Elevator 101: Glossary

Please use our Glossary of Terms to look up specific terms or words relating to elevators and  elevator systems.  If you cannot find a term or word that you are looking for, please feel free to contact us to help answer and questions you have.


AC - Alternating Current - A type of power for an elevator machine.

ADA - American Disabilities Act The Americans with Disabilities Act of 1990 was signed into law by President Bush on July 26, 1990. The ADA is designed to give civil rights protection to people with disabilities, similar to those granted by the Civil Rights Act.

Automatic Leveling Device - A device that automatically moves the platform, within the leveling zone only, towards the landing and automatically stops it at the landing.

Backup Nut - An internally threaded component, used in conjunction with a screw and nut drive, so arranged that it does not normally carry the load but is capable of doing so in the event of failure of the threads in the main driving nut.

Brake - An electromechanical mechanism employed to bring the lift to rest smoothly and hold it in position.

Cab (Car) - Finished portion of the elevator in which people ride in.

Capacity - Indicates the amount of weight a given elevator is able to support safely.

Car Gate - Door or gate that is connected with the car and travels with the car.

Car Operating Panel - A panel mounted in the car containing the car operating controls, such as call register buttons, door open and close, alarm, emergency stop and whatever other buttons or key switches are required for operating.

Carriage (Load-Carrying Unit) - The whole moving part of the lift designed in the form of a chair or platform, to carry a user on.

Code - A system of regulations pertaining to the design, manufacture, installation and maintenance of elevators, dumbwaiters, escalators and moving walks. The most widely recognized and used is ANSI A-17.1 sponsored by the National Bureau of Standards, The American Institute of Architects, The American Society of Mechanical Engineers, and published by ASME. It has been adopted by many states. Some states and cities have written their own codes, most of which are based on the ANSI A-17.1.

Continuous-Pressure Operation - Operation by means of operating devices, located at the carriage and elsewhere, used to control the movement of the carriage as long as the operating devices are manually maintained in the actuating position.

Control Valve - The device, which, on hydraulic elevators, controls the oil flow to and from the jack.

Controller - An assembly of electrical contactors, relays and/or other components constituting the electrical control equipment for the lift.

Cylinder - The outermost lining of a hydraulic jack.

DC - Direct Current - A source of power for an elevator machine.
Door Lock - Any type of mechanical lock designed to prevent the opening of a hoistway door from 
the landing side.

Door Sill - The threshold of a door opening with grooves to guide the bottom of the car door.

Drive - An electromechanical drive unit arrangement that causes the carriage to move when provided with an electrical power input.

Drive Unit - The complete assembly of an electric motor, brake and power transmission or hydraulic system that supplies the power for the movement of the carriage.

Electromechanical Interlocks - Electrically wired lock in the hoistway door that prevents the door from opening when the elevator is in use

Emergency Stop Switch - A hand-operated switch in the car push button station which, when thrown to the off position, stops the elevator and prohibits its running.

Escalators
Escalators are powered by constant-speed alternating current motors. Modern escalators have single piece aluminum or steel steps that move on a system of tracks in a continuous loop.

Escalators are required to have moving handrails that keep pace with the movement of the steps. The direction of movement (up or down) can be permanently the same, or be controlled by personnel according to the time of day.

Final Terminal-Stopping Device - A terminal electrical switch or similar stopping device that is positively and mechanically operated by the carriage so that it causes the power to be removed from the drive unit, independently of the functioning of the normal terminal landing stopping device, after the carriage has passed a terminal landing.

Follow -Through - the amount of additional free movement, normally associated with the operation of a sensitive edge or sensitive surface, provided in the actuation of an electrical switching device after the electrical contact has been opened.

Governor - A mechanical speed control mechanism. For elevator, it is a wire rope driven centrifugal device used to stop and hold the movement of its driving rope. This initiates the activation of the car safety device. It opens a switch, which cuts off power to the drive motor and brake if the car travels at a preset overspeed in the down direction. Some types of governors will also open the governor switch and cut off power to the drive motor and brake if the car overspeeds 
in the up direction.

Guard - A substantially constructed protective cover designed to prevent accidental contact with a potential hazard.

Guide Rails - Metal members formed into a suitable section or arrangement to retain and guide the carriage during its motion in the course of its travel.

Hoistway - The space enclosed by fireproof walls and elevator doors for the travel of an elevator. It includes the pit and terminates at the underside of the overhead machinery space floor or grating, or at the underside of the roof where the hoistway does not penetrate the roof. (Hoistway is sometimes called "hatchway" or "hatch".)

Hoistway Door - Door opening to hoistway at a landing.

Hoistway Enclosure - The fixed structure, consisting of vertical walls or partitions, which isolates the hoistway from all other areas or from an adjacent hoistway, and in which the hoistway doors and door assemblies are installed.

Hydraulic Drive (System) - A machine in which energy is applied by means of a fluid under pressure in a cylinder equipped with a plunger or piston.

