Elevator Car Roof Access via Position Feedback
Solution Overview
Problem
Existing elevator systems face difficulties in easily accessing the elevator car roof for maintenance, particularly in machine-room less elevators, where manual positioning is challenging due to lack of direct visibility and precise leveling, especially when operating in a rescue or maintenance mode with bypassed safety circuit switches.
Innovation Solution
The implementation of a roof position determination unit connected to the control unit and car position detection device, which activates a roof zone indicator to signal when the car roof is within a certain level range of a landing or shaft access, allowing for automatic stopping and easy maintenance access, using existing safety circuitry and software bypass means.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual positioning of the elevator car is performed from outside the shaft during maintenance, then the elevator car can be positioned to access the car roof, but the positioning precision is poor due to lack of direct visibility
Solution Approach 1:
The control unit receives actual position data from the car position detection device and uses this feedback to automatically adjust and position the elevator car at the correct level, eliminating the need for manual visual estimation and achieving precise positioning
Solution Approach 2:
The patent replaces manual mechanical positioning operations with an automated control system that uses electronic position detection and automatic control to achieve precise car leveling, substituting human visual estimation with electronic measurement and automated actuation
2Adaptability or versatility
If the safety circuit switches are bypassed to enable maintenance mode operation, then the elevator car can move with doors open or safety switches malfunctioning, but the safety monitoring capability is reduced
Solution Approach 1:
The control unit dynamically switches between different operating modes (normal operation mode and maintenance mode) by activating or deactivating the bypass means, allowing the safety circuit configuration to adapt to different operational requirements while maintaining appropriate safety monitoring for each mode
Solution Approach 2:
The control unit is pre-configured with the capability to bypass safety circuit switches when entering maintenance mode, allowing maintenance personnel to perform necessary operations without being blocked by safety switch status, while still maintaining controlled safety monitoring appropriate for maintenance operations
Data Source
Figure 1
Figure 2
AI summary
The invention relates to an elevator system (10) comprising at least one elevator (12) having an elevator car (14) with at least one car door (22), and an elevator shaft (16) comprising landing doors (32), at least one control unit (34) for controlling the elevator, a safety circuit (50) with a series connection of safety circuit switches (42, 44) which is connected to the control unit, whereby at least one safety circuit switch (42) is assigned to the car door status and at least one safety circuit switch (44) is assigned to a landing door status, and a car position detection device (38, 40), which control unit comprises an operating mode control (60) configured to switch between a first operating mode, wherein the safety circuit is activated and a second operating mode wherein at least one of the safety circuit switches of the safety circuit is bypassed by a bypass means (52). Upon activation of the second operating mode the control unit activates a roof position determination unit (62) which is connected with the car position detection device and/or with a separate roof position detection device, whereby - the roof position determination unit (62) of the control unit (34) comprises a roof zone indicator (66) which is activated when the car roof (15) is positioned within a certain level range with respect to a landing floor (30), and/or - the roof position determination unit (62) initiates a car operation stop circuit (63) in the control unit (34) to stop the elevator car (14) when the car roof (15) is positioned within a certain level range with respect to a landing floor (30). Via the invention operating personal is easily able to get access to the car roof in case of malfunction of a safety circuit switch or if he wants access to the car roof with a safety circuit switch open.