Tuesday, July 8, 2008


The ancient Greeks were the first to invent the elevator. They made an elevator, by using pulleys and winches. A pulley is a wheel with a rope wound around it. The rope would have weights on the bottom of each end. One end on one side of the rope would weigh more than the other end. The end with less weight would rise and the heavier end would lower, making the wheel turn around and around. To make the end that is rising stop, they would take weights off the heavier end. So the two ends would be almost equal in weight. A winch is a machine that has a wheel (or drum), with a rope wound around it. By running the rope over a pulley it is able to raise or lower items, making the pulley and winch work together. The ancient Greeks invented the elevator and now we are using the elevator frequently.

Uses of the Elevator
There are many varieties of elevators in use. Huge Fright elevators carry loaded trailer trucks to higher levels of factory buildings. Automobile elevators can carry cars from different floors in parking garages. Other elevators can carry miners hundreds of feet underground. Elevators in aircraft carriers lift planes to the deck for takeoff. One elevator is even taken to space so astronauts can reach their space capsules! But the most well known elevators are the elevators that take people to different floors, in apartments, offices, skyscrapers, and many other buildings. Those elevators are so you wouldn’t have to climb many levels of stairs to get to your destination. There are many different kinds of elevators.

Elevators: Now and Then
Before the 20th century, elevators mostly looked like birdcages. The elevator shafts (the building the elevator goes up and down in) were often opened. They were also controlled by operators, who moved a big control handle. Nowadays elevators are well lighted and has fan-like air to improve the air in the enclosed space of the elevator. They are also self-service or automatic. The self-service elevators work by having a passenger push a button for a specific floor. The button is called a floor selector. The selector is connected to the real elevator with steel tape. If the tape breaks, the elevator is not able to move until the tape is repaired. In a rooftop machine room, the controller and selector are working like a computer. They send instructions to the elevator motor. The instructions are followed and stop the motor so it sends the elevator to the right floor. To keep the elevators running regularly and have the passengers on all floors served, the controller would be set to an automatic schedule system. A schedule is like the system railroads use to make the trains move right. Electro-magnetic circuits keep doors from opening while the elevator is moving downward or upward. When a person is getting on or off of the elevator and is in between the door, special safety devices automatically opens, to let the passenger off or on.

The Man behind the Work of the Elevator
Elisha Graves Otis invented the elevator and also the elevator brake, which was the start of the regular usage of elevators. Elisha was born on August 3,1811. He was born on a farm near Halifax, Vermont. He was the youngest of six children. Otis tried over and over at establishing businesses in his early years. Otis had a poor health and had many financial problems also. In 1852, he moved to Yonkers, New York to put in machinery for the firm of Maize & Burns. Josiah Maize, of Maize & Burns, needed to move heavy items to higher floors. Otis was intrigued with the safety problems of the equipment. In 1853, Otis had put together an elevator in a one sided shaft. He did this using, a tough steel wagon spring machine with a ratchet. The spring would catch and hold, if the rope happened to give away. Otis familiarized his safety device on the floor of the Crystal Palace Exposition, in New York. With a large audience watching, Otis went up in the elevator. Halfway up, he had the hoisting cable cut with an ax, and it had torn the rope in half. Otis proved to the audience, that even though the rope was cut, the spring would be there to catch the elevator. Now people are using elevators regularly, without many dangers. This is due to the inventor of the safety- device, Elisha Graves Otis.

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