Improvements in and connected with Gas and Hydro-carbon Engines.
Year: 1897

page_text: Date of Application, 20th July, 1897
1000
7th Mov 1000
Improvements in and connected with Gas and Hydro-carbon Engines.
I, ETIENNE PETRÉANO, of 95, Boulevard Beaumarchais, Paris, France, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates to gas and hydrocarbon engines, and the improvements
comprise amongst other features of novelty a new mode of regulating the motion
of such engines.
The regulation of the motion of gas engines is effected at present in various
ways which may be generally reduced to two main types: The first method
which is the one most generally employed consists in altogether suppressing the
admission of the gas. In this case, the air admission valve being automatic, the
piston draws in, compresses and expels air alone. The exhaust valve is only open
at the moment of expulsion of the burnt gases and closes.immediately afterwards.
Or the air admission valve is closed at the same time as the gas inlet valve, and
the exhaust is completely open during the whole time 'occupied by the engine in
returning to its normal speed. In this case the piston draws in, and expels the
exhaust gases. The second method which is less usual, consists when the speed
of the engine tends to increase, in closing to a certain extent the admission of gas
alone without interfering with the admission of air, and the exhaust valve is
opened only for the expulsion of the burnt gases and is closed again immediately.
The last method is tantamount to varying the composition of the motive mixture
by causing it to be less rich in gas. Or again, the air inlet valve is closed to
the same amount as the gas inlet valve, and the exhaust opens only for the expulsion
of the burnt gases. This method again is equivalent to varying the initial pressure
of the motive fluid in the compression chamber because as the admissions are
throttled, the piston draws in a less amount of mixture of gas and air than in
the normal working of the engine.
The methods herein before described have the disadvantages of either causing
knocking or sudden jerks of the engine during the interval from the time at
which the supply of explosive mixture is entirely cut off, to the time at which a
complete charge of explosive mixture is re-admitted, or else of causing deposits
arising from the miss-fires due either to the change in the composition of the
explosive mixture or else to the change in its compression.
A third method consists in acting by varying the compression and the expansion,
but this method has the disadvantages of entailing an excessive consumption of
gas, since the explosive mixture becomes richer in gas in proportion as the speed
of the engine increases or varies.
Now the method of regulation carried out according to this invention avoids all
those drawbacks: The said method consists in principle in causing the governor
to admit a varying volume of previously produced mixture of gas or gaseous vapor
and air but with constant compression. Moreover in order to ensure that the
previously produced mixture shall retain the same composition during the entire
duration of the working of the engine, the governor may also be arranged to act

