IMPROVEMENTS IN GAS ENGINES
Year: 1884

page_text: I, ROBERT SKENE, of Wickham Street, in the County of Surrey, Engineer, do
hereby declare the nature of my said invention for "IMPROVEMENTS IN GAS
ENGINES to be as follows:-
=
My invention relates to that class of engines or motors, which are operated by
the pressure resulting from the combination by explosion of any suitable gas and
atmospheric air, known as gas engines, but particularly of the type having com-
bustion chambers not jacketed, and it is designed to effect greater economy in the
consumption of gas by the regulation of the degree of compression of the explosive
charge at will, as also an economy of power by a reduction in the charge of air to
be compressed, and further, greater steadiness in working and a greater rapidity of
compression, by causing the pistons of two combined cylinders to simultaneously
co-operate for that purpose.
To effect these objects :-
I combine two cylinders, either single acting and operating by the ordinary
connecting rods upon a single crank, or double acting and operating upon opposite
cranks. In the former case one explosion per revolution is obtained, in the latter
two explosions per revolution.
In the former case, I utilize one cylinder only for explosion and exhaust, and
the other for the suction of the explosive charge and compression of the same, the
two working chambers being in communication with each other by an explosion
chamber, and the exhaust and compression strokes in the respective cylinders
taking place simultaneously and in co-operation, to effect my desired results.
Similarly, in the latter case of double acting cylinders, I utilize the inward end
of each cylinder for explosion and exhaust, and the outward ends in each cylinder
for the suction of the explosive charge and for compression of the same, the
compression chambers of each cylinder being in communication by an explosion*
tube or passage from the outer end of one cylinder to the inner end of the other ;*
the exhaust valve being placed about one third of the length of the cylinder from
its inner end. The said tubes thus conveniently cross one another.
Between the cylinders and these explosion tubes or chambers I place a three way
oscillating plug valve, operated from an eccentric, or in other convenient manner,
which serves simultaneously to control the admission to the air cylinder, the emission

page_text: to the explosion chamber, and the ignition of the compressed charge, and which is
hereinafter more fully described.
The compression stroke of the one cylinder and the exhaust stroke of the other
take place simultaneously in the double acting cylinders, but in the single acting
cylinders the working piston may be slightly in advance of the air compressing
piston. If the exhaust valve be then closed by its cam or eccentric, or other
suitable means, before the end of the exhaust stroke, the two pistons will be
simultaneously co-operating to compress the new charge. Up to this time the new
explosive charge has been delivered without compression through the explosion
tube and into the exhaust chamber so as to displace the exhausted gases. It it is
evident that the total amount of compression produced will depend not only upon
the volume of the explosion tube relatively to that of the cylinder, but also upon
the point of closing of the exhaust valve, as from that point only compression sets
in, by the pistons co-operating to produce the same. This point of the closing of
the exhaust valve may be readily set and adjusted at any time, by the hand of the
attendant and automatically by the governor.
I find that I am able to considerably reduce the charge of gas as compared with
ordinary gas engines for the following reasons:-
As the temperature of the combustion chamber varies according to the amount
of gas consumed, and the elastic expansion of the charges increases with the
temperature, the hotter the chamber the less may be the charge to be compressed.
The elastic expansion of the exploded charge in a heated chamber is very great as
the product of explosion is water which immediately becomes converted into steam
of high pressure.
Thus after my engine has been at work some little time, and the temperature of
the explosion chambers has been considerably raised, I can by my novel appliances
steadily reduce the proportion of gas as the temperature of the explosion chamber
rises.
The first part also of the ingoing charge may be wholly atmospheric air, and thus
that portion of it which is allowed to pass through the exhaust valve causes no loss
of gas.
When the gas supply is cut off by the governor owing to the engine not working
full power, it may at the same time shift the cam that works the exhaust valve,
thus confining a large proportion of the exhaust gases and reducing the volume of
the fresh charge, to produce a given compressed volume of gases, which obtains the
full benefit of the elastic expansion from the heated explosion chamber.
