About us

First Floor:
Elevator Engineering
Elevator Glossary
Elevator Q & A
Elevator Remodeling

Second Floor:
True stories

Third Floor:
Building Disasters

Contact Us!
We'd enjoy hearing any comments.

All you need to know. ElevatorPro.Com

Elevator Glossary

If you are in a rush, just read the first few lines. These are written with the property manager/ building owner in mind. Purpose: to assist those coming in casual contact with elevators, those who read letters and proposals from elevator companies. (Some may be embarrassed to ask for an explanation of basic elevator terms and technology. This is written to provide a basic introduction to the industry and technology) These are not meant to be exacting technical definitions that no one else can understand.
This is what the top of a typical hydraulic elevator car looks like. The numeral "3" is stenciled on the elevator cartop emergency exit. This exit is normally locked from the top of the car . The two parallel beams connect the car to the car guides which ride on the hoistway rails. This is a very dangerous place to be.
The controller is the brain of the beast. It controls the movement and operation of the elevator. The controller shown here is a Schindler 211 Controller for hydraulic elevators. It is mounted to the power unit. You can see above the controller a UV5a valve, which is part of the power unit.
It counterbalances the weight of the elevator car. When the car goes up, it goes down.
The stationary lifting component in a hydraulic elevator. It is often buried in the ground. It is normally make of a steel tube with a steel cap welded on the bottom and a head at the top through which the piston slides. A synthetic rubber reinforced packing fits into the head of the cylinder and fits very tightly against the piston. When the piston is lifting the elevator, almost all of the load is transferred to the cylinder and in turn to the elevator pit floor on which it rests.
A Rube Goldberg affair composed of arms, belts, pulleys, chains and a motor that opens and closes the elevator doors. It is attached to the top of the elevator car and usually has an arm that is attached to the car door. When the elevator car is at a floor, linkages temporarily connect it to the hall (or hoistway) doors allowing them to open along with the car door. Perhaps the most commonly used door operator is the ubiquitous "G.A.L. operator." If you want to impress your elevator technician, ask him, "do we have G.A.L. operators on this car?"
A vertically challenging piece of equipment. Not to be confused with other sorts of contraptions that have no hoistway enclosure or interlocked car gates or doors or hoistway gates or doors with interlocks. If it costs a lot of money, it's an elevator. (all those redundant safety devices don't come cheaply) If it seems like a real bargain, it's a Lift in U.S. parlance. This is not to be confused with a Lift in other countries which is an elevator here. Got it?
You don't always see him, but he usually leaves a paper trail wherever he goes. It's his job. An inspector normally inspects your elevators from two to four times a year.

Very few inspectors actually work for the State of Pennsylvania, Department of Labor and Industry-Elevator Division. Most work for an insurance carrier who actually foots the bill for their work and in turn bills you for the inspection.

Like in any profession, some are better than others (Well, except for building management. They're all top notch.)

Have you ever noticed that they will sometimes find the most picayune things to write up? Some things have existed for many years-even since the elevator was constructed and inspected by that first inspector eons ago. And though they have been carefully and methodically doing their job for ages its only just this week that they find the screw that needs another quarter turn to make things just right. Did you ever get suspicious that they save up little deficiencies as a squirrel saves nuts, for the time they need something for their report? Come on ,haven't you had that thought from time to time? Well, how dare you. I would never suspect them of anything like that. And you shouldn't either. They are our friends and probably also know about this web page.

Where do inspectors come from? It is rumored that they are bred in captivity and fed a strict diet of Krispy Creme filled donuts, coffee and bowls of hot chili. But actually they're normally just recycled elevator mechanics who put years of knowledge to use following retirement, so you can rest easy at night and worry about more important things like R.O.I., and missing Braille plates.

The hole in the hall door, usually near the top of the door.
An often misunderstood, much maligned component. It is a small piece of metal and plastic that holds the elevator door in the track. The gib slides back and forth in the those slots you see on the floor when you get in and out of the elevator. There are normally two gibs for each individual door panel. The plastic part of the gib actually touches the track in each sill. There is also a metal part. If there is a fire and the heat melts the plastic, the metal part is still there sticking down in the groove and keeping the door in place and the flames out of the elevator hoistway.

