Reference

Elevator Glossary

The elevator industry speaks its own language. Every term defined precisely, with context for how each is used in the field.

B 1 term

Buffer An energy-absorbing device located in the pit beneath the car and counterweight travel paths, designed to safely decelerate the car or counterweight in the event of an overtravel beyond the normal limits.

C 4 terms

Car Door The door panels mounted on the elevator car that travel with it, driven by the door operator and coupled to the landing doors at each floor through the door coupler mechanism. Car Frame The structural steel framework that supports the elevator car enclosure, attaches to the guide rails via roller guides or slide guides, and houses the safety device. Controller The electronic system that manages all aspects of elevator operation including motor control, door timing, floor dispatching, safety circuit monitoring, and communication with building systems. Counterweight A stack of cast-iron or concrete blocks that balances the weight of the elevator car plus approximately 40–50 percent of the rated load capacity, reducing the work required of the motor.

D 2 terms

Dispatching The process by which the elevator controller assigns car calls and hall calls to specific elevators in a group, using algorithms to optimise wait time, travel time, and energy consumption. Door Operator A door operator is the powered device or assembly that opens and closes an elevator car door and, in common automatic systems, the landing door coupled to it.

G 3 terms

Governor A speed-sensing safety device mounted at the top of the hoistway that triggers the car safety mechanism if the elevator exceeds a preset overspeed threshold. Group Supervisory Control A control layer that coordinates two or more elevators serving a shared group of floors. Guide Rails Vertical steel T-shaped rails mounted inside the hoistway that guide the car and counterweight during travel and provide the gripping surface for the safety device in an emergency stop.

H 2 terms

Hoistway The vertical shaft or enclosure in which the elevator car and counterweight travel, extending from the pit at the bottom to the overhead at the top. Hydraulic Elevator An elevator whose lifting energy is applied by pressurized liquid acting on a cylinder and plunger or piston.

I 1 term

Interlock A combined mechanical latch and electrical contact on each landing door that prevents the door from opening unless the car is present, and confirms to the controller that the door is fully closed and locked.

L 2 terms

Landing Door The door assembly mounted in the hoistway wall at each floor, held closed by an interlock and opened by the door coupler when the car arrives at that landing. Load Weighing A load-weighing device detects the load on an elevator platform and supplies that information to the control system.

M 1 term

Machine-Room-Less (MRL) A machine-room-less elevator has no separate conventional machine room; equipment may be in the hoistway, pit or an adjacent cabinet.

O 1 term

Overhead The vertical distance between the top floor landing and the ceiling of the hoistway, required to accommodate the car, crosshead, and safety clearances when the car is at its highest point of travel.

P 1 term

Pit The space at the bottom of the hoistway below the lowest landing, housing buffers, the governor tension sheave, and other equipment required for safe elevator operation.

R 2 terms

Releveling The automatic correction of the car position at a landing after the initial stop, compensating for rope stretch or load changes that cause the car floor to drift out of alignment with the landing floor. Roping The arrangement of hoist ropes, sheaves, and attachment points connecting an elevator car, counterweight, and drive sheave. In 1:1 roping, rope speed equals car speed; in 2:1 roping, rope speed is twice car speed.

S 2 terms

Safety Device A mechanical device mounted on the car frame that grips the guide rails to stop the car in a controlled manner when triggered by the governor, preventing free-fall in the event of rope failure or overspeed. Sheave A grooved wheel over which the hoist ropes pass, transmitting motion from the motor to the car and counterweight through friction between the ropes and the groove surface.

T 2 terms

Traction Elevator An elevator system that uses steel wire ropes or belts passing over a grooved sheave to raise and lower the car, relying on friction (traction) between the ropes and sheave to transmit motion. Travelling Cable A flexible multi-conductor cable that connects the elevator car to the controller, carrying power for lighting, door operator, and communication circuits as the car moves through the hoistway.

U 1 term

Unintended Car Movement (UCM) A hazardous condition in which the elevator car moves away from a landing while the doors are open, or the doors open while the car is between floors, addressed by dedicated detection and prevention systems required by modern codes.