Ot"to cy`cle (?). (Thermodynamics)
A four-stroke cycle for internal-combustion engines consisting of the
following operations: First stroke, suction into cylinder of explosive
charge, as of gas and air; second stroke, compression, ignition, and
explosion of this charge; third stroke (the working stroke), expansion
of the gases; fourth stroke, expulsion of the products of combustion
from the cylinder. This is the cycle invented by Beau de Rochas in
1862 and applied by Dr. Otto in 1877 in the Otto-Crossley gas engine,
the first commercially successful internal-combustion engine
made.
© Webster 1913.