IMPROVEMENTS IN AIR AND GAS ENGINES
Year: 1871

page_text: LETTERS PATENT to Alexander Kirk Rider, of the City of New
York, in the State of New York, United States of America,
for the Invention of "IMPROVEMENTS IN AIR AND GAS ENGINES."
Sealed the 11th of April 1871, and dated the 21st January 1871.
COMPLETE SPECIFICATION filed by the said Alexander Kirk Rider
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 21st January 1871, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
KIRK RIDER, of the City of New York, in the State of New York,
United States of America, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN AIR AND GAS ENGINES," and have petitioned Her Majesty to grant
unto me, my executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that I am
the true and first Inventor thereof.
NOW KNOW YE, that I, the said Alexander Kirk Rider, do hereby
declare that the following Complete Specification, under my hand and

page_text: seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement:-
My Invention embraces important improvements in that class of air
engines which I will term the aspirating engine, in which two pistons
are employed in one cylinder which performs the double office of air
pump and power cylinder, taking in a fresh supply of cool air at each
stroke and heating and discharging it, obtaining motive power either
entirely by its expansion or partly. by the expansion of such air and
partly by gas, steam, or the like, derived from other sources.
This mode
of operation has been long known and involves marked advantages,
among which is the reduction of the cost of the engine from that
required, when two cylinders, one serving as a pump and the other as
a working cylinder are employed, and also an increased degree of
coolness and durability and facility for lubrication.
The first part of my Invention relates to combining this class of
aspirating or double piston engine with an internal or closed furnace
in which the air is heated, by passing through or over the fire, thereby
greatly increasing the power and efficiency of this class of engines over
those hitherto constructed.
The second part relates to inducing the peculiar motions of the inner
or shifting piston by simple, inexpensive, and very efficient mechanism.
H
The third part relates to making the engine reversible, so that it may
be applied as a transportation motor by means of a mere change of
position of certain parts with suitable changes of valve motion.
The fourth part relates to more perfectly regulating "the speed of the
engine under varying conditions of load without waste of fuel. This is
done by a peculiar valve and passages peculiarly arranged to be con-
trolled thereby, the valve being adapted to be operated by a governor.
The above parts are embodied in one form of the mechanism repre-
sented in Figures 1 to 5 inclusive.
The fifth part of my Invention relates to other novel means of
producing a proper motion of the changing piston or shifter.
The sixth part relates to the construction of the furnace and of the
adjacent parts where the air is heated by a fire maintained outside of
the cylinder and its connected passages.

page_text: The seventh part relates to devices for increasing the power by the
aid of a cut-off valve peculiarly arranged and operated to directly and
immediately control the admission of the heated air in the cylinder.
The eighth part relates to means for generating ammonia in or about
the furnace of an engine, and rendering available the great expansive
power of the ammonia at high temperatures to drive or aid in driving
the engine.
Passing lightly over those parts of the machine which have been long
known and in common use, I will devote attention mainly to the
features which I believe to be new and peculiar to my engines, and will
describe what I consider the best forms of mechanism for putting my
Invention into effect.
The accompanying Drawings, Figures 1 to 5, represent one style of
my novel engines and form a part of this Specification.
Figure 1 is a central vertical section showing in a clear light one form
of the construction and the relation to each other of the several parts.
The section shows but one of the rods which operate the shifter, but it
will be understood that there are two, the other being on this side of
the plane of section; Figure 5 shows a modification which involves
some of the novel points. The remaining Figures show details enlarged;
Figure 2 shows the regulating valve in position to increase the fire,
and thus indirectly to increase the speed of the engine; Figure 3 shows
the same valve in position to slacken the fire; and Figure 4 shows the
same valve in position to not only slacken the fire but also to directly
retard the engine by throttling it. The diagram at the side of Figure 5
is an indicator diagram taken on one of this style of my engines. The
several lines with the brief explanations marked thereon may be of service
to those familiar with this mode of ascertaining the conditions at
different points. Similar letters of reference indicate corresponding
parts in all the above-named Figures; B is the cylinder which also
serves as the air pump, as above stated. It is formed in the usual
manner, attached below to the furnace casing B' by flanges and bolts.
Above the cylinder B is a framing A which carries the pillow block and
slides; E is a piston, which I term the main piston, in which are fitted
the self-acting valves e, e, opening inward, and which has the connecting
rod G¹ hinged to its upper side in any convenient manner.
It is packed
with leather or other suitable material to make it tight. M is a piston,
which I term the inner or shifting piston, fitting closely.but easily in

