IMPROVEMENTS IN AIR ENGINES
Year: 1860

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for the
Invention of "IMPROVEMENTS IN AIR ENGINES."-A communication from
abroad by John Ericsson, of the City of New York.
Sealed the 18th January 1861, and dated the 31st August 1860.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition,
on the 31st August 1860.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN AIR ENGINES," to be as follows:-
In all air engines operated under condensed pressure, as hitherto con-
structed, the motive force of the working piston has been found insufficient,
owing principally to the rapid diminution of the acting pressure of the air by
its expansion during the movement of the piston from end to end of the
cylinder.
The present Invention not only obviates such diminution of the acting
pressure towards the end of the stroke, but it augments the same as well as
the effective force of the piston as it approaches the termination of the stroke.
This object is accomplished by combining with the working piston two other

page_text: pistons working in two cylinders, which the Inventor denominates equilibrium
cylinders, and which may be placed in a direct line at a certain distance from
each other, or they may be placed side by side; close to these cylinders is
placed a strong air-tight vessel or series of vessels, to which heat is applied,
and which vessel is called the heater; and also another strong air-tight vessel
or series of vessels which is or are kept cool by the application of cold water
or currents of atmospheric air. Within each of the equilibrium cylinders a
hollow piston, which may be called the equilibrium piston, is made to operate,
and both pistons are connected by a long piston of relatively small diameter,
resembling the ram of an bydraulic press. This piston, which is the working
piston, passes through air-tight stuffing boxes in the heads of the equilibrium
cylinders. The working piston is connected with the driving crank of the
engine by a crosshead and side rods, or by beams and connecting rods, as in
steam engines. By means of an air pump operated by auxiliary power, atmo-
spheric air is charged into the equilibrium cylinders and into the heater and
cooler, and after passing out of the cylinders, and before reaching the coolers,
the hot air passes through another vessel provided with a number of sheets of
wire gauze, which take up the heat from the air that has just escaped from
the cylinders. The cylinders, cooler, heater, and other parts are so arranged
that greater pressure is charged into the heater than into the cooler. By
means of certain connecting pipes and valves an alternating communication is
established between the heater, cooler, and equilibrium cylinders, the arrange-
ment being such that both ends of one equilibrium cylinder are simultaneously
in free communication with the heater, whilst both ends of the other equili
brium cylinder are at the same time in free communication with the heater,
whilst both ends of the other equilibrium cylinder are at the same time in free
communication with the cooler. The pressure in the heater being greater than in
the cooler, the working piston will be forced from or out of the cylinder which
is in communication with the heater into the cylinder communicating with
the cooler. When the working piston has completed the stroke the commu-
nications between the equilibrium cylinders, heater, and cooler are reversed
by means of valves operated as in non-expansive steam engines, and thus a
continuous motion is produced. The greater volume of air withdrawn from
the heater than that which is returned is compensated for by the dilatation
caused by heating the air during its passage through the heater or heaters.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office
on the 28th February 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of August, 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 William Edward Newton, Her special license that I, the said William
Edward Newton, my executors, administrators, and assigns, or such others as
I, the said William Edward Newton, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN AIR ENGINES," being a communication from abroad
upon the condition (amongst others) that I, the said William Edward
Newton, by an instrument in writing under my hand and seal, should par-
ticularly describe and ascertain the 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Edward Newton, 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, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
In all air engines operated under condensed pressure, as hitherto con-
structed, the motive force of the working piston has been found inadequate,
owing principally to the rapid diminution of the acting pressure by expansion
during the movement of the piston from end to end of the cylinder.
By the present Invention such diminution of the acting pressure towards
the end of the stroke is not only obviated, but by means of the present
improvements the pressure as well as the effective force of the piston may be
sensibly augmented as it approaches the termination of the stroke. These
objects are accomplished by placing two cylinders, which the Inventor calls

