AN ENGINE FOR PRODUCING MOTIVE POWER, WHEREBY A GREATER QUANTITY OF POWER IS OBTAINED FROM A GIVEN QUANTITY OF FUEL THAN HERETOFORE
Year: 1833

page_text: ERICSSON'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ERICSSON, of Albany Street, Regents Park, in the County of Middlesex,
Civil Engineer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fourth day of April, in the third year of His reign, did, for
Himself, His heirs and successors, give and grant unto me, the said John
Ericsson, His especial licence, full power, sole privilege and authority, that I,
the said John Ericsson, my exors, admors, and assigns, or such others as I, the
said John Ericsson, my exors, admors, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick upon Tweed, and
also in all His said Majesty's Colonies and Plantations abroad, my Invention
of "AN ENGINE FOR PRODUCING MOTIVE POWER, WHEREBY A GREATER QUANTITY OF
POWER IS OBTAINED FROM A GIVEN QUANTITY OF FUEL THAN HERETOFORE;" in which
said Letters Patent is contained a proviso that I, the said John Ericsson,
shall cause a particular description of the nature of my said Invention, and in
what manner the same is to be performed, to be inrolled in His said Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said John
Ericsson, do hereby declare the nature of my said Invention to consist in an
engine charged with air of any required density, and worked by the expansive
force of a portion of that air, which is heated by exposing its particles in a
constant state of change or intermixture to heated surfaces of metal in a
manner requiring less fuel than heretofore (that is to say):-
First, in a stove or furnace which generates the original degree of heat
required to work the engine, and then in a vessel which I call a regenerator or
heat returning apparatus, and which vessel, having been once brought to a proper
temperature, continually transfers the heat from the air escaping from the
working cylinder to the air entering into it, whereby no continuous consump-
tion of fuel will be required, except what will be necessary to generate heat
enough to compensate for losses by radiation and the loss occasioned by the
different capacity for heat of the air escaping from and that proceeding
towards the working cylinder, so that when once a proper temperature has
been given to the air, a much smaller quantity of fuel will be sufficient to
keep up the motive power of the engine than has heretofore been required for
that
purpose, while by increasing the density of the air with which the engine
is charged, and still keeping up the same temperature, increased power to any
required extent may be obtained; and it will be evident that as the loss by
radiation will be the same under every degree of pressure, and whatever heat
is given to the air will be returned with very little loss to the stove or furnace,
the denser the air which is used in the engine the more the economy of fuel
will be perceived. And in further compliance with the said proviso, I, the said
John Ericsson do hereby describe the manner in which my said Invention is
to be performed by the following statement thereof, reference being had to
the Drawing annexed, and to the figures and letters marked thereon, that
is to say:
DESCRIPTION OF THE DRAWING.
Figure 1 is a plan of one of my engines, arranged with two working

page_text: in the next Figure, which is a sectional elevation of the engine, both the top
line of the casing and the chimney will be shewn. A, A, are two working
cylinders, each constructed precisely like the cylinder of a high pressure steam
engine, and provided with metallic pistons, side valves, and passages, accord-
ingly, but to be worked by hot air instead of steam, and which I therefore
call the hot air cylinders. B, B, are the rods of the ordinary slides for pro-
ducing the up and down motion of the piston. C,.C, are the rods for working
what is called the expansive valves or slides, acting in the same manner as in
high pressure steam engines, and in this engine so regulated as to fill some-
thing less than three fourths of the cylinder with heated air before they close;
these said slide rods are all worked by eccentrics fixed on the crank shaft,
and with suitable gear, precisely as in the ordinary steam engines. F, F, are the
induction pipes, and G, G, the eduction pipes; the two former lead from E, E,
which are two stoves, through which the hot air passes on its way to the
working cylinders A, A, and the two latter lead to the horizontal cylinder
D, which is what I call the regenerator, since it is within this cylinder that
the hot air in its passage from the working cylinder meets the cold air in:
its passage to the stoves, and without coming in contact or mixing with
it, transfers its heat to the cold air, which carries the greater portion of that
heat back through the stove into the working cylinders, increasing its own
temperature of course in proportion as this transfer takes place, as will be
more particularly explained by the subsequent Figures.
Now it is evident
that some powerful agent will be required to cause the necessary circulation of
the hot and cold air for effecting this purpose, and it must be borne in mind
that in the engine now under description, no part of the apparatus containing
the circulating air which works the engine is open to the atmosphere.
this said purpose, therefore, I use the third cylinder K, placed between the
hot air or two working cylinders, and which, for the sake of distinction, I call
the cold air cylinder; it is of the same size as the hot air cylinders, and as
the up and down motion of its piston drives the cold air into the regenerator,
while the same motion draws the hot air from the working cylinders, I shall
describe this cylinder in connection with the regenerator by a longitudinal
section from A to B, which will be shown by the next Figure. E, E, I have
before described as two stoves. i, i, are the flues of the stoves, leading one
on each side into a flue I, I, which thus becomes common to both, and
forms a jacket surrounding the regenerator, having a chimney, not shown in
this Figure, rising from its upper surface to carry off the smoke, &c., into the.
atmosphere. d, d, are two pipes leading from the regenerator, and through
For

