Bath Lift Seat Locking for Automatic Backrest Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing bath tub lifts for the elderly or disabled require significant physical effort to separate and transport due to complex mechanisms and manual operation of securing means, making removal cumbersome.

Innovation Solution

A bath tub lifter design featuring automatic separation of the backrest and seat panel at the lowest end position, utilizing a locking bolt mechanism with a compression spring and guide recesses in the spindle base for easy actuation, allowing for secure coupling and effortless disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a locking-release device with manual safety means is used to couple the backrest and seat plate, then secure attachment is achieved, but significant physical effort and manual operation are required for separation

Engineering Contradiction:
Improvesecure attachmentVSAvoidseparation effort
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The system performs the separation action automatically through gravity and spring mechanisms when the seat plate is in the lowered position, eliminating the need for manual operation of safety means by the user

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The safety means are pre-configured to be automatically disengaged when the seat plate reaches the lowered position, preparing the system for easy separation before the user attempts to remove the backrest

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If the backrest and seat plate are securely coupled during use, then stability is improved, but the device becomes difficult to disassemble for transport

Engineering Contradiction:
Improvestructural stabilityVSAvoiddisassembly ease
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The coupling mechanism transitions from a locked state during use to an unlocked state for transport based on the dynamic position of the seat plate, automatically adapting between stable operation and easy disassembly modes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The backrest assembly can be easily separated from the seat plate through automatic disengagement of the locking mechanism, allowing the components to be transported separately with reduced effort

Inventive Principle:
Principle #1Segmentation

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

Enables the bath tub lifter to be easily removed and transported without great effort, simplifying the process and reducing physical exertion, while maintaining secure attachment when in use.

Implementation Method 1

a compression spring is provided which acts on the backrest and presses the at least one locking bolt against the lifting tube

Methodology Applied
Scientific EffectCompression spring: Spring

Implementation Method 2

the guide recess has a sloping section running obliquely downwards from the lifting tube jacket and a release section offset inwards relative to the lifting tube jacket for releasing the backrest and the seat plate from one another

Methodology Applied
Scientific EffectGravitational force: Gravitation

Data Source

PatentEP1743614B1Bath lift
Publication Date: 2010.03.03 AQUATEC OPERATIONS
  • EP1743614B1 patent drawingFigure 1
  • EP1743614B1 patent drawingFigure 2

AI summary

The lifting seat for use by the elderly and handicapped in a bath has a seat plate (2) and back rest (3) which are mounted on a vertical telescopic tube (4). This has a spindle (18) at its base which raises the seat. The seat plate and back rest have a lock which is automatically released when the seat reaches its lowest position. An independent claim is included for the lock.