IMPROVEMENTS IN COMPOUND STEAM-ENGINES
Year: 1881

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"
LETTERS PATENT to Henry Harris Lake, of the Firm of Haseltine, Lake,
and Co., Patent Agents, Southampton Buildings, London, for an Invention
IMPROVEMENTS IN COMPOUND STEAM-ENGINES." A communication from
abroad by James W. Chisholm, of Brooklyn, New York, United States of
America, Physician.
PROVISIONAL, SPECIFICATION left by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 21st February 1881.
"
HENRY HARRIS LAKE, of the Firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN COMPOUND STEAM-ENGINES."
[A communication from abroad by James W. Chisholm, of Brooklyn, New York,
United States of America, Physician.]
This Invention relates to three cylinder compound steam engines, and comprises
such a construction and arrangement of the cylinders and their ports and slide
valves that the full efficacy of the expansibility of the steam is utilized and the
back pressure is eliminated from the high pressure cylinders by further applying
the condensing principle of compound engines.
In one form of engine designed to embody the principle of this Invention the
two cylinders which receive steam from the boiler are in line with each other, and
their pistons are carried by one rod which is connected to a crank on the main
shaft separate from the crank of the low pressure cylinder.
Each of the two high pressure cylinders receives steam from the boiler alter-
nately on one side of its piston only. The steam after actuating the piston of the
first high pressure cylinder is at its terminal pressure allowed to pass into the
opposite end of the cylinder, thereby producing an equal pressure on both sides of
the first piston while steam is entering and expanding at one side of the second
high pressure cylinder, so that no resistance is offered by the first high pressure
piston to the steam as it acts in the second cylinder other than what is due to
friction and the weight of the piston.
While the live steam is entering the second high pressure cylinder the steam
from both sides of the piston of the first high pressure cylinder is passing to one
side of the low pressure cylinder, and so actuating its piston, the initial pressure of
such steam being the terminal pressure thereof, after performing work in the first

page_text: high pressure cylinder, and when this steam has caused the low pressure piston to
move to the other end of the cylinder the first high pressure cylinder is again ready
to receive live steam at one side of its piston as before described, the steam on the
other side being now at the terminal pressure of the steam in the low pressure
cylinder; and as the communication between this side of the first high pressure
cylinder and the low pressure cylinder remains open during the time condensation
is taking place a vacuum is formed in the first high pressure cylinder as well as in
the low pressure cylinder, thereby adding the area of the high pressure piston
to that of the low pressure piston for effective work during condensation of the
steam.
The steam in the second high pressure cylinder whilst the first high pressure
eylinder is taking live steam from the boiler is caused to fill both sides of the
cylinder and exhaust into the opposite side of the low pressure cylinder to that at
which the steam from the first high pressure cylinder exhausts, so that both the
high pressure cylinders alternately take live steam at one side only of their
pistons, and alternately exhaust from both sides of their pistons into the low-pressure
cylinder.
The slide valves of the high pressure cylinders are of the ordinary construction,
but they are provided with puppet cut off valves adapted to be operated at right
angles to the direction of motion of the slide-valves; these puppet valves are
operated by means of a simple and effective cut-off device constructed to be adjusted
to cause the puppet valves to close at any desired point of the stroke of the pistons.
Steam is admitted to the low pressure cylinder by means of an improved balance
valve sliding between the face of the ports, and a plate attached to the valve chest
cover.
In another arrangement of the three cylinders the first high pressure cylinder
is centrally located in the second cylinder, thus converting the second cylinder into
an annular cylinder, the two pistons being connected to one cross head as before.
The low pressure cylinder sets alongside the annular cylinder; they are connected
by a steam chamber, into which the steam from the annular cylinder passes before
being admitted into the low pressure cylinder. The slide valve of the low pressure
cylinder is located in this chamber, and there is a suitable arrangement of pipes
passing through this chamber and adapted to act as flues for some of the waste
heat from the boiler furnace or smoke stack to reheat the steam in the chamber
before it passes to the low pressure cylinder. The cylinders are further protected
by steam jackets and a covering of non-conducting material, so that all loss of
temperature from radiation is obviated. With this arrangement of the three
cylinders they may all be used as double acting cylinders, live steam from the
boiler being admitted to the first cylinder only at both sides of its piston alter-
nately, and after expanding and performing work therein it passes through a
valve chest into the annular or intermediate cylinder, where it further expands and
actuates the annular piston; and from this annular cylinder it enters the reheating
chamber, where condensation is prevented, and any water which may be in the
steam is re-evaporated. From this re-heating chamber the steam passes into the
low pressure cylinder through its slide valve, from which after further expanding
to actuate the low pressure piston it passes to a condenser of any suitable
construction.