Hydraulic Elevator - A power elevator where the energy is applied, by means of a liquid under pressure, in a cylinder equipped with a plunger or piston. Hydraulic elevators are commonly used for low rise applications up to six stories. In this system, a hydraulic cylinder and piston assembly is installed into the ground. Hydraulic oil is pumped by the pump unit through a feedline to the cylinder assembly. This causes the elevator car to rise upwards. Due to the design, hydraulic elevators are low speed (typically 100 to 150 foot per minute) and are inherently lower in cost than traction 
elevators.

Hydraulic - Holeless Hydraulic elevators do not use a conventional piston/casing arrangement. They use a pair of above ground cylinders, which makes it practical for environmentally or cost sensitive buildings with 2, 3, or 4 floors.Benifites Of MRL Elevators
The use of the MRL elevator will save a significant amount of energy (estimated at 70-80%) as compared to hydraulic elevators, as well as space.  The power feeders for the MRL are significantly reduced due to the more efficient design and the counter-balancing provided with traction 
equipment.

The MRL elevator eliminates the cost and environmental concerns associated with a buried hydraulic cylinder filled with hydraulic oil and so MRL’s have been labeled as “eco-friendly”. Over the years hydraulic elevators have come under greater scrutiny relative to environmental concerns due to the buried hydraulic cylinder.  Because the MRL elevator is a traction elevator with all its components above ground, this is not a concern for this equipment.

Hydraulic - RopedRoped Hydraulic elevators use both above ground cylinders and a rope system, which combines the versatility of inground hydraulic with the reliability of holeless hydraulic, even though they can 
serve up to 8-10 floors.

Interlock - A device having two related and interdependent functions which are: (1) to prevent the operation of the driving machine by the normal operating device unless the hoistway door is locked in the closed position. An electro-mechanical device that prevents operation of an elevator unless the hoistway doors are in the closed and locked position; (2) to prevent opening of a hoistway door from the landing side unless the elevator is in the landing zone and is either stopped or being 
stopped.

Jack (Hydraulic) - A unit consisting of a cylinder equipped with a plunger or piston which applies the energy by a liquid under pressure.

Landing - That portion of a floor, balcony, or platform used to receive and discharge passengers or freight.

Landing Door - The moveable door at the entrance of an elevator which provides access to the hoistway.

Limited Use / Limited Application (LU/LA) Elevators - The new solution to providing accessibility in commercial buildings, this is a small passenger elevator permitted to travel up to 25'. Ideal for buildings such as schools, town halls, office buildings and churches, that need more than a wheelchair lift. Requires a 14" pit, reduced overhead in existing buildings, reduced hoistway size, and can operate on single phase power.

Machine Room - This is a room constructed adjacent to the elevator hoistway to accommodate the drive system and the electrical box.

Machine-Room-Less (MRL) Elevators - Machine-Room-Less elevators are just that, elevators that don't require a machine room unlike the traditional designs of overhead traction and hydraulic elevator that do. The new lift design presents a departure from the traditional, looped over-the-top traction rope routing of traction elevators. The ends of the cables are fixed to the supporting structure, and the length of the cable are connected to the car and counterweight by means of a force-multiplying, energy saving compound pulley system. Machine Room-less elevators have become a welcome alternative to the older hydraulic elevator for low to medium rise buildings.

The MRL elevator utilizes a gearless traction type machine, which results in superior performance and ride quality compared with hydraulic elevators.  MRL’s can also operate at faster speeds thus increasing the perception of quality over a conventional hydraulic and require less space to do so.

Benifites Of MRL Elevators The use of the MRL elevator will save a significant amount of energy (estimated at 70-80%) as compared to hydraulic elevators, as well as space.  The power feeders for the MRL are significantly reduced due to the more efficient design and the counter-balancing provided with traction equipment.

The MRL elevator eliminates the cost and environmental concerns associated with a buried hydraulic cylinder filled with hydraulic oil and so MRL’s have been labeled as “eco-friendly”. Over the years hydraulic elevators have come under greater scrutiny relative to environmental concerns due to the buried hydraulic cylinder.  Because the MRL elevator is a traction elevator with all its components above ground, this is not a concern for this equipment.

Nut, driving - An internally threaded component that acts in conjunction with a screw to produce linear motion of the carriage, eg, a rotating screw engaging with a fixed nut or a re-circulating ball nut.

Overhead Clearance - This is the clearance needed to accommodate the components on top of an elevator car. It is measured from the upper level floor to the lowest obstruction at the top of the hoistway.

Over Travel - A short distance beyond the terminal floor as allowance for building inaccuracies, manufacturing or installation inaccuracies.

Pinion - A wheel with machine-cut teeth specially designed to engage with those of similarly 
toothed wheels or racks, used to transmit relative motion.

Pit - Portion of the hoistway extending from sill level of lowest landing to the floor at the bottom of the hoistway.

Platform - A flat and substantially horizontal structure that is part of the carriage and that supports a user or users.

Plunger - The inside moveable part of a hydraulic jack that attaches to an elevator car frame on direct drive application or drive sheave on a cabled hydraulic system.

