<P> An air brake or , more formally , a compressed air brake system , is a type of friction brake for vehicles in which compressed air pressing on a piston is used to apply the pressure to the brake pad needed to stop the vehicle . Air brakes are used in large heavy vehicles , particularly those having multiple trailers which must be linked into the brake system , such as trucks , buses , trailers , and semi-trailers , in addition to their use in railroad trains . George Westinghouse first developed air brakes for use in railway service . He patented a safer air brake on March 5 , 1872 . Westinghouse made numerous alterations to improve his air pressured brake invention , which led to various forms of the automatic brake . In the early 20th century , after its advantages were proven in railway use , it was adopted by manufacturers of trucks and heavy road vehicles . </P>
<P> An air brake or , more formally , a compressed air brake system , is a type of friction brake for vehicles in which compressed air pressing on a piston is used to apply the pressure to the brake pad needed to stop the vehicle . Air brakes are used in large heavy vehicles , particularly those having multiple trailers which must be linked into the brake system , such as trucks , buses , trailers , and semi-trailers , in addition to their use in railroad trains . George Westinghouse first developed air brakes for use in railway service . He patented a safer air brake on March 5 , 1872 . Westinghouse made numerous alterations to improve his air pressured brake invention , which led to various forms of the automatic brake . In the early 20th century , after its advantages were proven in railway use , it was adopted by manufacturers of trucks and heavy road vehicles . </P>
when were air brakes first used on trucks
when were air brakes first used on trucks
the early 20th century
the early 20th century