page_text: at the same time upon the valve controlling the admission of gas into the apparatus
(hereinafter called the vaporizer) in which the explosive mixture is produced
externally of the engine cylinder and prior to its admission into the latter. In
order to effect the regulation in the conditions above stated I cause the exhaust
valve to be operated by the engine governor at the same time as the said governor
acts upon the valve for admitting the previously produced explosive mixture into
the engine cylinder.
If the normal speed of the engine increases, the governor closes the valve
(hereinafter called the admission valve) for the admission of the previously pre-
pared explosive mixture and opens the exhaust valve during say, for instance a
fifth part of the suction stroke of the piston. The exhaust valve is then closed
and at that moment the admission valve is opened during the remaining four-
fifths of the piston stroke, so as to fill the remaining space in the engine cylinder
with the explosive mixture, whereupon the admission valve closes..
There is therefore now in the cylinder a certain proportion of previously pre-
pared explosive mixture and a certain proportion of exhaust gases. These exhaust
gases are absolutely inert and do not take any active part in the explosion.
When the piston returns to compress the total volume, the explosive mixture
constituting a part only of the entire contents of the cylinder will be compressed
to exactly the same pressure as if the entire cylinder was filled with explosive
mixture, that is to say to exactly the same pressure as in normal working. This
proportion of previously produced explosive mixture will therefore always be at
the most favorable pressure for exploding, although in smaller volume.
After the explosion which has thus been reduced in power but without possible
miss-fires, the gases will expand. During the next period the exhaust valve will
open.
If from any cause the speed of the engine should exceed the predetermined
maximum limit, the governor will entirely close the admission valve and will
open the exhaust valve completely.
At the same time that the governor is acting upon the mixture admission valve 3
and upon the exhaust, I may also cause it to act upon the inlet of the gas into
the apparatus hereinafter called the mixer in which the mixture of gas or gaseous
vapor and air is previously effected.
This arrangement has for object to prevent the composition of the mixture from
becoming altered during the entire period of the fluctuations in the speed of the 3
engine. Then as the air enters the apparatus only under atmospheric pressure
at each suction stroke of the piston, and if less mixture be drawn into the cylinder
and there is always the same inlet for the gas into the mixer, more gas will enter
in proportion than air.
In order to prevent this from happening the entry of the gas into the mixer must 4
be regulated in exactly the same manner as is the admission of mixture into the
engine cylinder and at exactly the same time.
A suitable arrangement of mechanism for effecting the regulation of the move-
ments of the engine in accordance with the present invention is as follows:-
Upon the shaft of the engine governor there is mounted a sleeve carrying two 4
sets of cams; one set being designed to control the admission valve, whilst the
other set of cams is designed to control the exhaust valve.
The sleeve is mounted with slight friction on the governor shaft and is actu-
ated by a forked arm of the governor. The first mentioned set of cams acts
through the medium of levers upon the admission valve, and the other set of 5
cams acts through the medium of a lever upon the exhaust valve.
Since the various cams are mounted on the same sleeve the admission valve and
the exhaust valve will be operated simultaneously, and the amount by which the
said valves are opened or closed will depend upon the shapes of the respective
cams.
In normal working the admission valve is opened during the first stroke 55
(assuming the engine to have a four-stroke cycle) and is then closed
during the remaining three strokes. The exhaust valve is opened during the fourth

page_text: stroke and is fully closed during the first three strokes. On a first increase in the
speed of the engine taking place the exhaust valve is opened during part of the
admission stroke in order to allow of a certain quantity of burnt gases entering
the cylinder; the exhaust valve is then closed during the remainder of the said
stroke, as also during the compression stroke and the explosion stroke, and it is
then opened during the whole of the fourth or exhaust stroke. The admission
valve is closed during the entrance of a certain volume of burnt gases into the
cylinder, and it is then opened until the end of the piston stroke for the purpose
of filling the remaining space in the cylinder with previously produced explosive
mixture. The admission valve is then closed during the second, third and fourth.
strokes.
On a greater increase in the speed of the engine, taking place, the exhaust valve
is opened for a longer time during a greater portion of the stroke in order to
allow a larger. volume of burnt gas to enter the cylinder. It remains closed during
the remainder of the stroke and during the other two strokes, and is opened during
the whole of the fourth stroke. The admission valve is only opened immediately
after the closing of the exhaust valve during the remainder of the suction stroke,
and it remains closed during the second, third and fourth strokes.
In the case of an increase of the speed of the engine exceeding the predetermined
maximum limit; the admission valve is wholly closed and the exhaust valve is
completely opened during the four strokes.
:
To regulate the entry of gas into the mixer, it is sufficient to connect the end of
the lever arm that actuates the admission valve by means of levers jointed to the
rod of a special valve (hereinafter called gas inlet valve) controlling the gas inlet
of the mixer. This valve which is preferably a double valve constructed as herein-
after described, opens and closes at each opening and closing of the admission
valve. By means of this connection on each admission of mixture into the cylinder
exactly the same volume of gas enters the mixer, so that the explosive mixture
has always the same composition.
The double gas inlet valve above referred to consists of two valves arranged one
above the other, the one for controlling the entry of the gas, and the other for
controlling the entry of the air; they are connected together in the following
manner: The said air valve is mounted on a hollow spindle in the interior of
which is arranged a solid spindle connected at its upper end by means of a pin
which passes through a slot in the hollow spindle, to a sleeve forming one with
the gas valve.
The solid spindle is screw-threaded at its lower portion and carries a nut and a
lock nut. The nut bears against a shoulder on the end of the hollow spindle.
The pipe union through which the gas enters, ends also in a shoulder. Between
these two shoulders is fitted a spring which tends to depress the hollow spindle
and also the solid spindle through the medium of the aforesaid pin, that is to say,
it has a tendency to move the two valves down upon their seats.
As there is no gas bag on the gas pipe, and as further it is not necessary in this
case because the suction produced by the piston has no effect whatever on the
entrance of the gas, there is need to regulate the entry of gas into the mixer in
accordance with the pressure of said gas, in order that there shall enter in the
mixer an amount of gas equal to that which is introduced into the cylinder.
To this end, when the pressure of the gas in the gas pipe is greater than the
normal pressure, the gas valve must be arranged to have a shorter stroke or lift.
This is effected by screwing the nut and the lock nut along the solid spindle so as
to cause the shoulder on the hollow spindle and consequently the hollow spindle
to rise again. The spring being more compressed acts through the medium of the
shoulder and of the nut upon the solid spindle so as to keep the gas valve pressed..
down with greater force upon its seat. Further, as the lever operates the valve
by bearing by means of a roller upon the lock-nut and as further the said lock-nut
has been raised by screwing it along the solid spindle at the same time as the nut,
the stroke of the valve will therefore be shorter. It is to be noted that the function

