Pneumatic devices are various tools and instruments that generate and utilize compressed air. Pneumatics are everywhere in important inventions, however, they are relatively unknown to the general public.
History of Pneumatic Tools – Bellows
The hand bellows used by early smelters and blacksmiths for working iron and metals was a simple type of air compressor and the first pneumatic tool.
Pneumatic Tools – Air Pumps and Compressors
During the 17th century, German physicist and engineer Otto von Guericke experimented with and improved air compressors. In 1650, Guericke invented the first air pump. It could produce a partial vacuum and Guericke used it to study the phenomenon of vacuum and the role of air in combustion and respiration.
In 1829, the first stage or compound air compressor was patented. A compound air compressor compresses air in successive cylinders.
By 1872, compressor efficiency was improved by having the cylinders cooled by water jets, which led to the invention of water-jacketed cylinders.
The best known pneumatic device is of course the pneumatic tube. A pneumatic tube is a method of transporting objects using compressed air. In the past, pneumatic tube were often used in large office buildings to transport messages and objects from office to office.
The first documented genuine pneumatic tube in the United States is officially listed in a 1940 patent issued to Samuel Clegg and Jacob Selvan. This was a vehicle with wheels, on a track, positioned within a tube.
Alfred Beach built a pneumatic train subway in New York City (a giant pneumatic tube) based on his 1865 patent. The subway ran briefly in 1870 for one block west of City Hall. It was America’s first subway.
The “cash carrier” invention sent money in little tubes traveling by air compression from location to location in department store so that change could be made. The first mechanical carriers used for store service was patented (#165,473) by D. Brown on July 13, 1875. However, it was not until 1882 when an inventor called Martin patented improvements in the system that the invention became widespread. Martin’s patents were numbered 255,525 issued March 28, 1882, 276,441 issued April 24, 1883, and 284,456 issued on September 4, 1883.
The Chicago postal pneumatic tube service began between the post office and the Winslow rail road station on August 24, 1904. The service used miles of tube rented from the Chicago Pneumatic Tube Company.
Pneumatic Tools – Hammer and Drill
Samuel Ingersoll invented the pneumatic drill in 1871.
Charles Brady King of Detroit invented the pneumatic hammer (a hammer which is driven by compressed air) in 1890, and patented on January 28, 1894. Charles King exhibited two of his inventions at the 1893 Worlds Columbia Exposition; a pneumatic hammer for riveting and caulking and a steel brake beam for railroad road cars.
Modern Pneumatic Devices
During the 20th century, compressed air and of compressed-air devices increased. Jet engines use centrifugal and axial-flow compressors. Automatic machinery, labor-saving devices,and automatic-control systems all use pneumatics. In the late 1960s, digital-logic pneumatic-control components appeared.