IMPROVEMENTS IN STEAM ENGINES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Maurice Bauer at the Office of the
Commissioners of Patents on the 22nd April 1881. A communication by
Léon Fournier, of Valence, in the French Republic.
MAURICE BAUER, Civil Engineer, of the Firm M. Bauer & Co., Solicitors of
Patents, at Paris, in the French Republic. "IMPROVEMENTS IN STEAM ENGINES."
A communication by Léon Fournier, of Valence, in the French Republic.
This Invention relates to what are known as high and low pressure engines, and
according to one arrangement a steam engine with two cylinders consisting of one
casting is employed. The steam enters the small cylinder as in the known engines
of this kind, expands therein to a trifling extent only, or not at all, and then passes
to the large cylinder in order to work therein with the required degree of
expansion. The cylinders of the engine are in some cases single acting, that is,
the steam enters only to one side (the outer one) of each piston in its respective
cylinder. The small cylinder may be furnished with a steam jacket, so that the
steam coming from the boiler enters the said jacket first, then the valve chest of
this cylinder, and from there is distributed by means of a slide valve through a
suitable passage into the small cylinder, acts upon its piston, and moves it together
with the piston of the larger cylinder which is fixed to the same rod.
When the two pistons have arrived at the opposite end of their stroke the valve
opens the exhaust, and the steam space in the small cylinder communicates with
the exhaust passage of the valve. The steam then passes by a suitable passage into
a pipe which conducts it into the valve chest of the large cylinder; from there its
admission into the large cylinder is regulated by a second slide valve. When the
two pistons return into their first position, the valve of the large cylinder opens a
passage which places the interior of the larger cylinder in communication with the
exhaust passage, and the steam escapes into the atmosphere, or into the condenser
as the case may be. Existing one cylinder steam engines may be arranged in
accordance with this system.
According to another arrangement an existing single cylinder steam engine may
be converted into a two cylinder one according to the above described system, and
may be made double acting, that is to say, with both pistons receiving the direct
action of the steam. For this purpose there is placed behind the existing small
cylinder a second larger one, so arranged that a space is left between the two for

page_text: This
the purpose of obtaining access to the stuffing box of the small cylinder.
intermediate space is formed by a jacket or case made of one piece with the cover
of the larger cylinder, and secured by screws to the cover of the small cylinder; it
is provided with an opening which may be closed by a suitable cover, which gives
access to the interior of the jacket or case when required.. Both cylinder pistons
are secured to one piston rod.
The internal arrangement of the two cylinders is similar to that of a single
engine, except that the exhaust steam passage of the small cylinder does not
communicate with the outer atmosphere or with a condenser, but with the valve
chest of the large cylinder. Each slide, valve has its own eccentric and valve rod.
The existing cylinder may be used for the larger cylinder if preferred, and a small
one added to it; in this case; the passages of the smaller cylinder may be made so
long that both valve faces come in line, and only one eccentric and one valve rod
is then required for both slide valves.
If the above mentioned two cylinders formed of one casting are provided with a
partition, they may also be constructed double acting.
This arrangement may be advantageously employed in the construction of
locomotives; in this case the larger cylinder would be arranged in front of the
already existing one, that is to say, behind the front buffers.