Rectangular Belt Speed Limiter for Elevator Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing elevator safety devices do not effectively provide a flexible and precise safety space for maintenance personnel, especially when they enter the elevator shaft pit or are on the car roof, as they rely on cable-based speed limiters that can be unstable and noisy, and lack automatic switching mechanisms for enhanced safety.
Innovation Solution
An elevator safety device featuring a speed limiter belt with a substantially rectangular cross-section and abutment elements attached to its external side, which works in conjunction with a switchable stopping device to create a variable safety space by blocking the belt's movement, allowing automatic activation via the elevator control system or manual intervention, and can be integrated with existing systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cable-based speed limiter is used, then the safety device can be implemented, but the system becomes unstable and noisy
Solution Approach 1:
The invention changes the physical form of the speed limiter from a cable to a belt with a substantially rectangular cross-section. This parameter change in the geometry and structure of the speed limiter element eliminates the instability and noise issues associated with cable-based systems while maintaining the core functionality of limiting car speed and activating safety brakes.
2Measurement precision
If a cable-based speed limiter is used, then the safety device can be implemented, but the precision of speed limitation is reduced
Solution Approach 1:
The invention changes the physical form of the speed limiter from a cable to a belt with a substantially rectangular cross-section. This parameter change in the geometry and structure of the speed limiter element eliminates the instability and noise issues associated with cable-based systems while maintaining the core functionality of limiting car speed and activating safety brakes.
3Reliability
If the stopping device is always closed to ensure safety, then maintenance personnel are protected, but the car cannot move normally
Solution Approach 1:
The invention makes the stopping device dynamic rather than static. The stopping device can switch between opened and closed positions based on operational needs. During normal operation, it remains opened to allow car movement. When safety is required (detected via sensors or manually activated), it closes to block the speed limiter belt and prevent car movement, thus providing both operational flexibility and safety.
Solution Approach 2:
The system incorporates feedback mechanisms through sensors that detect the presence of maintenance personnel or abnormal conditions. When such conditions are detected, the feedback signal triggers the stopping device to close, automatically creating a safe state without requiring constant manual intervention, thus balancing safety with operational convenience.
4Adaptability or versatility
If the safety space is fixed in size, then the system is simple, but it cannot adapt to different maintenance scenarios
Solution Approach 1:
The invention makes the stopping device dynamic rather than static. The stopping device can switch between opened and closed positions based on operational needs. During normal operation, it remains opened to allow car movement. When safety is required (detected via sensors or manually activated), it closes to block the speed limiter belt and prevent car movement, thus providing both operational flexibility and safety.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention concerns an elevator safety device 10 for implementing a safety space 12 in an elevator shaft 14 having a movable car in the elevator shaft, the elevator safety device 10 comprising a car safety brake device 16 adapted to stop a car in the elevator shaft 14, a speed limiter 18 adapted to actuate the car safety brake device 16 by using a speed limiter revolution element being spanned by pulleys around which it recirculates, at least one abutment element 22 fastened to the speed limiter element, and an actuating unit comprising at least one stopping device 24 which is switchable between an opened position, to allow a movement of the speed limiter element and to allow the at least one abutment element 22 to pass the stopping device 24, and a closed position, to block a movement of speed limiter element by cooperation of the stopping device 24 with said abutment element 22, wherein the speed limiter revolution element is a belt 20 having a substantially rectangular cross section.