The suction, discharge, and ignition of the gas is effected by an oscillating plug
valve between the explosion chamber and the cylinder, which serves to control the
incoming charge and discharge of the same into the explosion chamber, and is
conveniently worked by an eccentric on the crank shaft. At the outlet port of the
valve, next to the combustion chamber, is drilled a sinall hole in the valve seat,
which allows a small portion of the explosive gas to pass into a tube, inserted at
right angles to the plug, in the valve seat. About the middle of this tube the
explosive mixture enters. The inner end of the tube may be filled with a roll of
wire gauze and the outer end may be fitted with a screw for regulating the quantity
of gas to pass. The gases passing through the wire gauze impinge in a pocket
made in the plug, and coming out through an opening in the valve seat, are ignited
by an outside burner.
The pocket in the valve is partially filled with asbestos to prevent heating, and
a piece of spongy platinum or platinum wire, embedded in it, makes the lighting
certain.
As the plug oscillates it closes the outside opening in the seating, and at the same
time that it closes the outside opening, the pocket is opened to the combustion
chamber, and allows the charge to be ignited.
Or, alternatively, the small passage and tube may be dispensed with, and the
pocket in the valve utilized to open communication with a passage in the scating

page_text: leading to a chamber heated externally, and inade of fire resisting material, and
raised to such a temperature as will ignite the charge.
The cylinders may or not be water jacketed, and I prefer to attach to the pistons
a piece of non-conducting and fire resisting material, the same length as the stroke
of the piston, and another cylinder to the working cylinder, of slightly larger
diameter, in which the attachment to the piston travels but does not touch, to prevent
the heated gases from coming into contact with the working cylinder. The explosion
tube or chamber admitting the exploding charge is attached to the end of this
supplementary cylinder when such is used, but the engine will work without this
supplementary cylinder when the working cylinders are water jacketed.
Dated this 2nd day of January 1884.
FELL & WILDING,
Agents for the Applicant.
I, ROBERT SKENE, of Wickham Street, Lambeth, in the County of Surrey,
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
GAS ENGINES" 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 that class of engines or motors which are operated by
the pressure resulting from the combination by explosion by any suitable Gas and
atmospheric air known as Gas Engines, and applicable to the type having
combustion chambers not jacketed or jacketed only to the extent that may be
found desirable.
It is designed to effect greater economy in the consumption of Gas by the
regulation of the degree of compression of the explosive charge at will, as also an
economy of power by a reduction in the charge of air to be compressed, and a
greater rapidity of compression by causing the Pistons of two combined Cylinders
to simultaneously co-operate for that purpose.
Figure 1 is a general elevation and
Figure 2 is a general plan of my improved Gas Engine.
Figures 3. and 7 are a sectional detail of the Gas and exhaust Valves respectively.
Figure 4. is a sectional plan of the plug oscillating Valve.
Figure 5 is a vertical section of the oscillating plug Valve.
Figure 6. is a detail of the ignition Chamber.
To carry out my objects. I combine two Cylinders A A¹ which, as shewn, are
single acting, and operate by the ordinary connecting rods a, a, upon a single
crank B to produce rotation of the fly wheel shaft B₁ by the explosive action of
the mixture of gas and air in the said Cylinders. In the case of this Engine one
explosion explosion per revolution can be obtained as a maximum.
I utilize one cylinder A, Fig 2, only, for explosion and exhaust, the other
cylinder A¹ effecting the suction of the explosive charge of air and gas, and

page_text: together with the co-operation of the cylinder A. in the exhaust stroke effecting
simultaneously the compression of the fresh charge in the explosion chamber C.
This explosion chamber may be formed as a prolongation of one of the cylinders
itself, viz, that in which the explosion takes place, or may be either partly or
wholly exterior to the cylinder, and of any desired shape, so long as the required
volume relatively to that of the displacement of the piston is maintained.
