Torque-Controlled Brewing Unit for Consistent Coffee Compaction

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Solution Overview

Problem

Existing coffee machines with brewing units that allow flexible dosing of ground coffee face issues with inconsistent coffee quality due to varying degrees of coffee powder compaction and difficulty in cleaning, which affects the taste and aroma of the coffee.

Innovation Solution

A brewing unit with a torque-controlled compression piston and a sleeve cylinder system that allows precise adjustment of coffee powder compaction, combined with a sealing plug to prevent contamination and a heating device for optimal water temperature, ensuring consistent coffee quality and easy cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a compression piston is used to compact coffee grounds in the brewing unit, then the degree of compaction can be adjusted, but the compaction varies depending on coffee grind size leading to inconsistent coffee quality

Engineering Contradiction:
Improvecoffee compaction consistencyVSAvoidcoffee grind size variation
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs a load cell to measure the actual force applied during coffee compaction and provides feedback to the control unit. The control unit adjusts the motor drive to maintain a predetermined compaction force, ensuring consistent coffee quality regardless of grind size variations. This closed-loop feedback system directly addresses the inconsistency problem by continuously monitoring and correcting the compaction process.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If the brewing unit has a complex structure with multiple components, then coffee compaction can be controlled, but the brewing unit becomes difficult to clean

Engineering Contradiction:
Improvecoffee compaction controlVSAvoidcleaning difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent designs the compression piston to be detachably connected to the brewing unit body, allowing it to be easily removed for cleaning. By extracting the compression piston as a separate, removable component, the system maintains precise compaction control during operation while enabling simple cleaning by removing potential contamination sources. This modular approach resolves the contradiction between control precision and cleaning ease.

Inventive Principle:
Principle #2Taking out (Extraction)

3Force

If the compression piston is movably arranged in the brewing unit body, then coffee compaction is achievable, but coffee grounds can accumulate and affect quality

Engineering Contradiction:
Improvecoffee grounds compressionVSAvoidcoffee grounds accumulation
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent incorporates a cleaning device with a cleaning element that is movable relative to the brewing unit body to automatically remove coffee grounds from the compression piston and brewing chamber. This self-cleaning mechanism ensures that coffee grounds do not accumulate and affect subsequent brewing quality, while the compression piston maintains its compaction function. The system serves itself by automatically eliminating the harmful accumulation effect.

Inventive Principle:
Principle #25Self-service

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 brewing unit achieves consistent high-quality coffee by precisely controlling coffee powder compaction and water supply, enhancing flavor intensity and ease of maintenance.

Implementation Method 1

the drive of the compression piston is torque-controlled

Methodology Applied
Scientific EffectTorque control: Torque

Implementation Method 2

a heating device for optimal water temperature

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3695758B1Brew unit of a coffee machine, coffee machine and method of brewing coffee
Publication Date: 2021.09.15 LEEO TECH AG
  • EP3695758B1 patent drawingFigure 1
  • EP3695758B1 patent drawingFigure 2~4
  • EP3695758B1 patent drawingFigure 5~7

AI summary

The invention relates to a brewing unit (31) of a coffee machine (16) comprising a brewing unit body (32) having a receiving area (34), a brewing unit body filling opening (35) for coffee powder (14), and a dispensing opening (36) spaced apart from the brewing unit body filling opening (35), a discharge part (42) arranged at one end (33) of the brewing unit body (32), a sleeve cylinder (52) having a sleeve cylinder filling opening (55) for coffee powder (14) and a piston receiving area (54) and being movably arranged in the receiving area (34) of the brewing unit body (32) relative to the brewing unit body (32), a compression piston (62) being movably arranged in the piston receiving area (54) of the sleeve cylinder (52) relative to the sleeve cylinder (52), and a first motor (72) for driving the of the injection piston (62), wherein the drive of the injection piston (62) is torque-controlled.The invention further relates to a coffee machine (16) and a coffee brewing method.