IMPROVE- MENTS IN ENGINES TO BE WORKED BY THE ALTERNATE EXPANSION AND CONTRACTION OR STEAM AND OTHER DAD."
Year: 1860

page_text: LETTERS PATENT to Charles William Siemens, of Great George Street,
Westminster, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN ENGINES TO BE WORKED BY THE ALTERNATE EXPANSION AND
CONTRACTION OR STEAM AND OTHER DAD."
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents, with his Petition, on
the 26th August 1860.
I, CHABLES WILLIAM SIEMENS, of Great George Street, Westminster, in,
the County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN ENGINES TO BE WORKED BY THE ALTERNATE EXPANSION AND
CONTRACTION OF STEAM AND OTHER ELASTIC FLUIDS," to be as follows:-
The Invention has reference to that class of engines in which motive power
is obtained from the expansion and contraction by heat of steam or other
elastic fluids, by the aid of respirators or regenerators when actuated by a pair
or pairs of pistons working upon two combined cranks (or their substitutes)
set at right angles or other angles to each other. An engine of this nature
was described in the Specification of a Patent granted to me and bearing date
the Ninth day of June, 1856, No. 1363. In one modification of this engine,
two cylinders open at one end and heated at the other, and containing'
respirators or regenerators, had pistons-protected against the heat, which we're

page_text: attached to opposite points of an oscillating disc or cross frame carrying an
arm which was attached to the working crank, which cylinders communicated
freely, the one with the front and the other with the back of a third cylinder
containing a piston, which was worked by the engine from a point of the
oscillating disc at right angles with the former.
Now, one of the objects of the present Invention is, to improve upon this
arrangement by suppressing the third or charging cylinder which produce no
direct useful effect, and by adding two more working cylinders, which are to be
attached with their working pistons to two points of the oscillating disc at
right angles with those of the two other working cylinders. The four working
cylinders are closed in front, and communications are established from the
front end of the first to the heated or back end of the second through a
regenerator or respirator from the front of the second to the back of the third,
from the front of the third to the back of the fourth, and from the front of the
fourth to the back of the first named working cylinder, thus completing the
circle. In this way the front part of one cylinder answers the purpose of
charging cylinder to the next, and so on.
By this improved arrangement the available power of the engine is greatly
increased, the motion produced is more uniform, and the losses of heat by
leakage and radiation froin exposed. surface is reduced. This four-cylinder
arrangement may be greatly varied in form, instead of attaching the four pistons
to four equidistant points on an oscillating disc, they may be attached to a four-
throw crank or to two cranks at opposite points of the shaft, upon each of
which cranks two working cylinders, placed at right angles to each other,
are made to act, or the four working cylinders may be placed radially round
a central working crank. The supply of fresh steam or other elastic fluid to
the four working cylinders and their partial discharge at the
proper intervals
of each stroke may-be advantageously effected by 'n rotating valve, with four
radial apertures leading to the four cylinders and two.apertures endways, the
one communicating with the boiler or reservoir of elastic fluid in a state of
compression, and the other with the atmosphere or a condenser, while the
rotary plug is pierced with two apertures divided by an oblique partition. If
it is not desired to reverse the motion of the engine at any time, the commu-
nication pipes between the working cylinders do not require any valves or
cocks; but if the engine is to be made capable of being reversed, then a valve
or stop-cock is introduced, and a second passage is provided from the front of
the first cylinder to the back of the fourth, (and, so on with the other
cylinders,) which passage is likewise provided with a stop cock, which is
usually closed, but is opened when the stop-cock of the ordinary passage
is

page_text: closed. Instead of two separate cocks or valves, a two-way cock or valve may
be provided, and the four cocks or valves required to reverse the engine may
be combined by geering or levers, so that one movement of a handle effects
the purpose. The crank or wheel which gives motion to the distributing
valve should, in that case, not be fastened upon the shaft, but have liberty to
revolve freely through a half-revolution, or thereabouts, upon the motion of the
engine being reversed.
In heating the ends of the working cylinders by means of coal fires, con-
siderable difficulty has been experienced from the injurious effect produced
upon those portions of the vessel that are first struck by the fire. Moreover
when the engine is stopped for some time the radiated heat from the fire-place
is liable to attack portions of the heated vessels, and thus to accelerate their
destruction. I propose to remedy this inconvenience by placing the fuel in
a gas generator entirely separate from the engine, and conducting the gas
therein produced to the cylinder and burning it by means of a number of jets
of atmospheric air, distributed in such a way as to produce nearly an equal
heating effect over the entire surface of the heated vessel. The gas generator
consists of a cupola or of a furnace with a grate with a very deep layer of fuel
upon it which is traversed by a slow current of atmospheric air, or air and steam
causing decomposition of the incandescent-carbonaceous fuel which resolves
itself into carbonic oxide and carburetted hydrogen with an admixture of
nitrogen and other gases, which gases generate by their heat a further quantity
of carburetted hydrogen from the bituminous constituents of the coal. The
ash-pit and the other approaches to the fuel are capable of being closed suffi-
ciently air-tight to arrest the production of gas when the engine is stopped
without discharging the fuel from the furnace. This gas generator should be
place: below the level of the combustion chamber, in order to produce
a sufficient draught of air through the fuel by the ascending column of the
gases produced, or a fan or pump may be employed. The products of
the combustion of the gases in passing away from the heated cylinders, are
made. to traverse the tubes of a boiler surrounding the cylinders, and are
collected in a smoke box and delivered into a chimney. The smoke box is
traversed by tubes, or formed with narrow chambers, through which the
atmospheric air is made to circulate, which serves to support the combustion
of the gases.
By another arrangement I add the requisite amount of heat to the gases
when heated by the regenerator and forced by the charging cylinder or piston
into the heated portion of the working cylinder by an internal instead of an
external combustion. For this purpose I attach an open tube or chamber

