Coffee Dispensing Pressure Control for Consistent Extraction

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Solution Overview

Problem

Coffee machines face challenges in maintaining high-quality beverage extraction due to variations in coffee grind size and pressure, leading to inconsistent dispensing times and potential filter obstruction, which affects the taste and quality of espresso and filter coffee.

Innovation Solution

A coffee machine with a dispensing pressure control system that uses a pressure sensor and control unit to adjust the water flow rate and pressure in real-time, ensuring optimal extraction by monitoring and adjusting the dispensing pressure based on the coffee grind size and blend, thereby maintaining a consistent dispensing time and quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high pressure (above 10 bar) is used to improve water flow through coffee, then extraction efficiency improves, but filter obstruction and sealing member stress increase

Engineering Contradiction:
Improveextraction efficiencyVSAvoidfilter obstruction risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements dynamic pressure regulation that adjusts water pressure in real-time during the brewing process. The system transitions from high pressure (above 10 bar) during initial extraction to lower pressure when approaching dispensing completion, preventing filter obstruction while maintaining extraction efficiency. The control unit monitors flow rate and pressure sensors to dynamically adjust pump operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the pressure parameter throughout the brewing process rather than maintaining constant high pressure. The control unit receives signals from pressure and flow rate sensors to modify pump speed and pressure output, optimizing extraction while avoiding excessive pressure that causes filter obstruction and sealing member stress.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If coffee is ground very finely to improve contact surface with water, then extraction quality improves, but filter obstruction risk increases

Engineering Contradiction:
Improveextraction qualityVSAvoidfilter obstruction risk
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The system dynamically adjusts pressure parameters to accommodate fine coffee grounds. By reducing pressure when flow rate decreases (indicating near-completion), the system prevents filter obstruction even with very finely ground coffee that provides excellent contact surface area for high-quality extraction.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If pressure sensor and control unit are added to regulate dispensing pressure, then extraction consistency improves, but device complexity increases

Engineering Contradiction:
Improveextraction consistencyVSAvoidcontrol system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent implements a feedback control system where pressure sensors and flow rate sensors continuously monitor brewing parameters, and the control unit adjusts pump operation accordingly. This feedback mechanism ensures consistent extraction quality by maintaining optimal pressure throughout the process, automatically adapting to variations in coffee grounds and flow conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system automatically regulates pressure and detects brewing completion without user intervention. The control unit receives signals from sensors and autonomously adjusts pump operation, reduces pressure when completion is detected, and manages the entire brewing process to ensure consistency without requiring user expertise.

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 system ensures high-quality coffee production by maintaining consistent dispensing pressure and time, adapting to variations in coffee grind size and blend, preventing filter obstruction and enhancing the overall extraction process.

Implementation Method 1

a pressure sensor (21) arranged along the hydraulic circuit in fluid communication with the pump and the dispensing device

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 2

a hydraulic pump (4) which generates water pressure and regulates the water flow rate

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 3

a heating chamber (12) supplied with cold water and having a heating element (20) for heating the water to a dispensing temperature

Methodology Applied
Scientific EffectThermal heating: Heating

Data Source

PatentEP2314182B2A coffee machine with dispensing pressure regulation and a method relating thereto
Publication Date: 2018.10.03 GRUPPO CIMBALI SPA
  • EP2314182B2 patent drawingFigure 1
  • EP2314182B2 patent drawingFigure 2a~2c

AI summary

The present invention relates in particular to a coffee machine for producing and dispensing coffee-based beverages comprising a hydraulic pump (4), at least one dispensing device (13) comprising a filter unit (31) adapted to contain ground coffee and a supply unit (14) adapted to supply water to the filter unit when the filter unit is engaged with the supply unit and a hydraulic circuit which brings the hydraulic pump into fluid communication with the supply unit of the dispensing device, the hydraulic circuit comprising a supply duct (11) which supplies hot water under pressure to the supply unit. The machine further comprises a system for controlling the dispensing pressure which comprises a control unit (22), a pressure sensor (21) disposed along the hydraulic circuit in the vicinity of the dispensing device and adapted to transmit signals representative of the pressure detected to the control unit to detect the disposing pressure, in which system the hydraulic pump is adapted to supply variable quantities of water and may be actuated by an electronic drive controlled electronically by the control unit in order to select the flow of water supplied by the pump. The invention relates, moreover, to a method for controlling the dispensing pressure in a coffee machine.