Elevator Door Hook Monitor for Small Item Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing elevator door sensors fail to detect small items like straps across the doorway, leading to potential closure and movement of the elevator car, which is undesirable.
Innovation Solution
An elevator door interface monitor with moveable hooks that detect items across the doorway and trigger an indicator to prevent car movement, featuring coordinated hook movement and a biasing mechanism to ensure detection in both upward and downward directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional light curtain or mechanical switch sensors are used to detect items in the doorway, then the detection system is simple and cost-effective, but small items such as straps may not be detected and the elevator car may move away from the landing
Solution Approach 1:
The hook is designed to be moveable rather than fixed, allowing it to dynamically respond to items in the doorway. When an item contacts the hook, it moves from a retracted position to an activated position, triggering the sensor. This dynamic mechanism enables detection of small items that static sensors would miss, improving reliability without requiring complex sensor arrays
Solution Approach 2:
The hook acts as an intermediary mechanical element between the item and the sensor system. Instead of directly detecting small items with optical or mechanical sensors, the hook physically interacts with items in the doorway and translates this interaction into sensor activation, effectively mediating the detection process
2Reliability
If the hook is positioned to detect items across the entire interface, then detection coverage is maximized, but the hook may interfere with door operation or become exposed when doors are open
Solution Approach 1:
The hook is designed to move between a retracted position (when doors are open) and an activated position (when doors are closed). This dynamic positioning ensures the hook is exposed across the entire interface for maximum detection coverage when needed, but retracted when doors are open to prevent interference with door operation and passenger safety
Solution Approach 2:
The hook is preliminarily positioned in the retracted location when doors are open, preparing it for detection function before the doors close. This preliminary action ensures the hook is ready to detect items as soon as the doors close, while avoiding interference during the door operation phase
Data Source
AI summary
An illustrative example embodiment of an elevator door interface monitor includes at least one hook having a portion that is configured to be situated across the interface and moveable responsive to contact with an item situated at least partially in the interface. An indicator provides an indication of an item in the interface based on movement of the hook responsive to contact with the item.