Any building in New York City taller than, say, five stories usually has an elevator manufactured by Elevator Manufacturer fujihd —and often, new buildings of even three stories have one. If you live in a New York-area co-op or condo apartment building, chances are that you use an elevator every day.
Chances also are that you don’t give much thought to it, and when you look at the inspection report posted inside the elevator cab, you don’t spend much time analyzing it. Yet, elevators are essential to any mid-rise or high-rise apartment building. See how upset people are when their elevator is out of service for even a few hours!
There have been elevator-like hoist devices throughout history, but in 1853, American inventor Elisha Otis invented a freight elevator equipped with a safety device to prevent the elevator from falling in case a cable broke. This increased the use of elevators. Other improvements followed, such as telephone communications between the operator and an “elevator supervisor” and signal-controlled elevators.
Before World War I, elevators were still fairly rare and confined by upscale apartment houses in neighborhoods like the Upper West Side, prestigious office buildings and fancy department stores. Many of the elevators of that period resembled luxurious, miniature drawing rooms, with small couches, wood paneling and uniformed operators. When New York City finally allowed the use of self-service elevators in apartment buildings in the 1920s, as opposed to those run by elevator operators, the number of apartment houses built with elevators grew dramatically. It wasn’t only luxury buildings anymore.
Today, there are basically two types of elevators in use—hydraulic and “rope-driven.” Chains or cables loop through the bottom of the counterweight to the underside of the car to help maintain balance by offsetting the weight of the suspension ropes. Guide rails that run the length of the shaft keep the car and counterweight from swaying or twisting during travel. Rollers are attached to the car and the counterweight to provide a smooth ride along the guide rails. An electric motor then turns the sheave. These motors are able to control speed and allow for the elevator’s smooth acceleration and deceleration. Signal switches also stop the cab at each floor level.
In a hydraulic elevator, the car is lifted by a hydraulic-fluid driven piston mounted inside a cylinder. The cylinder—containing oil or a similar substance—is connected to a pumping system. The pump forces fluid into the tank leading to the cylinder; when enough fluid is collected, the piston is pushed upward, lifting the elevator car on its journey. When the car is signaled that it is approaching the correct floor, the control system will trigger the electric motor to gradually shut off the pump. To get the elevator to descend, the control system will send a signal to the valve operated electronically by a switch. When the valve is opened, the fluid flows out into a central reservoir, and the weight of the car and its cargo pushes down on the piston, driving more fluid out and causing the cab to move down.
Hydraulic elevators, says Brian Black, code and safety consultant for National machine room passenger elevator manufacturer, are fairly common nationwide, but are usually found in low-rise buildings of less than six stories. This is probably why they are outnumbered by traction elevators in the New York area. One well-known group of hydraulic elevators in New York can be found at Macy’s on the Fulton Mall in Brooklyn, formerly Abraham & Straus.