Foldable Elevator Car Top Extension for Long-Object Transport

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Solution Overview

Problem

Elevator cars are limited by their vertical height when transporting elongated objects, and existing top extensible sections either protrude, requiring additional hoistway space or obstruct maintenance access.

Innovation Solution

A foldable top extensible section for elevator cars that includes a top wall and side walls, which can be unfolded to provide additional space and folded flush with the car top for maintenance, with features like a fence for protection and motor-driven rope for wall movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a top extensible section is provided to transport elongated objects, then the elevator car can carry longer objects, but the hoistway height must be increased

Engineering Contradiction:
Improvelength of transportable objectVSAvoidhoistway height
Core Design Contradiction:
Length of moving objectVSLength of stationary object

Solution Approach 1:

The top extensible section is designed to be movable between an extended position (for transporting long objects) and a retracted position (flush with the car top). This dynamic configuration allows the elevator to adapt its internal volume without requiring the hoistway to be permanently taller, resolving the contradiction between transport capability and infrastructure requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The side walls of the top extensible section are designed to fold onto each other in a nested manner, with each wall containing the previous wall within its folding path. This nesting approach minimizes the space required during the folding operation, allowing the section to be fully retracted without interfering with the car's normal operation or requiring excessive clearance.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of moving object

If a top extensible section protrudes from the elevator car top, then additional space is provided for transport, but maintenance access is obstructed

Engineering Contradiction:
Improveadditional top spaceVSAvoidmaintenance access
Core Design Contradiction:
Volume of moving objectVSEase of repair

Solution Approach 1:

The top extensible section transitions from a static protruding structure to a dynamic, movable structure that can be retracted flush with the car top during maintenance operations. This allows full access to the car top surface while maintaining the capability to extend for transport, resolving the contradiction between volume provision and maintenance accessibility.

Inventive Principle:
Principle #15Dynamics

3Ease of repair

If the top wall is lowered to be flush with the top plate for maintenance, then access is improved, but the expansion space is lost

Engineering Contradiction:
Improvemaintenance accessVSAvoidexpansion space
Core Design Contradiction:
Ease of repairVSVolume of moving object

Solution Approach 1:

The system employs a dynamic configuration where the top wall and side walls can transition between extended and retracted states. During maintenance, the section is retracted to provide flush access; during transport, it is extended to provide expansion space. This temporal separation of functions resolves the contradiction between maintaining access and providing volume.

Inventive Principle:
Principle #15Dynamics

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 efficient transport of elongated objects without increasing hoistway height and allows safe maintenance access by providing a stable operating space on the folded side walls.

Implementation Method 1

at least a part of the plurality of side walls includes an electromagnetic connector connected between the upper portion and the lower portion, so that the electromagnetic connector keeps the upper portion and the lower portion stable in the unfolded state

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP3954645B1Top extensible section and the operating method thereof, elevator car assembly and elevator system
Publication Date: 2026.01.28 OTIS ELEVATOR CO
  • EP3954645B1 patent drawingFigure 1~2
  • EP3954645B1 patent drawingFigure 3
  • EP3954645B1 patent drawingFigure 4

AI summary

The present disclosure provides a top extensible section and an operating method thereof, an elevator car assembly, and an elevator system. The top extensible section (100) is installed above a top plate of the elevator car when in use. The top extensible section (100) includes a top wall (101) and a plurality of side walls (102), and has an unfolded state and a folded state; in the unfolded state, the top wall (101) and the plurality of side walls (102) of the top extensible section (100) define an expansion space which communicates with an inner space of the elevator car to provide an additional top space; and in the folded state, the top wall (101) of the top extensible section (100) is lowered to be substantially flush with the top plate of the elevator car, and the plurality of side walls (102) are folded to provide an operating space on the plurality of side walls.