page_text: which the circulating air is driven into the air pipes in the stoves, to be heated
for use in the working cylinders. U, U, are the stove doors. S is a safety valve.
X, X, are two air cocks for charging the regenerator at starting, as will be
hereafter explained. Y is an air pump or double acting blowing pump for
charging the apparatus with additional quantities of air when it may be
required to increase the density of the circulating air in the engine, and
communicates with the pipe N through the small pipe y. This pipe N is
one of the air circulating pipes, which will be more particularly explained by
the next Figure, and is the pipe through which the air which has passed
through the working cylinders A, A, is returned to the cold air cylinder K;
and the pipe O beside it is another air circulating pipe, through which the
circulating air is driven from the cold air cylinder K to the regenerator, whence
it passes through the stoves, thence expands through the induction pipes F, F,
into the working or hot air cylinders. The air pump. Y is worked by the
tension beams j,j, and serves, together with the safety valve, to regulate the
power of the engine. Z is a small water pump, to be worked in a similar
manner, and supplies water through the small pipe Q, Q, to a cooling apparatus,
which will be hereafter explained. L, L, L, is a treble crank shaft, the two
outer cranks of which are worked by the pistons of the two working
cylinders A, A, which thus cause the third crank to work the piston of the
cold air cylinder K, by which it will be seen that at starting the first impulse
must be given to the engine by charging the regenerator from some other source
than the cold air cylinder, which is worked by the two others."
Figure 2 is a longitudinal section of the said marine engine taken from
A to B of Figure 1, and it may save much repetition if I here state that
similar letters are used to denote similar parts in all the Figures. In this
Figure it will be seen that the top of the outer casing I, I, of the regenerator D
is shown, as also the chimney rising from it. K is the cold air cylinder. k, the
piston thereof. is an air passage leading from the upper part of the cylinder;
and t is a similar passage leading from the lower part of the cylinder; and M
is an ordinary slide valve, worked by an eccentric on the crank shaft in the
usual way, and alternately opening each passage to the circulating air pipe O,
while the valve m prevents any return of the air from that pipe. Thus it will
be seen that both the up and the down stroke of the piston forces air from the
cylinder into the pipe O, which I call the go-pipe, as distinguished from the
other air circulating pipe N, which I call the return pipe. Now the cylinder K
is supplied with air through the opening n, which communicates with the return
pipe N, and which, by means of the slide valve M, is always open to the

page_text: passage leading from the upper part of the cylinder when the piston is
descending, and to the passage leading from the lower part of the cylinder
when it is ascending. 'It should here be stated that it is the same air which
is driven out of the cylinder into the go-pipe O that returns back to it through
the return pipe N, after undergoing various changes of temperature in its
passage, and I will now describe what becomes of this air, which is what I
call the circulating air, after it gets into the go-pipe O, and before it arrives at
the return pipe N, previous to which, however, it will be necessary to describe
the internal arrangement of the regenerator D, D. This apparatus, as here
shown, is composed of one large horizontal cylinder, closed at both ends by the
plates f, f, and having a series of small horizontal pipes within it reaching from
end to end and passing through the plates f, f, so that air may be driven
through them from the chamber formed by the hollow cap H, and received
into the chamber formed by the hollow cap J at the opposite end of the
cylinder, without coming in contact in any way with any air that may be con-
tained in the body of the cylinder D between the two plates f, f, and filling
the spaces between the series of small pipes. These small pipes are supported
by and pass through division plates, numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, and 13. These plates do not fill the entire circle of the cylinder, but
have a segment cut alternately from the upper and lower part of them, so as
to admit the passage of air from one end of the large cylinder to the other.
Having now described the general internal arrangement of the regenerator, I
will proceed to describe the passage of the circulating air through it both from
and to the cold air cylinder K. In this Figure the piston is supposed to be
on the descent; the consequence is, that the slide valve M has opened the
passage leading from the lower part of the cylinder to the go-pipe O, and all
the air in the cylinder will be driven into and through that pipe in the direction
of the straight arrows till it enters the main body of the large cylinder D at b;
here the division plate N° 13 will cause the air to ascend till it arrives at the
aperture occasioned by the segment which has been cut from the upper part of
that plate, when the next division plate N° 12 will cause the air to descend,
and in this manner the air will be driven in the direction of the curved arrows.
to the other end of the cylinder D, whence it will be driven out at the aperture d,
into the stove through the pipe as shown in Figure 1. I will hereafter
describe particularly the passage of the air through the stove; but it will suffice
at present to say that having been driven through the stove E, where it requires
an additional portion of heat to compensate for what has been lost by radiation
and otherwise, and attains the proper degree of temperature, it enters the

