Elevator Car Positioning for Hoistway Maintenance Access

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Solution Overview

Problem

Current elevator systems require a larger volume to accommodate safety clearances for maintenance access, which increases overall system size, and existing solutions for automated maintenance positioning are limited in precision and efficiency.

Innovation Solution

An elevator system with a control system that programs and accurately drives the elevator car to specific maintenance locations within the hoistway using a position reference system (PRS) and unique codes, allowing maintenance from inside the car, reducing the need for extensive safety volumes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If technicians enter the hoistway through hoistway doors to access components, then maintenance access is achieved, but the system requires a larger safety volume resulting in increased overall system size

Engineering Contradiction:
Improvemaintenance accessVSAvoidsystem volume
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

Instead of having technicians exit the elevator car to access hoistway components (traditional approach), the invention inverts the approach by providing access panels on the hoistway wall that face the car interior, allowing technicians to access components from inside the car. This eliminates the need for technicians to enter the hoistway through hoistway doors and reduces the required safety volume.

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

Solution Approach 2:

The invention changes the spatial dimension of access by moving from a horizontal access approach (technicians entering through side hoistway doors) to a vertical/directional access approach (access panels on hoistway walls facing the car interior). This dimensional change allows maintenance activities to occur from within the car space, eliminating the need for additional safety volume in the hoistway.

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

2Reliability

If safety volume and clearance are provided for technician protection, then technician safety is improved, but the overall elevator system volume increases

Engineering Contradiction:
Improvetechnician safetyVSAvoidsystem volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The invention extracts the maintenance access function from the hoistway space and relocates it to the elevator car interior space. By providing access panels on the hoistway wall that face the car, the maintenance activities are taken out of the hoistway environment, eliminating the need for safety volumes and clearances in the pit and top of the hoistway while maintaining technician safety through controlled access from within the car.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If automated maintenance positioning is implemented, then maintenance efficiency is improved, but positioning precision is limited

Engineering Contradiction:
Improvemaintenance efficiencyVSAvoidpositioning precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The invention implements a feedback mechanism using sensors (such as optical sensors or encoders) that detect the position of the elevator car and provide real-time feedback to the control system. This feedback enables the control system to accurately determine when the car has reached the correct position aligned with the access panel, ensuring precise positioning for maintenance activities while maintaining high efficiency through automated control.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3328770B1Elevator maintenance from inside elevator car
Publication Date: 2022.05.11 OTIS ELEVATOR CO
  • EP3328770B1 patent drawingFigure 1
  • EP3328770B1 patent drawingFigure 2
  • EP3328770B1 patent drawingFigure 3

AI summary

A method of operating an elevator system (10) includes identifying one or more components (46, 48, 50, 52) in an elevator hoistway (14) requiring periodic maintenance and/or inspection and programming hoistway component locations of the one or more components into an elevator car control system. The elevator car (12) is driven to a programmed hoistway component location of a selected component of the one or more components utilizing the hoistway component location programmed into the elevator car control system. The selected component is accessed from inside the elevator car (12) to perform maintenance and/or inspection of the selected component.