Safety Devices in Lifts (Elevators)
Safety devices are essential components in elevator systems, designed to protect passengers, operators, and the equipment itself from potential hazards. These devices ensure that the elevator operates safely under normal conditions and in the event of an emergency.
Key Lift Safety Devices:
Safety Brakes (Overspeed Governor)
- Function: Activated in case of excessive speed, the safety brake system halts the elevator to prevent dangerous overspeed situations.
- Working: The overspeed governor detects any abnormal acceleration or deceleration and triggers the brake mechanism to stop the lift.
Buffers (Shock Absorbers)
- Function: Located at the bottom of the lift shaft, buffers absorb the impact in case of an unexpected stop or fall, preventing cabin damage.
- Types: Hydraulic, spring, or friction-based buffers.
Door Interlocks
- Function: These prevent the doors from opening when the lift is not at the floor level. The system ensures that the lift doors remain locked when the car is moving.
- Safety: Prevents passengers from accidentally falling into the shaft when the elevator is in motion.
Limit Switches
- Function: These switches are designed to stop the elevator from traveling beyond the designated floor, preventing it from going too high or low.
- Safety: Ensure that the elevator doesn’t exceed the mechanical limits, protecting both the elevator and its passengers.
Emergency Stop Button
- Function: This button allows passengers or operators to stop the elevator immediately in case of an emergency.
- Safety: It halts the elevator’s movement, allowing for a controlled emergency response.
Emergency Communication System
- Function: A two-way communication system allows passengers to communicate with the control center in case of an emergency.
- Safety: It helps ensure that rescue teams are promptly notified in case of a breakdown or emergency.
Emergency Power Supply (Battery Backup)
- Function: Provides power to the lift’s lighting, communication systems, and emergency controls during a power failure.
- Safety: Ensures that the elevator can still be used to safely bring passengers to the nearest floor in case of a power outage.
Pit Stop Switch
- Function: Located at the bottom of the lift shaft, this switch stops the elevator when it reaches the lowest point, preventing it from going beyond its range.
- Safety: Protects against cabin damage due to over-travel at the lower end.
Load Weighing Device
- Function: Monitors the weight inside the lift to prevent overloading.
- Safety: If the elevator exceeds the maximum weight capacity, it will not operate, ensuring no damage to the system or risk to passengers.
Overload Alarm
- Function: Alerts when the elevator is overloaded beyond its rated capacity.
- Safety: Prevents operation when the weight exceeds safe limits, ensuring optimal performance.
Speed Limiter (Governor)
- Function: Monitors the speed of the lift. If it exceeds a pre-set limit, the governor activates safety brakes.
- Safety: Ensures the lift doesn’t reach unsafe speeds.
Anti-Tilt Device
- Function: Prevents the elevator car from tilting or swaying excessively, ensuring a smooth and stable ride.
- Safety: This device provides stability, especially in older buildings or with heavy loads.
Fire Alarm and Fire Protection System
- Function: Detects fires and activates emergency protocols, such as automatically bringing the lift to a designated fire-safe floor.
- Safety: Keeps passengers safe in case of a fire, preventing them from being trapped in a dangerous situation.
Seismic Sensors
- Function: These sensors detect seismic activity (e.g., earthquakes) and stop the elevator from operating until it is safe to resume.
- Safety: Protects passengers in earthquake-prone areas by preventing the lift from moving during tremors.
Cabin Tilt Detection System
- Function: Detects if the cabin has tilted out of alignment due to abnormal conditions.
- Safety: Prevents further movement if the cabin is tilted, reducing risk to passengers and machinery.