page_text: 'the cylinder, and prolonged downward towards the fire to prevent the
heat acting injuriously on the packing of the main piston; N is a check
valve to prevent the air from returning to the cylinder; is a pipe
leading to the furnace, which is for the purpose of carrying down the
air; P is the regulating valve, and C is the furnace. The changing
piston or shifter M is connected by two rods J, passing through the
main piston E to the cross head I, which latter works in slides provided
in the framing A, and receives motion from connection to the crank and
main piston as will be presently explained. The connecting rod G'is
of peculiar conformation. Between the main piston E and the crank
pin it is a direct connection, but it is provided with an offset G³, which
carries the point of attachment g, by which the upper connecting link H
transmits motion to the cross head I and through the piston rod J to
the inner or shifting piston M. The position of this offset G2 and
point of attachment.g, may be varied within wide limits and yet pro-
'duce very nearly the required effect; it may be beyond or above the
crank pin as shown, or between the piston and crank pin, or it may be
nearer to or further from the line of the 'connecting rod proper, or it
may form a right angle with the other two bearings on the connecting
rod; these proportions depending on the stroke given to the shifting
piston, the length of the connections, and the relative motions required
to be imparted to the shifting piston. The proportions given in the
Drawing are a medium of those which I have tried with success.
When it is necessary to make the engine reversible as for purposes of
locomotion or navigation the offset is duplicated one being formed on
each side of the connecting rod. The offsets G³, G², may then be con-
nected as 'shown in Figure 1, by a link slot G₁, as shown, in such a manner
that the upper connecting link H can be shifted at its lower end to the
reverse side opposite to its former point of attachment, and thus reverse
the engine's motion, the valve motion being correspondingly changed as
will be understood. This form is shown in Fig. 1. For stationary
engines however but one offset and point of attachment is necessary, as
shown in Fig. 5.
In order to obtain the best result the shifting piston or shifter M.
should start to come out or toward the main piston considerably in
advance of the termination of the inward stroke of the latter, so as to be
nearly or quite in contact with the main piston at the commencement of
its up or outward stroke and should remain close to the main piston,

page_text: during nearly all of the up or outward stroke, a little before the end of
which the shifter should rapidly descend so as to reach its lowest or
extreme inward position, a little before the half of the inward stroke.
of the main piston has been performed. The arrangement of parts.
described fulfils these conditions.
In engines of this class hitherto constructed, any lead on the shifting-
piston was considered detrimental and avoided as much as possible, only
ȧ very small amount being permitted on account of rendering the motion
more easy at the end of the stroke. In my engine on the contrary it is.
purposely made as much as possible with the simple connections adopted'.
the effect of which, may be seen on the indicator card at the points a, b,.
where the rise above the Marriott curve appears. The lower end of H,.
may be connected to either end of the link G and may be firmly held in
either end by means of a suitable key or pinching screw or other suitable
means. The lower end of H is shifted from one end to the other end of
the link G, to cause the engine to revolve in the opposite direction. In
other words the engine is reversed by changing the union of the con-.
nection from one end to the other of the link G and making
corresponding changes. by ordinary or suitable. means in the positions of
the excentrics or other means which operate the valves, as will be
readily understood.
It will be observed that the lower end of the link H operated by a pin g,.
traverses in a circuit, the centre of which is one side of the central line of
the engine, and that the central line is nearly or quite tangential to said
circuit, I ascribe to this relation much of the excellence of this motion.
"

