Improvements in and relating to Internal Combustion and Compressed Air Engines."
Year: 1896

page_text: Date of Application, 12th Dec., 1896
Complete Specification Left 13th Sept. 1897-Accepted, 11th Dec., 1897
Date of Application, 12th Dec., 1896
Complete Specification Left, 13th Sept., 1897-Accepted. 11th Dec., 1897
"Improvements in and relating to Internal Combustion and
Compressed Air Engines."
I, THOMAS TOMLINSON, of 128 Stephen's Green, in the City of Dublin, Civil and
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to internal combustion and compressed air engines and
comprises the improvements hereinafter set forth.
An important feature of iny said invention consists in the application of the energy
produced by the explosion of any suitable compound direct to the compression of air
or other gas or mixture thereof, such compressed air or other gas being utilized solely,
or in conjunction with the gases generated by the explosions, to drive a compressed
air engine of any suitable description. I am thus enabled to provide a motor which
can be stopped, or started, or reversed at will, and the speed of which can be regulated
as may be desired independently of the compressor, and which is therefore especially
suitable for the propulsion of motor cars or the like.
According to my said invention I employ a suitable combustion or explosion
cylinder containing an unattached or other suitable piston which latter may, however,
have a rod attached arranged to pass through the cover and act as a guide. One end
of this cylinder is arranged for the combustion or explosion of a charge of any suitable
material, and the other as a compressor for air or other gas. In connection with this
cylinder I also provide two reservoirs for compressed air or other gas one of which
reservoirs is intended to contain compressed air or other gas at a high pressure and
communicates with the compression end thereof through a way or port fitted with a
valve opening inwardly relatively to the said reservoir, and the other of which
reservoirs is intended to contain air or other gas at a low pressure and communicates
with the said compressor end through a way or port fitted with a valve opening
outwardly relatively to the said reservoir.
The above mentioned piston is normally retained at the inner or that extremity of
the cylinder furthest removed from the ports or ways communicating with the high
and low pressure reservoirs by the pressure in the compression end of the cylinder
which is that of the low pressure reservoir, and which must be maintained slightly
above that of the atmosphere. At the explosion end of the cylinder and behind the
said piston a charge of explosive mixture is inserted in any convenient manner; in
the case of a gas or mixture of gases, for instance, it is pumped in against the
pressure of the low pressure reservoir by a suitably operated pump. This charge is
then exploded in the usual manner and the piston is forced outwards, first compressing
the air in the other or compression end of the cylinder to that of the high pressure
reservoir, and then opening the valve and forcing it into the latter. The exhaust
valve then opens, the valve leading to the high pressure receiver closes, and as soon
as the air left as cushion in the clearance or space at the closed end of the
compression cylinder expands to its pressure and returns the piston for a certain
distance, the valve of the low pressure reservoir opens and completes the said return

page_text: stroke, the exploded gases being swept from the compression cylinder, and the latter.
ready for another charge and explosion.
In some cases I find it desirable, in order to minimise the vibration due to the
explosion and to increase the power of the engine, to use two pistons in the explosion.
(or compression) cylinder with the explosive charge placed between, and the cylinder
connected at each end to the high and low pressure reservoirs. In this case the end
recoil of the pistons may be either cushioned as already described or may be entirely
taken up by the air of the low pressure reservoir in which latter case it
will be feasible to use much higher explosive energy without undue recoil and
vibration.
The high and low compressed air reservoirs may consist of single vessels or may
be male up of any suitable number of vessels connected together."
In combination with the above described explosion cylinder or cylinders and
compressed air reservoirs I employ any ordinary engine with appropriate valve gear
and of suitable dimensions and design for the work to be done forining a compressed
air engine, and I connect the inlet and outlet of the engine respectively to two
compressed air reservoirs.
It will be obvious that if a difference of air pressure (the "working pressure") be
maintained between these reservoirs by the continual withdrawing of air from the
low pressure reservoir and its compression in the high pressure one at substantially
the same rate as it passes from the latter and is expelled into the former during the
operation of the air engine, then the power which operates the compression from the
low pressure reservoir into the high pressure one will in fact perform the work done by
the air engine through the medium of the air acting as though it were in fact a
gearing.
