IMPROVEMENTS IN TRIPLE EXPANSION STEAM ENGINES
Year: 1885

page_text: I GEORGE RODGER, of Michaelson Villa, Barrow-in-Furness in the County of
Lancaster, Engineer do hereby declare the nature of the said Invention for
IMPROVEMENTS IN TRIPLE EXPANSION STEAM ENGINES to be as follows :—
My Invention relates to compound engines for marine purposes and consists in a
certain arrangement and construction of cylinders hereafter described, in which the
steam is used three times and three grades of pressure are obtained, namely first at
initial pressure and then expanded and used at a lower pressure and again expanded
and used at low pressure.
In constructing an engine according to my Invention,
use three cylinders, one
a high pressure cylinder one an intermediate, which two are bolted, or cast together
side by side and work on a single crank. The third cylinder is the low pressure
cylinder. I will now describe an engine of the oscillating type with my improve-
ments applied thereto. The engine is provided with a single crank and upon the
crank pin of which the piston rod heads all work. The three cylinders are
connected together with leads, pipes, or passages so that the steam from the
generator enters, the high pressure cylinder, does work there and is then expanded
into a second cylinder of larger size and does work there. These two cylinders are
cast, or bolted together side by side so as to work on the same trunnions, the two
piston rod heads working upon the crank pin simultaneously in the same direction,
at a certain distance apart so that the piston rod head of the low pressure cylinder
comes between those of the high and intermediate pressure cylinders. The steain
after use in the intermediate cylinder is led to the low pressure cylinder and does
work therein, it being condensed in the usual manner after final expansion. This
low pressure cylinder is positioned opposite the combined high and intermediate
cylinders.
בד

page_text: COMPLETE SPECIFICATION.
Improvements in Triple Expansion Steam Engines.
I GEORGE RODGER, of Michaelson Villa, Barrow in Furness in the County of
Lancaster, Engineer do hereby declare the nature of the said Invention for
IMPROVEMENTS IN TRIPLE EXPANSION STEAM ENGINES and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
My Invention relates to compound engines for marine or land purposes and
consists in a certain arrangement and construction of cylinders hereafter described
in which the steam is used three times and three grades of pressure are obtained,
namely first at initial pressure and then expanded and used at a lower pressure
and again expanded and used at a still lower pressure.
In constructing an engine according to my Invention I use three cylinders, one
a high pressure cylinder, one an intermediate which two are bolted, or cast together
side by side and work a single crank. The third cylinder is the low pressure
cylinder also working the same crank. I will now describe an engine of the
oscillating type with my improvements applied thereto. The engine is provided 1
with a single crank and upon the crank pin of which the piston rod heads all
work. The three cylinders are connected together with leads pipes, or passages so
that the steam from the generator enters one the high pressure cylinder does work
there and is then expanded into a second cylinder of larger size and does work
there. These two cylinders are cast, or bolted together side by side so as to 2
work on the same trunnions; the two piston rod heads working upon the crank pin
simultaneously in the same direction, at a certain distance apart, so that the piston
rod head of the low pressure cylinder comes between those of the high and
intermediate pressure cylinders. The steam after use in the intermediate cylinder
is led to the low pressure cylinder and does work therein, it being condensed in the 2
usual manner after final expansion. This low pressure cylinder is positioned
opposite the combined high and intermediate cylinders.
In order that my Invention may be more clearly understood, I will now proceed
to describe the same more fully and show. how my Invention may be carried out
into practical operation, reference being had to the annexed four sheets of Drawings
making a part of this Specification and to the letters and figures of reference
marked thereon, like letters and figures being used to denote the same, or corre-
sponding parts throughout the Drawings.