page_text: shifter has descended to its lowest position, the piston E follows it to a
smaller extent, and as the shifter rises to meet the piston, it reduces the
space between the shifter M and the piston E and causes the main body
of the air which is enclosed between the shifter and the piston to be
driven downward through the self-acting valve N, and through the
connected passage O to pass through or over the fire and be heated. The
passage of this cool air through or in contact with the fire raises its
temperature and increases its pressure very greatly. Now the shifter
having risen until it is nearly in contact with the piston, the latter
commences to rise, and both move upward with a motion very nearly
coincident. It is in this portion of the revolution that the power of the
heated air is given off through the crank D to the shaft D¹, and its
connections. A sufficient momentum is stored in the fly wheel, in case
of a single engine, to enable it to perform the remainder of its revolution,
as will be readily understood. The passage Q communicates through the
peculiar valve P with two passages o¹, o³, which lead the former under
the fire grate and the latter above it. The valve P is capable of turning
easily upon its axis; and in case it is adjusted to cause the compressed
air to pass through the passage Oi, it blows the fire and urges it. In
case it is adjusted so as to close the passage O¹ and open the passage 03
it causes the compressed air to flow into the furnace above the fire, and
in this condition its influence in urging the fire is almost inappreciable.
Under ordinary conditions the valve will be adjusted so that a portion of
the air will flow through the passage O¹ and urge the fire, while another
portion will flow through the passage O². The relative proportion may
be varied by changing the position of the valve P, and thus the fire may
be increased or not by the action of the engines, or it may be urged in
varying measures at pleasure.
The construction and arrangement of my valve P allows the ap-
plication of a governor, not represented, which may be driven by a band
from the main shaft D¹ of the engine and generate a motion corre-
sponding thereto. The action required is precisely that of the ordinary
governor, and the connection therefrom to this valve P may be of any
ordinary or suitable character, and will require no special detailed
description. There is a peculiarity however about the valve P which
whether operated by the governor or by hand causes it to perform an
important function in addition to that before explained. Its form and its
relation to the parts are such that after it has been turned in the proper
direction to a sufficient extent to shut off the air from the channel O¹, and

page_text: :
has thus caused all the air to flow through the channel O³, under the
conditions which are the least conducive to the urging of the fire, a still
further motion in the same direction will bring into play a new agency
for still further or more rapidly reducing the velocity of the engine.
The valve will under such extreme conditions partially throttle or
obstruct the flow of air downward through the passage O. This position
of the valve, and this condition of that portion of the mechanism is
clearly shown in Figure 4. In case of the breaking of a belt, or any
other sudden relief of the engine from resistance when laboring heavily
and carrying a very hot fire, the engine is liable to attain a dangerously
high speed. The shutting off of the air from the passage O' under such
circumstances will in time reduce the heat of the furnace, and thus
restore the proper conditions. But in the interim damage may be done.
My valve P prevents this by checking the motion of the air through the
passage O, under these extraordinary circumstances. In case the valve
is operated by a governor this action will result automatically. I have
omitted to describe the fire-brick lining of the furnace and many details
which will be readily understood by those familiar with this branch of
engineering. Among these is the exhaust valve the passage to which is
represented by R. Although my engine works preferably by exposing
the air directly to the fire, or in other words forcing it through the fire
and causing it to support combustion, some of its novel features may be
made available if the air is heated by external fire by means of heat
transmitted through metallic or other suitable surfaces.
The Drawings, Figures 6 to 8, represent another form of my novel
engines and also form a part of this Specification. Figure 6 is a central
vertical section through the entire engine, showing clearly the novel
parts with so much of the ordinary parts as is necessary to indicate their
relations thereto; Figure 7 is a corresponding vertical section through
the furnace and adjacent parts with a modified construction containing
only a portion of the Invention; Figure 8 is a horizontal section on the
line S, S, in Fig. 7. Similar letters of reference indicate like parts in
all these Figures.
B is the cylinder, and A a framing fixed thereon, while D is the crank
upon a main shaft D', to which the power is communicated; E is a piston
which I term for convenience the working piston; G, the connecting rod
leading from the working piston E to the crank pin d; M is a piston
which, to avoid confusion, I term the shifter or changing piston, and J