page_text: to the hot end of each working cylinder, which tube or chamber may be lined
with advantage with platinum or other refractory material. Two branch pipes
leading into this chamber supply at the proper moment, the one a current
of inflammable gas and the other a current of oxygen or atmospheric air,
which are ignited at the point of junction, and in mixing with the heated gases
contained in the cylinder raise their heat to an amount equal to that of the
losses of licat sustained in consequence of their expansion behind the working
piston and from incidental causes. In order to ignite the gases a heated
rod of metal or fire-clay is introduced into the combustion chamber before
starting the engine, which rod remains hot afterwards in consequence of the
combustion of the gases themselves. Or a platinum wire is introduced,
which is heated on starting the engine by means of a galvanic current. If
the gases supplied are pure hydrogen and oxygen in due proportion, steam
will be produced which will take the place of the supply of steam other-
wise introduced at the same period of cach stroke from the boiler, the only
difference being that it is in a highly heated state, and is therefore intro-
duced at the liot extremity of the regenerator. The surplus steam is discharged
from the engine as before from the cool extremity of the regenerators, and at
the time when the greatest expansion has taken place. If carburetted
hydrogen gas and atmospheric air are used, a mixture of steam, carbonic acid,
and a large proportion of nitrogen will result from their combustion and will
coustitute the working medium of the engine, a portion of such mixed gases
being discharged at each stroke as before when steam ouly was used. Or in
some cases, especially when the pressure at one period of the stroke is the
same as that of the atmosphere, I open a valve or valves and blow through
the cylinder so as to fill it with fresh air. It is not then necessary to pump
in compressed air, as the gas will be burned by the air in the cylinder. Water
is placed round the cooler portions of the cylinder or cylinders which contain
the working pistons, which may be advantageously kept cooler when a mixture
of gases is used that when pure steam is employed. Instead of using pure
carburetted hydrogen, or such as is supplied by gasworks, the gas obtained
from a gas generator such as that herein-before mentioned may be used.
This gas should, however, be cooled and purified to some extent before it is
compressed by means of a pump worked by the engiue into a reservoir ready
for admission into the combustion chamber of the engine. For this purpose
1 pass the gas downwards through a series of tubes traversing the chambers
or reservoirs containing the stores of compressed air and gases so as to yield
their sensible licat to the same. These tubes extend downwards and terminate
under water contained in a lower chamber; the punip draws the gases from

page_text: above the surface of this water or liquid and forces them into the reservoir
above; they may be previously cooled by refrigerators or condensers if required.
Atmospheric air is forced by the other extremity of the same, or by another
pumping cylinder into the chamber provided for compressed air. The air and
gases are admitted into the combustion chambers at suitable intervals by
means of rotating valves similar to those herein-before mentioned, or b
any other arrangement of valves. The air and gas reservoirs and the valves
for their distribution may be dispensed with by providing two separate pumping
cylinders for each working cylinder, worked by a crank, (or its substitute,) at
ight angles or nearly so with the working cylinder and discharging into the
combustion chamber direct. This method of heating may also be advantageously
applied to other engines worked by the alternate expansion and contraction
of elastic fluids as well as those above described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles William Siemens in the Great Seal Patent Office on
the 28th February 186...
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of Great George Street, Westminster, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of Angust, in the year of our
Lord One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles William Siemens, Her special license that I, the said
Charles William Siemens, my executors, administrators, and assigns, or
such others as I, the said Charles William Siemens, my executors, adminis-
trators, 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 ENGINES TO BE WORKED BY THE
ALTERNATE EXPANSION AND CONTRACTION OF STEAM AND OTHER ELASTIC FLUIDS,"
upon the condition (amongst others) that I, the said Charles William Siemens,
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

page_text: nature of the said Invention, and 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 Charles William Siemens, 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 :-
The Invention has reference to that class of engines in which motive
power is obtained from the expansion and contraction by heat of steam or
other elastic fluids, by the aid of respirators or regenerators when actuated
by a pair or pairs of pistons working upon two combined cranks (or their
substitutes) set at right angles or other angles to each other. Engines of this
nature were described in the Specifications of Patents granted to me and
bearing date respectively the 9th day of October 1852, No. 326, for "Engines to
be worked by Steam and other Elastic Fluids," and the 9th-day of June 1856,
No. 1363, for "Improvements in Engines wherein Superheated Steam is
used."
In one modification of this engine, two cylinders open at one end and heated
at the other and containing respirators or regenerators had pistons protected
against the heat, which were attached to opposite points of an oscillating disc
or cross frame carrying au arın which was attached to the working crank,
which cylinders communicated freely the one with the front, and the other
with the back of a third cylinder containing a piston, which was worked by
the engine from a point of the oscillating disc at right angles with the former.
Now, one of the objects of the present Invention is to improve upon
this arrangement by suppressing the third or charging cylinder, which pro-
duced no direct useful effect, and by adding two more working cylinders,
which are to be attached with their working pistons to two points of the
oscillating disc at right angles with those of the two other working cylinders.
The four working cylinders are closed in front, and communications. are
established from the front end of the first to the heated or back end of the
second through a regenerator or respirator, from the front of the second
to the back of the third, from the front of the third to the back of the fourth,
and from the front of the fourth to the back of the first-named working
cylinder, thus completing the circle. In this way the front part of one
cylinder answers the purpose of charging cylinder to the next, and so on.
In heating the ends of the 'working cylinders by means of coal fires, con-
siderable difficulty has been experienced from the injurious effect produced