Position Indicator -  A device that indicates the position of the elevator car in the hoistway. It is called a hall position indicator when placed at a landing, or car position indicator when placed in the 
car.

Power Unit - That device on hydraulic elevators which supplies the motive force to run the car.

Preventive Maintenance - Inspections, tests, adjustments, cleaning and similar activities carried out on elevator equipment with the intention of preventing malfunctions from occurring during operation. It is designed to keep equipment in proper operating order and is done on a scheduled basis. It is also referred to as scheduled maintenance.

Pump - The device which draws oil from the tank and pushes it through the oil line to the jack to move the elevator up.

Push Button Station - A decorative device containing one or more hand-operated devices (buttons or switches) by which the passenger tells the controller what action is desired.

Rail - This is the metal track that guides the elevator in a vertical path.

Rack - A metal or plastic strip in which specially shaped teeth have been cut or molded. These teeth engage with a pinion to form a positive driving means to convert rotary motion into linear 
motion.

Ramp - A structure or structural member providing an inclined surface connecting one level with 
another.

Rated Load - The load that a lift is designed and installed to carry at the rated speed.

Rated Speed - The speed at which a lift is designed to operate in the up direction with the rated load on the carriage.

Relay - An electric device that is designed to interpret input conditions in a prescribed manner and after specified conditions are met, to respond and cause contact operation or create change in associated electric control circuits.

Roller Guides - Guide shoes which use rollers that rotate on guide rails rather than sliding on the rails.

Roomless Machine - Drive system of elevators that do not require a machine room.

Roped Hydraulic - A drive system that utilizes a hydraulic jack connected to the car wire ropes or indirectly coupled to the car via wire ropes and sheaves.

Safeties - Mechanical devices normally attached to the carriage to stop and sustain the carriage on the guide rails or otherwise, in the event of suspension or drive failure.

Screw, Driving - An externally threaded driving component that acts in conjunction with a driving nut.

Sensitive Edge - A protective device attached to any edge of the carriage, which, when activated by contact with an obstruction, stops the lift.

Sensitive Surface - A protective device similar in effect to a sensitive edge but so arranged as to 
protect a whole surface, such as the underside of a platform or other large area.

Sill - The bottom horizontal member of an entrance which provides the foundation and footing for 
the entrance frame. The sill extends the full width of the door travel.

Single Speed Door - A type of door consisting of one horizontal sliding panel.

Sling - L-shaped, heavy duty metal support that the elevator car rests on. The sling travels up and 
down, carrying the elevator car.

Specifications - A detailed itemized description of the plans, materials, dimensions and all other requirements proposed for the installation of the equipment.

Stair Chair Lift (Stairchair) - A stair lift equipped with a carriage in the form of a chair.

Stair platform Lift - A stair lift equipped with a carriage in the form of a platform.

Stair lift - A non-portable, permanently installed elevating device for transporting persons with physical disabilities between two or more levels by means of a guided carriage moving substantially 
in the direction of a flight of stairs or a ramp.

Tank - A container to store the oil used to move the elevator.

Traction Machine - An electric machine in which the friction between the hoist ropes and the 
machine sheave is used to move the elevator car with the cable.

Traction Elevators -Traction elevators are commonly used for mid and high rise applications six stories and above. In 
this system, there is typically a large motor above the elevator hoistway which turns a large drive sheave. Multiple steel wire ropes are attached to the top of the elevator car frame. These hoist ropes then route vertically up the hoistway and over the drive sheave grooves. As the motor turns the drive sheave, the traction between the drive sheave and the hoist ropes causes the elevator to 
go up and down.

Traction elevators are more complex due to the higher speeds of travel (typically 250 to 2000 foot per minute) and the necessary addition of safety equipment to ensure safe operation. As a result, they are higher in cost than hydraulic elevators.

Travel - The vertical distance between the bottom and top limits of travel.

Traveling Cable - A cable made up of electric conductors, which provides electrical connection between an elevator or dumbwaiter car, or material lift, and a fixed outlet in the hoistway or machine room.

Two Speed Door - A type of door consisting of two horizontal sliding panels, which move, in the same direction.

Vertical Platform Lift - A non-portable, permanently installed elevating device for transporting persons with physical disabilities on a platform that moves vertically between permanent levels.

Vertical Platform Lift (Enclosed) - A vertical platform lift having an enclosed runway to a minimum height of 1070 mm above the top landing.

Vertical Platform Lift (Unenclosed) - A vertical platform lift having a partially enclosed or unenclosed runway.

Wheelchair and attendant platform - A platform designed to accommodate and support one person with a physical disability, sitting in a wheelchair or standing on the platform, accompanied by an attendant.

Wheelchair Platform - A platform designed to accommodate and support only one person with a physical disability sitting in a wheelchair.

Winding Drum - A geared drive machine in which the suspension ropes are fastened to and wind on a rotating drum.

Working Pressure - The pressure measured at the pumping unit when lifting the carriage with rated load at rated speed.

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