IMPROVEMENTS IN STEAM ENGINES
Year: 1862

page_text: LETTERS PATENT to James Humphrys, of Tower Hill, in the County of
Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES."
Sealed the 19th September 1862, and dated the 21st March 1862.
PROVISIONAL SPECIFICATION left by the said James Humphrys at the
Office of the Commissioners of Patents, with his Petition, on the 21st
March 1862..
I, JAMES HUMPHRYS, of Tower Hill, in the County of Middlesex, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
STEAM ENGINES," to be as follows:-
My Invention relates to improvements in the slide valves and in the
arrangement of the parts of compound steam engines, that is to say, engines
in which there are two cylinders, the steam being worked at high pressure in
one and expansively in the other.
The first part of my Invention consists of a novel description of slide valve
applicable to such engines, whereby with great simplicity of construction
considerable economy is effected in the transmission of the steam from the
high-pressure to the low-pressure. cylinder.. My valve is a treble-ported slide
valve, the laps at the extreme ends of the valve cut off from and supply to the
small cylinder the high-pressure steam from the boiler. This steam, after

page_text: having acted on the piston in that cylinder, is conveyed through a passage
forming part of the valve into the large cylinder, which it enters and leaves
for the condenser by the inner portion of the valve, which portion is an ordinary
double-ported slide valve.
The second part of my Invention consists of improvements in the arrange-
ment of the parts of compound engines, whereby great simplicity and acces-
sibility are obtained. These engines may be vertical, but arranged horizontally,
are particularly adapted for driving screw propellers. The small cylinder for
the high-pressure steam is placed within the large cylinder, so that the outer
piston is an annulus; the annulus has two rods and the small piston has one
rod, the three rods are attached to a cross head working in guides forming
part of the main A frames of the engines; from this cross head a connecting
rod with a wide fork at the cross head end is attached to the crank pin. The
eccentrics and their rods for working the slide valve are placed outside the
outer bearing of the main shaft.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Humphrys in the Great Seal Patent Office on the
20th September 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HUMPHRYS, of Tower Hill, in the County of Middlesex, Engineer, send
greeting. oi
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of March, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and, grant unto me, the
said James Humphrys, Her special licence, that I, the said James Humphrys,
my executors, administrators, and assigns, or such others as I, the said James
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;
STEAM ENGINES," upon the condition (amongst others), that I, the said James
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 in what manner the same.

page_text: 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.
J
NOW KNOW YE, that I, the said James Humphrys, do hereby declare
the nature of my 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, reference being had to the Drawings hereunto annexed, that
is to say:
-
My Invention relates to improvements in the slide valves and in the
arrangement of the parts of compound steam engines, that is to say, engines
in which there are two cylinders, the steam being worked at high pressure in
one and expansively in the other.
"
The first part of my Invention consists of a novel description of slide valve
applicable to such engines, whereby with great simplicity of construction
considerable economy is effected in the transmission of the steam from the
high-pressure to the low-pressure cylinder. My valve is a treble-ported slide
valve, the laps at the extreme ends of the valve cut off from and supply to the
small cylinder the high-pressure steam from the boiler. The steam, after
having acted on the piston of the small cylinder, is conveyed through a passage
forming part of the valve into the large cylinder, which it enters and leaves
for the condenser by the inner portion of the valve, which portion is an ordinary
double-ported slide valve.
The second part of the Invention consists of improvements in the arrange-
ment of the parts of compound engines, whereby great simplicity and acces-
sibility are obtained. These engines may be vertical or placed at any angle with
the horizon, but arranged horizontally, they are particularly adapted for driving
the screw. The small cylinder for the high-pressure steam is placed within
the large cylinder, so that the outer piston is an annulus; this annulus has
two rods and the small piston has one rod; these three rods are attached
to a cross head working in guides forming part of the main A frames of the
engine; from this cross head a connecting rod with a wide fork at the cross
head end is attached to the crank pin. The eccentrics and their rods for
working the slides are placed outside the outer bearing of the crank shaft.
And in order that my said Invention may be most fully understood and
readily carried out I proceed to describe the accompanying Drawings.
Figure 1 is a horizontal section shewing my arrangement of engine and
the slide valve. a is the high-pressure cylinder; b, b, the large or annular
cylinder; c, c, c, are the piston rods; d is the cross head; c, the connecting
rod; and ff, are the eccentrics; h, h, is the air-pump rod; and k, k, the

page_text: cold-water pump rod. The cylinder covers and bottoms are cast hollow, so
that the spaces may be filled with steam, as also the space g, g, between the
two thicknesses of metal which form the inner cylinder. At Figure 2, A is a
transverse section through one cylinder of a pair of compound engines, and B
is an end elevation of the other cylinder..
Figure 3 is a longitudinal elevation of a compound engine showing the
eccentrics and rods, and apparatus for working the slide and reversing the
engines, and also a portion of the surface condensers r, r. The course of the
steam is indicated by the arrows in Figure 1. The steam is admitted to
the high-pressure cylinder a through the passages I, 1, and is conveyed from it
through the passage m, m, forming part of the valve, into the expansion
cylinder b, b, through the ports or passages n, n, whence it passes into the
condenser by the eduction passage p, p, p.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim as my improve-
ments in steam engines,-
First, the construction and arrangement of slide valves in compound steam
engines, herein-before described.
And, second, the arrangement of the parts of compound steam engines,
herein-before described.
In witness whereof, I, the said James Humphrys, have hereunto set my
hand and seal, this Nineteenth day of September, One thousand 'eight
hundred and sixty-two.
JS. HUMPHRYS. (L.S.)