page_text: upon those portions of the vessel that are first struck by the fire. Moreover
when the engine is stopped for some time, the radiated heat from the fire,
place is liable to attack portions of the heated vessels, and thus to accelerate
their destruction. I propose to remedy this inconvenience by conducting
inflammable gas or vapor in pipes to the heating vessel or cylinder, to be
there burned in small jets directed against its outer surface, or by introducing
into the cylinder the hot products of combustion resulting from the ignition
of the mixed gas and air, or in combining these two methods of heating; and
I prefer to apply the heat internally and externally in such proportions that
the vessel may be heated externally to such an extent as to keep it up to a
high temperature, though not so high as to cause any injury to the metal,
whilst the heat applied internally is that which serves to produce the power;
or instead of supplying currents of gas and air in a state of ignition, I
sometimes supply to the interior of such heated vessel currents of steam
or air, which have been heated to a very high degree by any known method.
When steam is used as motive medium, I pass the products of the
external combustion through tubes or passages of a boiler, in the manner
as shown in my Patents above alluded to; or when either gas or air is used as
motive medium, I pass the products of combustion through tubes, or over the
surface of an air reservoir, to impart heat to the air which is used to support
combustion..
:
When steam is used as a working medium, it is admitted according
to my present Invention through a superheating apparatus in passing from
the boiler to the engine at the commencement of each effective stroke, en-
tering at the heated end of the regenerator, and a discharge of steam from
each working cylinder is allowed to take place from the cooler end of the
regenerator at the instant when the greatest expansion and cooling has taken
placed; this is accomplished by ordinary slide or other valves.
:
When gases are used as the working medium and internal firing is resorted
to, I attach an open tube or chamber to the hot end of each working, cylin-
der, which tube or chamber having recesses presenting highly heated surfaces
may be lined with or consist of platinum or other refractory material.
Two branch pipes leading into this chamber supply at the proper moment,"
the one a current of inflammable gas or liquid convertible into gas by the
heat of the chamber, and the other a current of oxygen, or atmospheric air"
which being mixed are ignited on coming in contact with the highly heated
substance, and in mixing, with the heated gases contained in the cylinder
raise their heat to an amount equal to that of the losses of heat sustained
in consequence of their expansion behind the working piston and from
·

page_text: incidental causes. In order to ignite the gases, a heated mass of metal,
or fire-clay, or piece of incandescent material, may be introduced into
the combustion chamber before starting the engine, which material remains
hot afterwards, in consequence of the combustion of the gases themselves;
or a platinum wire is introduced, which is heated on starting the engine
by means of a galvanic current; or sponge of platinum may be employed
to produce ignition; or the tube itself is heated sufficiently by means
of a flame or blow-pipe jet directod against it to ignite the gases passing
through the saine. If the gases supplied are pure hydrogen and oxygen
in due proportiou, steam will be produced, which will take the place of
the supply of superheated steam, otherwise introduced at the same period
of each stroke at the hot extremity of the regenerator. The surplus steam
is discharged from the engine, as before, from the cool extremity of the
regenerators and at the time when the greatest expansion has taken place.
If carburetted hydrogen gas and atmospheric air are used, a mixture of
steam, carbonic acid, and a large proportion of nitrogen will result from their
combustion and will constitute the working medium of the engine, a portion
of such mixed gases being discharged at each stroke as before when steam
only was used.
Or in some cases, especially when the pressure at one period
of the stroke is the same as that of the atmosphere, I open a valve or valves
and blow through the cylinder so as to fill it with fresh air. Water is
placed round the cooler portions of the cylinder or cylinders which contain the
working pistons, which may be advantageously kept cooler when a mixture
of gases is used than when pure steam is employed. Instead of using pure
carburetted hydrogen, or such as is supplied by gasworks, the gas obtained
from a gas generator such as will be hereafter described may be used. This
method of heating may also be advantageously applied to other engines worked
by the alternate expansion and contraction of elastic fluids. Or it may be
used with advantage in combination with an external application of heat, as
before described.
But in order that my invention may be more fully understood and readily
carried into effect, I. will now describe the best method I am acquainted with
of performing the same.
On Sheet I. of the accompanying Drawings is represented one description
of. my improved engine. Figure 1 shews a longitudinal section; Figure 2
shews a sectional plan; Figures 3 and 4 are cross sections of the same. The
same letters indicate similar parts in all the Figures.
A box-shaped vertical framing A is fixed to a strong base plate B. Five
cylinders C¹, C2, C3, C4, D, are cast in one with the framing A; the cylinders

page_text: C1,C2, C3, C4, are of equal diameters, and constitute the four working cylinders,
while the central cylinder D constitutes the reservoir for combustible gases.
To one end of each of these cylinders C1, C2, C3, C4, are fixed other cylinders E¹,
E, E³, E, being continuations of the same; they are closed at the unattached
end, and have cast in one piece with them smaller vessels a', a³, a³, a4, com-
municating freely at one end with the cylinders E', E, E³, E, the other ends
being attached against the framing A, in the side of which corresponding
openings are formed. On the opposite side of the box-shaped framing A,
corresponding holes of a smaller size are formed, which are closed by a por-
tion of the covers F1, F2, F3, F4, to the cylinders C1, C2, C3, C4, formed into
passages ƒ¹‚ƒ³‚ƒ³‚f, communicating with the front of these cylinders.
Traversing the width of the box framing A are pipes G1, G2, G3, G4, forming
a communication between the small vessels a, a, a³, a', and the passages
|ƒƒƒ³ƒª. The small vessels a', a², a³, a, are filled with layers of metallic
gauze b¹, b, b³, b, held in position by gratings at either end, which layers of
metallic gauze constitute the regenerators of the engine. Thus it will be seen
that a communication is established, for instance, between the back of the
cylinder E and the front of the cylinder C, firstly, through the passage a¹
into the regenerator b', and thence through the pipes G₁into the passage f
of the cylinder cover F. In like manner a communication is established
between the back of the cylinder E and the front of the cylinder C³, between
the back of the cylinder E3 and the front of the cylinder C4, and lastly between
the back of the cylinder E and the front of the cylinder C¹, thus completing
the circle. The box framing A is closed on all sides, and is filled with cold
water, which consequently surrounds the cylinders C1, C2, C3, C4, and also the
pipes G1, G2, G3, G4, and tends to keep them cool. A continuous circulation
of cold water is maintained by means of the pipes c, c', leading up to a reser-
voir above. Each of the four working cylinders C, C2, C3, C4, are provided
with hollow pistons H1, H2, H3, H+, formed in such a manner that when they
are at the end of the back stroke they completely fill out the cylinders E¹, E³,
Es, E. To these pistons are fixed strong piston rods 11, 12, 13, 14, passing
through the stuffing boxes of the cylinder covers F1, F2, F3, F4, and having
sockets at their ends into which fit the spherical ends of the connecting
rods J, J, J³, J*, connecting them to the oscillating disc K of means of the
"Penn's heads "d', d, d³, d, working on four spherical projections fixed on
the circumference of the disc, and situated 90 degrees apart from each other.
By means of these spherical connections, the connecting rods J', J, J³, J4,
can follow freely the oscillating motions of the disc K. This disc is attached
by a socket in its centre to a fixed spherical projection g, forming part of the
B