page_text: working cylinder by the induction pipe F, through the valves C and B, and
having performed its office there escapes by the eduction pipe G into the cham-
ber formed by the cap H; this chamber being open to the series of small
horizontal pipes in the regenerator, the hot air rushes through them and passes
into the chamber formed by the cap J, meeting the cold air in its passage as it
circulates round the external surface of these pipes, and transferring its heat so
rapidly that it is nearly cool when it reaches the chamber J, while the cold air
to which the heat has thus been transferred increases its temperature to such a
degree that when it is driven into the stove it is nearly hot enough for the
working cylinder, and requires very little additional heat from the stove to
bring it to the proper temperature. The air in the cap J
I should
passes, or,
rather say, is drawn thence by the action of the piston in the cold air cylinder K
into the return pipe N, N, whence it passes through the aperture n and slide
valve M into the upper part of the cylinder K, to supply it with cold air for
the up stroke; and in order that it may be sufficiently cooled when it reaches
the cylinder K, I introduce a cooling apparatus in the middle of the return
pipe N, as shewn at P, p, Q, q, which is a cold water bath with a series of hori-
zontal pipes, through which the air passes (as will be better shewn in another
Figure) in order to be discharged or freed from that portion of heat which must
remain in consequence of the condensed air going to the cylinder not having so
great a capacity for heat as the rarified or expanded air escaping from it. The
pump and pipe supplying this bath with water were shown at Z and Q in Figure 1
Qbeing the same pipe which is here marked with that letter. is the open
waste pipe for the bath, for it is evident that the supply in marine engines need not
be economized. Before I leave the description of the regenerator I must point
attention to the small divisions in the pipes e and p, Figure 2, and the pipe T, T,
Figure 3. I have abstained from particularly describing the interior arrange-
ment of these pipes until now because I feared it would render the description
of the other parts of my engine confused if I did not. But it is most essential
to the practical working of the engine to disturb the progress of the air through
all the pipes in the regenerator, the stove, and the cooling apparatus, and cause
it to undulate in the same manner as I do in the main cylinder of the regene-
rator, so as to create that rapid change or intermixture of particles herein-before
alluded to, and for this purpose I introduce a wire through the centre of each
pipe or tube in the regenerator, each pipe in the stove, and each pipe in the
cooling apparatus, with small fan-shaped dises or divisions alternately placed
above and below in the pipe, as shown in one of the pipes e, in Figure 2, as
also in the pipes p, p, p, p, p, and T, T, in Figure 3, and a separate view of