Though small, a gib is strong. But it takes lots of abuse. Often, when a door is hit hard, by delivery people or building tenants, the gibs will bend or break off. If this happens when the elevator is moving in the down direction it can cause extensive and expensive damage to the elevator. Usually though, the damage is minimal.

I have heard some managers complain, "Why don't you make it stronger? I don't think it should break." If it was made so strong that it wouldn't break, then something else would bend or break, and it would be a lot more expensive than a door gib.

This device prevents the elevator from overspeeding. When an elevator overspeeds, the governor "trips" causing it to grip a cable. The cable which normally moves up and down with the elevator, now becomes stationary while the elevator continues to move. The governor cable pulls on the safety device and brings the car to a rapid stop.
Amazingly strong steel cables make up of over a hundred individual wires of high strength flexible steel. Most traction elevators have at least four hoist cables. Don't be surprised if not all the grooves on your elevator machine sheave are filled with a cable. Sometimes sheaves have additional grooves, so the sheave can be used for differing applications. People are often surprised to hear that the core of each cable is not steel but a twisted fiber, sort of like a manila rope.
The structure that surrounds the elevator. Sometimes it is partially open at the rear as in some hotels and office buildings. Hoistways are meant to be fire resistant enclosures. Normally the walls, and elevators are all 1 and 1/2 hour fire rated. Elevator doors normally have a 1 and 1/2 "B" label rating. The elevator door entrance frames also have this same fire rating. Sometimes people look for this label. Sometimes they have come off or been painted over, or are hard to find. No, no, no, the elevator car doors (the doors that you can see when you are inside the elevator) are not required to be fire rated.
An elevator moved by a fluid under pressure, acting upon a piston. The majority of hydraulic elevators have a single piston/cylinder design. The cylinder is usually buried in the ground as deep as the building's height. The hydraulic fluid, normally a paraffin based antiwear hydraulic oil, is designed for operation under high temperatures and pressures. It is stored in a tank in the elevator machine room. When you push a button to go up, a motor begins turning. A screw type pump forces oil from the tank into the cylinder. The pressurized oil forces the piston, which is connected to the elevator car in the up direction. When you want to come down, the oil in the cylinder is released through a valve back into the tank. You will notice when standing in the machine room, that the elevator sounds different depending upon whether it is going up or down. Its always louder in the up direction, because the motor and pump are turning. To go down, the valve opens allowing oil back into the tank. The noise you hear is the oil rushing through the piping and gushing up into the reservoir tank. Boring historical tidbit: Some earlier hydraulic elevators actually used water as the fluid that lifted the elevator. About 15 years ago I got to see one of these contraptions in operation in an old Philadelphia building. A large city water line was hooked up to the elevator! To make the elevator go up water was allowed to flow into a monstrous steel and brass cylinder. When the elevator came down, all this water simply ran into the sewer system. Can you imagine the water bill each month?

But that isn't the whole story. To use the water more efficiently(!) the cylinder actually had cables wrapped around and around it, with sheaves attached, here there and everywhere in the hoistway. When the piston moved one foot, the elevator moved perhaps 10 feet.
Your elevator is inspected from two to four times a year. Though the report is often prepared by a third party inspection company, it will be issued to you on very official looking state paper. Believe it or not, elevator companies don't mind receiving these reports. It's frequently helpful to have another party (we all like parties) having another look see every so often.

Important note: THE ELEVATOR COMPANY DOESN'T KNOW ABOUT THE REPORT UNTIL YOU GIVE THEM A COPY. It might seem to make sense that a copy would automatically be sent to your service company, but that's not how it works. This is the government. Actually to be fair to them, it's most important that the owner gets a copy. It is the owner's responsibility to then give a copy to the service company. PLEASE REMEMBER TO INCLUDE ALL PAGES INCLUDING THE LAST PAGE WITH THE LISTING OF CODES.

