Curved Rack Guide for Compact Sanitary Washing Nozzle Storage

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Solution Overview

Problem

Existing sanitary washing devices that advance and retreat with respect to a toilet are often too tall, making them unsightly and potentially cumbersome.

Innovation Solution

A sanitary washing device with a flexible rack and rack guide featuring first and second curved portions in different directions, allowing the nozzle unit to be stored along the first curved portion, and a supporter with an upwardly convex surface to further suppress the device's height, while maintaining effective washing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the nozzle unit is advanced and retracted using a linear rack guide, then the washing function is effective, but the device height increases

Engineering Contradiction:
Improvewashing functionVSAvoiddevice height
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The rack guide is designed with curved portions instead of a straight linear path. The rack guide includes a first curved portion and a second curved portion that guide the rack through arc-shaped trajectories, allowing the nozzle unit to be stored in a compact position while maintaining effective washing coverage. This curvature enables the nozzle to reach the necessary positions without increasing the overall device height.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The rack guide transitions from a one-dimensional linear path to a two-dimensional curved path with multiple portions. The first curved portion and second curved portion create a complex spatial trajectory that allows the nozzle unit to be positioned effectively while reducing the vertical space required for storage and operation.

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

2Length of stationary object

If the device height is reduced for compactness, then aesthetics improve, but the washing performance may be compromised

Engineering Contradiction:
Improvedevice heightVSAvoidwashing performance
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The curved rack guide portions enable the nozzle unit to traverse an arc-shaped path that maintains adequate distance from the toilet bowl for effective washing. The curvature radius and arc angles are designed to ensure the nozzle reaches optimal washing positions while being stored compactly, thus preserving washing performance in a space-efficient configuration.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Length of stationary object

If a flexible rack is used with curved guide portions, then the device becomes more compact, but the structural complexity increases

Engineering Contradiction:
Improvedevice heightVSAvoidrack guide structure
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The rack guide incorporates curved portions with specific radius values (e.g., R1, R2) that are optimized to balance compactness and manufacturability. The curvature is designed to be smooth and continuous, avoiding sharp angles or complex geometries that would significantly increase manufacturing difficulty while still achieving the desired compact form factor.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP4682319A1Sanitary washing device
Publication Date: 2026.01.21 TOTO LTD
  • EP4682319A1 patent drawingFigure 1
  • EP4682319A1 patent drawingFigure 2
  • EP4682319A1 patent drawingFigure 3

AI summary

A sanitary washing device includes a casing, a nozzle unit configured to advance and retreat between the casing and a toilet, a flexible rack connected to the nozzle unit, a gear configured to engage the rack, a drive motor configured to advance and retract the nozzle unit by moving the rack via the gear, and a rack guide configured to guide the rack. The rack guide includes a first curved portion curved to be upwardly convex, and a second curved portion positioned further back than the first curved portion. The second curved portion includes a portion bent upward as the second curved portion extends backward.