page_text: which is shown at Figure 4, which is a wire with the fan-shaped discs fastened
on to it in different positions, and which wire I introduce in the form here
shown into the pipes, as the readiest mode of keeping the discs in their proper
position.
This arrangement would of course cause the air to take the direction shown
by the small red arrows in its passage through the pipe c.
Now it is evident,
by the arrangement herein-before mentioned of the regenerator, that the circu-
lating air is not open to the atmosphere in any part of its course through the
engine, and that therefore, by the application of the air pump Y, and loading
the safety valve S, it may be brought to any required density, and made to circu-
late continually at that density, by which incans any power may be given to the
engine that the strength of its materials will justify, and its power increased
at pleasure, while the quantity of fuel will not require to be porportionally
increased, inasmuch as there will not be any greater loss by radiation in conse-
quence of its increased density.
Figure 3 is a transverse section of the said marine engine, supposed to be
taken from C to D of Figure 1, and with one of the stoves removed, so as better
to expose
the position of the working cylinder which is behind it. This Figure
shows distinctly one of the division plates N° 2 of the regenerator with the
segment taken from the bottom. It also shows the air cooling apparatus P,
and the five small pipes p, p, p, p, p, which it contains for the air to pass through.
E is one of the stoves before mentioned. dis the pipes, shown also in Figure 1,
through which the air is driven into the stove from the main cylinder of the
regenerator. g is a large horizontal pipe; and T, T, is one of a series of ten
bent or serpentine smaller pipes rising from it and passing in the direction here
shown through the flue of the stove and over the top of the fire, from the imme-
diate action of which the pipes are at this point protected by the guards or
shields V, V, which are made of cast iron or fire clay. These serpentine pipes
descend into another large pipe h, which when it leaves the stove becomes the
induction pipe F of the working or hot air cylinder A. It will be well here to
refer to Figure 1, where the plan of these ten serpentine pipes is shown in red
lines on one of the stoves. The flue of the stove, it will be seen, communicates
with the jacket or casing round the cylinder D, at the other end of which is the
chimney R. It is only necessary further to add that there should be casings
around the lot cylinders, and that they, as well as all the hot connecting pipes,
stoves, and the casing of the cylinder D, should be carefully excluded from the
atmosphere by outer coverings or coatings of non-conducting substances, such
as powdered charcoal, brick, clay, or the like, to prevent loss of heat by radia-.

page_text: tion. The casings round both the working cylinders have not been shown in
the Drawings, from a fear of confusing them, but they are very important, and
the red lines in Figure 1, drawn round one of them will show how they are to be
applied. a is a flue or passage from the stove to the casing; and I is a division
plate which causes the heat to pass round the cylinder, while w is a flue or
passage leading from the casing of the working cylinder to the casing of the
regenerator, and provided with a damper.
Having now finished my description of the Drawings, I will proceed to describe
the manner of setting the engine to work, or what is commonly called starting
it. This I effect by charging the regenerator with compressed air by means of
a hand pump at either of the cocks X, X, while the expansive slides are kept
shut or thrown out of gear, having first lighted the fire and heated the pipes in
the stove to nearly a red heat, and thus brought them, as also the regenerator
and the working cylinders, to the required temperature. The expansive slides
being then opened or thrown into gear, the engine will commence working.
Now whereas it is evident that heat may be used over and over again
by means of a regenerator, in manner herein-before described, if any other
circulating medium be used instead of atmospheric air, and I do not confine
myself therefore to the use of this last mentioned medium, nor do I claim as
my Invention the cylinders, pistons, valves, and other known separate parts of
the engine herein-before described, which are, in fact, common to many engines
now in use, but I claim the engine I have described as a whole, and in particular
I claim the regenerator (whatever may be the circulating medium used therein)
whereby I am enabled to obtain a greater quantity of power from a given
quantity of fuel than has heretofore been accomplished; and such my Invention
being, to the best of my knowledge and belief, entirely new and never before used
within that part of His said Majesty's United Kingdom of Great Britain and
Ireland called England, His said dominion of Wales, or Town of Berwick upon
Tweed, or in any of His said Majesty's Colonies and Plantations abroad, I
do hereby declare this to be my Specification of the same, and that I do verily
believe this
my said Specification doth comply in all respects, fully and without
reserve or disguise, with the proviso in the said herein-before in part recited
Letters Patent contained. Wherefore I do hereby claim to maintain exclusive
right and privilege to my said Invention.
In witness whereof, I, the said John Ericsson, have hereunto set my
band and seal, this Third day of October, in the year of our Lord One
thousand eight hundred and thirty-three.
JOHN (L.S.) ERICSSON.

page_text: AND BE IT REMEMBERED, that on the Third day of October, in the
year of our Lord 1833, the aforesaid John Ericsson came before our said Lord
the King in His Chancery, and acknowledged the Specification aforesaid, and
all and everything therein contained and specified, in form above written.
And also the Specification aforesaid was stamped according to the tenor of
the Statute made for that purpose.
רד
Imrolled the Fourth day of October, in the year of our Lord One thousand
eight hundred and thirty-three.