page_text: continuation D' of the gas reservoir D. Projecting from the centre and
perpendicularly to the plane of the disc K is an arm K', the end of which
passes into a cylindrical hole in the circumference of the wheel I attached to
the shaft M, supported by the plummer blocks e, e', on brackets fixed to the
base plate B, B. The oscillating disc K. is further provided with a projection
at the lowest point of its circumference, or between the connecting rods J¹,J",
which projection is connected with the rod N; by means of a universal joint
sliding up and down in a cylindrical boss formed on the rod N; this rod is
carried by the plummer blocks h, h, fixed to the base plate B, B, and is
capable of sliding backwards and forwards in its bearings. By this connection
of the disc K to the rod N, the former is prevented from turning round on its
axis. but can freely oscillate in every direction, causing the rod N at the same
time to slide backwards and forwards, thus giving motion to the piston rod o
of the pump O to be described hereafter,
It will be evident that on turning
the shaft M, and with it the wheel L, an oscillating motion will be imparted
to each point of the circumference of the disc K, which will result in the
successive motion of the four pistons H, H, H, H, and that vice versa, if
a successive reciprocating motion be imparted by the motive power to the
pistons H, H, H3, H4, it will be converted into the rotatory motion of the
wheel Land shaft M, which motion is by this particular arrangement rendered
remarkably regular, and well adapts this engine for its application to screw
propellers. Previously to starting the engine, a number of gas burners, of
which one is shewn at 1, are ignited in order to heat the cylinders E1, E², E³, E4,
to a considerable degree, for this purpose a casing 2, 2, is provided, having a
chimney 3. The casing 2, 2, may be made with double sides, and a current
be established between them, which becoming heated may be made to support
the combustion of the gas jets. This second casing is not shewn in the Drawing
in order to avoid complication. The working of the engine takes place in the
following manner :-Combustible gases are formed in a separate generator P,
to be described hereafter, and are thence conducted through the pipe p and
valve box y to one side of the pump O, the piston of which is actuated by the
disc K in the manner before described, the quantity of gas passing in at
each stroke being regulated by means of the cock j. Thence the gases are
forced through the pipe into the gas reservoir D, D¹, where they are
cómpressed very considerably. While this is taking place on one side of
the piston of the pump O, atmospheric air is drawn through the cock ju
into the other side of the pump, and is thence forced through the pipe z
into a reservoir Q contained in the gas generator, where it becomes heated
to a considerable degree. From these reservoirs D and Q, the combus-

page_text: tible gases and atmospheric air pass respectively through the pipes k, l,
and the cocks 7, A, to the rotatory distributing valve R.. This valve,
which is shewn to a larger scale in Figures 5 and 6, serves to distri-
bute the combustible gas and air in regular rotation to each of the four
working cylinders, and consists of an outer cylinder R, having four holes in
its side, to which are fitted the four pipes m, m2, m, leading to the ends
of the cylinders E, E, E, E. Into the cylinder is fitted a smaller one r
open at the ends, but having a diaphragm across the middle of it, and fur-
nished-with two apertures in its side, one on each side of the diaphragm. The
ends of the outer cylinder communicate, one with the pipe from the gas
reservoir, the other with the pipe from the air reservoir; thus gas enters on
one side and atmospheric air on the other side of the diaphragm of the.inner
cylinder, which in revolving discharges a certain quantity of gas and air
together through the before-mentioned openings in its side consecutively into
each of the four pipes m³, m², m³, m³. The inner cylinder receives its rotatory
motion in the following manner :-Formed in one piece with it is a long hollow
spindle, passing through stuffing boxes at each end of the onter cylinder,
and having a small disc y, with a projection attached to one end of it.
Through this hollow spindle passes a solid ones, having attached to each end a
small crank t,, the arm of one of which t catches against the projection ou
the disc
1 and thus when caused to revolve carries the inner cylinder round
with it. These cranks receive their motion from the oscillating disc K. by
means of the two connecting rods S, S', which pass through tubes crossing the
box fraine A. The gas and air uniting after they leave the distributing valve,
pass, for instance, along the pipe m' to a part where the same is enclosed in a
small furnace U, and heated to a high degree by a jet of gas; opposite the gas
flame small cups of platinum or other refractory metal are fixed, with their
open ends into the pipe, one edge being slightly elevated above the other so
as to form an obstruction to produce an eddy in the current of mixed gases;
these cups being heated to a high degree without being exposed to the cooling
effect of a strong current, serve to ignite the gases with great certainty on
their passage towards the heated vessels; the highly heated gases resulting from
this combustion enter into the back of the cylinder El, at the same time that
other gases are passing from the front of the cylinder Co through the rege-
nerator b', and also enter at the back of the cylinder E' in a highly heated
state, having taken up heat from the regenerator. The expansive force of
these mixed gases causes the piston. H to begin its forward stroke. When
the piston El has arrived at half stroke, the piston H is at the end of
its forward stroke, and begins its return stroke, but owing to that point of the