I provide, moreover, for operating the compression from the low pressure reservoir
to the high pressure one by the direct action of explosive mixture. For this purpose
I arrange for the pressure in the low pressure reservoir to stand at or near a certain
suitable predetés mined pressure above that of the atmosphere, the pressure in the
high pressure reservoir being constantly at or near the desired working pressure
above that in the low pressure reservoir. I arrange the compressed air reservoirs and
compression cylinder, or cylinders so that the latter, which is closed at both ends,
will communicate at or near its outer extremity with both of the said reservoirs by
valves, which may be either self-acting or operated by suitable gearing, that leading
into the high pressure reservoir being non-return and opening only under superior
pressure from without, and that leading out of the low pressure reservoir being also
non-return and opening only under greater pressure from within.
The exploded gases may be utilized in a cylinder of suitable dimensions to pump
or help to pump the explosive mixture-or may be made use of in any other inanner
-so long as this utilization does not interfere with the proper return of the piston or
pistons.
In a farther modification of my said invention I employ both air compressed by
the energy generated by the explosions and likewise a portion of the said energy
direct, to work the engine. In this case I may employ as before the free piston or
pistons and explode the mixture behind it or between the two when two pistons are
employed. According to this further modification I employ a method which is in
effect the converse to that herein before described. That is to say in place of util-
ising the explosion of the gases, as a means of compressing air supplied from the low
pressure reservoir into the high pressure one, I use the air contained in the high
pressure reservoir to compress the exploded gases into the low pressure one. In lieu,
however, of having the low pressure reservoir connected at each end to the explosion
cylinder I only connect it at the point of contact of the pistons if there be two
pistons. I have in this case my low pressure reservoir divided into two parts by a
piston having a rod at one side passing through a gland in order that the piston area
shall be larger on one side than the other in a suitable proportion. The side of the
low pressure reservoir having the smaller piston area is connected by a tube or other
suitable neaus to the high pressure reservoir so that the pressure may be maintained

page_text: at the expense of the high pressure reservoir in the event of an occasion arising when
the energy used by the engine exceeds the supply, or when the energy is generated
faster than is used by the engine. It will be seen that whilst in the former arrange-
ment the energy put into the compressed air is solely and directly employed, in the
present arrangement the exploded gas itself it utilized as the medium, so adinitting
of all, or practically all, the energy being utilized. The air in the compressed air
reservoir and on one side of the piston acts simply as the compression cylinder of a
single acting steam engine, this is to say, it takes up energy only to give it out again
at a later stage.
Dated this 12th day of December 1896.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicant.
"Improvements in and relating to Internal Combustion and
Compressed Air Engines."
I, THOMAS TOMLINSON, of 128 Stephens Green, in the City of Dublin, Civil and
Electrical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
My invention relates to internal combustion and compressed air engines and com-
prises the improvements hereinafter set forth.
An important feature of my said invention consists in the application of the energy
produced by the explosion of any suitable compound direct to the compression of air
or other gas or mixture thereof, such compressed air or other gas being utilized
solely, or in conjunction with. the gases generated by the explosions, to drive a
compressed air engine of any suitable description. I am thus enabled to provide a
motor which can be stopped, or started, or reversed at will, and the speed of which
can be regulated as may be desired independently of the compressor, and which is
therefore especially suitable for the propulsion of motor cars or the like.
In the accompanying drawings:-
Figure 1 is a diagrammatical view showing one form of my apparatus.
Figure 2 shows a modification thereof, and
Figures 3, 4, and 5 show various methods of linking or connecting the pistons
together.
Figures 6, 7, 8, 8, 8 and 9 are various views drawn to a greatly enlarged scale
showing details of construction hereinafter described.
According to my said invention, and first referring to Figure 1, I employ suitable
combustion or explosion cylinders a, a, consisting preferably of two steel or other
tubes placed back to back secured at their adjacent ends in a casting or piece a*, as
inore clearly seen in Figure 7 and containing two pistons b, b1, which latter are fitted
with rods c, c', arranged to pass through the glands a¹ at the ends of the cylinders a.
