Wall-Mountable Hand Dryer with Forward Nozzles to Reduce Device Depth

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Solution Overview

Problem

Conventional hand dryers either require significant depth for opposing nozzles to dry both hands simultaneously or necessitate a 'hand-over-hand' method that is inefficient and uncomfortable, limiting design flexibility and user experience.

Innovation Solution

A wall-mountable hand dryer with separate left-hand and right-hand nozzle sections positioned forward, allowing for one-sided drying with a downwardly pitched guide part to encourage hands to pitch downward, eliminating the need for opposing nozzles and enabling a compact design while ensuring effective drying across the full hand span.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If opposing nozzles are used to dry both hands simultaneously, then drying efficiency is improved, but device depth increases significantly

Engineering Contradiction:
Improvedrying efficiencyVSAvoiddevice depth
Core Design Contradiction:
ProductivityVSLength of stationary object

Solution Approach 1:

The hand dryer is segmented into a left nozzle section and a right nozzle section, with each nozzle section having independent nozzles that can be positioned forward. This segmentation allows the drying function to be distributed across multiple zones, enabling effective one-sided drying of each hand without requiring deep opposing nozzle arrangements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a deep, back-mounted nozzle arrangement to a forward-positioned nozzle configuration. By moving the nozzles forward and using a downwardly pitched guide part, the design exploits the vertical and horizontal dimensions more effectively, achieving compact depth while maintaining drying effectiveness through high-speed air momentum directed downward onto the hands.

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

2Device complexity

If a single large nozzle is used for hand-over-hand drying, then device complexity is reduced, but user comfort and drying effectiveness deteriorate

Engineering Contradiction:
Improvenozzle configurationVSAvoiduser comfort
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

Instead of a single large nozzle, the system is divided into multiple nozzle sections (left and right) with multiple nozzles in each section. This segmentation provides dedicated drying zones for different parts of the hands, eliminating the need for awkward hand-over-hand motion and improving user comfort while maintaining reasonable device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each nozzle section is equipped with nozzles positioned to direct high-speed air onto specific areas of the hands. The left nozzle section targets the left hand and the right nozzle section targets the right hand, providing localized drying action that is both effective and comfortable, rather than requiring users to maneuver their hands under a single centralized nozzle.

Inventive Principle:
Principle #3Local quality

3Length of stationary object

If nozzles are positioned close to the wall, then device depth is reduced, but air momentum and drying effectiveness are compromised

Engineering Contradiction:
Improvedevice depthVSAvoidair momentum
Core Design Contradiction:
Length of stationary objectVSSpeed

Solution Approach 1:

The patent positions the nozzles forward rather than close to the wall, and directs the air flow downward at an angle using a downwardly pitched guide part. This angular downward direction allows the air momentum to be effectively utilized across the hand surface area, achieving good drying effectiveness with a compact depth by exploiting the vertical dimension and angled projection rather than relying solely on horizontal distance from the wall.

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

4Productivity

If opposing nozzles are used for two-sided drying, then both hands are dried simultaneously, but the requirement for sufficient depth restricts design flexibility

Engineering Contradiction:
Improvesimultaneous drying capabilityVSAvoiddesign flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The hand dryer is divided into independent left and right nozzle sections, each capable of drying one hand effectively. This segmentation provides design flexibility by allowing each section to be optimized independently for forward positioning and angled downward flow, while still achieving simultaneous drying of both hands through the combined action of the two sections.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using opposing nozzles that face each other from front to back (requiring deep configuration), the patent inverts the approach by using nozzles that face downward from top to bottom. This inverted directional arrangement allows both hands to be dried simultaneously by directing air downward onto the palms or backs of hands, achieving the same productivity goal with much greater design flexibility and compact depth.

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

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 allows for efficient, one-sided drying of hands without the need for opposing nozzles, increasing the effective depth on the wall, reducing user discomfort, and preventing spray-back, while maintaining high-speed air momentum for effective moisture removal.

Implementation Method 1

a motor-driven fan to force air at high pressure through an opposing pair of narrow, slit-like nozzles... This creates two opposing thin sheets, or 'blades', of high velocity air

Methodology Applied
Scientific EffectHigh-speed air flow: Jet

Implementation Method 2

The air is heated to promote evaporative drying of water moisture on the hands of the user

Methodology Applied
Scientific EffectEvaporative drying: Evaporation

Data Source

PatentEP2744381B1A hand dryer
Publication Date: 2017.11.08 DYSON TECH LTD
  • EP2744381B1 patent drawingFigure 1
  • EP2744381B1 patent drawingFigure 2
  • EP2744381B1 patent drawingFigure 3~4

AI summary

A wall-mountable hand dryer for drying one side of a user's hands at a time, the dryer having two nozzle sections - one for each hand - which nozzle sections are positioned towards the front of the dryer so that they are spaced away from the wall in use, the nozzle sections each extending to span the width of a user's open hand and being arranged for directing drying air down onto the front or back of said hand as it is inserted lengthwise underneath the nozzle sections from the front of the dryer, wherein the dryer comprises a downwardly pitched guide part positioned behind each nozzle section for guiding the pitch of the user's hands underneath the nozzle sections.