page_text: disc to which it is connected just then passing the "dead centre," the
piston H does not recede to any great extent until the piston H' is near the
end of its forward stroke; when this takes place the piston H2 yields to the
pressure of the expanding gases. In passing through the regenerator b¹ and
the cooler C, they deposit the greater portion of their heat, and lose pressure
rapidly.
It has been stated, that at the commencement of every effective stroke a
fresh quantity of gas is admitted into the cylinder E'; it will therefore be
necessary, before beginning a fresh stroke, to allow a quantity equal to that
admitted to escape. This is effected when the piston H is at the end of its
return stroke, the front portion of the piston rod being made hollow, and
having holes u¹ communicating with the front of the cylinder, and other
holes v¹ communicating with the hollow gland of the stuffing box, which in its
turn communicates with the atmosphere or a condenser by means of the pipes
T, T; thus the gases find their escape through the hole into the hollow
part of the piston rod, and thence through the holes v into the hollow glands
and into the pipes I, T, and the pressure in the cylinder is reduced to that of
the atmosphere or that of the condenser. As soon, however, as the piston H
begins its forward stroke, the hole passes into the stuffing box, and the
communication with the atmosphere or condenser is cut off. The gases in
front of the piston H are first slightly compressed, and are then forced back
through the pipes G'into the regenerator b', where they take up the heat they
before deposited, aud re-enter the back of the cylinder E' in a highly heated
state, causing the piston H' to make another ellective stroke while the piston
He remains in a comparatively quiescent state. A precisely similar action goes
on in regular rotation between the cylinder E and C³, between E3 and C4, and
between E and C. A certain amount of heat is lost at every stroke, firstly,
from the expansion of the gases. in the working cylinders; secondly, from
their condensation while passing through the pipes G, G, G", G; and, thirdly,
by radiation from the working cylinder. To make up for these losses, there
is, firstly, the heat engendered from the combustion of the gases at the begin-
ning of each effective stroke, and a further quantity of heat is supplied
externally from a number of gas jets surrounding the heated ends of the
working cylinders. The loss of heat from radiation is prevented as much as
possible by a sheet iron casing covering the heated portions of the engine.
In many cases it is required to be able to reverse the notion of the engine.
To effect this, reversing valves are fitted to the passages f', f, f", f, as shown
to an enlarged scale in Figures 7, 8, and 9, but which are omitted in Figures
1, 2, 3, and 4, to avoid complication. It will be seen, that when the valve is

page_text: in the position as shown in Figures 7 and 8, the communication of the cylinders
is in the order as already described, but if the valve is turned 90°, as shewn
in Figure 9, then the front of the cylinder C is made to communicate with
the back of the cylinder E by means of the pipe w, and the back of the
cylinder E is made to communicate with the front of the cylinder C+ by
means of the pipe w'. These four reversing valves may with facility be all
actuated by the motion of one lever, being each provided with a bell-crank
lever, all of which are connected together by links.
It will be necessary, in reversing the motion of the engine, that the relative
position of the distributing valve R be also reversed, for this reason, it must
be capable of being turned half a revolution in the reverse direction without
the engine moving. It will be readily seen that this can be done by means of
the handle 4, the cam arrangement before described admitting of such motion.
On starting the engine, it may be required to set the valve R by hand in the
most favourable position for commencing motion. To effect this, the spindles
may be pushed laterally so that the arm of the crank passes out from
between the projection on the face of the disc 7, and the valve may then be
moved into any position by hand. A small spiral spring 5 forces the spindle s
back again into its original position.
I have now to describe the gas generator. This consists of the outer
cylinder P, and the inner cylinder. consisting of the two parts V, VI, which
latter are lined with fire-clay. The lower portion V is fixed at the top to the
outer cylinder P, and has at the bottom a fire grate a. The upper portion Vi
is separated from V by a cast-iron ring W, provided with a number of radial
holes. Upon this ring W slides an outer ring X, provided with holes corre-
sponding in position with those of the ring W, so that by turning the ring X
these holes may be more or less closed. The top portion VI of the gas gene.
rator rests upon the ring. W, and can be removed by means of the handles. It
is closed at the top by a removable cover Y; set in a sand bed to prevent the
escapc of gas. In the annular space between the cylinder P and the cylinder
Vis formed a reservoir Q, into which compressed air is pumped by the pump
O, through the pipe . This reservoir does not reach quite up to the top of
the space between the cylinders V and P, and the remaining space is filled
in with layers of metallic gauze 6. Between the fire grate x and the bottom
of the air reservoir Q is an ash-pit, which is accessible through the openings
Z,, in the cylinder P and reservoir Q, but which openings are closed by
covers, as shown, when the generator is at work. When the engine is to be
started, the cover Y is removed, the cylinder V is filled partially with coke
upon which is thrown a layer of incandescent fuel, and this is covered with