At the outer or other extremities of the rod c, c¹ are provided other pistons d, d¹
which latter are arranged to work in cylinders a², a, which may form extensions of
the cylinders a as shown. The pistons d, d' and the cylinders a², as form air feed pumps
air being drawn in from the atmosphere on the out stroke and compressed on the
instroke into a low pressure receiver e' hereinafter described. The central portion a*
of the cylinders a is water jacketted (as shown at a** Figure 7) and is arranged for
the combustion or explosion of a charge of any suitable material, and the two ends
thereof as compressors for air or other gas. In connection with the cylinders a are

page_text: provided two tubular or other reservoirs or receivers e, el (Figure 1) for compressed
air or other gas. The reservoir or receiver e is intended to contain compressed air
or other gas at a relatively high pressure and communicates with the compression
ends of the cylinders a, through suitable ways or ports f, f, fitted with valves g, g
opening inwardly relatively to the said receiver, and which valves g and g' may be
arranged to be mechanically opened when the pistons are at the inner end of their
stroke so as to make the explosion take place under the pressure of the high pressure
reservoir and so be more intense. The reservoir or receiver e¹ is intended to contain
air or other gas at a relatively low pressure and communicates with the said com-
pressor ends through ways or ports A, A fitted with valves i, , opening outwardly
relatively to the said reservoir or receiver. e*, e3* are valves opening inwardly for
admitting air to the cylindrical extensions a, a, at the rear of the pistons d, d',
and are ways or ports communicating between the inner ends of the said
cylindrical extensions a³, a' and the low pressure reservoir or receiver e¹ and
governed by outwardly opening valves f, f
The pistons b, 6 are when at rest retained in the position shown in Figure 1, that
is at or near the central or that portion of the cylinders a furthest removed from
the ports or ways f, f, and h, h, (communicating respectively with the high and low
pressure reservoirs or receivers, e, el) by the pressure in the compression ends of the
said cylinders which is that of, the low pressure reservoir e' and which pressure must
be maintained above that of the atmosphere.
The high pressure reservoir or receiver e is connected through a pipe 2 and
valve with the inlet of an ordinary double cylinder (or other suitable) compressed
air engine; and the low pressure reservoir or receiver e¹ is connected with the
exhaust or eduction of the said engine through a pipe e and valve e**.
In order to start the apparatus in the first instance it will be necessary to obtain
an initial pressure in the reservoirs e and e'. For this purpose I may disconnect and
work by hand an air feed-pump which is geared to the air engine j and which is
adapted to supply through the inlet e the excess of air, if any, required to make up
for the air fed into the explosion chamber when the engine is at work and which is
not supplied by the action of the pistons d, d' in the cylinders a², a³ or I may use an
ordinary hand or foot pump for this purpose.
It will be obvious that if a difference of air pressure (the "working pressure") be
maintained between the reservoirs or receivers e, e¹ by the continual withdrawing of
air from the low pressure reservoir or receiver e¹ and its compression in the high
pressure reservoir or receiver e, at substantially the same rate as it passes from the
latter and is expelled into the former during the operation of the air engine j, then
the power which operates the compression from the low pressure reservoir or
receiver e¹, into the high pressure reservoir or receiver e, (ie. the energy of the
explosion which takes place between pistons b and 61) will in fact. perform the work
done by the said air engine ; through the medium of the air acting as though it
were a gearing.
The apparatus operates as follows:-The reservoirs e and el are first pumped up so
that the pressure in e¹ stands at any desired amount above the atmosphere and that
(i.e. the pressure) in e at any desired amount above that in e¹ (the difference between
e and e¹ constituting the working pressure). On opening the valve o the air pressure
becomes the same in front of, and behind, the pistons b, b¹ and these move outward
since the area exposed to pressure is greater on the inner or explosion chamber side
of the pistons b, b¹ than on the outer side. This movement continues until the
outward moving pistons close the openings from the front to back of the pistons.
During this time the charge of gas or gasified oil or the like which is to form, with
the air, an explosive mixture is introduced and then the explosive mixture so formed
is fired and the pistons b, 6 and d, d' are forced outwards by the explosion
forcing the air which has entered the cylinders a, a from the reservoir el
into the reservoir e and also drawing air at atmospheric pressure into the
cylinders a², a³. The exhaust valve is then opened and the burnt gases escape
allowing the pistons to return under the pressure in the cylinders a, a which is at

page_text: first that due to any cushioning allowed to bring the pistons to rest at the end of
the outstroke and afterwards that of the low pressure reservoir e¹. On this stroke
the air in the cylinders a, as is compressed into the low pressure reservoir e', the
relative diameters of the cylinders a, a, a and a³ being such that the work expended
on this return stroke in the cylinders a, a is sufficient to do the work of compression
in a, a³ and expulsion of the compressed air into e¹.