Certain improvements are made in the valve gear to enable the valve rod of the
central cylinder and the valve rod of the annular cylinder to be operated from one
link movement, and the improvements in the cut-off valves and operating mechanism
and balance slide valve mentioned above are adapted to be applied to both the
constructions of the engine set forth; and it is obvious that certain modifications
may be made without departing from the nature of the said Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Harris Lake in the Great Seal Patent Office on the
19th August 1881.
"
HENRY HARRIS LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN COMPOUND STEAM-ENGINES."
A communication from abroad by James W. Chisholm, of Brooklyn, New York,
United States of America, Physician.
This Invention relates to compound steam-engines and embraces several
improvements in the construction and combination of the various cylinders, their
valves and steam passages, whereby the efficiency of this class of steam-engines is
greatly increased. Two high pressure cylinders are arranged in line with one
another, and their pistons are carried by one piston rod, which by means of a
connecting rod is attached to a crank on the main shaft set diametrically opposite
the crank of the low pressure cylinder. The slide valves of the high pressure
cylinders are so constructed and operated that steam from the boiler enters the two
high pressure cylinders alternately at one side only of their pistons, so as to drive
the piston rod alternately in opposite directions. The steam after it has entered
one end of one of the cylinders, and forced the piston to the other end is allowed
to pass freely to the other side of the piston while the other cylinder is taking
steam, so that the piston of the first cylinder has an equal pressure of steam on
both of its sides, and offers no resistance to the steam actuating the piston of the
second cylinder other than that due to friction and the weight of the piston; in
other words, the back pressure is entirely eliminated, thereby permitting steam of
high tension to be used without loss of mechanical energy from this cause.
same action of the steam occurs in the second high pressure cylinder when the
first one is taking steam. The steam while passing from the working sides to
the other sides of the pistons of the high pressure cylinders also exhausts into
the low pressure cylinder, whose valves are constructed and operated to admit the
steam to the cylinder at the proper time for "lead," thus actuating by further
expansion the piston of the low pressure cylinder, and the steam gradually
decreases in pressure on both sides equally of each of the high pressure pistons,
thereby keeping each high pressure piston in equlibrium during the whole time
the steam is exhausting into the low pressure cylinder, and while the piston of
the other high pressure cylinder is being actuated by live steam from the boiler.
The
After each supply of steam has partly expended its force in actuating the piston
of one or the other high pressure cylinder, and by its second expansion is utilized
in driving the piston from one end to the other of the low pressure cylinder, the
high pressure pistons are surrounded by steam, having a pressure equal to that in
the low pressure cylinder, whose slide valve now opens the passage for such steam
to the condenser, the valves of the bigh pressure cylinders alternately also leaving
the exhaust ports open during the time condensation is taking place, so that a
vacuum is formed on the side of each high pressure piston opposite to that on
which the live steam acts at the time the live steam is so acting, thereby adding
he area of the high pressure pistons to that of the low pressure piston for effective
work due to the vacuum formed in the condenser.
The slide valves of the high pressure cylinders are connected by one rod which
s operated by a link motion and excentrics, and they are provided with adjustable
ut off valves, also connected together and operated by means of a separate
xcentric. The slide-valve of the low pressure cylinder is actuated by means of
he link. motion and excentrics, which operate the high pressure slide-valves. The
aid slide valve is balanced and held against its seat by means of a plate that is

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suspended on the valve chest cover, and provided with short pistons meting
recesses in the cover. And the high pressure valve chests are connected to the low
pressure valve chest by suitable passage ways.
In the accompanying Drawing,
Figure 1 is a front elevation of a compound steam-engine, constructed according
to my Invention.