page_text: "equilibrium cylinders," in a direct line at a certain distance from each other.
Close to these cylinders is placed a strong air-tight vessel or series of vessels
to which heat is applied; and also another strong air-tight vessel or series of
vessels kept cool by the application of cold water or currents of atmospheric
air. Within each of the equilibrium cylinders a hollow piston, which may be
called the "equilibrium piston," is made to operate, and both pistons are con-
nected by a long piston of relatively small diameter, resembling the ram of a
hydraulic press. This piston, which the Inventor calls the working piston,
passes through air-tight stuffing boxes in the heads of the equilibrium cylin-
ders. The working piston is connected with the driving crank of the engine
by a crosshead and side rods, or by beams and connecting rods as in steam
engines. By means of an air pump operated by auxiliary power, atmospheric
air is charged into the equilibrium cylinders and into the heater and cooler,
but this is effected in such a manner that a greater pressure is charged into
the heater than into the cooler. The pressure in the equilibrium cylinders will
vary, as will be hereafter explained.
By means of certain connecting pipes and valves, an alternating communi-
cation is established between the heater, the cooler, and the equilibrium
cylinders, the arrangement being such that both ends of one equilibrium
cylinder are simultaneously in free communication with the heater, whilst both
ends of the other equilibrium cylinder are at the same time in free communi-
cation with the cooler. The pressure in the heater being greater than in the
cooler, the working piston will be forced from or out of the cylinder, which is
in communication with the heater and into the cylinder communicating with
the cooler. When the working piston has completed the stroke, the com-
munications between the equilibrium cylinders and the heater and cooler are
reversed by valves operated as in non-expansive steam engines, and thus a
continuous motion is produced; the greater column of air withdrawn from the
heater than that which is returned is compensated for by the dilatation caused
by heating the air during its passage through the heater or heaters, all of which
will be more fully explained by the following description, reference being had
to the Drawing which represents a longitudinal vertical section of the improved
air engine.
a and b are cylinders placed in a direct line with each other, and provided
with close heads at both ends. These cylinders are the equilibrium cylinders;
c is a piston resembling the ram of a hydraulic press, and may be made either
hollow or solid. This piston, which is the working piston, passes through the
heads of the equilibrium cylinders with air-tight packings at c', c¹, and is con-
nected to a crank d on a driving shaft e, by means of connecting rods d', and a

page_text: crosshead du fixed in the working piston; ƒ and g are hollow pistons fitted in
the cylinders a and b, and filled with pounded charcoal; they are attached at
opposite ends of the working piston c; h is a strong air-tight vessel placed
near the equilibrium cylinders, and partially filled with a number of discs
of wire cloth. This vessel is the heat deposit vessel; i is another strong air-
tight vessel surrounded with brickwork, and provided with fire-places at i³, ¹,
and a flue ¹¹, connected with a smoke pipe or chimney; k is a strong air-
tight vessel provided with head plates ¹, and head chambers and m, these
latter being put in communication by a series of small tubes in the head plates;
n is a strong air-tight vessel to act as a cooler, either by being freely exposed
to the atmosphere or by being immersed in a surrounding cistern of cold water,
or other means usually adopted for purposes of refrigeration; a¹ and b¹ are
pipes for forming a communication between the equilibrium cylinders .and
the heater; is a pipe communicating between the head chamberland cooler n;
is a pipe communicating between the vessel k and the heater i; h', h³, h',
represent a bent pipe for forming a communication between the two extreme
ends of the equilibrium cylinders and the head chamber m; o is a stop-cock
for opening or shutting off the communication between the pipes a' and l¹; p¹
is a pipe communicating between the heat deposit vessel h and the vessel k;
q is a pipe through which the heater and other parts may be charged with
compressed atmospheric air; 1, 2, 3, 4, 5, and 6, are valves cerated by
ordinary valve gear attached to the crank shaft in such a manner that 1 and 2
open the communication between the cooler and equilibrium cylinders, whilst
the pistons fand 9 move towards the extreme outer ends of the cylinders; the
valves 3 and 4 communicating between the cylinders and heat deposit vessel,
whilst the said pistons move towards the inner heads. The valve 5 operates
so as to form communications between a¹ and a when the equilibrium piston
moves to the right, and a communication between a and h¹ when the piston
moves to the left. In like manner the valve 6 communicates between band h¹
when the piston 9 moves to the right, and between 6 and 6 when it moves
to the left.
Having now described the various parts of this improved air engine, I will
now explain the manner of putting the same into operation.
Compressed air is charged into the interior of the engine through the pipe q.
by means of an air pump actuated by auxiliary power. It will be seen by
inspecting the Drawing, that the compressed air will enter the heater i first,
and from thence the vessels kc and h, and also the equilibrium cylinder a, through
the valves 3 and 5. As the equilibrium cylinder b is at the same time in
communication with the cooler by means of the valves 2 and 6, and the various