It will thus be seen that the explosive energy of the charge between the pistons b, b¹
is expended partly in pumping from reservoir e¹ into reservoir e (in cylinders a, a)
and partly in pumping air from atmospheric pressure into reservoir el (in
cylinders a, a³) that is partly in maintaining the required difference of pressure
between e and e, to enable the engine; to do its work, and partly in supplying to the
reservoir el the air withdrawn from it into the explosion chamber to be there mixed
with gas to form an explosive. mixture and there ignited, expanded, and expelled.
The amount so supplied to the reservoir el at every stroke must not exceed that
withdrawn to supply the explosion (and any leakage), any required in excess of that.
so supplied inust be supplied by the auxiliary feed pump already alluded to.
The exploded gases may be utilized in a cylinder of suitable dimensions to pump.
or help to pump the air feed necessary for the explosive mixture-or the said exploded
gases may be made use of in any other manner-so long as its utilization does not
interfere with the proper return of the piston or pistons.
In neither the arrangement shown in Figure 1 nor of that shown in Figure 2 need
the diameters of the compression cylinders a², a³, be the same as the diameter of
nor need they necessarily consist in prolongations of the same (see Figures 4
and 5).
In Figure 2 I have shown a modification of my said invention wherein I employ
the exploded gases to work the engine under pressure determined by the air pressure
in the high pressure reservoir. In this case I may employ, as before, the free
pistons b, b', and explxle the mixture between the two pistons. I connect the low
pressure reservoir or receiver el to the explosion cylinders only at the point of nearest,
approach of the pistons by means of a way or passage e governed by a valve es. The
extensions or prolongations a2, 3 of the cylinders a are closed at their ends, thus
forming compression cylinders, and are connected with the high pressure reservoir
or receiver e through ways or passages f2, f3, governed by valves g², g³. f5, f5 are
inlet valves for admitting atmospheric air, to the compression cylinders a², a³,
and f,fare circumferential holes, slots or apertures for allowing the air to escape
from the said cylinders on the return stroke of the pistons d, d' and which holes are
governed by sleeves f by the moving of which latter along the cylinders a³, «ª more
or less of the said holes or apertures can be closed so as to regulate the point at
which the pistons d, d begin to compress the air in the said compression
cylinders a, a. In this case the valves g, gl (of Figure 1) are omitted from the
ways or passages f,f. The inlet to the air engine j is connected to the low pressure
reservoir el by a pipe governed by a valve el, and the eduction pipe therefrom is
arranged to discharge direct into the atmosphere.
2
In this arrangement I may also, instead of discharging from the air feed pump
direct into the high pressure reservoir e, discharge into an intermediate receiver and
draw from this through the valves f for compression into e.
This
The action of the apparatus in the case of Figure 2 is as follows:-The reservoirs e
and el are pumped up as before to any desired pressure with a fixed suitable and
comparatively small difference between them, e being at the higher pressure. Upon
opening the valve o the pistons b and 6 move outwards as before explained.
movement continues as before until such outward movements of the pistons close the
openings from the front of the pistons to the back, the gas or gasified oil or other
matter forming an explosive compound with air being introduced. The explosive
mixture is then exploded and the pistons b, b1 are forced outwards against the pressure
of the reservoir e (which communicates freely with the cylinders in front of the
pistons b and b) and also against the gradually increasing resistance of the air
compressed in a², a³ and expelled into e. When the explosive charge between the

page_text: pistons 6 and 61 is expanded to the pressure of the receiver e¹ on account of this out-
ward movement of the pistons (the cylinders a, a and a², as being so proportioned that
the pistons are then at rest or nearly so) the valve e to the reservoir el is opened and
the return stroke is made under the difference of pressures between e and e¹
which act upon the two sides of the pistons b, bl. It will thus he seen that the energy
of explosion is expended partly in doing work against the air pressure in e in the
cylinders a, a, and partly in compressing from atmospheric pressure and forcing
into e (in cylinders a², a³) a certain volume of air to make up wholly or in part. for,
but not to exceed, the volume withdrawn from e to make the explosive charge at each
stroke. The equivalent of the work done against the pressure in e exists at the end
of the outgoing stroke in the form of a volume of hot gas under pressure and is
transferred to the reservoir el on the return stroke from which it is drawn to supply
the air engine j. Any extra volume of air required to supply the explosion chamber
must be supplied as in the former case by means of an auxiliary feed pump.
