Cleaning head and hard surface cleaning device having a cleaning head

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Solution Overview

Problem

Hard surface cleaning devices, such as floor cleaning devices, face challenges in achieving high mechanical resilience while minimizing manufacturing costs, particularly due to the mechanical stress on drive shafts subjected to high torque and bending moments, which often requires costly metal materials and complex manufacturing processes.

Innovation Solution

The drive shaft is composed of a metal inner shaft part surrounded by a plastic outer shaft part, allowing for high mechanical strength and cost-effective manufacturing, with the plastic outer shaft enabling adaptation of the external geometry and the metal inner shaft providing mechanical load capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the drive shaft is manufactured from metal, then high mechanical strength is achieved, but manufacturing costs increase

Engineering Contradiction:
Improvemechanical strengthVSAvoidmanufacturing costs
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The drive shaft is constructed as a composite structure with an inner metal shaft portion providing mechanical strength and an outer plastic shaft portion reducing manufacturing costs. This composite design allows the drive shaft to withstand high torsional and bending moments while being more cost-effective than a fully metal construction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different portions of the drive shaft have different material properties - the inner portion uses metal for strength where mechanical loads are highest, while the outer portion uses plastic for cost-effective manufacturing and geometric adaptability. This local differentiation of material quality optimizes both strength and manufacturing efficiency.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the drive shaft is manufactured from plastic, then manufacturing costs decrease, but mechanical strength is reduced

Engineering Contradiction:
Improvemanufacturing costsVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The drive shaft combines plastic and metal materials in a composite structure where the plastic outer portion provides cost-effective manufacturing and geometric flexibility, while the metal inner portion ensures sufficient mechanical strength for withstanding high torsional and bending moments.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The plastic material is used locally in the outer shaft portion where geometric adaptability is needed, while the metal material is concentrated in the inner shaft portion where mechanical strength is most critical for load-bearing functions.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If the drive shaft geometry is adapted to different applications, then versatility increases, but manufacturing complexity increases

Engineering Contradiction:
Improvegeometry adaptabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The plastic outer shaft portion allows for cost-effective adaptation of the drive shaft's external geometry to different applications through injection molding or other plastic forming processes, while the metal inner shaft provides a standardized structural core.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The outer plastic portion is designed with local geometric variations to accommodate different applications, while the inner metal shaft maintains a consistent structural form, thereby achieving versatility without proportionally increasing overall manufacturing complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4173536B1Cleaning head and hard surface cleaning device having a cleaning head
Publication Date: 2024.12.04 ALFRED KARCHER SE & CO KG
  • EP4173536B1 patent drawingFigure 1
  • EP4173536B1 patent drawingFigure 2
  • EP4173536B1 patent drawingFigure 3

AI summary

The invention relates to a cleaning head (14) for a hard surface cleaning device (10), wherein the cleaning head (14) has at least one cleaning roller (104, 106) rotatable about a pivot axis (40) and held non-rotatably on a drive shaft (34) that can be driven by rotation. To further develop the cleaning head (14) such that it has high mechanical strength and low manufacturing costs, the invention proposes that the drive shaft (34) has at least one inner shaft part (44) made of metal, which is surrounded by an outer shaft part (46) made of a plastic material. The invention also relates to a hard surface cleaning device (10) with such a cleaning head (14) and with a drive motor (38) for driving the drive shaft (34) of the cleaning head (14).