Coffee Brewer Stripper Geometry to Prevent Powder Jamming

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Solution Overview

Problem

Coffee powder residues accumulate and jam between the stripping element and the rear wall of the driver part, preventing the stripping element from assuming its rest position and potentially causing collisions with the upper piston, leading to malfunctions in brewing devices.

Innovation Solution

The rear surface of the stripping element is equipped with a projection featuring inclined deflection surfaces, resembling a wedge shape, to transport away coffee powder residues to the side, and a cam with a bevel is added to ensure the element returns to its rest position without colliding with the upper piston.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a stripping element is used to remove coffee powder cake from the piston surface, then the brewing chamber can be cleaned effectively, but coffee powder residues accumulate behind the stripping element and jam it, preventing it from returning to its rest position

Engineering Contradiction:
Improvestripping element functionalityVSAvoidcoffee powder residue accumulation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The harmful coffee powder residues are extracted from the problematic area by directing them onto the deflection surfaces of the projection, which guide them away from the gap between the stripping element and driver part rear wall, preventing accumulation and jamming

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The projection with deflection surfaces acts as an intermediary element between the stripping element and the coffee powder residues, redirecting the residues away from the jamming location and preventing the harmful effect

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If tolerances in injection-molded parts are relatively large, then manufacturing is easier and costs are lower, but gaps between moving parts allow coffee powder residues to slip through and accumulate

Engineering Contradiction:
Improveinjection molding processVSAvoidstripping element operation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The large tolerances and resulting gaps, which were originally harmful by allowing coffee powder residues to slip through, are converted into a beneficial feature by using the deflection surfaces to actively direct these residues away from critical areas, transforming the gap from a problem source into a controlled flow path

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of operation

If coffee powder residues are not removed from the gap between the stripping element and driver part rear wall, then the stripping element cannot return to its rest position, but adding removal mechanisms increases device complexity

Engineering Contradiction:
Improvestripping element retractionVSAvoidstripping element structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The projection with deflection surfaces is integrated directly into the stripping element structure, merging the residue deflection function with the existing stripping element without adding separate complex mechanisms, thus maintaining simplicity while improving operation

Inventive Principle:
Principle #5Merging (Combining)

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

This design effectively prevents coffee powder accumulation, allowing the stripping element to return to its rest position and preventing collisions, thereby ensuring the brewing device's operational reliability and preventing malfunctions.

Implementation Method 1

a projection which is arranged on the area facing the piston surface and has at least one deflecting surface which is inclined with respect to the stripping direction

Methodology Applied
Scientific EffectWedge: Wedge

Data Source

PatentEP2042062B1Brewing device for a coffee machine
Publication Date: 2010.04.14 SCHAERER AG
  • EP2042062B1 patent drawingFigure 1
  • EP2042062B1 patent drawingFigure 2
  • EP2042062B1 patent drawingFigure 3

AI summary

The apparatus (1) has a brewing cylinder (6), a top piston and a bottom piston (4) retained in a frame (2) for displacement relative to one another. A coffee-powder-feed device fills a brewing chamber with coffee powder, and a stripping element (19) strips off coffee-powder cake that remains on a surface (4a) of the bottom piston. A rear-side surface of the stripping element has a protrusion (32) arranged on a region directed towards the piston surface, and includes deflecting surfaces (33, 34) inclined in relation to a stripping-off direction.