Frost-Proof Drain Fitting Plastic Intermediate Spindle

Solution Overview

Problem

Frost-proof outlet fittings are susceptible to frost damage when hoses under pressure are connected during cold conditions, leading to potential freezing and material failure, and existing solutions are either costly or prone to operational errors.

Innovation Solution

The use of plastic for the intermediate spindle and tube reduces thermal conductivity, allows for elastic expansion to compensate for freezing water volume changes, and incorporates design features like guide ribs and support ribs for radial extensibility and stability, along with a metal valve seat housing for enhanced sealing and connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If metal intermediate spindle and tube are used, then thermal conductivity is improved, but frost damage risk increases

Engineering Contradiction:

Improvethermal conductivityVSAvoidfrost damage risk

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter of the intermediate spindle and tube from metal to plastic, fundamentally altering the thermal conductivity parameter. This reduces heat transfer from the warmer indoor environment to the colder outdoor environment, thereby reducing the risk of frost damage while maintaining adequate thermal insulation performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material construction by combining plastic intermediate spindle and tube with metal valve seat housing and connecting pieces. This composite approach allows the plastic components to provide thermal insulation against frost damage, while the metal components ensure structural strength, sealing performance, and connection reliability.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If plastic intermediate spindle and tube are used, then frost damage resistance is improved, but thermal conductivity decreases

Engineering Contradiction:

Improvefrost damage resistanceVSAvoidthermal conductivity

Core Design Contradiction:

Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent employs composite material construction by combining plastic intermediate spindle and tube with metal valve seat housing and connecting pieces. This composite approach allows the plastic components to provide thermal insulation against frost damage, while the metal components ensure structural strength, sealing performance, and connection reliability.

Inventive Principle:

Principle #40Composite materials

3Weight of moving object

If plastic intermediate spindle is used, then weight is reduced, but structural strength decreases

Engineering Contradiction:

ImproveweightVSAvoidstructural strength

Core Design Contradiction:

Weight of moving objectVSStrength

Solution Approach 1:

The patent employs composite material construction by combining plastic intermediate spindle and tube with metal valve seat housing and connecting pieces. This composite approach allows the plastic components to provide thermal insulation against frost damage, while the metal components ensure structural strength, sealing performance, and connection reliability.

Inventive Principle:

Principle #40Composite materials

4Ease of manufacture

If plastic intermediate spindle is used, then manufacturing cost is reduced, but manufacturing precision decreases

Engineering Contradiction:

Improvemanufacturing costVSAvoidmanufacturing precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the material parameter of the intermediate spindle and tube from metal to plastic, fundamentally altering the manufacturing characteristics. Plastic components can be produced through injection molding, enabling cost-effective mass production with consistent dimensional accuracy and integrated features.

Inventive Principle:

Principle #35Parameter changes

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 effectively reduces the risk of frost damage by improving insulation, reducing material stress, and allowing for cost-effective production while maintaining structural integrity and operational reliability.

Implementation Method 1

The use of plastic for the intermediate spindle and/or the intermediate tube leads to improved insulation in the longitudinal direction of the frost-proof outlet fitting due to the choice of material. The thermal bridge formed by the intermediate tube or the intermediate spindle accordingly has poorer thermal conductivity than in the outlet fittings known from the prior art

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

There is also the possibility of adjusting the wall thickness of the intermediate spindle or the intermediate pipe to a certain degree of radial extensibility, which prevents the frost-related stresses from becoming so great, even if the fitting freezes, that the material of the outlet fitting fails. Rather, the change in volume of water in the fitting when it freezes is compensated for by elastic expansion of the plastic component(s)

Methodology Applied

Scientific EffectElastic expansion: Elasticity

Data Source

PatentEP2479462B1Frost-proof drain fitting

Publication Date: 2015.10.14 GEBR KEMPER GMBH CO KG METALLWERKE

Figure 1
Figure 2~5

AI summary

The fitting has a valve housing (10) provided with a valve seat (26), an outlet housing (30) and an intermediate spindle (50). The intermediate spindle is formed in an intermediate tube (80) so as to connect outlet housing with the valve housing. The intermediate spindle and/or the intermediate tube are formed of plastic. The wall thickness of the intermediate spindle is small in relation to the wall thickness of the intermediate tube.