IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1859

page_text: LETTERS PATENT to Edward Humphrys, of Deptford, in the County
of Kent, for the Invention of "IMPROVEMENTS IN MARINE STEAM
ENGINES."
Sealed the 15th November 1859, and dated the 15th June 1859.
PROVISIONAL SPECIFICATION left by the said Edward Humphrys
at the Office of the Commissioners of. Patents, with his Petition,
on the 15th June 1859.
I, EDWARD HUMPHRYS, of Deptford, in the County of Kent, do hereby.
declare the nature of the Invention for "IMPROVEMENTS IN MARINE STEAM
ENGINES," to be as follows:-
This Invention has for its object the arrangement of marine steam engines
on what is well known as Wolfe's system in a more compact and convenient
form than heretofore. For this purpose I employ in combination with each
low-pressure cylinder two high-pressure cylinders, which, are placed between
the end of the low-pressure cylinder and the crank shaft. The two high-
pressure cylinders are mounted on the cover of the low-pressure cylinder, one
on each side of its piston rod, and the pistons of the high-pressure cylinders are
connected with the piston of the low-pressure cylinder by rods passing
directly from one to the other through the cover of the. low-pressure cylinder;
thus the power generated by the pressure of the steam on the pistons in the
high-pressure cylinders is transmitted to the piston of the low-pressure cylinder,
and the piston rod of this cylinder transmits the power of the whole to the
crank shaft. By this arrangement a compound engine is obtained, which

page_text: does not occupy more space than an engine having a single cylinder of the
size of the low-pressure cylinder of the compound engine, with the further
advantage that the power generated both in the high and low pressure
cylinders is communicated to one crank by a single connecting rod. The
slide valves of the high-pressure cylinders and the slide valve of the low-
pressure cylinder are connected together, and are actuated by one pair of
excentrics, and the link motion as described in the Specification of my Patent
of the 10th November 1858, & numbered 2522.
Engines arranged in the manner above described are applicable both for
driving screws and paddle wheels; for driving a screw shaft, I usually employ
a pair of compound engines placed horizontally, and for driving paddle wheels a
pair of compound engines placed vertically, but the cylinders may be arranged in
an inclined position, either to drive a screw or paddle shaft. In place of two
high-pressure cylinders, a greater number may be employed, or a high-pressure
cylinder containing an annular piston may be substituted for the two high-
pressure cylinders, but not, I believe, in either case so advantageously.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Humphrys in the Great Seal Patent Office on
the 15th December 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
HUMPHRYS, of Deptford, in the County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of June, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Edward Humphrys, Her special licence that I, the said Edward
Humphrys, my executors, administrators, and assigns, or such others as I, the
said Edward Humphrys, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
MARINE STEAM ENGINES," upon the condition (amongst others) that I, the
said Edward Humphrys, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said. Invention, and

page_text: in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Edward Humphrys, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:
This Invention has for its object the arrangement of marine steam engines on
what is well known as Wolfe's system in a more compact and convenient form
than heretofore. For this purpose I employ in combination with each low-
pressure cylinder two high-pressure cylinders, which are placed between the end
of the low-pressure cylinder and the crank shaft. The two high-pressure
cylinders are mounted on the cover of the low-pressure cylinder, one on each side
of its piston rod, and the pistons of the high-pressure cylinders are connected
with the piston of the low-pressure cylinder by rods passing passing directly from
one to the other through the cover of the low-pressure cylinder; thus the power
generated by the pressure of the steam on the pistons in the high-pressure
cylinders is transmitted to the piston of the low-pressure cylinder, and the
piston rod of this cylinder transmits the power of the whole to the crank shaft.
By this arrangement a compound engine is obtained, which does not occupy
more space than an engine having a single cylinder of the size of the low-
pressure cylinder of the compound engine, with the further advantage that the
power generated both in the high and low pressure cylinders is communicated
to one crank by a single connecting rod. The slide valves of the high-pressure
cylinders and the slide valves of the low-pressure cylinder are connected
together, and are actuated by one pair of eccentrics, and the link motion as
described in the Specification of my Patent of the 10th November 1858.
Engines arranged in the manner above described are applicable both for
driving screws and paddle wheels: for driving a screw shaft, I usually employ a
pair of compound engines placed horizontally, and for driving paddle wheels
a pair of compound engines placed vertically, but the cylinders may be
arranged in an inclined position either to drive a screw or paddle shaft. In
place of two high-pressure cylinders, a greater number may be employed, or
a high-pressure cylinder containing an annular piston may be substituted
for the two high-pressure cylinders, but not, I believe, in either case so
advantageously.
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawings hereunto

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal section of one of the cylinders of a pair of screw
engines of ordinary construction, having a pair of high-pressure cylinders
mounted on its cover according to my Invention. a is the low-pressure
cylinder; b, its piston; c, the rod of the piston b; the end of this rod is
steadied by guides d, carried by the frame; e is the connecting rod, and f the
crank; g, g, are the high-pressure cylinders, containing pistons h, h, which by
rods i, i, are connected with the piston 6 of the low-pressure cylinder. The
cylinder a at its further end has a cover fitted to it in the usual way; at its
other end the cylinder has a portion a' of the cover cast in one piece with it;
the other portion a of the cover is circular; it carries the stuffing box, and
fits into the part a', to which it is secured by bolts. The part a' of the cover
is fitted with stuffing boxes for the rods i, i; these stuffing boxes are introduced
from the interior of the low-pressure cylinder before the piston and further
cover are in their places; the cylinders a and g, g, are all fitted with a steam
jacket k, k.
The valves of each set of cylinders are all actuated by the same eccentrics,
the arrangement being similar to that described and shewn in the Specification
of a former Patent granted to me, No. 2658, 1857, each of the high-pressure
cylinders having, however, its own valve, the rods of which are connected
with the valve of the low-pressure cylinder, one on each side.
Figure 2 is a vertical section of one of the cylinders of a pair of paddle
engines of ordinary construction, having high-pressure cylinders combined
with it in a manner similar to that already described; of this arrangement no
additional explanation is necessary, the form of the parts where they differ
from the corresponding parts shown in Figure 1 being clearly shewn by the
Drawing.
In witness, I, the said Edward Humphrys, have hereunto set my hand
and seal, this Fifteenth day of December, in the year of our Lord
One thousand eight hundred and fifty-nine.
EDW. HUMPHRYS. (L.S.)