page_text: fresh fuel up to the top of the cylinder V. The doors of the ash-pit are thien
opened and the openings in the ring W are closed by sliding the ring X
upon them. The cover Y being still removed, the fire will begin to burn
upwards and as soon as it has become sufficiently spread the cover Y is
replaced, the doors of the openings Z, Z, are closed, and the ring X turned so
as to admit of air passing through the holes of the ring W. Supposing that
the two reservoirs D and Q are charged with compressed gas and air respec-
tively, and that the gas jets 1, 1, and 7, 7, have been lit for a sufficient time,
the engine will be ready to start; by the action of the pump O, atmosphericair
will be drawn in through the apertures of the ring W, which air on coming in
contact with the mass of incandescent fuel is converted into carbonic acid
gas and nitrogen, and is mixed with a large proportion of carburetted hydrogen
evolved from the fresh fuel in the upper part of the generator, which gases
are likewise drawn down by the action of the pump. As the air and gases
slowly perincate the mass of incandescent fuel they are converted into carbonic
oxide, carburetted hydrogen, and hydrogen, with an admixture of nitrogen, in
which form they pass through the grate, and ascend in the space between
the cylinder V and the side of the reservoir Q. At the top they are drawn
through the layers of wire gauze 6, where they deposit any dust, &c. that may
have been carried along with them; they are then caused to descend again
between the cylinder P and the reservoir Q, and are eventually drawn out
through the pipe p, as before described. Atmospheric air is during this time
pumped into the reservoir Q, and there becomes considerably heated by the
combustible gases passing along on either side of the reservoir, which gases in
consequence become considerably cooled. They, however, attain a higher
degree of heat again by being considerably compressed in the reservoir D), and
should they require to be still more heated they may be conducted through a
coil of pipes surrounding the heated portion of the working cylinders on their
way to the distributing valve R. The object of passing the products of dis-
tillation from the green coal or other fuel contained in the upper cylinder V
through a layer of highly incandescent fuel below, is to convert tar, naptha,
steam, and other vapours into permanently elastic and inflammable gases, such
as hydrogen and carbonic oxide. If before starting the engine the reservoirs
D and Q are not charged with gas and air from the previous working, a hand
pump may be employed for that purpose. In certain cases I inject steam into
the gas generator, which in passing over the highly heated carbonaceous
surface is also converted into combustible gases; this steam may be con-
veniently generated by the heat of the gases produced, and the vessel Q should
in that case be filled with water instead of compressed air; or I allow a small

page_text: stream of water to flow upon the fresh fuel at the top. The fuel is occa-
sionally replenished from the top; occasionally the fuel may be stirred by
introducing an iron bar from above. To remove the clinkers through the
grate the engine has to be stopped, unless a second generator and stop-cocks
in the gas pipes are provided.
Auother arrangement of my improved engine is shown in Figures 3, 4,
and 5, on Sheet II. of the accompanying Drawings. Figure 3 is a vertical
section; Figure 4, a side elevation; and Figure 5, a sectional plan. Similar
letters refer to similar parts in each of the Figures.
Here the four working cylinders C1, C2, C3, C4, are ranged side by side, and
are cast in one piece with box framing A, attached to the base plate B by
means of the upright side frames B.. The cylinders C¹, C², C³, C+, project
considerably beyond the box framing A, which is filled with cold water, and
over the projecting portions are fitted the cylinders E', E, E, E, of a larger
dianieter, so that an annular space is left between the cutside of the cylinders
C, C, C, C4, and the inside of the cylinders E1, E2, E3, E.; these latter are
closed at one end, and are bolted against the framing at the other. In the
annular spaces between the cylinders are rolls of wire gauze b', 6, 3, 4, which
constitute the regenerators of this engine. Small pipes e¹, e, e, et, are fixed
across the box framing A and round the cylinders C1, C2, C3, C4, and com-
municate at one end with the annular spaces containing the regenerators, and
at the other end with annular passages f¹, f, f³, f, formed round the lower
part of each cylinder, and closed by the cylinder covers F', F2, F3, F4. These
passages are so arranged that communications are formed from the cylinder E',
through the regenerator b' and cooling pipes e', to the bottom of the cylinder C
in like manner from E to the bottom of C3, from E3 to the bottom of C+,
and from E to the bottom of C₁, by means of the extra connecting pipe X.
Each cylinder is furnished with a hollow piston H³, H, H³, H+, formed in
such a manner that they fill out the upper part of cylinders E¹, E², E³, E+,
when at the end of the up stroke. The piston rods 11, 12, 13, 14, are furnished
with cross heads and guides, and connected by means of the connecting rods
J, J, J3, J4, to the four-throw crank shaft M, in such a manner that, for
instance, when the piston II4 is at the end of the up stroke, the piston H' is at
half up stroke, H at the end of the down stroke, and E³ at half down stroke.
Covering the hot ends of the cylinders E³, E, E³, E4, are the reservoir for
combustible gases D, and the air reservoir Q. The gas and air forced into
these reservoirs by means of the pump O, actuated from a cross head on
the piston rod 1', which pump draws the gases from a separate gas generator.
The gas and air are admitted from the reservoirs into the cylinders E', E²,

