Magnetic Rotary Control Knob With Anti-Slip Adhesive Base

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Solution Overview

Problem

Existing control devices for household appliances, such as hobs, face issues with precise rotary position setting and unwanted movement of the control element, leading to potential errors in operating condition settings due to tolerances and slipping.

Innovation Solution

The control device features a control element base and cap that are held by magnetic force, with an adhesive element on the base providing increased frictional resistance and a rotational position adjustment system using magnets for precise positioning, along with a haptically perceptible latching mechanism to prevent undesired movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the operating element is held by magnetic force only, then the operating element can be easily positioned and removed, but undesired slipping occurs during rotation leading to positioning errors

Engineering Contradiction:
Improveease of positioning and removalVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent combines magnetic holding force with an adhesive element (friction element) to create a composite securing mechanism. The adhesive element is integrated into the operating element base, creating a multi-functional attachment system that provides both easy positioning/removal (magnetic) and secure anti-slip holding (adhesive/friction).

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent merges two different holding mechanisms (magnetic force and adhesive friction) into a single integrated system. The adhesive element is combined with the magnetically held structure to provide complementary functions: magnetic attraction for easy attachment/detachment and adhesive friction for preventing slip during operation.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If the adhesive element protrudes significantly, then frictional resistance and positioning precision are improved, but the operating element becomes harder to clean and more complex to manufacture

Engineering Contradiction:
Improverotary position setting precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The adhesive element is designed with localized protrusion only in the radial direction where it contacts the receptacle surface, while maintaining a flush or recessed profile in other areas. This selective protrusion provides maximum frictional resistance at the contact interface without creating cleaning difficulties or excessive manufacturing complexity throughout the entire component.

Inventive Principle:
Principle #3Local quality

3Reliability

If the adhesive element covers the entire underside, then positioning security is maximized, but material costs and production complexity increase

Engineering Contradiction:
Improvepositioning securityVSAvoidmaterial consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The adhesive element is applied selectively only in the regions where frictional contact with the receptacle is required for positioning security, rather than covering the entire underside. This localized application reduces material consumption and simplifies production while maintaining adequate positioning security through strategic placement at critical contact points.

Inventive Principle:
Principle #3Local quality

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

This configuration enhances the precision of rotary position setting, reduces errors, and ensures secure, user-friendly operation by preventing unwanted movements and providing clear feedback to the user.

Implementation Method 1

at least one adhesive element is formed on an underside of the operating element base that faces the operating element receptacle, the material of which has a greater frictional resistance or coefficient of friction than the underside

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the operating element can be held on an operating element mount of the operating device by means of magnetic force and can be moved relative to the operating element mount and can be positioned detachably from there

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP2821709B1Operating device with an operating element with an adhesive element on the bottom of the operating element and household device with such an operating device
Publication Date: 2017.04.19 BSH HAUSGERATE GMBH
  • EP2821709B1 patent drawingFigure 1
  • EP2821709B1 patent drawingFigure 2
  • EP2821709B1 patent drawingFigure 3

AI summary

The invention relates to an operating device (8) for a household appliance (1), comprising an operating element (10) which is held on a control element receptacle (9) of the household appliance (1) controlled by the operating device (8) by means of magnetic force and is movable relative to the control element receptacle (9) and removable from it, and the operating element (10) has a control element base (10b) and a control element cap (10a) which covers the control element base (10b) from above, at least partially, and which is connected to the control element base (10b) and is rotatable relative to the control element base (10b) for adjusting operating conditions of the household appliance (1), wherein at least one adhesive element (42) is formed on an underside (24a) of the control element base (10b), the material of which has a higher frictional resistance than the underside (24a). The invention also relates to a household appliance (1) with an operating device (8).