Improvements in Steam Engines.
Year: 1885

page_text: Improvements in Steam Engines.
I, FREDERICK WILLIAM CROHN, Engineer of 16 Burney Street Greenwich
London do hereby declare the nature of my invention for IMPROVEMENTS IN
STEAM ENGINES-WITH A VIEW TO GREATER ECONOMY AND NOISELESS WORKING,
to be as follows:-
I construct a steam engine having a crank shaft and rotary motion; in the
cylinders of which the steam acts in a similar way to what it does in the well
known" Cornish" pumping engine; that is, that during the stroke of the piston
in one direction there is steam pressure in one end of the cylinder and the other
end of the cylinder (opposite side of piston) is open to the exhaust, but during the
return stroke of the piston, both ends of the cylinder or cylinders are placed by
the slide or valve, in communication with each other and the piston, being in
equilibrium, or nearly so is pushed or pulled back to its original position by its;
piston-rod and connections with the other cylinders.
I distribute the steam in the cylinders by means of valves, slide valves or piston
valves, suitably constructed preferably by the latter and when I use slide valves
I cause a strain on their gear in one direction by means of a balance piston
attached to the valve rod and I actuate these valves by any known valve-gear or
reversing gear. I can also apply expansion or cut off valves to such slides or
valves so as to increase the expansion. I construct these engines either with one
or more simple cylinders or I exhaust the first cylinder into the second and that
again into the third; on the "compound" or "multiple compound" systems; all
the cylinders being of similar construction to the drawing attached hereto
I prefer to make them with three cranks at equal angles, one to each cylinder,
as triple compounds," the exhaust steam from the first cylinder driving the
second and from that-driving the third.
"
The advantages I seek to gain by my improvements, are:
1.) Economy in fuel; as only one end of each cylinder is opened to the exhaust
and the internal temperatures are thereby kept more uniform.
2.) Noiseless working at high speeds-as the rods of the piston and connecting
rods as well as the valve gear are always strained in one direction; the cylinders
being single acting, as distinctly shewn in my drawing.

page_text: I FREDERICK WILLIAM CROHN of N° 16, Burney Street Greenwich Kent
Engineer do hereby declare the nature of my invention for IMPROVEMENTS IN
STEAM ENGINES and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention has for its object improvements in Steam engines especially
with a view to economy and noiseless working in High speed multiple cylinder
single acting engines.
I seek to gain economy by causing the steam to work in the cylinders of my
engines in such a way that when the pistons are moving in one direction, there
is boiler or receiver steam in one end of a cylinder and the opposite end of the
same is in communication with the receiver, condenser, or the atmosphere.
The return stroke of the piston is caused by its rods and connections, for the
two ends of the cylinder are placed, by a passage in the slide, piston-valve or
other valves, in communication with each other and the piston is almost in
equilibrium.
Each of the cylinders I use is constructed to work on this principle and is
consequently single acting. I can combine any number of these cylinders, in an
engine by having a crank. shaft with as many cranks as there are cylinders;
such cranks to be at suitable angles with each other to produce nearly uniforin
rotary motion.
I work the valves of these cylinders by any known gear or motion and
I prevent back lash and noise in the valve gear by balance pistons or other devices,
so that the rods shall always be strained either in tension or compression.
By reason of one end of the above named cylinders being devoted to hot or
boiler steam and the opposite end only being opened to the exhaust, there will be
less variation in temperature in them and consequently less internal condensation
and less loss of beat.
The cylinders being single acting and the piston and connecting rods being only
strained in one direction ensures comparatively noiseless working. at high speeds.
I prefer to make these engines "triple compounds" by having a crank shaft with
three cranks at equal angles and one of the above described cylinders, of pro-
portionate size, to each crank. The first cylinder to exhaust into the second; the
second into the third and the third into the condenser.
DESCRIPTION OF THE DRAWINGS.
Drawing No 1, (filed with my Provisional Specification) shews one of a set of
cylinders fitted with a piston valve and Drawing No 2 a similar cylinder fitted
with a slide valve. The letters on either drawing indicate similar parts.
S is the inlet for steatu-either boiler steam or the exhaust steam from the
previous or higher pressured cylinder of the set.
HP is the hot steam port-P: the piston.

page_text: C: the passage in the valve which places the two ends of the cylinder in com-
munication with each other for the return stroke of the piston.
L: is the cool steam port; or equilibrium port.
E: the exhaust cavity and port.
BP: in Drawing No 2 is a balance piston, to cause the valve gear to be always
in tension. This device is not needed in the cylinder as shewn on Drawing N° 1,
because the steam entering on the top of the piston valve puts its valve gear
always in compression.
N: is a small pipe or passage communicating with the condenser, receiver, or
atmosphere for the purpose of taking away the leakage from the piston valve or
balance niston