page_text: two small parallel rods, which serve as piston rods to the shifter and
connect it to a cross head, I, traversing in ways or guides in the framing A;
I is a connection through which the motion is communicated to the
oross head I, and thus to the changing piston or shifter M from a crank
pin d' which is formed in the solid forging, or is otherwise mounted in
the position represented relatively to the other parts. It being under-
stood that the upper piston should be packed, and that the lower piston
or shifter should be fitted to work with tolerable tightness without packing,
that the lower piston may be hollow and filled with charcoal or analogous
non-conductor, and that the most highly heated parts may be defended by
a coating of fire-brick or the like, and that other ordinary and suitable
devices may be employed at various points to promote the end sought;
the valve N opens downward automatically to allow the air to be shifted
from its cool position above the shifter to the heated space below the
shifter. The lower edge of the cylinder B is provided with a deep lip or
hanging curtain B' of a little greater diameter than itself, and a casting T
formed as represented encloses this curtain B both on the outside and
inside. These parts are both permanently fixed at uniform distances apart,
so as to provide a space both outside and inside of the curtain B', through
which the cool air received from above shall be compelled to traverse at.
cach stroke, and thus be presented for a relatively long period to the
heating action of the several surfaces. The furnace C is fed' through a
door C¹ at one side, which it will be understood opens out through a
suitable aperture provided and properly enclosed in the independent
castings B' and T. The hot gases from the furnace after expending a
portion of their heat against the furnace crown (where it is very directly
applied to the heating of the air above) descend around walls F and pass
under the rounded lower edge of the casting T. Thence ascending in an
annular space outside they impart heat to the exterior face of said
casting, and ultimately escape through the flue C² leading to a chimney
not represented. R is an exhaust valve passage controlled by an exhaust
valve, not represented, worked by excentrics or suitable cams or the like,
not represented. Its function, as also those of other parts (not here
explained fully), correspond with those of similar parts in other air
engines. W is a valve which performs an important function in con-
trolling the supply of air from the hot spaces around and in contact with
the casting T to the base of the working cylinder or cylinder proper.
This valve W is worked by a rod w passing through a stuffing box, and
actuated by a cam or other suitable part upon the engine, not repre-

page_text: sented.. Its function is to hold back the supply of air to the base of the
cylinder, and thus render it practicable to accumulate a considerable
pressure of air in the heating chambers while the exhaust passage R is
open. A little before the changing piston has descended to its lowest
depression the valve W is lifted or moved from its scat, and the hot air
under high pressure is allowed to enter and heat the changing piston in
the last portion of its descent. It continues to flow into the cylinder
and force up the changing piston M and its associated working piston E,
and gives motion actively to the engine. I make the valve W in a
dishing form by forging it or working it with dies from thin boiler iron
or analogous material which will yield by its elasticity to adapt itself to
any slight warping or change of position of the parts. It is operated by
a rod n, so as to move it back into a cavity, as represented, when not in
use. This withdrawal of the valve W. takes it out of the current of
heated air, and keeps it at a much lower temperature than it would
otherwise attain. Its seat is formed in a casting separate from the main
cylinder [see Figures 7 and 8]. It may be accurately turned and forced
to adapt it to the correspondingly finished face or rim of the valve W.
The removable seat is indicated by X, and a screw bolt which retains it
in place is marked x. The valve W may be worked horizontally or
vertically or in various inclined and intermediate positions as con-
venience may dictate. The current of intensely hot gases from the
heating chamber or furnace is led to the cut-off valve through a narrow
aperture, as shown; and not only is the valve arranged to be drawn back
out of the direct impact of this hot current but the seat X is also to some
extent similarly protected. The hot gas is not allowed to strike it
directly. Its position partially protects it from the heat.
Some of the novel features of this part of my Invention may be
employed without the others. Thus, for example, a certain distinctly
appreciable advantage accrues from my arrangement for given motion
to the shifter, which may be realised either with the improvements in
other parts of the engine or without them. The connecting rod G
reaching from the crank pin downward to the main piston compels a
lingering of the main piston on the upper center, or at the top of its
stroke to give a long time in which cool air may be drawn through its
valves, while the connection H reaching upward from the crank pin d¹
to the cross head I connected to the shifter, compels a lingering of the
latter on the lower center. This gives a very desirable relation of the
motions and distances apart of the two pistons throughout the active