page_text: E3, E, in regular rotation through the pipes and 1 by means of the valves
R1, R2, R3, R4, which consist of small cylinders having three openings, one
communicating with the cylinders E¹, E², E³, E+, hy small pipes y', y, y³, y',
the other two openings being connected with the gas and air pipes from the
reservoirs. Plungers Z1, Z2, Z3, Z4, working up and down in these cylinders
alternately open and close the communication between these pipes. When
the mixed gas and air enter the pipe y4, they pass through a portion which is
heated considerably by means of a jet of gas, and are thereby ignited, and the
resulting highly heated expansive gases enter the top of the cylinder E+, and
cause the piston E to make the down stroke. A subsequent absorbtion of
the heat of these gasos then takes places on their passing through the
regenerator 64 and pipes et into the bottom of the cylinder C through the
pipe X. in a similar manner to that shewn in the before-described engine.
When the gases have arrived in the bottom of the cylinder C, it becomes
necessary to allow a certain volume to escape, equal to that generated by the
combustion of the gases at the top of the cylinder E. This-is-effected-by
communication being formed between the annular passages f", f,f,, and
outlet valves K', K², K³, K+, which, when the pistons H1, H2, H3, H4, are at
the end of up stroke, are successively opened by means of connecting rods
m1, ma, m³, m³, actuated by small cams on the revolving shaft L, which receives
its motion by means of a pitch chain from the crank shaft M. The spindles
of the plungers Z1, Z2, Z3, Z, admitting gas and air, are also moved by cams
on the shaft L. The cylinders E¹, E2, E3, E4, and the compressed gases are
heated in the first instance by gas jets supplied by the pipes 1, 1, a chimney 3
being provided to take off the products of combustion.
This arrangement of engine inay be advantageously adapted to locomotives,
-in which case the four cylinders would be placed in a horizontal position, and
in the place of the cranks N¹ and N4, there would be substituted the driving
wheels of the locomotive, with crank pins attached to them, as is ordinarily the
case where outside cylinders are employed. It is also directly applicable for
screw propeller and other purposes. My improved method of supplying heat
is.also applicable to caloric engines generally.
Sheet II., Figures 1 and 2 represent an application to that class of
caloric engines where a working piston and a displacer are used within one
* cylinder. Figure 1 is a longitudinal section, and Figure 2 side elevation of
the same.
The cylinder A consists of two parts, of which the upper one A is sur-
rounded by a metal casing v, leaving an air space between it and the cylinder.
This casing is perforated at e; e, and i, i, and a circular gas pipe is introduced

page_text: having small apertures for the issue of gas against the sides of the cylinder,
which gas is consumed by the circulation of air produced through the
apertures e, e, and i, . The lower part of the cylinder is fitted into the
cylindrical portion of the vertical frame B, leaving an annular space between
the frame and the cylinder. This space is filled with cold water from a cistern
not shewn in the Drawing, and a circulation is kept up by means of the two
pipes C, C. The base plate C carries the crank shaft D by means of two
plummer blocks. The crank E has two crank pins g, h, formed in one piece,
but in such a manner that the pink is from 30 to 45 degrees in advance of the
ping, both being at the same distance from the centre of the crank shaft. The
crank ping is connected to the working piston F by means of the connecting
rod, and the crank pin h works the displacer G by means of the split
connecting rod I and the piston rod K, which works through a stuffing box
with a long gland, as shown in the Drawing, the long gland being for the
purpose of protecting the stuffing box from the heat of the cylinder A. The
displacer G contains the regenerator b, consisting of discs of wire gauze
placed between two circular metal gratings. An air pump O and a second
pump l'arc provided, being worked by an excentric Q upon the main shaft. D.
The pump
P is fitted with a plunger p, and is intended to force liquid fuel
such as paraffine or spirits of wine, or rosin, oil, &c., into the combustion
chamber R.
Figure 6 is a section of the combustion chamber R to an enlarged scale.
The air is supplied to this chamber directly from the pump O by the pipe o,
whilst the liquid fuel passes through the pipe into the upper part of the com-
bustion pipe m, which leads into the cylinder A'. It is important that the
discharge of air and liquid fuel into the pipe m should take place simul-
taneously, and since the one is an elastic and the other a non-elastic fluid, it is
necessary that the plunger p should only be moved upwards during the latter
portion of the stroke; to accomplish this the crosshead is made to slide
freely over the lower portion of the plunger p, and can only move it when it
strikes either the fixed collar t. or the moveable screw collar t¹. It will be
perceived that the effective stroke of the plunger 2 will be less than that of the
air-pump piston by the amount of play between the collars and t¹, and that
the upward motion of the plunger will not take place until towards the end of
the upward movement of the air-pump piston, when both will discharge simul-
taneously. The quantity of liquid fuel pumped can be regulated between certain
limits by varying the position of the moveable collar t. The pipe m contains
a spiral bar or screw n, past which both the liquid fuel and air have to descend,
and the pipe as well as the spiral within it being heated by means of the gas
P
с

page_text: burner S, the liquid fuel is readily evaporated, and the vapours so formed
mixing with the air, is fired on passing the ignitor or cavity s. The position
of the excentric working the pumps is so regulated that the discharge of com-
pressed air and liquid fuel takes place immediately after the main crank pin g
has passed the upper centre so as to increase the power of the descending
stroke by the heat produced in the combustion. The products of combustionare
discharged on completion of the down stroke of the piston F, when its upper
edge descends below the side opening and exhaust pipe T. A second side
opening U is provided at the same level as the passage T, but is furnished with
a valve admitting free access of air into the cylinder, but preventing egress
in that direction. The length of the connecting rods fand I, and of the piston
rod K, are so adjusted that while the piston F descends the displacer G nearly
touches the same, whereas in ascending the displacer will be removed from
the upper surface of the piston by double the amount of lead of the crank
pin over the crank pin y. In consequence of this arrangement the gases
imprisoned above the working piston, are also above the displacer G, and
therefore in a heated condition during the descent of the piston, but are con-
tained in the comparatively cool receptacle between the displacer and the piston
during its ascent. When the piston F reaches its lowest position a rush of
gases will take place through the exhaust pipe T, which will, however, be
rapidly checked in consequence of the increasing distance between the piston
and displacer, and a partial vacuum will be formed, causing atmospheric air to
penetrate through the valve U, while the upward motion of the column of
gases in the exhaust pipe will prevent the re-entry of the discharged gases into
the cylinder. A change of a considerable portion of the gases forming the
working medium of the engine is thus produced at each stroke, tending to
cool the same, aud assisting the perfect combustion of the inflammable
vapours; if the contents of the pump O should not suffice for that purpose the
circulation of cold air through the cylinder may then be effected by the appli-
cation of blowing apparatus.
In the arrangement just described for supplying beat to working cylinders
of regenerative or caloric engines, the reservoirs for containing compressed air
and gases and the valve arrangement connected with the same, described in
reference to Sheet I. and Sheet II., Figures 3, 4, and 5, are entirely dispensed
with. Instead of supplying currents of heated products of combustion to the
working cylinders, compressed air or steam in a highly heated condition may
be substituted, in which case the combustion apparatus and fuel pumps will be
entirely dispensed with, and heating apparatus of a more powerful description
than those already shown will have to be substituted as well as a steam

