Tilted Single-Disc Floor Scrubber for Self-Propelled Cleaning

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Solution Overview

Problem

Existing floor treatment machines with dual counter-rotating disc-shaped work heads are prone to drift and uneven cleaning due to asymmetries and torque reactions, leading to reduced cleaning efficiency and increased work time, while simpler, cheaper machines with self-propulsion are sought after.

Innovation Solution

A hand-guided floor treatment machine with a single disc-shaped work head having a rotational axis tilted slightly away from vertical, combining transverse and rearward tilt components to enhance contact pressure and propulsion, allowing for effective cleaning and self-propulsion with reduced complexity and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If dual counter-rotating work heads are used, then torque reaction balance is improved, but machine complexity and manufacturing cost increase

Engineering Contradiction:
Improvetorque reaction balanceVSAvoidmachine complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent extracts the torque balancing function from the dual work head configuration and relocates it to the handle assembly. By providing counter-balancing weights in the handle that can be adjusted independently, the invention eliminates the need for complex dual motor-gearbox-work head assemblies while maintaining torque reaction balance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The adjustable counter-balancing weights in the handle allow the operator to self-adjust the machine for optimal torque balance based on specific operating conditions, floor types, and workload requirements. This eliminates the need for fixed complex mechanical balancing mechanisms.

Inventive Principle:
Principle #25Self-service

2Stability of the object's composition

If dual counter-rotating work heads are used, then torque reaction balance is improved, but manufacturing cost increases

Engineering Contradiction:
Improvetorque reaction balanceVSAvoidmanufacturing cost
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent extracts the torque balancing function from the expensive dual work head assembly and relocates it to a simpler handle assembly with adjustable weights. This dramatically reduces manufacturing complexity and cost while maintaining the essential torque balancing capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive, complex mechanical balancing mechanisms with simple, adjustable weight components that are cheaper to manufacture and easier to replace if needed.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If work head axis is tilted for self-propulsion, then ease of operation is improved, but cleaning uniformity deteriorates

Engineering Contradiction:
Improveself-propulsionVSAvoidcleaning uniformity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The machine provides self-propulsion through the tilted work head configuration, but the operator maintains control over cleaning uniformity through the adjustable handle pressure and the ability to manually adjust the work head tilt angle to optimize both propulsion and cleaning distribution.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The work head tilt angle can be adjusted dynamically during operation to balance between self-propulsion effectiveness and cleaning uniformity, allowing the operator to adapt to different floor conditions and cleaning requirements.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If handle twisting for differential pressure is applied, then self-propulsion is improved, but cleaning effect on one side deteriorates

Engineering Contradiction:
Improveself-propulsionVSAvoidcleaning effect
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent uses counter-balancing weights in the handle to offset the asymmetric pressure distribution caused by handle twisting. This allows the operator to maintain propulsion effectiveness while compensating for the reduced cleaning effect on one side of the work head.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The adjustable counter-balancing weights allow dynamic compensation for the asymmetric pressure distribution, enabling the operator to optimize both propulsion and cleaning effectiveness throughout the cleaning process.

Inventive Principle:
Principle #15Dynamics

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 tilted work head design ensures consistent cleaning pressure across the work head, retains cleaning liquid, and provides forward propulsion, improving cleaning efficiency and reducing work time while simplifying the machine's design and reducing manufacturing complexity.

Implementation Method 1

Because the friction of the work head brushes is higher in the depressed inner edge regions, a linear propulsion effect arises in a working direction perpendicular to the transverse direction, when the inner depressed brush regions are both moving backwards when rotating.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4338649A1Floor treatment machine
Publication Date: 2024.03.20 NUMATIC INTERNATIONAL LIMITED
  • EP4338649A1 patent drawingFigure 1
  • EP4338649A1 patent drawingFigure 2
  • EP4338649A1 patent drawingFigure 3

AI summary

The present invention concerns the field of floor treatment machines such as scrubbers, finishers or polishers. Floor scrubbers typically have rotating work heads equipped with bristles for working the floor to remove dirt. The invention provides a hand-guided floor treatment machine comprising a handle portion (41) connected to a base portion (11), which base portion is provided with a rotatable generally disc-shaped floor-facing work head (4) having a substantially vertical axis of rotation (V), the machine being provided with drive means (15) for rotatably driving the work head, wherein the rotational axis of the work head is slightly tilted away from the vertical in a direction which has a transverse component and a rearward component so that the work head is biased into contact with the floor in a region rearwardly and to one side of the work head, whereby in use rotation of the work head through the biased region provides propulsion predominantly in a forward direction.