degree of grinding by measuring the volume of freshly ground coffee powder before and after brewing, using the difference in volume to adjust the grinding parameters, ensuring precise control and consistent quality without relying on factory settings or indirect measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the degree of grinding is determined indirectly from throughput time or factory settings, then the device complexity is reduced, but the measurement precision and manufacturing precision deteriorate

Engineering Contradiction:
Improvecomplexity of grinding determination systemVSAvoidprecision of degree of grinding measurement
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces indirect mechanical measurement methods (throughput time) with direct physical parameter measurement (volume of coffee powder). By measuring the actual volume of ground coffee powder in the brewing chamber, the system achieves precise determination of the degree of grinding without complex mechanical sensing systems, thus maintaining low device complexity while improving measurement precision.

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

Solution Approach 2:

The patent uses the volume of coffee powder as a proxy indicator (copy) for the degree of grinding. Instead of directly measuring grinding characteristics, it measures the resulting volume of ground coffee, which correlates with the degree of grinding. This indirect but accurate measurement approach resolves the contradiction between simplicity and precision.

Inventive Principle:
Principle #26Copying

2Ease of operation

If the coffee powder quantity is not precisely controlled, then the ease of operation is improved, but the reliability deteriorates due to overfilling or underfilling

Engineering Contradiction:
Improvesimplicity of coffee dosingVSAvoidconsistency of coffee powder quantity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the volume of coffee powder is measured and compared against target values. The system automatically adjusts grinding parameters based on this feedback to maintain consistent coffee powder quantity and degree of grinding, ensuring reliable operation without requiring manual intervention or complex user operations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of grinding parameters based on volume measurements, eliminating the need for manual calibration or intervention. The coffee machine automatically compensates for variations in coffee bean properties, grinder wear, and dosing inconsistencies, maintaining reliable operation through self-service adjustment.

Inventive Principle:
Principle #25Self-service

3Device complexity

If the degree of grinding is not adjusted for aging processes, then the device complexity is reduced, but the manufacturing precision deteriorates over service life

Engineering Contradiction:
Improvecomplexity of aging compensation systemVSAvoidconsistency of grinding quality over time
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent implements dynamic adjustment of grinding parameters based on real-time volume measurements. Instead of static factory settings, the system continuously adapts grinding time and intensity to compensate for aging effects such as grinder wear and coffee bean property variations, maintaining consistent manufacturing precision throughout the service life without requiring complex predictive models.

Inventive Principle:
Principle #15Dynamics

4Ease of manufacture

If the volume measurement is used instead of weight measurement, then the ease of manufacture is improved, but the measurement precision could deteriorate

Engineering Contradiction:
Improvesimplicity of volume detection systemVSAvoidprecision of coffee powder measurement
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent changes the measurement parameter from weight to volume, which is more easily measured using simple level sensors or displacement measurements in the brewing chamber. By measuring the volume of ground coffee powder at a known density state (compacted or loose), the system achieves adequate measurement precision for controlling coffee dosing without requiring complex weight measurement systems, thus improving ease of manufacture while maintaining sufficient precision.

Inventive Principle:
Principle #35Parameter changes

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 approach allows for precise adjustment of grinding parameters, maintaining consistent brewing quality and reducing the risk of overfilling or underfilling, thus preventing machine damage and ensuring a consistent taste across the coffee machine's lifespan.

Implementation Method 1

the brewing chamber is closed by driving an electric actuator and the coffee powder is compressed in the process

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

The volume can be determined by determining the piston position in the brewing chamber, which is known in terms of its dimensions and thus its volume

Methodology Applied
Scientific EffectVolume displacement measurement: Displacement

Data Source

PatentEP2654530B1Method for metering coffee grounds
Publication Date: 2015.12.09 BSH HAUSGERATE GMBH
  • EP2654530B1 patent drawingFigure 1
  • EP2654530B1 patent drawingFigure 2

AI summary

The invention relates to a method for operating a fully automatic coffee machine in order to ensure a uniform brewing quality during the service life thereof by determining a grind level by capturing physical characteristic values about the ground coffee, in that a characteristic value of an amount of ground coffee is detected before and after infusing preparation water and a parameter for determining the grind level of a subsequent brewing process is determined therefrom.