Compact Check Valve Layout for Low-Dead-Volume Beverage Injection

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Solution Overview

Problem

Existing beverage preparation machines have a significant dead volume of hot fluid between the check valve and the piercing needle, which poses safety and health risks due to potential bacterial growth and occupy excessive space, making them bulky and inefficient.

Innovation Solution

A compact check valve design with a cylindrical chamber, a plug member, and an elastic element that aligns the valve inlet and outlet with the movement direction of the plug member, reducing dead volume by ensuring the plug member remains closed under typical fluid pressures and only opens when fluid flows from the inlet to the outlet, with the elastic member housed in the upper cavity to maintain compactness and prevent fluid contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional check valve design is used, then the valve can effectively prevent backflow, but a large dead volume of hot fluid remains between the check valve and the piercing needle, promoting bacterial growth

Engineering Contradiction:
Improvebackflow preventionVSAvoidbacterial growth
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The plug member is nested inside the body chamber, with the protruding part fitting inside the bore of the lower wall. The cylindrical sealing element divides the chamber into upper and lower cavities, creating a compact nested structure that eliminates dead volume while maintaining backflow prevention functionality

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The check valve is segmented into distinct functional parts: the plug member with protruding part for flow control, the cylindrical sealing element for cavity division, and the elastic element for actuation. This segmentation allows each component to perform its specific function efficiently without creating unnecessary dead zones

Inventive Principle:
Principle #1Segmentation

2Stress or pressure

If a traditional check valve design is used, then the valve can maintain fluid pressure, but the valve occupies excessive space, making the beverage preparation machine bulky

Engineering Contradiction:
Improvefluid pressure maintenanceVSAvoidcheck valve volume
Core Design Contradiction:
Stress or pressureVSVolume of stationary object

Solution Approach 1:

The check valve design transitions from a conventional linear arrangement to a compact three-dimensional configuration. The plug member moves axially within the cylindrical chamber, utilizing the vertical dimension for actuation while maintaining a compact horizontal footprint. The elastic element is positioned in the upper cavity to provide vertical actuation force

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The plug member is nested within the body chamber, with the protruding part fitting inside the bore of the lower wall. This nested configuration maximizes the use of internal space, allowing the valve to maintain fluid pressure effectively while occupying minimal external volume

Inventive Principle:
Principle #7Nested doll (Nesting)

3Object-affected harmful factors

If the plug member is positioned close to the piercing needle to reduce dead volume, then bacterial growth is reduced, but the valve becomes more sensitive to pressure fluctuations and may open prematurely

Engineering Contradiction:
Improvebacterial growthVSAvoidvalve opening stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The elastic element acts as an intermediary between the fluid pressure and the plug member. It provides a predetermined threshold force that the fluid pressure must overcome to open the valve, filtering out minor pressure fluctuations. The elastic element is housed in the upper cavity to maintain this buffering function while keeping the overall valve compact

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastic element provides beforehand cushioning by pre-loading the plug member against the seat with a predetermined force. This cushioning effect ensures that the valve will not open prematurely due to small pressure variations, while still allowing it to open when the fluid pressure exceeds the threshold during normal operation

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 significantly reduces the risk of bacterial growth by minimizing dead volume to the internal volume of the piercing needle, making the beverage preparation machine safer and more compact, allowing for precise brewing with reduced space requirements.

Implementation Method 1

an elastic element housed in the body upper cavity in order to press the plug member protruding part against the valve seat

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the fluid in the conduit 9b can exert a pressure on a first surface 26b of the plug member 3b, and can move the plug member 3b to its open position, if the fluid pressure exceeds a predetermined threshold

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Data Source

PatentEP2904295B1Check valve, injection assembly, and beverage preparation machine.
Publication Date: 2016.08.03 NESTEC SA
  • EP2904295B1 patent drawingFigure 1
  • EP2904295B1 patent drawingFigure 2(a)~2(b)
  • EP2904295B1 patent drawingFigure 3

AI summary

The present invention is directed to a check valve 10, an injection assembly 60, and a beverage preparation machine 100, which is integrated in the injection assembly 60. The check valve 10 of the present invention is made of a body with a first fluid outlet 21, and a plug member 30 that is movable inside the body 20. The plug member 30 has a fluid inlet 32 and a second fluid outlet 31 into a first cavity 11, wherein the fluid can exercise a pressure on a first surface 381 of the plug member 30 opposing the first fluid outlet 21. The fluid pressure can overcome the force of an elastic element 40, which biases the plug member 30 into a closed position. If the force of the elastic member 40 is overcome, the plug member 30 is moved into an open position. In the closed position a fluid path from the cavity 11 out of the first fluid outlet 21 is closed, whereas in the open position said fluid path is open. To move the plug member 30 from its initial closed position to its open position, a fluid pressure on the first surface has to be equal to or larger than a predetermined threshold.