Figure 2 is a side elevation of the same partly in section.
Figure 3 is a vertical section of the two high pressure cylinders, their valve
chests and valves.
Figure 4 is a vertical section of the low pressure cylinder, its valve chest and
valve, and
Figure 5 is a transverse section through the line x, x, Figure 2.
Figures 3, 4, and 5 are drawn to an enlarged scale.
The engine to which my improvements are shewn applied in the Drawing is of
the vertical inverted cylinder type, but they may be applied to other kinds of
engines.
The two high pressure cylinders a and a¹ are secured in position in line with
one another, and are supported by the standards b. The low pressure cylinder c
is connected by steam passages from its steam chest to the steam chests of the high
pressure cylinders a and a¹, and is supported by the standards b'. These standards
b and b¹ rest upon the bed-frame d, which is provided with journal boxes for the
reception of the crank shaft ď².
The piston-rod e is common to the two pistons a³, a³, of the high pressure
cylinders a, a', and is fastened to the crosshead e¹ fitted to work in slides in the
standards b, the said cross head being connected to the crank d' by means of the
connecting rod e². Diametrically opposite the crank d² on the shaft d² is another
crank which is connected to a crosshead (working in slides in the standards 6') by
means of a connecting rod in the ordinary manner, and to this cross head is attached
the piston rod f of the low pressure cylinder-piston fl.
On the sides of the cylinders a and a¹ are formed the steam chests a¹ and a³.
The slide valves g and g¹ are held by nuts in the ordinary manner on the rod g³
which passes through a stuffing box at the lower end of the steam chest a³ and
through a pipe g³ uniting the steam chests a¹ and a*. The lower end of the rod g³
works in a hole in the standard b, and has secured on it the block h in which the
end of the arm h' works; this arm is keyed to the shaft h2 which has bearings
in the standards b, b'; on the end of this shaft is secured the arm or lever h³
provided at its end with a block which fits in the link i carried by the two
excentric rods i¹, 3, of the excentrics is, is, which are secured on the crank shaft d¹;
the position of the link i relatively to the block on the arm h³ is governed by the
hand lever j connected at its lower end to the centre of the link i by the rod j¹,
and pivoted to a bracket which is provided with a notched sector 3, by means
of which the link i may be held in any desired position by engagement of the end
of the spring latch (on the side of the hand lever 2) with the notches of the
sector 13.
The cut off valves k, k', carried by a vertical rod k² bear respectively against the
backs of the slide valves g, g¹, and close and open ports cut through the said
valves g, g¹, to admit steam into the cylinders a and a¹. For this purpose the
lower end of the rod k² is connected to the short arms of the lever fitted to
turn freely on the shaft h²; the lever is pivotted to the end of the excentric
rod of the excentrick keyed on the shaft d¹. To regulate the cut off of the
steam or the times when the valves k and k leave the ports through the valves g
and g¹ open, these valves k and k³ are secured to the rod k² by the right and left
hand screws, as shewn, and the said rod is so fitted to the arm ³ as to be capable
of free rotation, which is effected by the following means, that is to say :-
-The
upper end of the rod 2 passes up through a stuffing box on the top of the steam
chest a and through the centre of a pinion with which it is caused to turn by
means of a spline or feather, which leaves it free to move longitudinally; this

page_text: pinion is held in the bracket in such a manner that it may rotate, but can
have no longitudinal motion therein; a rack & fitted to slide on the bracket gears
with the pinion L, so that as the rack is moved either to the right or left the
pinion is caused to turn and carries the rod k² with it, and so causes the cut off
valves k and k to approach or recede from one another, thereby leaving the ports
in the valves g and g¹ open a greater or less time as they are operated by the
excentric k6.
