Hose Extrusion Head Centering via Threaded Fastening

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hose extrusion heads face challenges in achieving precise centering of the mouthpiece relative to the mandrel, leading to inconsistent wall thickness and increased material consumption due to high frictional forces and stick-slip effects, which limit accuracy and require large safety allowances.

Innovation Solution

A hose extrusion head design featuring a fastening element that minimizes friction between the mouthpiece and the head housing by using a tension-based fastening system, allowing for precise centering and reduced material consumption by reducing the safety allowance needed to maintain target wall thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a clamping surface is used to secure the mouthpiece to the head housing, then the mouthpiece is firmly held in position, but high frictional forces occur that prevent precise centering and cause stick-slip effects

Engineering Contradiction:
Improvemouthpiece positioning stabilityVSAvoidcentering precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent removes the clamping surface entirely from the system. Instead of pressing the mouthpiece against a clamping surface, the mouthpiece is secured using screws that engage directly with threaded bores in the mouthpiece, eliminating the source of high frictional forces while maintaining secure positioning.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the friction-based clamping mechanism with a threaded fastening mechanism. The screws engage with internal threads in the mouthpiece, providing secure attachment without requiring high friction forces, thus enabling precise centering without stick-slip effects.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If the mouthpiece is firmly clamped to reduce movement, then positioning stability is improved, but the frictional force increases making centering difficult

Engineering Contradiction:
Improvemouthpiece fixation stabilityVSAvoidfrictional force
Core Design Contradiction:
Stability of the object's compositionVSForce

Solution Approach 1:

The patent extracts and removes the clamping surface that generated excessive friction. The mouthpiece is instead secured through threaded bores that engage with screws, providing stable fixation without relying on high friction forces between contact surfaces.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fastening mechanism from friction-based clamping to thread-based mechanical engagement. This parameter change in the fastening system allows stable fixation with significantly reduced frictional forces, enabling precise centering.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If a centering device is added to center the mandrel, then centering precision is improved, but the device complexity increases and it can only be used for transverse spray heads

Engineering Contradiction:
Improvecentering precisionVSAvoidcentering device complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of adding a complex centering device to center the mandrel, the patent inverts the approach by making the mouthpiece adjustable relative to the head housing. The mouthpiece can be positioned and centered directly, eliminating the need for complex mandrel centering mechanisms and enabling use with both transverse and longitudinal spray heads.

Inventive Principle:
Principle #13The other way round (Inversion)

4Strength

If a large safety allowance is used to ensure minimum wall thickness, then hose strength is guaranteed, but material consumption increases

Engineering Contradiction:
Improvehose strengthVSAvoidhose material consumption
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The patent replaces the friction-based clamping system with a threaded fastening system, enabling precise centering of the mouthpiece. This precision ensures uniform wall thickness without variations caused by stick-slip effects, allowing the use of smaller safety allowances while maintaining hose strength requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs mass forces generated by the hose material flow to reduce frictional forces during centering operations. This hydraulic-like effect using the material itself enables easy adjustment and precise centering, ensuring uniform wall thickness with minimal safety allowance.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 enables precise centering of the mouthpiece, reducing the total frictional force required, leading to more accurate hose production with reduced material usage and lower operational force, thus achieving homogeneous wall thickness and minimizing material waste.

Implementation Method 1

a radial movement of the mouthpiece relative to the head housing leads to only too little friction between the fastening element and the mouthpiece

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

During operation of the extruder to which the hose extrusion head is attached, the very high mass forces of the hose material lead to a decrease in the frictional force on the contact surface

Methodology Applied
Scientific EffectInertia: Inertia

Data Source

PatentEP3116701B1Hose extrusion head and method for producing a hose
Publication Date: 2021.04.21 KRAUSSMAFFEI EXTRUSION GMBH
  • EP3116701B1 patent drawingFigure 1
  • EP3116701B1 patent drawingFigure 2~3

AI summary

The invention relates to a hose extrusion head for producing a hose (50), said head comprising a head housing, a duct (14) formed in the head housing (12) for supplying a hose material (22), a pin (16) which is arranged in the duct (14), a die (18) and at least one securing element (20). According to the invention, the securing element (20) is attached by one end (39) to the die (18) such that said end (39) follows the movement of the die (18).