Built-In Cistern Wall Recesses for Lower Material Use

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional cisterns face issues such as high material consumption, long cooling times, complex manufacturing processes, excessive flush flow, and high drinking water consumption, along with challenges in implementing dual-flush technology and splash-out during flushing.

Innovation Solution

A cistern design featuring a plastic body with integrally formed springs, elongated recesses, and reduced wall thickness, which reduces material usage and manufacturing costs, incorporates a spring-loaded actuating device for simplified installation, and serves as packaging for cistern components, enhancing structural rigidity and flushing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cistern is divided into two separate cisterns (urine cistern and feces cistern), then hygiene conditions improve and clogging is reduced, but device complexity increases and installation space requirements increase

Engineering Contradiction:
Improvehygiene conditionsVSAvoidcistern structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cistern is divided into two separate functional chambers: a first cistern for collecting urine and a second cistern for collecting feces. This segmentation allows each chamber to be optimized for its specific function, improving hygiene conditions and reducing clogging while maintaining a relatively simple overall structure through shared components like the siphon system and flush mechanism.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a cistern is divided into two separate cisterns, then clogging is reduced, but installation space requirements increase

Engineering Contradiction:
Improveclogging preventionVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The second cistern (for feces) is positioned vertically above the first cistern (for urine), with the outlet of the second cistern extending down into the first cistern. This nested vertical arrangement allows both cisterns to occupy a compact footprint space while maintaining separate collection functions, effectively reducing the horizontal installation area required.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If separate urine and feces collection systems are implemented, then hygiene conditions improve, but manufacturing cost increases

Engineering Contradiction:
Improvehygiene conditionsVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

While the cistern is divided into two separate collection chambers for hygiene purposes, many components are shared between both systems including the siphon mechanism, flush valves, water supply lines, and control electronics. This merging of common components reduces manufacturing complexity and cost compared to implementing two completely separate toilet systems.

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

The design achieves lower material consumption, reduced manufacturing and transport costs, simplified installation, and efficient water usage, while minimizing splash-out and packaging waste, with a cost-effective and reliable flushing mechanism.

Implementation Method 1

a first siphon tube (33) for automatically discharging the urine from the first cistern (3) when a urine level in the first cistern (3) rises to a predetermined level

Methodology Applied
Scientific EffectSiphon action: Syphon

Implementation Method 2

a second siphon tube (34) for automatically discharging the feces from the second cistern (4) when a feces level in the second cistern (4) rises to a predetermined level

Methodology Applied
Scientific EffectSiphon action: Syphon

Data Source

PatentEP4499930B1Cistern, especially built in cistern, for a wc or urinal
Publication Date: 2026.05.06 VIEGA TECHNOLOGY GMBH & CO KG
  • EP4499930B1 patent drawingFigure 1
  • EP4499930B1 patent drawingFigure 2a~2b
  • EP4499930B1 patent drawingFigure 2c~2d

AI summary

The invention relates to a cistern (1), in particular a flush-mounted cistern, for a toilet or urinal, comprising a cistern body (1.1) made of plastic for receiving water, a drain valve (3) which has a closure body (3.1) that can be moved from a closing position into a flushing position, wherein the closure body (3.1) has a seal (12) which sealingly lies on a valve seat (2) in the closed position, and an actuation device (15) for actuating the drain valve (3). The aim of the invention is to provide such a cistern (1) in a particularly inexpensive manner using little material. According to the invention, this is achieved in that the cistern body (1.1) has at least two, preferably at least three, substantially parallel elongated depressions (1.15) in the front wall (1.13) and/or rear wall (1.14) of the cistern body when viewed from the outside.