Application: Air or gas blower.
This device was first exhibited by Root at the 1867 Paris Exhibition. The wheels were about three feet in diameter and seven feet long, and delivered a large volume of air at a considerable pressure when driven at high velocity. It was, however, used as early as 1859 as a gas exhauster by G. Jones of Birmingham, England.

Outer lobe profiles are circular in section, and in air delivery work a slight clearance is maintained between mating surfaces to eliminate friction.

This unit found much use in supercharging of internal combustion engines. General Motors 2-cycle Diesels, for example, used a helical 3-lobed Roots Blower for scavenging and pressure boost, as was evidenced by the characteristic "whine" of said engines as was used in GMC-Greyhound highway coaches.

H. Roehl 1950-00-00