Elevator Car Working Platform With Self-Locking Retraction

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Solution Overview

Problem

Existing elevator cars require significant manual effort to move and secure a working platform between stowed and lowered positions, posing safety risks due to potential sudden drops and complex, expensive structures.

Innovation Solution

An elevator car with a retractable working platform mechanism using pull means, including belt reels and self-locking mechanisms, to facilitate easy movement and secure positioning, reducing the risk of injury and eliminating the need for scissors mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a scissors mechanism is used to move and hold the working platform, then the platform can be supported and positioned, but the structure becomes complex and expensive

Engineering Contradiction:
Improveplatform support reliabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of platform support from the complex scissors mechanism and implements it using a simple retracting mechanism with spring element and blocking mechanism. This removes unnecessary structural complexity while maintaining the core support function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The retracting mechanism uses a spring element that automatically provides retracting force to compensate for the platform weight, and a blocking mechanism that automatically holds the platform in position. This self-service approach eliminates the need for complex control systems and manual operation mechanisms.

Inventive Principle:
Principle #25Self-service

2Device complexity

If the working platform is moved manually without assistance, then the structure can be simple, but significant force is required to push it back up and safety risks arise

Engineering Contradiction:
Improvemechanism simplicityVSAvoidplatform movement ease
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The spring element acts as a counterweight mechanism, providing retracting force that compensates for the platform weight. This reduces the manual force required to move the platform by approximately half, making operation easier while keeping the mechanism simple.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The retracting mechanism serves as an intermediary between the platform and the user, mediating the force interaction. The spring element and blocking mechanism together create a simple yet effective system that assists manual operation without adding significant complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the working platform can be lowered freely, then the operation is simple, but sudden drops or freefall can cause injury

Engineering Contradiction:
Improveplatform lowering easeVSAvoidinjury risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The blocking mechanism provides beforehand protection by preventing uncontrolled platform descent. It allows controlled lowering while blocking sudden drops, cushioning against the harmful effect of freefall before it can occur.

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

Solution Approach 2:

The spring element converts the potentially harmful force of gravity (which could cause freefall) into a beneficial retracting force that controls platform descent and compensates for weight during normal operation, transforming a harmful factor into a useful function.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

The solution allows for safe, effortless movement and secure positioning of the working platform, meeting safety requirements and reducing structural complexity and costs.

Implementation Method 1

The retracting mechanism can comprise a spring mechanism for generating the retracting force. That is, a spring return force of the spring mechanism can correspond to the retracting force.

Methodology Applied
Scientific EffectSpring mechanism: Spring

Implementation Method 2

the pull means can comprise a self-blocking mechanism configured to prevent movement of the pull means when a specific activation force towards the lowered position is exceeded

Methodology Applied
Scientific EffectSelf-blocking mechanism: Ratchet

Data Source

PatentEP4663589A1Elevator car and elevator assembly
Publication Date: 2025.12.17 OTIS ELEVATOR CO
  • EP4663589A1 patent drawingFigure 1
  • EP4663589A1 patent drawingFigure 2
  • EP4663589A1 patent drawing

AI summary

The disclosure relates to an elevator car (1) defining an interior space (4) for accommodating passengers and/or cargo. The elevator car (1) comprises a working platform (8) moveable up and down within the interior space (4), and pull means (10) mounted to the elevator car (1) above the interior space (4) and connected to the working platform (8) for moving the working platform (8) between a stowed position and a lowered position and holding the working platform (8) at an operational position. The pull means (10) comprises a retracting mechanism. A retracting force of the retracting mechanism is set to compensate for the weight of the working platform (8) or less. The disclosure also relates to an elevator assembly having an elevator shaft (2) and the elevator car (1).