In both the herein before described arrangements I connect the high and low pressure
cylinders by passages e and to a cylinder w in which moves a piston w² so
arranged that the piston areas upon the sides connected to the high and low pressure
reservoirs are so proportioned that the piston will be in equilibrium when the pressures
in these two reservoirs stand in any desired relation to each other. The movement of
this piston which obviously indicates whether explosions are required or not, is used
just as the movement of a governor is to control the frequency of the explosions and so to
regulate the rate of production of energy by the demands of the engine j. This
cylinder may be used solely as a governing cylinder with small volume (as in
Figures 6 and 7) or it, may be used as an actual equalizing cylinder with large
volume this depending upon whether I rely upon the instantaneous response of the
explosions to the possible demands of the engine or not.
It should be noted that this governor cylinder as shown in the detail drawing
Figure 7 is arranged with special reference to the arrangement shown in Figure 2;
if intended for use with an arrangement such as that shewn in Figure 1 it should be
reversed.
In most cases I prefer to link the free pistons together so as to ensure absolute
equality of movement and I may also use the motion of the linkage to operate the
valves. This linking of the pistons and also an alternative arrangement of the
cylinders and a³ are shown diagrammatically in Figures 3, 4, and 5 all valves being
omitted, however, in this instance, but the lettering of the Figures otherwise
correspond with cach other and with Figures 1 and 2. Figure 3 represents
diagrammatically a simple form of linking in which the rods c, c¹ are continued
through the pistons d, d¹ and attached to crossheads ", z¹ moving on guides y*, y';
these crossheads are connected by links b*, b* to a lever ** pivoted centrally as
shown. Figure 4 represents the same linking of pistons. In this case, however, the
cylinders a², a³ are placed underneath the cylinders a, a instead of in line there with
and the compression in them is on the outstroke as in Figure 2. Figure 5 represents
also the linking of pistons and the placing of the cylinders a² and as underneath. In
this case compression takes place on the instroke (as in Figure 1) and the two
cylinders a² and as become one with two pistons d, d¹.
The pumping from atmosphere done in the cylinders a², ³, is only effected as a
measure of economy, the apparatus would work quite well with the pistons b, b¹, ad
cylinders a, a, only; but then all the air feed would have to be supplied by the
auxiliary air feed pump through the opening e*.
Although I find it desirable, in order to minimize the vibration due to the explosion
and, to increase the power of the engine, to use two pistous in the explosion (or
compression) cylinders a with the explosive charge placed between them and the
cylinders connected at their outer ends to the high and low pressure reservoirs or
receivers, it is obvions that a single piston may be employed.
The high and low pressure compressed air reservoirs may consist of single vessels,
or they may be made up of any suitable number of vessels connected together, and

page_text: for motor car work the hollow framing of the car when such is employed may be
utilized for the purpose.
Any arrangement by which a measured explosive charge may be conveniently
introduced into the space between the pistons, b, b¹ may be made use of, such for
instance, as an auxiliary feed cylinder, with piston geared to the air engine shaft, and
with valves through which are drawn a mixed charge of air and vapor which would
be then compressed, delivered into the explosion or central portion a* of the cylinders
a between the pistons and fired, the compressed air from the compression cylinders
(a² and a³ in Figure 2) being delivered into an intermediate reservoir from which
the feed cylinder would draw its charge.
I prefer, however, to use the arrangement shewn in the detail views Figures 6, 7,
8 84, 88, and 9 as admitting of the safe use of a higher degree of compression of the
charge before firing, and of its being also applicable to the utilization of the heavier
petroleum oils.