page_text: generator in case highly superheated steam be supplied. In the latter case the
water surrounding the working cylinders and cooling tubes will be kept to
such a temperature that the steam within the tubes and cylinder will
not actually condense, and may be in open communication with the steam
boiler, the box frame being made strong enough to withstand the pressure.
Having now described the nature of my Invention, and the best methods
I am acquainted with of performing the same, I wish it to be understood
that I do not confine myself to the precise details herein set forth, nor do E
claim as my Invention many of the arrangements described if taken separately.
I do not claim generally the arrangement of four working cylinders acting
upon one driving shaft, nor do I clain the exploding of a mixture of inflam-
mable gases or vapours with atmospheric air within the working cylinder or
of passing into such cylinder the hot products of combustion either of a gas or
coal furnace, the same having often been attempted before in various forms,
and are well known means of expanding gases for the purpose of effecting
increased displacement of working pistons; I do not claim, morcover, the
application of furnaces for producing inflammable gases by imperfect com-
bustion of solid fuel, the same having been used before in connection with
engines and otherwise; nor do I claim the construction of caloric engines by
introducing a piston and a displacer into one cylinder, the same being a well-
known arrangement, nor the renewal at each stroke of a portion of the steam or
gases acting as the working medium of regenerative engines, the same having
been described in my Patents of the 9th October 1852, No. 326, and 9th June
1856, No. 1368, together with other arrangements of which I have taken
advantage in constructing my present engine; but what I claim is,-
First, constructing regenerative engines of four working cylinders closed at
both ends, with intercommunications through regenerators or respirators so
arranged that the front of the first cylinder communicates continuously with
he back or heated portion of the second, the front of the second with the
back of the third, the front of the third with the back of the fourth, and the
rout of the fourth with the back or heated portion of the first-named
ylinder, and of connecting the four working pistons of these cylinders to one
otating shaft so as to render their motion consecutive, causing the front part
f any one of the four cylinders to act the part of charging cylinder to the
ack or heated portion of the succeeding cylinder, as herein-before more fully
escribed.
Second, effecting the consecutive motion of four such working pistous in
taching the same to four equidistant points of the circumference of e discor

page_text: cross frame carrying a central radial arm perpendicular to the plane formed
by the four points of attachment, which arm is connected to a working crank.
Third, reversing regenerative engines with four working cylinders, as
described, by introducing valves into the four communicating passages, which
being moved in concert reverse by one movement the order of succession of
communication between adjoining cylinders, the supply and discharge valves
of the engine being at the same time reversed in their relative times of
action.
Fourth, heating regenerative and caloric engines by the application of jets
of gas flame, which gas may be conveniently produced by the imperfect com-
bustion of solid fuel in a separate furnace or gas generator, and the utilizing
the waste heat of the products of combustion in heating the air to support
combustion.
Fifth, imparting heat to the gases which constitute the working medium of
regenerative or caloric engines by introducing amongst them at such times
when they are heated to the utmost extent by means of respirators or regenc-
rators highly heated currents of steam or air or the heated products of
combustion produced by igniting a mixture of air and inflammable gas com-
pressed and fired before reaching the cylinder, which in mixing with the larger
volume of heated gases contained within the cylinder impart additional heat
to the same without acting separately and destructively upon the sides of the
cylinder.
Sixth, combining the two methods of internal and external heating in
regenerative or caloric engines.
Seventh, firing a mixture of inflammable gases or vapours and atmospheric
air before entering the heated chamber or cylinder of regenerative or caloric
engines by passing the same through a pipe or chamber with recesses pre-
senting highly heated or incandescent surfaces, substantially as herein-before
described.
Eighth; cooling the working cylinder or working cylinders of regenerative
or caloric engines by causing a current of atmospheric air to pass through
the same at the completion of each effective stroke, as described in reference
to Sheet II., Figures 4 and 5.
Ninth, combining the heating and cooling arrangements of the working
cylinders of regenerative and caloric engines in the manner as herein-before
described.
Tenth, generating inflammable gases for heating regenerative or caloric
engines by placing fuel in an upright receptacle, and by introducing amongst it

page_text: jets of atmospheric air from without at a certain elevation, so as to produce a
zone or interinediate layer of highly incandescent fuel, which on being tra-
versed by the raw products of distillation from the fresh fuel supplied above,
as well as by steam or other vapours which may be introduced, will convert
the same into permanently elastic combustible gases, such as hydrogen and
carbonic oxide, an apparatus of this naturo-having been described in reference
to Sheet I., Figures 1 and 2.
Eleventh, utilizing the sensible heat of the inflammable gases produced in
the above-named apparatus by transferring the same either to atmospheric air
supporting the subsequent combustion of those gases or to water, the vapors
from which may be used with advantage in the same apparatus, in order to
be also converted into inflammable gas, as herein-before described.
In witness whereof, I, the suid Charles William Siemens, have hereunto
set my hand and seal, this Twenty-eighth day of February, in the year
of our Lord One thousand eight hundred and sixty-one.
C. D. ABEL,
20, Southampton Buildings,
Chancery Lane.
C. W. SIEMENS. (L.s.)