The gas is drawn by the aforesaid suction stroke through the valve D from the
gas main The piston valve d, shown in detail Figure 3, being operated by the
rod e, from the eccentric E against the reaction of the spiral spring e¹ to admit
the gas when required. As soon as the forward action of the eccentric rod e is
withdrawn, the Gas Valve d returns to its seat by the reaction of the spiral spring e¹,
and cuts off the Gas supply-This is automatically regulated by the governor F. of
any known construction, which, by an increase of speed lifts the striking Gas rod e
so as not to operate the Gas Valve D.
The air inlet to the suction Cylinder A¹ is controlled by the plug Valve G, shown
in detail Fig 4, which is oscillated by means of the rod g, conveniently attached
to the eccentric E and partaking of its reciprocating movement.
When the suction stroke, drawing gas through the Gas Valve D and air through
the air Valve G¹, Fig 5, has been completed, and the Pistons H H¹ begin to return
to the back ends of the Cylinders A A¹ the movement of the plug valve G is so
timed that the combined Gas and Air charge is delivered into the explosion
chamber C. whilst at the same time the exhaust products of the last explosion are
ejected, both by the forward movement of the new charge, and by the return of the
Piston H through the exhaust passage K and exhaust Valve K¹ (detail Fig 7) It
will be seen that this exhaust passage K, Fig 2, is placed at some distance from
the end of the Cylinder A (about 1/3 of the stroke) so that the exhaust passage is
closed before the termination of the exhaust stroke by the Piston itself.
The exhaust Valve K is however controlled by the rod k pressed against the
reaction of the spiral spring ¹ by a cam L operating upon a roller l, attached to
the end of the said rod. The said cam L lifts the exhaust Valve from its seat, it
being returned thereto immediately by the action of the spiral spring. The cam L
slides on the shaft B¹ on a feather, and is automatically moved thereon by the
levers operated by the rise and fall of the governor balls. The surface of the
cam L is provided with throws or steps of different lengths so that the time during
which the exhaust Valve remains open is regulated by the position of the cam L,
which is set at the most economical point of compression with Gas and air, and is
shifted by the governor to the place most economical with air only.
From the point then at which the exhaust Valve is closed, the two Cylinders
H. H cooperate in compressing the new charge. It is evident that the total
amount of compression produced will depend not only upon the Volume of the
explosion chamber C. relatively to that of the Cylinders, but also upon the point of
closing of the exhaust valve. I find very good results from making the combustion
chamber one third the Volume of the Cylinder, and shutting the exhaust Valve
when the Pistons have travelled two thirds of their stroke and thus compressing
the last one third of stroke. By this means it will be evident there remains only
to be compressed when the exhaust is closed the fresh charge, composed of a
combustible mixture, which will give a high initial pressure of explosion and is
again wholly discharged upon exhaust. When the Governor rises so as not to
operate the Gas Valve D, it at the same time moves the cain that operates the
exhaust valve, so as to shut the exhaust at the half or other preferred fractional
stroke of the Piston.
The heat of the combustion chamber will expand the charge of air and give out
power for several further strokes without any fresh charge of Gas or explosion.
Or the richness of the charge in Gas may be reduced.
This Engine is most economical when not working to full power, that is to say,
not exploding every revolution, as part of the heat is utilized in expanding the
intermediate charges of air only.

page_text: If the Engine is required to work full power constantly, it is better to have
the combustion chamber water jacketed; but in small Engines I jacket only the
Cylinder and use any liquid not easily evaporated such as oil, so as to equalize the
temperature all over the Cylinders; or jacketing the explosion Cylinder only will
suffice Without this arrangement the combustion chamber would cause the end of
the Cylinder to which it is attached to expand more than the other end.
The Cylinder may also be further protected by lengthening the combustion
chamber and attaching a nonconducting block of plumbago or other suitable
material to the Piston as far as will fill the additional length of the combustion
chamber.