Figure 6 is a horizontal section; Figure 7 a vertical longitudinal section on the
line x, x, Figure 6; Figure 8 a transverse section on the line y, y, Figures 6 and 7;
and Figure 9 a transverse section on the line z, z, Figures 6 and 7.
k is a casing or chest which communicates with the compression end of the
cylinders a through the opening k and the pipes * and with the low pressure
reservoir e' through the opening ** when the arrangement shewn in Figure 2 is
adopted (should the arrangement shown in Figure 1 be used then the opening ** is
to the atmosphere) and with the central portion of the casting a* between the pistons
through the opening k². The opening k³ is alternately put in communication with
the openings and ** by the reciprocating movement of the piston l, which
reciprocating movement is imparted through a connecting rod crank m and crank
shaft m³, the latter being rotatably mounted in suitable bearings m* in the closed
casing * attached to the end of the chest and being provided with a chain or
sprocket wheel n, shown in Figures 6 and 9, fixed upon one of its extremities, and
receiving rotary motion from a pitch or driving chain and another chain or sprocket
wheel upon the crank shaft or other suitable rotating part of the air engine j.
Upon the opposite end of the shaft m', to that carrying. the chain or sprocket
wheel n is fixed a commutator m² (Figures 6 and 9) for use when an electric
ignition device is employed. The admission of the air under tension, moreover,
from the high pressure reservoir or receiver e to the valve casing k through the
opening is governed by a gridiron valve o (Figure 6) which is normally held
open by a spring p against the stop p¹ but which is closed for regulating or
governing purposes as hereinafter described. During its reciprocating or to aud
fro movement within the casing k the valve alternately opens and cuts off or closes
communication between the passages or ways k¹ k**- and the explosion or
central portion between the pistons through the port k2.
For measuring the supply of oil or spirit to be introduced into the explosion or
central portion of the cylinders, a I provide a circular hole k³ in the casing k, in
which hole is arranged a corresponding piston or plunger valve q having a number of
holes or apertures q¹, q¹. The number and dimensions of these holes or apertures q¹
will vary as required by circumstances, such for instance as whether gas or previously
vaporized oil, or merely heated non-vaporized oil is being used. The casting k is
pierced vertically by a series of holes (see Figures 6, 8, 84 and 8B) in pairs which
correspond to the holes q' in the piston q when this is at the outer end of its travel.
The casting k is also pierced longitudinally by the holes A, B and C (closed at the ends)
of which A communicates with a reservoir of air at high pressure (provided by a sinall
air pump or otherwise) through the coiled pipe t' while B and C are connected by the
pipe and the coil t respectively to oil reservoirs so arranged that upon opening con-
nection between B and C oil flows from C to B (or vice versa) by the action of a small
pump for instance. The casting k is also pierced horizontally and transversely by a
series of holes * and * of which (Figure 84) connects A with the holes k* while
run from B to C (oil or gas outlet and inlet) and open into the hole in the
casting in such positions relatively to the holes (see Figure 6) that when the

page_text: piston q is at the inner end of its stroke these holes communicate with the top and
bottom of the inner holes q¹ so that at this part of the stroke of q there is a free flow
of oil from C to B (see Figure 8B). The action is then as follows:-At the back end
of the stroke of q oil (or gas) passes through the outer holes g' (Figure 8) and upon
the advance of q the connection with C and B is cut off leaving a measured quantity
of oil (or gas) in the outer holes q¹. At the forward end of the stroke of q the holes
q (both inner and outer) come opposite the holes in the casting k and through
them the high pressure heated air passes, forcing the oil (or gas) before it down the
outer line of holes y, and through corresponding holes in the cylinder casting until
at the 84 and is of
at the points (Figures 8, 84 and 8B) it is broken up by the action of the hot air
passing down the inner line of holes g' and corresponding holes in the cylinder casting
also to the points . Reciprocating or to and fro motion is imparted to the valve g
by a cam or wiper r upon the shaft m', which cam bears against an anti-friction
roller q rotatably mounted in the projecting extremity of the piston or plunger
valve and giving endwise movement thereto through the revolution of the cam or
wiper against the springs s which are secured to the said piston or plunger valve q
and to a T-shaped piece S which is attached to the casing as shown. The oil and
air are heated before introduction by being passed through coils t, t¹ located in a
cylindrical casing u lined with asbestos or other suitable refractory material u'; at the
lower extremity of this cylindrical casing is a burner by which the coils are heated.
