Elevator Pivotable Balustrade for Counterweight Collision Avoidance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The risk of injury to maintenance personnel on an elevator car roof during inspection runs is high due to the close passing of the car and counterweight, exacerbated by the potential for collision with omega-shaped counterweight guide rails and drive units in engine-room-less elevators, where the balustrade is offset and may not provide adequate protection.
Innovation Solution
A pivotable balustrade on the elevator car roof is designed to be secured in either an inclined or vertical fall protection position, increasing the horizontal distance from the counterweight and incorporating a locking mechanism to prevent unintended movement, with safety switches or sensors to ensure the balustrade is in a secure position before allowing inspection runs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the balustrade is arranged offset inwardly to provide fall protection, then fall protection is improved, but the horizontal distance from the counterweight is reduced increasing collision risk
Solution Approach 1:
The balustrade is designed to be pivotable between a first position (inclined outwardly) and a second position (vertical or inwardly inclined). The system dynamically adjusts the balustrade position based on operational mode: during inspection runs, it pivots to the first position to maximize horizontal distance from the counterweight and reduce collision risk, while during normal operation, it returns to the second position to provide optimal fall protection. This dynamic reconfiguration resolves the contradiction by allowing the balustrade to optimize for different functions at different times.
2Reliability
If the balustrade is positioned vertically for maximum fall protection, then fall protection is improved, but the accessible area for maintenance personnel is reduced
Solution Approach 1:
The balustrade pivots between positions to dynamically balance fall protection and accessibility. During normal operation, the vertical second position provides maximum fall protection. During inspection runs, the balustrade pivots to the first position (inclined outwardly), which increases the accessible area on the car roof while still maintaining adequate fall protection through the inclined configuration.
3Adaptability or versatility
If the balustrade is made pivotable to adjust position, then adaptability is improved, but device complexity increases
Solution Approach 1:
The balustrade incorporates a pivot mechanism with locking capability that allows it to assume different positions (first position inclined outwardly, second position vertical or inwardly inclined). This dynamic design provides adaptability for different operational modes while maintaining relatively simple construction through the use of pivot joints and locking mechanisms rather than complex active control systems.
Solution Approach 2:
The system includes sensors that detect the balustrade's position and provide feedback to the control unit. The control unit monitors whether the balustrade is in the first or second position and can trigger appropriate responses, such as preventing inspection run mode activation when the balustrade is not in the correct position. This feedback mechanism ensures safe operation while managing the complexity of the pivotable design.
4Reliability
If safety sensors are added to detect balustrade position, then safety is improved, but device complexity increases
Solution Approach 1:
Sensors are positioned to detect whether the balustrade is in the first or second position and provide this information to the control unit. The control unit uses this feedback to enforce safety logic, such as preventing the elevator from operating in inspection run mode when the balustrade is not in the required first position. This feedback-based safety system improves reliability by ensuring proper balustrade positioning while maintaining manageable complexity through the use of standard sensor and control unit components.
Data Source
AI summary
An elevator includes a car movable in an elevator shaft and a counterweight movable together with the car in the elevator shaft in a direction of movement opposite to the direction of movement of the car. The car has a car roof and a balustrade arranged on the car roof at a side of the car facing toward the counterweight. The balustrade can be pivoted between a first fall protection position and a second fall protection position. In each of these fall protection positions the balustrade can be secured in order to prevent unintended movement of the balustrade. In the first fall protection position, the balustrade has an inclined orientation. In the second fall protection position, the balustrade has a vertical orientation.