page_text: Figure 5 is a front elevation of Figure 4 showing a double set of engines
arranged and constructed according to my Invention.
Figure 6 is a side elevation and Figure 7 an end view of a modified arrangement
of cylinders and parts.
With reference to Figures 1. 2 and 3 of the Drawings and in constructing an
engine of the diagonal oscillating type according to my Invention, I use three
cylinders, namely a high pressure cylinder A an intermediate pressure cylinder B
which two cylinders A and B are cast together side by side as shown at Figure 1
or bolted together side by side. The piston rod heads a b of these cylinders A
and B work on a single crank C. The third cylinder D is a low pressure cylinder
and its piston rod head d works on the crank C, and between the piston rod
heads ab of the high and intermediate pressure cylinders A and B. The
cylinders A B and D are carried by the bed plate E namely the cylinders A and B
are provided with trunnions F and H common to both cylinders and working in
trunnion blocks, at one side of the frame E. The low pressure cylinder is carried
by trunnions J. K working in trunnion blocks at the other side of the frame E.
L is the entablature of the engine. M the shaft. N the condenser. P the air
pump. feed and bilge pump. R is the steam supply valve through which the
steam from the generator enters the high pressure cylinder A. through the trunnion F
and the cylinder valve e. From and after use in the high pressure cylinder A the
steam passes through the cylinder valve f and is expanded into the intermediate
cylinder B. The valves e and f and their ports and passages being so arranged
that the steam after use in the top of the cylinder A is led to the bottom of the
cylinder B and after use in the bottom of the cylinder A is led to the top of the
cylinder B. The steam after use in the cylinder B passes through the valve f and
belt and trunnion E through the pipe S which pipe S connects the trunnion H
with the trunnion J of the low pressure cylinder D so that the steam after use in
the intermediate cylinder B passes through the pipe S and trunnion J and through
the valve g to the cylinder D where it is again expanded and used at low
pressure and from which it is exhausted through the trunnion K. and pipe T to the
condenser N. U is the valve gear for the valves e and fof the cylinders A and B
and V is the valve gear for the valve g of the cylinder D. W is the starting gear
for the engines.
By the arrangement above described the pistons of the cylinders A and B work
together exerting their effort through their rods a and b on the crank C at one end
of the engine, and the piston of the low pressure cylinder D exerts its effort through
its rod d on the crank C between the rods a and b from the opposite end of the
engine.
In the general arrrangement of engines according to my Invention as shown at
Figures 4 and 5 the same essential features of the engines shown at Figures 1. 2
and 3 are retained, namely the high and intermediate pressure cylinders A and B
which are in this case vertical are bolted together and their piston rod heads a b
work on the one crank C and the low pressure cylinder D which is horizontal is
arranged so that its piston rod head & comes between the piston rod heads a and b
and works on the same crank C. The cycle of the steam leads to the high pressure
cylinder A and from the high pressure cylinder A to the intermediate pressure
cylinder B and from the intermediate pressure cylinder B to the low pressure
cylinder D being the same as the cycle of steam leads above described in reference
to Figures 1. 2 and 3.
With reference to Figures 6 and 7 it will be seen that the high and intermediate
cylinders A B are connected together as previously set forth, but the engines are
arranged to take up less space than those above described the two cylinders being
positioned one on either side of the centre line of the shaft M; and having a
common piston rod head a-b. The piston rod head d of the low pressure cylinder D
is fitted onto the crank pin immediately by the side of the head a-b. By this
means it will be obvious that less space is longitudinally occupied than with the
arrangements as set forth with the other figures of the Drawings and at the same

page_text: time the desideratum of a shorter crank pin is obtained thereby effecting also a
further element of strength.
One, two, or more groups of cylinders as above described may be arranged to
work two, or more cranks on the same shaft, or line of shafting.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
First. Arranging steam engines of the type herein described with two of their
cylinders formed, or connected together all three piston rod heads being arranged
to work upon a single crank substantially as and for the purposes set forth.
Second. In engines of the type herein described arranging the piston rod head
of the low pressure cylinder upon the crank pin between the piston rod heads of
the high and intermediate pressure cylinders substantially as set forth.
Third. In engines of the type herein described arranging the piston rod heads of
the high and intermediate cylinders upon the crank pin by the side of the piston
rod head of the low pressure cylinder, substantially as and for the purposes set
forth.
Fourth. The arrangement of cylinders and of parts connecting the same to a
single crank substantially as set forth with reference to Figures 1. 2 and 3 of the
Drawings.
Fifth. The arrangement of cylinders and of parts connecting the same to a
single crank, substantially as set forth with reference to Figures 4 and 5 of the
Drawings.
Sixth. The arrangement of cylinders and of parts connecting the same to a
single crank, substantially as set forth with reference to Figures 6 and 7 of the
Drawings.