A device designed to keep the elevator hoistway door (or hall door ) closed when the car is at another floor. Secondary function: to be a source of headaches for the elevator technicians.
Elevator maintenance contracts used to be shorter, simpler and easier to understand. Enter the lawyers (on boths sides). They are now sometimes rather ponderous documents made for lawyers and engineers. At times people seem more concerned with ancillary issues such as insurance than in what is really being maintained and the safety issues surrounding the maintenance.

Contract types:
Full Maintenance-also called names like Complete and Comprehensive. What is usually included? Regular preventive maintenance visits and callbacks, most major parts. What is not included? any repairs needed as a result of misuse or vandalism or for reasons outside of the elevator company's control. This includes acts of God, power outages, power fluctuations (usually beyond plus or minus 10%). Potentially big ticket items like underground piping and cylinders are also excluded. Additionally, most of these contracts include straight time callbacks only. Callbacks for service outside of normal hours usually result in an invoice being generated for the overtime portion of the callback plus travel time costs.

Oil and Grease-This contract usually includes one maintenance visit per month. Parts and callbacks are not included. The contract is less expensive up front, but back end costs including callbacks and repairs could end up costing more on an annual basis than a full maintenance contract. For lightly used elevators this may be the most cost effective maintenance program. Many elevator companies also will not cover very old elevators on anything but this type of contract.

This is a modern elevator platform showing steel stringer supports, steel sheet fireproofing and attached hydraulic piston. This design uses a cantilevered platform, with the piston (the shiny tube) and hoistway guide rails at the front of the hoistway. The white tube below the piston is called the cylinder. The piston lifts the car when hydraulic fluid is pumped into the cylinder, which is stationary. Most hydraulic elevators have the piston at the center of the platform. This offset piston design is used on low-rise buildings to keep costs down.
POWER UNIT (also called pump unit)
A major component of a hydraulic elevator which consists of a reservoir tank for the oil, a motor, pump and valve. Sometimes a controller is attached to the front or side of the power unit. This however is at least from an operational standpoint, considered an entirely separate major component.
We can thank Elisha Graves Otis for this device. It quickly brings an elevator to a rapid stop if it overspeeds while moving in the down direction, by forcefully gripping the rails. The jaw type devices are usually attached to the bottom of the elevator car frame. Buildings having occupied space under the elevator pit also normally have safety devices on the counterweight. The original Otis safety device was designed to work when the ropes broke, which being then made of fiber were prone to do. Otis publicly demonstrated his invention in New York in 1854. Things have been going up since then. His safe elevators gave people confidence in elevators and allowed architects to design increasingly taller buildings.

Pictured at the top is an old style elevator and safety device at Sassafras Market, the corner of Race Street and 3rd Street, Philadelphia, PA.

The photo at the bottom shows a modern safety device. The gap being pointed to is where the T-shaped steel rail passes through the safety device. If the elevator car were to exceed its predetermined maximum velocity, these clamps will immediately grip the rail and bring the elevator car to a quick stop.

Also called a full load safety test -This test is performed every five years on traction elevators. A traction elevator is a elevator in which the elevator cab or car is moved by cables. If your elevator has a capacity plate reading 2,500 pounds, then that amount in steel, concrete or lead weights is placed on the elevator. Both the governor and safety device are tested during this test.

This test puts a strain on your elevator equipment. Though uncommon, damage can occur as part of this test. Any repairs necessitated as a result of this test are at an additional cost.

Many elevators were installed years ago and still don't have a phone. The latest craze is to use push to talk, auto dial phones. You push a single button and the designated phone number is automatically dialed. They normally require a dedicated phone line. Some try to hook them up to an in house line or have it go directly to a receptionist desk. You may be asking for trouble.
An elevator that uses cables to move the car. Like the tires on your car needing traction on the road, the cables get "traction" by the way they ride in the grooves of the machine sheave. Also sometimes called electric elevator, geared elevator or gearless elevator.
A component of the elevator power unit (or pump unit) which controls the speed at which oil flows into and out of the cylinder, and thereby the speed or velocity of the elevator. A hard start or stop is usually related to the valve operation.

Copyright (c) 1999 ElevatorPro.com All rights reserved.
Reproduction in whole or in part in any form without express written permission is prohibited.