Coffee Machine Dual Hydraulic System for Controlled Cold Extraction

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Solution Overview

Problem

Existing coffee machines produce cold coffee extracts with altered sensory profiles due to high bitterness and metallic aromas, and suboptimal quality due to uncontrolled extraction temperatures.

Innovation Solution

A coffee machine with a dual hydraulic system and calibrated non-return valves, along with a thermal stabilizer, allows for controlled cold extraction at higher brewing pressures and stable temperatures between 25°C and 35°C, maintaining the body and balance of aromatic profiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If cold extraction is performed directly at room temperature or low temperatures to accelerate beverage preparation, then the beverage is already cold directly in the cup, but the sensory profile is altered with bitter/metallic aromas and extraction quality becomes suboptimal

Engineering Contradiction:
Improvebeverage preparation timeVSAvoidextraction quality
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The patent changes the temperature parameter from room temperature/low temperature to a controlled range of 25-35°C, and adjusts the pressure parameter to 4-25 bar. This combination of parameter changes enables cold extraction to achieve both speed and quality, producing a beverage that is cold in the cup with optimal extraction and pleasant aromatic profile without bitter/metallic notes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a dynamic hydraulic system with a distribution valve that can switch between hot and cold extraction pathways, and a pump that can dynamically adjust pressure. This dynamic control allows the system to adapt to different extraction requirements and maintain optimal conditions for cold extraction, resolving the contradiction between speed and quality

Inventive Principle:
Principle #15Dynamics

2Device complexity

If cold extraction is performed with uncontrolled water temperature and room temperature variations, then preparation is simplified, but extraction quality becomes inconsistent and suboptimal

Engineering Contradiction:
Improvetemperature control systemVSAvoidextraction consistency
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent incorporates temperature sensors and a control unit that continuously monitor water temperature and adjust the thermal stabilizer accordingly. This feedback mechanism ensures the water temperature remains within the optimal 25-35°C range, guaranteeing consistent extraction quality without requiring complex manual temperature control

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a thermal stabilizer as an intermediary device between the water reservoir and the brewing system. This thermal stabilizer acts as a buffer that maintains water temperature within the optimal range, isolating the extraction process from ambient temperature variations and ensuring consistent results

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If high pressure is applied during cold extraction to improve body and creaminess, then the aromatic profile balance improves, but the system complexity increases with dual hydraulic lines and calibrated valves

Engineering Contradiction:
Improvearomatic profile balanceVSAvoidhydraulic system configuration
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent designs a multi-functional hydraulic system where the same pump and distribution valve serve both hot and cold extraction pathways. The calibrated non-return valves are integrated into the existing hydraulic architecture, allowing the system to perform multiple functions (hot extraction, cold extraction, temperature control) without proportionally increasing complexity

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

Solution Approach 2:

The patent utilizes hydraulic principles with calibrated non-return valves that automatically regulate pressure based on their opening pressures (first valve: 3-8 bar, second valve: 0.05-3 bar). This passive pressure regulation mechanism eliminates the need for active pressure control systems, achieving precise aromatic profile control through hydraulic design rather than complex electronic control

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 results in a cold coffee extract with enhanced body, creaminess, and sweeter taste, similar to traditional espresso, while preserving freshness and reducing bitter notes.

Implementation Method 1

said first line is provided with a first non-return valve calibrated at a first opening pressure and said second line is provided with a second non-return valve calibrated at a second opening pressure lower than said first opening pressure

Methodology Applied
Scientific EffectNon-return valve pressure calibration: Valve

Implementation Method 2

a thermal stabiliser of the water coming from said water tank and/or from said connection to a water supply

Methodology Applied
Scientific EffectThermal stabilization: Heat Exchanger

Data Source

PatentEP4418963B1Coffee machine for preparing coffee with highly flexible use
Publication Date: 2025.10.15 DE LONGHI APPLIANCES SRL
  • EP4418963B1 patent drawingFigure 1
  • EP4418963B1 patent drawingFigure 2
  • EP4418963B1 patent drawingFigure 3

AI summary

The coffee machine comprises a water supply pump (2), a first water heating boiler (3), a brewing unit (4) comprising a hot water dispensing head (5), a first hydraulic connection line (11) for connecting said first boiler (3) to said dispensing head (5), a second by-pass line (12) of the first boiler (3), hydraulically connecting said pump (2) to said dispensing head (5), distribution valve means (14) switchable between a first connection configuration of said supply pump (2) to said first line (11) and a second connection configuration of said supply pump (2) to said second line (12), the first line (11) being provided with a first non-return valve (17) calibrated at a first opening pressure and the second line (12) being provided with a second non-return valve (18) calibrated at a second opening pressure lower than the first opening pressure.