The low pressure cylinder slide valve m is also operated from the shaft h² by
being connected to the arm m¹ through the medium of the connecting link m² and
valve rod m³, which passes through a stuffing box at the bottom of the steam
chest c¹. A valve plate n having ports formed in it to admit steam to the valve m
bears against the back of the latter, and is held in position and kept steam tight
by the flanges m* on the back of the valve m, and is connected to the steam-
chest cover by the bolt n¹. It is provided with two pistons n² which fit into
recesses formed in the said steam-chest cover, and steam is admitted to the backs
of these pistons through the holes m³ in the cover. The size of these pistons and
pressure of steam admitted to them are such that the total pressure of the steam
which enters the chest against the front of the plate n is just exceeded so as to
keep the working parts of the valve m tight, and yet allow the valve m to move
with the least amount of friction. Instead of employing steam admitted to the
pistons n² springs may be placed in the recesses to hold the plate n against the
valve m.
The condenser is not shewn in the Drawing, as any ordinary form thereof may
be used. It is connected to the outlet o at the side of the low pressure cylinder c
between it and the steam chest c'.
The operation of this engine will be understood by referring to Figures 3, 4,
and 5 of the Drawing. With the parts in the position shewn in these Figures live
steam is about to enter the cylinder a at the upper side of the piston a² through
the valve g and port 1, and the steam now in the lower part of this cylinder is
under the influence of the condenser and passes out by the passages 2 and 3 to the
opening 5 in the valve m through the port 6 in the valve-plate n into the space 7
under the valve plate, where it mixes with the steam now passing by the port 8
from the upper side of the piston of the low pressure cylinder and passes with it
to the condenser through the passage 9 and outlet 0.
Whilst live steam is acting
on the upper side of the piston a² and the condensation of the steam in the lower
part of the cylinder a and the upper part of the cylinder c is taking place, the
live steam which has actuated the piston a³ and now fills the cylinder a' under
the piston a³ passes by the port 10 under the valve g¹ through the passage 11 to
the upper side of the piston a³ by the passage 12, and also from the passage 11
to the underside of the low pressure cylinder piston f¹ through the opening 13 in
the valve m and port 14. When the pistons have moved to the opposite ends of
their cylinders the action of the steam in the cylinder a¹ will be the same as that
above described in cylinder a, and vice versa.
Having thus fully described the said Invention as communicated to me by
my foreign correspondent, and the manner of performing the same, I wish it
understood that I claim,-
First. The combination of two cylinders whose pistons are connected to one
piston-rod with slide valves adapted to admit live steam alternately to the
opposite ends of each cylinder only, and to allow the steam after actuating
the piston of each cylinder to pass freely to their other sides whilst the live steam
is actuating the other piston, substantially as and for the purpose set forth.
Second. In combination with two high pressure cylinders their connected pistons
and slide valves constructed and operated substantially as described, a low
pressure cylinder connected with the exhaust ports of the high pressure cylinders
provided with a valve adapted to admit the steam to its piston from the high
pressure cylinders alternately, and wbile it is expanding on both of their pistons,
as and for the purpose hereinbefore set forth.

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Third. In a compound steam engine, two cylinders adapted to take live steam at
one side only of their pistons which are connected to one piston rod and actuate a
crank on the main crank shaft, in combination with a low-pressure cylinder and
its piston which is connected to a crank set diametrically opposite the crank of the
high pressure pistons, substantially as and for the purpose set forth.
Fourth. The combination with the high pressure steam cylinders a and a¹
provided with suitable pistons, ports, and valves, and a common piston rod of the
low pressure cylinder c connected therewith by steam passages and provided. with
the slide valve m, the suspended valve plate n, and the valve pistons m², n²,
substantially as herein shewn and described.
Fifth. In my improved compound steam engine the combination with the
slide-valve m provided with back flanges m* of the suspended valve-plate n and
pistons n², n², substantially as herein shewn and described, whereby said valves are
held steam tight in their respective seats, as above set forth.
Sixth. In my improved steam engine the combination with the low pressure
cylinder c and valve chest c¹ provided with the valve chest cover, having cylindrical
perforated recesses of the pistons n², n², and suspended valve plate n, substantially
as herein shewn and described.
Seventh. In the said steam engine the combination with the cut-off valve rod k²
provided with right and left hand screws, the slide valves k, k', and pinion 7 of the
rack 2, substantially as herein shewn and described, whereby said rod is adjusted
as above set forth.
In witness whereof, I, the said Henry Harris Lake, have hereunto set my
hand and seal, this Nineteenth day of August, in the year of our Lord One
thousand eight hundred and eighty one.