elevator, in machinery, device for transporting people or goods
from one level to another. The term is applied to the enclosed
structures as well as the open platforms used to provide
vertical transportation in buildings, large ships, and mines; it
is also applied to devices consisting of a continuous belt or
chain with attached buckets for handling bulk materials. Simple
hoists were used from ancient times. From about the middle of
the 19th cent., power elevators, often steam-operated, were used
for conveying materials in factories, mines, and warehouses. In
1853 the American inventor Elisha G. Otis demonstrated a freight
elevator equipped with a safety device to prevent falling in
case a supporting cable should break. This increased public
confidence in such devices and served as an impetus to the
industry. Otis established a company for manufacturing elevators
and patented (1861) a steam elevator. After the introduction by
Sir William Armstrong of the hydraulic crane (1846), the
hydraulic principle was app