Elevator Landing Door Mechanical Locking Mechanism
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Solution Overview
Problem
Existing elevator systems lack a reliable mechanism to prevent elevator car operation during maintenance and inspection, as maintenance personnel may forget to engage safety switches, and current solutions are not universally applicable across different elevator types.
Innovation Solution
A mechanical hoistway access control device comprising base plates, a slider, a latch, and elastic members that mechanically lock the landing door switch, ensuring the elevator car remains stopped during maintenance by preventing the landing door from fully closing, thus blocking the engagement of the landing door switch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a landing door switch is used to control elevator operation, then the elevator car can be stopped when the landing door is opened, but the elevator car may resume operation once the landing door is completely closed during maintenance, regardless of whether a maintenance person is in the hoistway
Solution Approach 1:
The invention divides the door closing process into two distinct phases: normal closing (where the slider is retracted and the landing door switch can engage) and maintenance closing (where the slider protrudes and prevents landing door switch engagement). This segmentation ensures that during maintenance, even if the landing door is completely closed, the protruding slider mechanically blocks the landing door switch from engaging, thereby preventing elevator car operation and ensuring maintenance personnel safety.
2Reliability
If a safety switch is provided in addition to landing door switches, then elevator operation can be controlled during maintenance, but maintenance personnel may forget to operate the safety switch since the operation method differs depending on elevator types
Solution Approach 1:
The invention extracts the safety function from the electrical control system (landing door switches and safety switches) and implements it through a purely mechanical mechanism - the slider that protrudes during maintenance. This mechanical protrusion automatically prevents landing door switch engagement, eliminating the need for maintenance personnel to manually operate additional safety switches. The safety function is thus 'taken out' from complex electrical operations and replaced with an automatic mechanical blockage system.
3Reliability
If the landing door is opened manually during maintenance, then the elevator car does not travel, but there is always a chance that a maintenance person may forget to operate the safety switch
Solution Approach 1:
The invention implements a self-service safety mechanism where the slider automatically protrudes when the landing door is opened during maintenance (detected by the door opening mechanism). This automatic protrusion then self-blocks the landing door switch from engaging when the door is closed, without requiring any manual intervention from maintenance personnel. The system serves itself by automatically activating the safety blockage function, eliminating human error in safety switch operation.
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
The mechanical hoistway access control device reliably prevents elevator car operation during maintenance and inspection, reducing the risk of accidents and ensuring safe conditions by mechanically locking the landing door switch engagement, applicable to various elevator models without requiring electrical components or complex wiring.
Implementation Method 1
configured to protrude out from a door closing side end of the landing door by a first elastic member to take an extended position
Implementation Method 2
a second elastic member attached to the latch and configured to bias the latch in the latching direction
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A mechanical hoistway access control device (1) for an elevator landing door (2) includes a first and a second base plates (7a, 7b) mounted on the hoistway side of a landing door panel and arranged in parallel with one another, a slider (8) slidably arranged between the first and second base plates (7a, 7b) and configured to move in conjunction with a car door and configured to protrude out from a door closing side end (12) of the landing door (2) by a first elastic member (10) to take an extended position when the landing door (2) is opened with no elevator car at the landing, and a latch (9) attached to the landing door (2) and configured to engage with the slider (8) to keep the slider (8) in the extended position once the slider (8) protrudes out from the door closing side end of the landing door (2).