Stepper-Driven Pinch Valve for Hygienic Beverage Flow Switching

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Solution Overview

Problem

Existing beverage preparation machines, such as espresso machines, face challenges with solenoid valves being heavy, expensive, and sensitive to contamination, requiring continuous power and leading to heating issues, while pinch valves are less sensitive but lack versatility in fluid distribution and flow control.

Innovation Solution

Incorporating a pinch valve with a linearly or rotary-operating actuating mechanism, utilizing a stepper motor drive with squish wedges or an eccentric disc, allowing for versatile fluid passage control and metering, reducing contamination sensitivity and energy consumption, and enabling hygienic operation with space and cost savings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solenoid valves are used for fluid control, then reliable switching function is achieved, but the device becomes heavy, expensive, and sensitive to contamination with continuous power requirement

Engineering Contradiction:
Improveswitching functionVSAvoidvalve weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces the electromagnetic solenoid valve with a mechanically actuated pinch valve using a cam mechanism. The cam is rotated by a stepper motor to mechanically open or close the hose, eliminating the need for continuous electromagnetic power and reducing sensitivity to fluid contamination while maintaining reliable switching function.

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

2Reliability

If solenoid valves are used for fluid control, then reliable switching function is achieved, but contamination sensitivity and heating issues increase

Engineering Contradiction:
Improveswitching functionVSAvoidcontamination sensitivity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the electromagnetic solenoid valve with a mechanically actuated pinch valve using a cam mechanism. The cam is rotated by a stepper motor to mechanically open or close the hose, eliminating the need for continuous electromagnetic power and reducing sensitivity to fluid contamination while maintaining reliable switching function.

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

3Object-affected harmful factors

If pinch valve is used to reduce contamination sensitivity, then hygienic operation is improved, but fluid distribution versatility is limited

Engineering Contradiction:
Improvecontamination sensitivityVSAvoidfluid distribution function
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent enhances the basic pinch valve by integrating a cam mechanism with multiple positioning capabilities. The cam can be rotated to different angles by the stepper motor, enabling the single pinch valve to control multiple fluid paths (coffee outlet, cappuccino outlet, steam, hot water) and perform both switching and proportional mixing functions, thus achieving multi-functionality.

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

Solution Approach 2:

The patent transforms the static pinch valve into a dynamic system by adding a rotatable cam mechanism driven by a stepper motor. This allows the valve to dynamically adjust between different positions (fully open, fully closed, intermediate positions) and control multiple fluid paths, providing versatility in fluid distribution while maintaining the hygienic benefits of pinch valve design.

Inventive Principle:
Principle #15Dynamics

4Force

If stepper motor with cam mechanism is used, then device complexity increases, but actuating force and switching path are improved

Engineering Contradiction:
Improveactuating forceVSAvoidactuating mechanism
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent uses a stepper motor that can be held currentless in positioned states, applying actuating force only during switching transitions rather than continuously. This partial action reduces energy consumption and allows the use of a relatively simple cam mechanism to achieve the required actuating force and switching path without excessive complexity.

Inventive Principle:
Principle #16Partial or excessive action

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 lighter, cheaper, and more hygienic beverage preparation machine with enhanced fluid distribution and flow control capabilities, allowing for precise metering and switching of fluid streams, suitable for various beverages like coffee, water, steam, or milk, with the ability to maintain fluid flow without continuous power.

Implementation Method 1

a linearly operating actuating mechanism with a stepping motor drive is used. In the case of the linearly operating actuating mechanism, the actuating mechanism then advantageously contains one or more squish wedges. In the case of the rotary operating actuating mechanism, the actuating mechanism then advantageously contains at least one eccentric disc.

Methodology Applied
Scientific EffectStepper motor drive: Linear Motor

Implementation Method 2

In the case of the linearly operating actuating mechanism, the actuating mechanism then advantageously contains one or more squish wedges. In the case of the rotary operating actuating mechanism, the actuating mechanism then advantageously contains at least one eccentric disc.

Methodology Applied
Scientific EffectMechanical compression: Compression

Data Source

PatentEP2099341B1Beverage preparation machine with a pinch valve
Publication Date: 2011.07.06 JURA ELEKTROAPPARATE AG
  • EP2099341B1 patent drawingFigure 1
  • EP2099341B1 patent drawingFigure 2a~2c
  • EP2099341B1 patent drawingFigure 3a~3c

AI summary

A beverage preparation machine has at least one pinch valve (1) in the fluid line system, wherein the pinch valve (1) has at least two fluid passage lines (20, 21) and is designed to execute valve and/or control functions on the fluid passage lines (20, 21). The operating mechanism of the pinch valve (1) is set up for coupled activation of the valve and/or control functions and a drive with a stepper motor (25) is provided.