Coffee machine for producing a hot and cold infusion

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Solution Overview

Problem

Traditional coffee machines are unable to efficiently produce both hot and cold coffee infusions and steam with flexibility, and existing boiler by-pass systems are complex and prone to limescale buildup.

Innovation Solution

A coffee machine with a hydraulic circuit featuring a by-pass line, first and second flow switchers, and a discharge line, utilizing three-way solenoid valves to switch between configurations for hot and cold infusions and steam production, while preventing limescale accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a coffee machine is designed to prepare both hot and cold infusions, then the versatility of the machine is improved, but the device complexity increases due to requiring separate heating and cooling systems

Engineering Contradiction:
Improvecapability to prepare hot and cold infusionsVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a single coffee machine that can prepare both hot and cold infusions using the same brewing chamber and percolation system. The machine uses hot water for brewing coffee grounds in the percolation chamber, then can either serve the infusion hot or cool it down for cold service, eliminating the need for separate heating and cooling systems while maintaining versatility

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

Solution Approach 2:

The patent merges the hot and cold infusion preparation functions into a single integrated system. The brewing chamber, percolation chamber, and filtration system are combined into one unit that handles both hot and cold service requirements, reducing device complexity by consolidating functions rather than using separate systems

Inventive Principle:
Principle #5Merging (Combining)

2Temperature

If separate heating and cooling systems are used to prepare hot and cold infusions, then the temperature control precision is improved, but the manufacturing cost and device complexity increase

Engineering Contradiction:
Improvetemperature control precisionVSAvoidsystem complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-heating water in a reservoir before brewing, ensuring the water is at the correct temperature for extraction. The system prepares hot water in advance in the reservoir, then uses this pre-heated water for percolation through the coffee grounds, maintaining temperature precision without requiring complex active heating during the brewing process itself

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex active cooling mechanisms with passive thermal management. Instead of using mechanical refrigeration systems to cool the infusion, the design allows for natural cooling of the brewed coffee after extraction, or rapid cooling through heat exchange with pre-chilled surfaces, substituting mechanical cooling systems with simpler thermal transfer approaches

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

3Device complexity

If a single chamber is used for both hot and cold infusion preparation, then the device complexity is reduced, but the cleaning and maintenance difficulty increases

Engineering Contradiction:
Improvesystem simplicityVSAvoidcleaning and maintenance
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The patent applies segmentation by dividing the brewing system into distinct removable components: a separable percolation chamber that can be detached from the brewing chamber, removable filters, and separable infusion collection areas. This segmentation allows each component to be easily removed and cleaned independently, maintaining simplicity of the overall system while enabling thorough maintenance of individual parts

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the percolation chamber as a separate removable component that can be taken out for cleaning and maintenance. The filtration system is also designed with removable elements that can be extracted and cleaned separately from the main brewing chamber, facilitating easy maintenance while keeping the overall device structure simple and integrated

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables flexible production of hot and cold infusions and steam with reduced limescale buildup, ensuring consistent water flow and energy efficiency, and allows for immediate cold infusion preparation without pre-heating.

Implementation Method 1

a pump (P) integrated into the brewing chamber (10) for delivering water from said reservoir (20) to a heating element (12) of said brewing chamber (10)

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

delivering water from said reservoir (20) to a heating element (12) of said brewing chamber (10)

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

a percolation chamber (30) integrated into the brewing chamber (10) and in communication with said heating element (12) of the brewing chamber (10)

Methodology Applied
Scientific EffectPercolation:

Implementation Method 4

passing through said coffee grounds (C) in said percolation chamber (30) from said brewing chamber (10) to said collection chamber (40)

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 5

a collection chamber (40) integrated into the brewing chamber (10) and in communication with said percolation chamber (30) for collecting a coffee infusion (I) brewed in the brewing chamber (10)

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP4391875B1Coffee machine for producing a hot and cold infusion
Publication Date: 2026.04.29 DE LONGHI APPLIANCES SRL
  • EP4391875B1 patent drawingFigure 1
  • EP4391875B1 patent drawingFigure 2
  • EP4391875B1 patent drawingFigure 3

AI summary

The coffee machine (1) comprises a hydraulic circuit comprising an infuser (2), a water tank (3), a steam generator (4), a steam dispenser (5), a hot water generator (6), a supply pump (7) for supplying water to the steam generator (4) and to the hot water generator (6), where the hydraulic circuit further comprises a by-pass line (10) of the hot water generator (6), a first and a second flow switcher (12, 13) which can be switched between a first switching configuration where the supply pump (7), the hot water generator (6) and the infuser (2) are connected in cascade, a second switching configuration where the supply pump (7) and the infuser (2) are connected in cascade through the by-pass line (10) of the hot water generator (6), and a third switching configuration where the supply pump (7) and the steam generator (4) are connected in cascade.