Pinch Valve Design for Automatic Air Venting in Coffee Machine Pumps

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Solution Overview

Problem

Existing valve devices for hydraulic circuits in coffee machines are expensive, unreliable, and cause performance degradation due to complex construction and unstable flow, especially during priming and low flow rates, and fail to effectively manage air accumulation leading to pump malfunction.

Innovation Solution

A simple and economical pinch valve with a flexible tube, comprising a first and second body that slide along a sliding axis to create a passage gap, using elastic means to maintain a closed position and an actuation portion to open, allowing air bubbles to escape through a hydraulic branch, coordinated with the movement of a brewing unit to ensure reliable pump priming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional three-way valve devices are used to vent air from the pump delivery, then air can be removed from the hydraulic circuit, but the device complexity increases and production cost becomes expensive

Engineering Contradiction:
Improveair venting functionVSAvoidvalve construction
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the venting function from a complex three-way valve and implements it through a simple two-position valve element that only needs to switch between open and closed states. The valve element is integrated directly into the pump housing, eliminating the need for separate complex valve assemblies while maintaining effective air venting capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The valve device is merged with the pump housing structure, where the valve element is positioned within the pump assembly and shares the same housing. This integration combines the pumping function and venting function into a single compact unit, reducing overall device complexity and production cost.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If traditional three-way valve devices are used to vent air from the pump delivery, then air can be removed from the hydraulic circuit, but manufacturing cost increases

Engineering Contradiction:
Improveair venting functionVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the venting function from a complex three-way valve and implements it through a simple two-position valve element that only needs to switch between open and closed states. The valve element is integrated directly into the pump housing, eliminating the need for separate complex valve assemblies and reducing manufacturing cost.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The valve element is designed as a simple, inexpensive component that can be easily manufactured and replaced if needed. By using a basic two-position design rather than a complex three-way valve, the component becomes more affordable and easier to produce at scale.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If traditional valve devices are used to vent air, then air removal is possible, but pump performance degrades especially at low flow rates

Engineering Contradiction:
Improveair venting functionVSAvoidpump performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The valve element is designed to be actuated by the pump's own operating conditions, switching automatically based on flow rate and pressure. During normal operation, the valve remains closed to maintain pump performance, while during priming or low flow conditions, it opens to vent air, thus adapting dynamically to operational needs without degrading pump performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The valve device utilizes the pump's own operational parameters (flow rate, pressure differential) to automatically control the venting function. The system self-regulates without external intervention, opening the valve only when air venting is needed and closing it during normal operation to maintain optimal pump performance.

Inventive Principle:
Principle #25Self-service

4Reliability

If complex three-way valve devices are used, then air venting can be achieved, but flow stability becomes unstable

Engineering Contradiction:
Improveair venting functionVSAvoidflow stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent extracts the venting function from a complex three-way valve and implements it through a simple two-position valve element that only needs to switch between open and closed states. This simplification eliminates the flow instability issues associated with complex valve mechanisms while maintaining effective air venting capability.

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

The valve device ensures reliable and efficient pump functioning by automatically venting air bubbles, reducing production costs, and maintaining high performance even after inactivity, thus preventing pump failure and ensuring consistent coffee preparation.

Implementation Method 1

a valve device (10) comprising elastic means (13) configured to maintain the valve device (10) in the closed operating position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the valve device (10) also comprises an actuation portion (16), drivable in order to compress the elastic means (13) and move the first and second bodies (11, 12) apart from each other

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

a deformable segment (50a) of the flexible tube (50) is pinched by an engagement element (29)

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP4237715B9Valve device
Publication Date: 2025.12.10 DE LONGHI APPLIANCES SRL
  • EP4237715B9 patent drawingFigure 1~2
  • EP4237715B9 patent drawingFigure 3~5
  • EP4237715B9 patent drawingFigure 6~7

AI summary

The invention concerns a valve device (10) suitable to selectively obstruct a flexible tube (50), comprising a first body (11) and a second body (12) operatively associated with each other, which are mobile with respect to each other along a sliding axis (X), thus configuring an open operating position and a closed operating position and thus defining a passage gap (15) configured to be passed through by the flexible tube (50). The invention also concerns a machine (60) for preparing beverages comprising a valve device (10) and a corresponding functioning method.