Elevator Inspection Operation Device Latching Relay Control
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Solution Overview
Problem
Existing elevator maintenance operation apparatuses do not ensure safe return to normal operation as they lack requirements for a closed and locked landing door, non-actuated stop devices, and secure access to the electric reset device.
Innovation Solution
An elevator inspection operation apparatus with an operation mode selector switch, a return switch outside the pit, and a latching relay that maintains the inspection mode until the return switch is manipulated, ensuring secure transition back to normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an operation mode selector switch is provided in the pit to allow inspection operation, then one maintenance worker can inspect pit apparatus and operate the elevator car, but the requirements for safe return to normal operation (locked door, non-actuated stop devices, authorized access) cannot be satisfied
Solution Approach 1:
A latching relay is introduced as an intermediary device between the operation mode selector switch and the elevator control system. The latching relay maintains the inspection operation state even after the switch is returned to normal position, ensuring that the elevator cannot resume normal operation until safety conditions are verified. This mediator enforces the safety requirements while allowing easy inspection operation initiation.
2Reliability
If the electric reset device is installed in a locked cabinet or associated with emergency unlocking key to ensure authorized access, then safety requirement is satisfied, but device complexity and cost increase
Solution Approach 1:
The latching relay circuit is designed to automatically verify safety conditions (door locked, stop devices not actuated) and enable the return to normal operation without requiring manual intervention from authorized personnel. The system self-monitors its own safety conditions and automatically permits resumption of normal operation when conditions are met, eliminating the need for locked cabinets or emergency keys.
3Reliability
If a latching relay is used to maintain inspection operation state until return switch is manipulated, then safe return to normal operation is ensured, but device complexity increases
Solution Approach 1:
The latching relay circuit is merged with the existing operation mode selector switch and integrated into the elevator's control system. The latching relay uses the same control signals and wiring infrastructure already present in the elevator control architecture, combining multiple functions (mode selection, safety monitoring, state maintenance) into a unified control circuit that minimizes additional complexity.
Data Source
AI summary
An elevator inspection operation apparatus for performing an inspection operation for a car in a pit of an elevator includes: an operation mode selector switch configured to switch an operation mode between a normal operation and the inspection operation; a return switch, which is provided outside the pit of the elevator, and is to be manipulated when the operation mode is to be switched from the inspection operation to the normal operation; and a latching relay configured to be latched to an inspection operation side when the operation mode has been switched from the normal operation to the inspection operation by the operation mode selector switch, and to maintain a latched state until the return switch is manipulated when the operation mode has been switched from the inspection operation to the normal operation by the operation mode selector switch.