page_text: revolution, while all the motions are smooth crank motions. This
noiseless and very nearly absolutely correct motion obtained in this
simple manner is equally available with an outside furnace, as repre-
sented, or with a closed furnace, in which the fire should be maintained
under pressure, or with various other modifications.
The Drawing, Fig. 9, represents another part of my Invention, and
also forms a part of this Specification.
+
I form ammoniacal gas, or more briefly ammonia, in the furnace,
and render available the power due to its great expansion by heat in
impelling the engine, in addition to the other effects due to the use of
the fluids employed. I use atmospheric air in liberal quantities, passing
it through the fire, or in the immediate vicinity thereof, and render
available the expansion of the air and the gases to drive the engine.
This alone is old. But I also introduce water or vapor of water into
the furnace, and do this in such quantities and under such conditions ]
with regard to the temperature, pressure, etc. as shall produce ammonia
by the combination of the nitrogen of the air with the hydrogen of
the water.
. My theory of the action is that the water is decomposed, its oxygen
combining with the carbon of the fuel, while its hydrogen combines a
with the nitrogen of the air to form ammonia.
I can arrange the details of an engine to work according to my Inven-
tion in various forms. The accompanying sketch indicates the general
arrangement.
i
M is a small boiler or heated vessel adapted to generate a small 2
quantity of steam by the aid of the small lamp m, or of a furnace
under or within, or properly related to the boiler. Water is introduced
in this boiler M, and it is converted into steam, and the steam is led
through the pipe N into the furnace of the air engine to mingle with
the air. I propose to have this pipe in two branches, with some ready a
means of controlling the flow, either automatically or at will, so as to
pass the greater portion of the steam under the grate or over the surface
of the fuel, as shall be found expedient. When the steam enters above
the fuel it may go charged with water in its condition as water, either in
the form of occasional drops, or preferably in a fine spray. I can effect a
this by taking the steam from the water surface in the boiler M, and in
this or any case I can maintain the supply of water in the boiler by
regular pumping or other ordinary means.

page_text: I have ascertained by experiment that under proper conditions the
effect of my Invention, is very marked, and the gain due to its employ-
ment over the air engine having no water attachment is very great.
The air being heated drives the piston as usual, except that a portion of
its nitrogen is combined with the hydrogen of the water to form a more
expansible gas. The water generates steam, and its expansion is available
to drive the engine in the obvious manner, except so far as a portion or
the whole of the water is decomposed into its elements, oxygen and
hydrogen. I believe the whole of the water to be thus decomposed, the
oxygen combining with the carbon of the fuel to form carbonic acid and
carbonic oxyd, the hydrogen combining with the nitrogen of the air to
form ammonia. The ammonia thus formed passes off through the engine
with the other heated gases, contributing its tension to aid in impelling
and increasing the useful effect of the engine; but the action of the
ammonia differs from that of the unchanged nitrogen and the other
gases, in the fact that it is more highly expansible by heat and con-
densible by cold, or by the pressure of water. Instead of expanding its
volume once for about five hundred degrees of heat, it expands in a
much larger ratio. I propose to condense the ammonia after its dis-
charge from the engine by the presentation of water to absorb it for use
in the arts.

page_text: the several connections of the working piston E and, shifter M, for the.
purposes set forth.
6th. The cut-off valve W and seat X, protected from the action of the
current of heated gas, and arranged, and operating relatively to the
furnace or correspondingly heated portion of the engine, and to the
cylinder B and pistons E and M, and their connections, as set forth.
7th. The casting B' and casting T, constructed and arranged as repre-
sented relatively to the furnace C, cylinder B, pistons E, M, and their
connections and passages, for the purposes herein set forth.
8th. The means, substantially, as herein described, for generating 1
ammonia in or about the furnace of an engine, and rendering available
the great expansive power of the ammonia at high temperatures, to aid
in driving the engine, as herein specified.
In witness whereof, I, the said Alexander Kirk Rider, have hereunto
I set my hand and seal, this Twentieth day of December One 1
thousand eight hundred and seventy.
Witness,
THOMAS DREW STETSON,
Patent Agent,
New York.
ALEXANDER KIRK RIDER. (L.S.)