Mechanical Hoistway Access Control for Elevator Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elevators may resume operation during maintenance without ensuring safety, as existing systems rely on manual intervention and varying safety switch operations, posing risks of unintended movement or intrusion.
Innovation Solution
A mechanical hoistway access control device with pivotably attached blocking members on both landing and car doors, preventing complete closure of the landing door when the elevator car is not present, and using a latch mechanism to lock the door during maintenance, ensuring the elevator car remains stopped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a landing door switch device is released by unlocking its interlocking mechanism from the landing and opening the landing door manually during maintenance, then the elevator car does not travel when the landing door is open, but the elevator car may resume operation once the landing door is completely closed during elevator maintenance regardless of whether a maintenance person is in the hoistway
Solution Approach 1:
The patent introduces an intermediary mechanical blocking member that physically prevents the landing door from closing completely during maintenance mode. This blocking member acts as a mediator between the door closing force and the door switch, ensuring that the door switch cannot be engaged while maintenance personnel are in the hoistway. The blocking member is simplicity-designed as a mechanical component that can be manually positioned, avoiding complex electrical or electronic control systems while reliably preventing unintended door closure and elevator resumption during maintenance.
2Reliability
If inspection mode switch is added in addition to landing door switch devices, then elevator operation can be controlled during maintenance, but there is always a chance that a maintenance person might forget to operate the safety switch since the method of operating a safety switch differs depending on types of elevators
Solution Approach 1:
The patent implements a self-service safety mechanism where the blocking member is automatically positioned by the door opening action itself. When the landing door is opened during maintenance, the blocking member is naturally moved into a position that prevents door closure, without requiring maintenance personnel to manually operate any switches or controls. This eliminates the need for operators to remember or correctly operate complex safety switches, as the system automatically enters a safe state through the simple action of opening the door.
3Reliability
If mechanical blocking member is used to prevent complete closing of landing door during maintenance, then elevator operation is reliably prevented, but the device requires additional mechanical components on both landing door and car door
Solution Approach 1:
The patent merges the blocking function with the existing door interlocking mechanism. The blocking member is integrated into the door assembly structure, utilizing the existing mechanical framework of the elevator door system. Rather than adding completely separate blocking devices, the invention combines the blocking functionality with the door's existing mechanical components, such that the blocking member works in conjunction with the interlocking mechanism already present in the door assembly, thereby reducing the number of additional components needed.
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 device reliably prevents elevator operation during maintenance and inspection, reducing the risk of accidents by mechanically blocking the landing door switch engagement, applicable to various elevator models without requiring electrical components or complex wiring.
Implementation Method 1
a first blocking member (12) mounted on a position on a landing door frame (9) above a landing door (5)... The first blocking member (12) is configured to fall down in the first horizontal position to mechanically block complete closing of the landing door
Implementation Method 2
a second blocking member (3) mounted on a position on a car door frame (23) above a car door (19)... The second blocking member (3) is configured to fall down in the second horizontal position before the first blocking member (12) falls down to prevent the first blocking member (12) from falling down
Implementation Method 3
The landing door switch device, including an interlocking mechanism and a door switch, is configured to be released by mechanically interlocking with an elevator car door when the elevator car door is opened
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A mechanical hoistway access control device for an elevator landing door 19 includes a first blocking member 2 mounted on a position on a landing door frame 23 above a landing door, and a second blocking member 3 mounted on a position on a car door frame above a car door. The first blocking member is pivotably attached between an upright position and a first horizontal position extending in the door opening direction about a horizontal shaft. The second blocking member is pivotably attached between an upright position and a second horizontal position about a horizontal shaft, the second horizontal position being where the second blocking member protrudes out to the landing door side to block movement of the first blocking member.