The oil and air ways or passages k unite as indicated at 5 (Figure 8) thereby
forming reduced inlets through which the hot oil and air are injected into the
explosion or central portion of the cylinders a between the pistons, b, b', in the form
of spray, if the holes q, q contained oil, or intimately mingled air and vapour, if they
contained gas or vaporized oil or spirit.
The firing or ignition device consists of a platinum or other tube w which projects,
as clearly shown in Figure 8 into the cylindrical casing u above the burner v and is
heated thereby to a white heat. In lieu of, or in addition and as an auxiliary to,
the incandescent ignition tube w, I may also employ an electric ignition device in
combination with the commutator m³, in which case the wires or conductors are
passed through the hole or aperture a provided for that purpose in the explosion or
central portion a* of the cylinders a. kis a passage or way and pipe by which the
overflow or excess of oil escapes to be afterwards pumped back into the oil feeding
apparatus.
In order to regulate or control the working speed of the pistons b, b', I provide.
moreover a suitable governing or regulating device already alluded to comprising a
cylinder w' fitted with a piston w and communicating with the high pressure
reservoir e through the pipe or passage e, and with the low pressure reservoir e¹
through the pipe or passage of Figure 7. The piston or plunger valve q is extended
as shown at g2 and is provided with a nut or head q³, and the rod o' of the gridiron
valve o is likewise extended and provided with a similar nut or head o². w³ is a cross-
head connected to the extensions q², o', as shown, and firmly fixed to the outer end
of the piston rod w of the piston w². It will be seen that any abnormal variation
in the pressures in the receivers e, el will cause the piston 2 to move in one or the
other direction in the cylinder w³, such movement in one direction causing the cross-
bead to move inwardly upon the extensions q, o and admitting of the free
operation of the oil-measuring piston or plunger valve q, and allowing the gridiron
valve o to remain open under the action of the spring p and a sufficient supply
of air to pass therethrough to the explosion or central portion a of the cylinders a
And such movement in the other or reverse direction moving the said cross-head w³
outwardly upon the extensions q, o against the nuts or heads q, o2, and thus so
acting upon the said valves q and o as to render them inoperative, and to stop the
explosions by arresting the supply of oil and air to the cylinder. In this manner I
am enabled to proportion the number of explosions to the demands of the engine.
w', w, (Figure 7) are set screws forming adjustable stops for limiting the travel of the
pistou in the cylinder w, and thus regulating its action as may be found
'necessary.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. An internal combustion engine with a free piston or with free pistons back to
back (in the latter case preferably linked together) acting against suitable air
pressure providing compressed air as required for operating a compressed air engine
by pumping air from a low pressure reservoir (as e¹) into a high pressure
reservoir (as e) at the same rate as the compressed air engine (as j) draws air from the
high pressure reservoir and exhausts it into the low pressure reservoir.
2. An internal combustion engine with a free piston or with free pistons back to
back (in the latter case preferably linked together) acting against a suitable air
pressure providing compressed air as required for operating a compressed air engine
by allowing the explosive charges to expand down to the pressure of compression and
then expelling them into a reservoir from which the compressed air engine (as j)
draws its supply exhausting it to the atmosphere.
3. An internal combustion engine with a free piston or with free pistons back to
back (in the latter case preferably linked together) acting against a suitable air
pressure providing compressed air as required for operating a compressed air engine
in which the air necessary for the explosive mixture is supplied to the explosive
chamber through openings in front of the pistons and closed by their advance so as
to measure the volume of the air charge.
4. An internal combustion engine with a free piston or with free pistons back to
back (in the latter case preferably linked together) acting against a suitable air
pressure providing compressed air as required for operating a compressed air engine
in which the number of explosions is regulated according to the demands of the
compressed air engine by the movement of a piston (as w¹) acted upon by the
pressures in two reservoirs (as e and e¹).
5. An internal combustion engine with a face piston or with free pistons back to
back (in the latter case preferably linked together) acting against a suitable air
pressure providing compressed air as required for operating a compressed air engine
in which oil previously heated is sprayed by air or vapour pressure direct into a
mass of heated air in the combustion chamber.
6. The improvements relating to internal combustion and compressed air engines
substantially as described and as illustrated in the accompanying drawings.
Dated this 13th day of September. 1897.
A. F. SPOONER,
323 High Holborn, London, Agent for the Applicant.