Handle for a door of a domestic appliance with specific light guidance, and door and domestic appliance

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Solution Overview

Problem

Existing handle designs for household appliances face limitations in light emission due to the positioning and accessibility of light sources and light guides, leading to complex constructions, high light losses, and potential damage to the light guide components.

Innovation Solution

A handle design featuring a separate light guide element and light source, where the light guide is embedded between a transparent front strip and a handle bracket, allowing for precise and intense light emission circumferentially, with the front strip serving as both a cover and a radiating element, and the light guide being elastically deformable for tolerance compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the light source and light guide are arranged in the handle itself, then the light can be emitted from the handle, but the positioning is limited by the shape of handle blocks and the light guide is accessible from the front causing potential damage

Engineering Contradiction:
Improvelight emission capabilityVSAvoidlight guide protection
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The light guide element is extracted from the traditional handle block structure and repositioned to run along the front bar, where it is protected from front access while maintaining light emission functionality. The light guide is now integrated into the front bar structure rather than being exposed in handle blocks.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The light guide element is repositioned from a vertical arrangement in handle blocks to a horizontal arrangement along the front bar. This dimensional change allows the light guide to be protected from front access while maintaining its light-conducting function, as it now runs along the length of the front bar rather than being exposed in vertical handle blocks.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If the light guide is accessible from the front, then it can be integrated into the handle structure, but it can also be damaged

Engineering Contradiction:
Improvehandle structure integrationVSAvoidlight guide damage risk
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The light guide element is extracted from the vulnerable front-facing handle block position and repositioned within the protected structure of the front bar, eliminating direct front access while maintaining integration into the overall handle assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The light guide element is positioned within the front bar structure in advance, creating a protective arrangement that prevents direct exposure to potential damage sources from the front, while still allowing for functional integration into the handle design.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If a door-side light source is used to irradiate light into the handle, then the light source is not in the handle, but the construction becomes complex and light losses are high

Engineering Contradiction:
Improvehandle construction simplicityVSAvoidlight loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The front bar serves as an intermediary structure that houses the light guide element, allowing the light source to be positioned in the handle while the light guide runs through the transparent front bar to the visible face. This intermediary arrangement simplifies construction compared to door-side lighting while reducing light losses through direct coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If the front bar is made thick to provide structural support, then the handle is more stable, but the structure in perpendicular direction is increased

Engineering Contradiction:
Improvehandle stabilityVSAvoidhandle thickness
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The front bar is constructed as a composite structure combining transparent material for the light-transmitting face with structural support elements. This allows the bar to maintain sufficient thickness for structural stability while the transparent face remains relatively thin for optimal light transmission and visual appearance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The front bar exhibits different thickness characteristics in different regions: the light-transmitting face is kept thin for optimal optical properties, while the rear structural portions provide necessary support. This local variation in thickness optimizes both structural strength and light transmission without unnecessarily increasing overall handle thickness.

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 design enables a compact, protected, and flexible generation of light images with high intensity and sharp contours, improving the visual appearance and mechanical stability of the handle while minimizing light losses and protecting the light guide.

Implementation Method 1

a light guide element (13) with which light from the light source can be emitted in a defined manner from the front bar (7)

Methodology Applied
Scientific EffectLight guidance: Waveguide (optics)

Implementation Method 2

Light that is emitted by the light guide element can be radiated through at least a translucent material area of ​​the front strip (7)

Methodology Applied
Scientific EffectLight transmission through translucent material: Refraction

Implementation Method 3

the light guide element (13) is designed to be elastically deformable, in particular compressible in a direction perpendicular to the front bar (7)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3918157B1Handle for a door of a domestic appliance with specific light guidance, and door and domestic appliance
Publication Date: 2023.11.01 BSH HAUSGERATE GMBH
  • EP3918157B1 patent drawingFigure 1~2
  • EP3918157B1 patent drawingFigure 3~5
  • EP3918157B1 patent drawingFigure 6~7

AI summary

One aspect relates to a handle (6) for a door (4) of a domestic appliance (1), having an elongate front strip (7) and at least one handle block (8), which is connected to the front strip (7) and by means of which the handle (6) can be positioned on the door (4), and having at least one light source (15), which is arranged in the handle (6), and having at least one light-guiding element (13) with which light from the light source (15) can be radiated from the front strip (7), wherein the front strip (7) takes the form of a plate which is transparent at least in certain regions and which covers the light-guiding element (13) on the front side, wherein light which is radiated from the light-guiding element (13) is able to be radiated at least through a light-permeable material region of the front strip (7). The invention also relates to a door (4) and to a domestic appliance (1).