Elevator Safety Device with Pivotable Light Beam
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Solution Overview
Problem
Existing elevator safety devices, such as those using laser sensors, face challenges with complex installation requirements, potential eye damage from uncontrolled laser irradiation, and susceptibility to dust and damage due to moving reflector plates in the sill groove, making them difficult to install and maintain.
Innovation Solution
An elevator safety device with a light projector, reflector, and light receiver arranged between the elevator car and shaft, supported by a pivotable support member and cam mechanism, allowing the light beam to adjust its path during door opening and closing, preventing eye exposure and reducing dust accumulation by fixing the reflector in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a door edge sensor using a laser sensor is used to detect objects during door closing, then foreign object detection capability is improved, but the risk of eye damage from uncontrolled laser irradiation increases
Solution Approach 1:
The laser beam is controlled to be emitted only during the door closing operation and automatically stopped when the door is fully closed or opens, creating a periodic on-off action that eliminates continuous exposure risk while maintaining detection capability during the critical closing phase
Solution Approach 2:
The light beam path is made dynamic by positioning it to pass through the door closing side edge, allowing the detection zone to automatically adjust with door movement while limiting laser exposure to only when necessary for safety detection
2Measurement precision
If a second reflector plate is provided on the upper portion of the opposite door panel to reflect laser beam before full closure, then detection accuracy is improved, but the complexity of door panel installation and adjustment increases
Solution Approach 1:
The reflector plate is extracted from the moving door panel and relocated to the stationary door frame structure, eliminating the need for precise door panel inclination adjustment while maintaining the ability to reflect the light beam for detection purposes
Solution Approach 2:
The detection system is segmented into fixed components (light projector, light receiver, and reflector plate all mounted on door frame) rather than requiring integration with the moving door panel, simplifying installation and reducing adjustment complexity
3Adaptability or versatility
If the reflector plate is moved within the sill groove to accommodate door movement, then adaptability to door movement is improved, but susceptibility to dust accumulation and damage increases
Solution Approach 1:
The reflector plate is extracted from the sill groove environment and repositioned to the door frame structure, removing it from the dust-prone area while maintaining its functional role in the detection system
Solution Approach 2:
Instead of moving the reflector plate with the door (original approach), the solution inverts the approach by keeping the reflector plate stationary on the door frame and allowing the light beam path to adapt to door movement
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
Facilitates easy installation and operation by allowing the light beam to adjust its path automatically, preventing eye exposure and reducing the risk of false object detection due to dust, while maintaining effective foreign object detection during door closure.
Implementation Method 1
a reflector reflecting the light beam emitted from the light projector; and a light receiver configured to receive the light beam reflected by the reflector
Data Source
AI summary
An elevator safety device includes: a light projector configured to emit light beam; a reflector reflecting the light beam emitted from the light projector; and a light receiver configured to receive the light beam reflected by the reflector. The light projector and the light receiver are arranged between a car landed on a landing floor and a wall of an elevator shaft and above an upper end of an entrance opening. The reflector is arranged between the car landed on the landing floor and the wall of the elevator shaft and below a lower end of the entrance opening.