IMPROVEMENTS IN COMPOUND MARINE STEAM ENGINES
Year: 1884

page_text: I, WALTER BROCK, of the firm of Denny and Company of Dumbarton, in the
County of Dumbarton, North Britain, Engineer, do hereby declare the nature of
my said invention for "IMPROVEMENTS IN COMPOUND MARINE STEAM ENGINES"
to be as follows:-
My said Invention has for its object to arrange or combine together the parts of
compound marine engines in an improved manner, and so that the steam may be
expanded through four successive stages; and my improved arrangements are such
as to secure a satisfactory disposition of the various strains. My Invention is
more especially designed for advantageous application in recompounding existing
compound engines to enable them to be worked with steam of higher pressures, but
is also applicable in the construction of new engines.
In carrying out my Invention according to one modification, in the case for
example of a screw-propeller engine with two crauks, four cylinders are used, and
the third is placed over one crank whilst the fourth or low-pressure cylinder is
placed over the other crank, these two being thus arranged like the high-pressure
and low-pressure cylinders of an ordinary two-cylinder compound engine. The
first or high-pressure cylinder is placed above the third cylinder and the second
is placed above the fourth or low-pressure cylinder, the pistons of the first and third
cylinder being on one rod connected to one crank and the pistons of the second
and fourth cylinders being on another rod connected to the other crank.
When the engines are so large as to make it desirable to have two low-pressure
cylinders and three cranks I modify my improved arrangement by placing the two
additional cylinders, one above each of the low-pressure cylinders.
EDMUND HUNT,
Applicant's Agent.

page_text: "
I, WALTER BROCK, of the firm of Denny and Company, of Dumbarton, in the
County of Dumbarton, North Britain, Engineer, do hereby declare the nature of
my said invention for "IMPROVEMENTS IN COMPOUND MARINE STEAM ENGINES,"
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, that is to say:-
My said Invention has for its object to arrange or combine together the parts of
compound marine steam engines in an improved manner, and so that the steam
may be expanded through four successive stages; and my improved arrangements
are such as to secure a satisfactory disposition of the various strains.
My Invention is more especially designed for advantageous application in
recompounding existing compound engines to enable them to be worked with
steam of higher pressures, but it is also applicable in the construction of new
engines.
And in order that ny said Invention and the manner of performing the same
may be properly understood I hereunto append three sheets of explanatory
drawings or diagrams, to be hereinafter referred to and showing three modes of
carrying out my Invention.
Figure, 1, on sheet, 1, of the drawings is a side elevation of an inverted-cylinder
screw-propeller engine with two cranks. In this example there are four cylinders,
A, B, C, D, the third, C, being placed over one crank, whilst the fourth or low-
pressure cylinder, D, is placed over the other crank, these two being thus arranged
like the high-pressure and low-pressure cylinders of an ordinary two-cylinder
compound engine. The figure may be taken to represent a two-cylinder compound
engine which has been recompounded or supplemented by additional cylinders
according to my Invention so as to work with steam of higher pressure and expand
it through four stages. The first or high-pressure cylinder, A., is placed above the
third cylinder, C, and the second cylinder, B, is placed above the fourth or low-
pressure cylinder, D, the pistons of the first and third cylinders, A, C, being on
one rod connected to one crank, and the pistons of the second and fourth
cylinders, B, D, being on another rod connected to the other crank. The high-
pressure steam is supplied through a pipe connected at, E, to the valve casing of the
first cylinder, A, and after working in that cylinder passes by a pipe, F, partly
indicated by dotted lines, to the valve casing of the second cylinder, B, from which
a pipe, G, indicated by dotted lines leads it to the third cylinder, C, whence it
finds its way round the cylinder to the fourth cylinder, D. The valve casing of the
first cylinder, A, is arranged directly over that of the third cylinder, C, and the
valve is worked by a continuation, H, of the rod, I, working the valve of
the latter. The valve casing of the second cylinder, B, not being directly over that
of the fourth cylinder, D, its valve is worked by a rod, J, which is attached by a
cross bar to an extension, K, of the rod L, which works the valve of the cylinder, D.
Or instead of the cross bar a lever or levers may be used for working the rod, J,
from the rod, K.
Figures, 2, and 3, on sheet, 2, of the drawings are a plan and a side elevation of
an engine similar to that shown on sheet, 1, and herein before described showing a
mode of constructing a new engine with my improvements. The valve casings are
arranged at the sides of the cylinders and so that the valves of the first and third
cylinders, A, C, are worked by the same rod, I, and so that the valves of the
second and fourth cylinders, B, D, are similarly worked by another rod, L. The
general arrangement is like that of the engine shown on sheet, 1, and the same
reference letters are used to mark like parts.

page_text: When the engines are so large as to make it desirable to have two low-pressure
cylinders, D1, D2, and three cranks, I modify my improved arrangement in the
manner shown on sheet, 3, of the drawings. In this modification, of which
figure, 4, is a side elevation, the two additional cylinders, A, B, are placed, one
above one low-pressure cylinder, D 1, and the other above the other low-pressure
cylinder, D 2, the third cylinder, C, being placed between the two low-pressure
cylinders.
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
1. The arrangement of four cylinders working with four stages of expansion, in
combination with two cranks substantially as herein before described and as shown
in figures, 1, 2, and 3, of the accompanying drawings.
2. The arrangement of five cylinders working with four stages of expansion, in
combination with three cranks substantially as hereinbefore described, and as shown
in figure, 4, of the accompanying drawings.
Dated this twenty-first day of November 1884.
EDMUND HUNT,
Applicant's Agent.