AN IMPROVED METHOD OF SUPPLYING STEAK TO COMPOUND OR DOUBLE CYLINDER EXPANSIVE STEAK ENGINES,. AND IN APPARATUS EMPLOYED FOR THAT PURPOSE
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the
Office of the Commissioners of Patents, with his Petition, on the
25th August 1871.—A communication from abroad by Messrs. Leon
Allart Rousseau, senior and junior, of Roubaix, Nord, France,
Manufacturers.
I, CHARLES DENTON ABEL, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, do hereby
declare the nature of the said Invention for "AN IMPROVED METHOD OF
SUPPLYING STEAK TO COMPOUND OR DOUBLE CYLINDER EXPANSIVE STEAK ENGINES,.
AND IN APPARATUS EMPLOYED FOR THAT PURPOSE," to be as follows ;-
In compound steam engines of ordinary construction the high-pressure
steam is caused to pass from the boiler, first, into the small or high-
pressure steam cylinder, and after acting therein with or without expan-
sion it passes into the large or low-pressure cylinder, in order to act
expansively therein..
Now the present Invention consists, firstly, in so arranging the steam
cylinders and their communications with each other and with the boiler

page_text: that high-pressure steam can be made to pass simultaneously from the
boiler into both cylinders, whereby the power of the compound engine
will be greatly increased, while when such increase of power is not
needed the steam can be made to pass, first, into the small cylinder,
and thence into the large cylinder as in ordinary compound engines.
For this purpose the steam pipe from the boiler is provided with two
branches, one of which communicates with the small cylinder, while the
other communicates with the large cylinder; and the latter branch is
provided with a cock or valve by which the communication between
the large cylinder and the boiler can be cut off. This branch also
communicates by means of a pipe with the exhaust port of the small
cylinder, so that the exhaust steam can pass from the latter through
such pipe into the large cylinder, and the said pipe is provided, firstly,
with a cock or valve by which its communication with the largo cylinder
may be cut off, and secondly with a branch, also provided with a cock
or valve through which the exhaust steam from the small cylinder may
be made to pass to the condenser. From this arrangement it will be
seen that if the cock on the branch steam pipe to the large cylinder
be opened while the cock on the pipe communicating with the exhaust
port of the small cylinder is closed and the cock on the branch leading
from the small cylinder to the condenser is opened high-pressure steam
will enter the large and small cylinders simultaneously, whereas if the
cock establishing a communication between the large cylinder and the
boiler be closed, while that establishing a communication between the
exhaust of the small cylinder and the large cylinder is opened, and the
cock on the exhaust pipe from the small cylinder to the condenser is
closed, the steam from the boiler will first enter the small cylinder and
will pass thence into the large cylinder as in ordinary compound engines.
Instead of forming the steam pipe from the boiler to the engine with
two branches, as described, the boiler may communicate with each
cylinder through a separato steam pipe.
The above described arrangement necessitates the adoption of special
means of security in direct connection with the steam cylinders, whereby
any possible excess of pressure in the cylinders and the accidents which
might result therefrom may be prevented; and this Invention consists
therefore, secondly, in fixing at the upper and lower ends of the large
and small steam cylinders safety valves of any suitable known cop-

page_text: struction, which are loaded to an extent corresponding with the maximum
pressure which the steam is allowed to exert in the cylinders, so that
if such pressure be exceeded at any time the safety valve will open,
and the pressure will thus be reduced to the said maximum.