page_text: pipes before described, it will be seen that the pressure in a will force the
working piston c into the equilibrium cylinder b until it reaches the termination
of the stroke, when the position of the valve is reversed, as before stated. A
left-handed movement of the piston will then take place in like manner by the
equilibrium cylinder 6 being in communication with the heater, whilst a is in
communication with the cooler. In this manner a continuous reciprocating
movement will be kept up as in a steam engine. It is proper here to state
that the heated air as it passes off from the equilibrium cylinders through the
valves 5 and 6, the pipe h', and the head chamber m, gives out its heat to the
numerous tubes in the vessel k. On the other hand the cold air from the
opposite ends of the equilibrium cylinders after having passed through h and h¹,
comes in contact with the heated tubes, and therefore, when entering the
heater at 1, a very considerable elevation of temperature has been effected,
which will materially assist the heater. In like manner the heat lost by the
exhaust air in passing through the tubes of k will materially assist the cooler
in reducing the temperature of the air before it enters the equilibrium cylinders
through the valves 1 and 2.
If the cooler n be removed, and the air from be permitted to escape into
the atmosphere, and if the valves 1 and 2 open directly into the atmosphere,
this improved air engine will operate well and prove of great practical utility.
Its power will, however, be greatly increased by applying the cooler and
charging the interior with air of greater density than the atmosphere. It is
evident that the wire discs in the vessel h will effectually take up the heat,
which without their application would be carried into the cold ends of the
cylinders by the air which passes in from the heaters when the valves 3 and 4
first open until an equilibrium of pressure is established. On the other hand,
the cold air from the cylinder will in its turn take up the heat deposited in the
wires in its passage to the heaters.
It is evident that the cold exhaust valves need not be opened until the
compresion of the cold air has established an equilibrium of pressure at both
ends of the cylinder; and it is also evident that the hot inlet valve may be
closed somewhat before the termination of the stroke of the piston, and that
both the exhaust and inlet valves at the cold ends of the equilibrium cylinders
may be self-acting, the former opening out of, and the latter into the equili-
brium cylinders, and it is likewise evident that the valves may be constructed
on the several plans adopted in steam engines.
It is also evident that the two equilibrium cylinders with their pistons may
be placed side by side, and that the working piston may be divided trans-
versely through its middle, thereby forming two pistons, and that the two

page_text: pistons thus formed may be connected by a beam or similar device, by which
a reciprocating movement would be produced, and motive power obtained as
described.
It is also evident that the heaters and coolers may be constructed of different
forms in order to present a great extent of surface, and that these vessels may
be placed in various positions provided they are connected with the equili-
brium cylinders as described, and it is moreover evident that the hot ends of
the equilibrium cylinders may be heated by separate furnaces, the heat from
which may be made to act on such hot ends in various ways.
I do not therefore confine myself to the precise arrangement shown on the
plan, but what I consider to be new in the above described machine, and
therefore desire to secure by Letters Patent, is,-
First, the combination of the equilibrium cylinders, the equilibrium pistons,
and the working piston for the purposes above set forth.
Second, the combination of the equilibrium cylinders. The equilibrium
pistons, the valves 5 and 6, the vessel k, and the tubes therein contained, for
the purposes above set forth.
Third, the combination of the equilibrium cylinders, equilibrium piston,
the valves 3 and 4, and the heat deposit vessel, for the purposes above set
forth.
Fourth, the combination of the equilibrium cylinders, the equilibrium
piston, the valves 5 and 6, and the heater, for the purposes above set forth.
Fifth, the combination of the equilibrium cylinder, the equilibrium pistons,
the valves 1 and 2, and the cooler, as set forth.
Sixth, the combination of the equilibrium cylinders, the equilibrium pistons,
the valve 5, and the bent pipe h, h, h, or any equivalent communication for
carrying the hot exhaust air from the cylinder a to that end of the vessel k
which is nearest to the cylinder b.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Twenty-eighth day of February, in the year
of our Lord One thousand eight hundred and sixty-one.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.S.)