Building Design and Construction

Definitions of Elevator Terms

Annunciator. An electrical device that indicates, usually by lights, the floors at which an elevator landing signal has been registered.
Buffer. A device for stopping a descending car or counterweight beyond its bottom terminal by absorbing and dissipating the kinetic energy of the car or counterweight.
The absorbing medium may be oil, in which case the buffer may be called an oil buffer, or a spring, in which case the buffer may be referred to as a spring buffer.

Bumper. A device other than a buffer for stopping a descending car or counterweight beyond its bottom terminal by absorbing the impact.
Car. The load-carrying element of an elevator, including platform, car frame,
enclosure, and car door or gate.
Car-Door Electric Contact. An electrical device for preventing normal operation of the driving machine unless the car door or gate is closed.
Car Frame. The supporting frame to which the car platform, guide shoes, car safety, and hoisting ropes or hoisting-rope sheaves, or the plunger of a hydraulic elevator are attached.
Car Platform. The structure on which the car and its floor are mounted.
Car Switch. A manual operating device in a car by which an operator actuates the control.
Control. The system governing the starting, stopping, direction of motion, acceleration, speed, and retardation of the car.
VVVF Control. A method of controlling the smooth starting and stopping of alternating-current motors, utilizing solid-state, variable-voltage, variablefrequency controls. This system is displacing dc motors for medium and highspeed elevators.
Generator-field control employs an individual generator for each elevator, with the voltage applied to a dc driving-machine motor adjusted by varying the strength and direction of the generator field.
Multivoltage control impresses successively on the armature of the drivingmachine motor various fixed voltages, such as those that might be obtained from multicommutator generators common to a group of elevators.
Rheostatic control varies the resistance or reactance of the armature or the field circuit of the driving-machine motor.
Single-speed, alternating-current control governs a driving-machine induction motor that runs at a specified speed.
Two-speed alternating-current control governs a two-speed driving-machine induction motor, with motor windings connected to obtain various numbers of poles.
Dispatching Drive. A device that operates a signal in a car to indicate when the car should leave a designated floor or to actuate the car’s starting mechanism when the car is at a designated floor.
Driving Machine. See Machine.
Emergency Stop Switch. A car-located device that, when operated manually, causes the car to be stopped by disconnecting electric power from the drivingmachine motor.
Hoistway. A shaft for travel of one or more elevators. It extends from the bottom of the pit to the underside of the overhead machine room or the roof. A blind hoistway is the portion of the shaft that passes floors or other landings without providing a normal entrance.
Hoistway Access Switch. A switch placed at a landing to permit car operation with both the hoistway door at the landing and the car door open.
Hoistway-Door Electric Contact. An electrical device for preventing normal operation of the driving machine unless the hoistway door is closed.

Hoistway-Door Locking Device. A device for preventing the hoistway door or gate from being opened from the landing side unless the car has stopped within the landing zone.
Leveling Device. A mechanism for moving a car that is within a short distance of a landing toward the landing and stopping the car there. An automatic maintaining,
two-way, leveling device will keep the car floor level with the landing during loading and unloading.
Machine (Driving Machine). The power unit for raising and lowering an elevator car.
Electric driving machines include an electric motor and brake, driving sheave or drum, and connecting gearing, belts, or chain, if any. A traction machine  drives the car through friction between suspension ropes and a traction sheave.
A geared-drive machine operates the driving sheave or drum through gears. A gearless traction machine has the traction sheave and the brake drum mounted directly on the motor shaft. A winding-drum machine has the motor geared to a drum on which the hoisting ropes wind. A worm-geared machine operates the driving sheave or drum through worm gears. A helical-geared machine operates the driving sheave through a helical-type gearbox.
Hydraulic driving machines raise or lower a car with a plunger or piston moved by a liquid under pressure in a cylinder.
Nonstop Switch. A device for preventing a car from making registered landing stops.
Operating Device. The car switch, push button, lever, or other manual device used to actuate the control.
Operation. The method of actuating the control.
Automatic operation starts the car in response to operating devices at landings, or located in the car and identified with landings, or located in an automatic starting mechanism, and stops the car automatically at landings. Group automatic operation starts and stops two or more cars under the coordination of a supervisory control system, including automatic dispatching means, with one button per floor in each car and up and down buttons at each landing. Selective collective automatic operation is a form of group automatic operation in which car stops are made in the order in which landings are reached in each direction of travel after buttons at those landings have been pressed. Single automatic operation has one button per floor in each car and only one button per landing, so arranged that after any button has been pressed, pushing any other button will have no effect on car operation until response to the first button has been completed.
Car-switch operation starts and stops a car in response to a manually operated car switch or continuous-pressure buttons in a car.
Parking Device. A device for opening from the landing side the hoistway door at any landing when the car is within the landing zone.
Pit. Portion of a hoistway below the lowest landing.
Position Indicator. Device displaying the location of a car in the hoistway.
Rise. See Travel.
Rope Equalizer. A device installed on a car or counterweight to equalize automatically the tensions in the hoisting ropes.

Runby. The distance a car can travel beyond a terminal landing without striking a stop.
Safety. A mechanical device attached to the counterweight or to the car frame or an auxiliary frame to stop or hold the counterweight or the car, whichever undergoes overspeed or free fall, or if the hoisting ropes should slacken.
Safety Bulkhead. In a cylinder of a hydraulic elevator, a closure, at the bottom of the cylinder but above the cylinder head, with an orifice for controlling fluid loss in case of cylinder-head failure.
Slack-Rope Switch. A device that automatically disconnects electric power from the driving machine when the hoisting ropes of a winding-drum machine become slack.
Terminal Speed-Limiting Device (Emergency). A device for reducing automatically the speed of a car approaching a terminal landing, independently of the car-operating device and the normal terminal stopping device if the latter should fail to slow the car as intended.
Terminal Stopping Device. Any device for slowing or stopping a car automatically at or near a terminal landing, independently of the car-operating device. A final terminal stopping device, after a car passes a terminal landing, disconnects power from the driving apparatus, independently of the operating device, normal terminal stopping device, or emergency terminal speed-limiting device. A stopmotion switch, or machine final terminal stopping device, is a final terminal stopping device operated directly by the driving machine.
Transom. One or more panels that close an opening above a hoistway entrance.
Travel (Rise). The vertical distance between top and bottom terminal landings.
Traveling Cable. A cable containing electrical conductors for providing electrical connections between a car and a fixed outlet in a hoistway.
Truck Zone. A limited distance above a landing within which the truck-zoning device permits movement of a freight-elevator car with its door or the hoistway door open.
Truck-Zoning Device. A device that permits a car operator to move, within a specified distance above a landing, a freight-elevator car with its door or the hoistway door open.

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