Intellectual Property Law for Engineers, Scientists, and Entrepreneurs. Howard B. Rockman

      Elisha Graves Otis was an American industrialist and founder of The Otis Elevator Company. Practically everyone reading this essay has been on an elevator and seen the name Otis; however, Mr. Otis did not invent the elevator. He is famous for inventing a safety device that prevents elevators from falling if the hoisting cable fails.

      Throughout the centuries, humans have employed many, many ingenious forms of elevating people, animals, and a variety of loads. The earlier lifts used man, animal, and water power to raise loads. In ancient Greece, Archimedes developed an improved lifting device operated by ropes and pulleys, where the hoisting ropes were coiled around a winding drum operated by a capstan and levers. By C.E. 80, gladiators and wild animals rode crude elevators up to the arena level of the Roman Coliseum.

      Early elevators were open cars comprising a platform using hoists that were difficult to move vertically. The hoists were typically worked manually by people or animals. Where available, water wheels and water power were employed for the hoisting.

The first elevator designed for a human passenger was built in 1743 for King Louis XV of France. His elevator went up only one floor from the first to the second, and was known as the “flying chair.” It was outside of the building, and was entered by the King from his balcony off his apartments. The mechanism comprised a carefully balanced arrangement of weights and pulleys deployed inside a chimney. Men stationed inside the chimney raised or lowered the flying chair at the King’s command, who used it primarily to visit his lady friend’s apartment on the second floor, as some literature has indicated.

      In the 1800s elevator technology began to move forward, and they no longer had to be worked manually. For example, in 1823, two British architects built a “steam powered ascending room” to take tourists up on a platform for a view of London. Several years later, their invention was expanded upon by other architects, who added a belt and counterweight to the steam tower. Eventually, hydraulic systems using water pressure to raise and lower the elevator car were designed and constructed. Hydraulic elevators were safer, but steam‐powered elevators also remained. Accidents occurred when the cables holding the elevator aloft snapped. The public was not enthusiastic about getting on these dangerous elevators, so passenger elevators were basically just a novelty.

      One Otis Tufts patented an elevator design with doors that opened and closed automatically, and had bed seats inside. However, his design did away with the typical cable system because of safety issues, and instead employed what we consider an impractical and expensive system of threading the elevator car vertically upon a giant screw. Can you imagine what the cost would be in today’s tall buildings?

      In his early days, Otis designed and built a grist mill, but did not earn enough from the mill, so he converted it into a sawmill, which also was not successful. By that time, he had a family, and he started building wagons and carriages, which was within his capabilities. His wife then passed away, leaving him with two sons, one eight and the other still in diapers.

      He then remarried, and moved to Albany, New York, working as a doll maker. He tired of taking all day to make only a dozen toys, and later invented and patented a robot wood turner that could produce bedsteads four times faster than could be done manually. His boss gave him a $500 bonus, and Otis then started his own business making bedsteads. He also started designing a safety brake that could stop trains instantly, and an automatic bread baking oven. As luck would have it, his business failed when the stream he was using as a water power supply was diverted by the city of Albany to be used as a fresh water supply.

      Becoming disillusioned with Albany, Otis relocated to Yonkers, New York, in 1852 as the manager of an abandoned saw mill which was to be converted into a bedstead factory.

      While cleaning up the factory, Otis wondered how he could lift all the trash, as well as heavy equipment and machinery to the upper levels of the factory. He knew that cables lifting hoisting platforms of the day often broke, and he and his workers were unwilling to risk their lives. So he and his two sons designed a safety elevator and tested it successfully. In the beginning, he thought so little of this invention that he neither patented it nor requested a bonus from his superiors. Ultimately, Otis did file for and obtained U.S. Patent No. 31,128 on January 15, 1861.

His safety device consisted of a used wagon spring attached to both the top of the hoist platform and the overhead lifting cable. Under ordinary circumstances, the spring was kept in place by the downward pull of the platform’s weight on the lifting cable. However, if the cable broke, the pressure on the spring was suddenly released, and the spring caused laterally extending ratchets to spring open in a jaw‐like motion. When this occurred, both of the ratchets moved laterally outward and engaged sawtooth ratchet‐receiving bar beams that Otis had installed on either side of the elevator shaft, bringing the falling elevator to a complete halt.

      After the bedstead factory declined, Otis took the opportunity to make an elevator company out of his work, and he first named his company the Union Elevator Works. Later, the name was changed to Otis Brothers and Company. His new elevator business did not start out well, but the 1854 New York World’s Fair appeared to offer him a chance at gaining publicity. At the New York Crystal Palace, Otis constructed an elevator according to his designs, and ordered the only rope holding the platform on which he was standing to be cut. The rope was cut by a man handling an ax, and the platform fell only a few inches and then halted. His ratcheted safety locking mechanism had worked, and the public gained a greater willingness to ride in traction elevators, which then came into common usage and helped make present‐day skyscrapers accessible. After the World’s Fair, Otis continuously received orders, and he also developed different types of engines, such as a three‐way steam valve engine that could transition the elevators between up to down and stop rapidly.

      Before Otis’ invention of the elevator brake, buildings only reached seven stories high, because elevators were considered too dangerous to ride in. The first elevator shaft actually was built in 1853, four years ahead of the first safety elevator built by Otis. Architect Peter Cooper was confident that a safe elevator would soon be invented, and designed New York’s Union Foundation Building with an internal cylindrical shaft, thinking that being the most efficient shape. Cooper opined that somehow somebody later on would develop an elevator to fit in the shaft. Otis later did design an elevator just for that building.

      In 1857, the first Otis passenger elevator was installed at 488 Broadway in New York, following which the Otis elevator appeared in the Eiffel Tower in Paris and the Empire State Building in New York.

      In 1890, an elevator was installed in the Washington Monument in Washington, D.C. In 1913, an elevator was installed by Otis Company in the 60‐story Woolworth Building in New York City, which at the time was the world’s tallest building.