The ignition of the compressed charge is effected by the same oscillating plug
valve G which serves to control at the same time the incoming charge, and discharge
of the same into the explosion chamber.
At the outlet port M. of the valve, Figure 4, next to the combustion chamber is
drilled a small hole m, in the valve seat, which allows a small portion of the
explosive gas to pass into a tube inserted at right angles to the plug in the Valve
scat. About the middle of this tube, the explosive mixture enters. The inner end
of the tube may be filled with wire gauze, and the supply passage may be fitted
with a set screw N for regulating the quantity of Gas to pass. The gases, passing
through the wire gauze impinge in the Pocket, m³, made in the plug, and, coming
out through an opening P in the Valve seat, are ignited by an outside burner, p.
The pocket m' in the Valve is partially filled with asbestos to prevent heating, and
a piece of spongy platinum or platinum wire Q, imbedded in it, makes the lighting
certain.
As the plug G oscillates by the operation of the eccentric E and rod, g, it closes
the outsi 'e opening in the seating, and at the same time that it closes the outside
opening the pocket is opening to the combustion chamber and allows the charge to
be ignited.
Or, alternatively, the small passage and tube may be dispensed with, and the
pocket (Fig 5) in the Valve utilised, to open communication with a passage in the
seating, leading to a chamber r, Fig 6, conveniently of cast iron, and placed in
an external chimney T, so that it can be raised to and maintained at such a
temperature as will ignite the explosive charge, by means of the gas jet S at the
bottom of the chimney.
This cast iron ignition chamber may be made in the form of a ball or Cylinder",
Fig 6, with considerably more space in it than is necessary for ignition, as thereby
less heat outside is necessary to keep up the temperature, the explosion inside
assisting very much in doing so.
The Cylinders are conveniently water jacketed as shown.
This Engine may be made double acting by using the outer ends of the Cylinders
for drawing in the charge, the two co-operating together for exhaust and compression,
the cranks being placed opposite to one another in the Crank shaft.
I wish it to be particularly understood that I do not confine myself to the special
form of construction shown, as it may be varied indéfinitely without departing
from the nature of the invention The oscillating valve may be replaced by the
ordinary suction and discharge valves as used in other Gas Engines, and a small
plug valve used for lighting only.
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 The general construction of a Gas Engine, whether single or double acting,
wherein two Cylinders united by an explosion chamber simultaneously co-operate
during the first part of their return stroke after explosion in practically discharging
the whole of the burnt products of the explosion, and during the remaining part of
their stroke in compressing the whole of the new charge into the combustion
chamber substantially as specified.

page_text: 2nd In such a Gas Engine the combination of two adjacent single acting
Cylinders with explosion chamber, into which the explosive charge is compressed
by the simultaneous co-operative action of the two pistons during the latter portion
of their return stroke after explosion wherein the whole charge is ignited
substantially as described.
3rd In such a Gas Engine the adaptation of an exhaust Valve lifted independently
by a cam or eccentric motion and of which the time of lift is adjustable by hand
and automatically by the governor, so as by the closing of the Valve to cause the
most economical degree of compression both with a combustible charge and with a
charge of air only, substantially as described.
4th In such a Gas Engine the combination with the two co-operating Cylinders
of a Valve connecting the explosion Chamber and one of the two Cylinders,
whereby the admission of air and gas, the discharge into the explosion chamber,
and the ignition of the same, is effected by an automatic movement, such as that
resulting from a cam or eccentric on the revolving crank shaft substantially as
described.
5th In a Gas Engine the construction of the plug Valve G containing a pocket
with or without an asbestos or platinum filling and coming into juxta position
with a passage throttled by a set screw by which any desired quantity of the
combustible Gas may be admitted to effect ignition substantially as described.
6th In a Gas Engine the construction of the igniting chamber substantially as
described in reference to Fig 6.
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1
tal 100
FELL & WILDING,
Agents for the Applicant.