page_text: of the air valve is not really to regulate the entrance of air into the apparatus,
but merely to cause the air and gas to spread out in a thin layer or sheet and to
be mixed and stirred up together at their entry into the apparatus in order that
the friction between the molecules may facilitate their diffusion.
The gas entering under pressure and being lighter than the air will flow in more
rapidly than the latter, and consequently the amount of air entering the apparatus
will be the difference between the volumes of mixture to be replaced in the appa-
ratus and the volume of gas that has entered.
When the pressure of the gas in the pipe is less than the normal pressure, the
.stroke of the gas valve should be longer. This is effected in the same way, but
by turning the nut and lock nut in a direction the reverse of that in the previous
case.
The air valve then bears upon its seat whilst the gas valve is raised. The gas
enters below the air valve into the union which allows of the entry of air whence
it enters the apparatus at the suction stroke.
In the mode of regulation just described, the essential feature is the introducing
into the cylinder of a smaller volume of explosive mixture, the remaining space
being filled with exhaust gases. It is to be noted that a regulation of the same
kind might be effected by filling the remaining space of the cylinder, not with
exhaust gases, but with pure air. For that purpose it would be sufficient to have
a supplementary valve controlled by the governor by means of special cams which
in normal working, would keep it always closed, and which in the case of an
increase in speed would keep it open only during a longer or shorter fraction of
the admission stroke. In this case the governor would act upon the exhaust valve
in the ordinary manner, that is to say, would open it only at the fourth stroke.
The first mentioned arrangement is however preferred because the result is
better. In fact by thus sending supplementary air into the cylinder, the previously
produced mixture diffuses much more quickly in that air, than in burnt gases and
consequently the composition of the mixture would tend to vary. By using the
exhaust gases I avoid this diffusion, and consequently the variations in the com-
position of the previously produced explosive mixture.
I apply to the working face of the piston of the engine a disc of less diameter
than the piston. This disc has for object to prevent (with the mode of regulation
herein before described) the previously produced mixture from impinging with
too great velocity against the exhaust gases introduced into the cylinder during a
fraction of the admission stroke, and causing a kind of mixing of the previously
produced mixture with the said exhaust gases. This disc allows to a certain
extent of the the separation in the interior of the cylinder, of the total volume into
two parts, one, nearest the piston consisting of burnt gases, and the other furthest
away from the piston, consisting of previously produced mixture.
Further this disc being also at a high temperature since it is exposed to the heat
of explosion in the compression space, promotes the instantaneous ignition of
the previously produced active mixture.
Dated his 20th day of July 1807
Improvements in and connected with Gas and Hydro-carbon Engines.
I, ETIENNE PETRÉANO, of 95, Boulevard Beaumarchais, Paris, France, Engineer,
do hereby declare the nature of this invention and in what manner the same is

page_text: to be performed, to be particularly described and ascertained in and by the follow-
ing statement:―
This invention relates to gas and hydrocarbon engines, and the improvements
comprise amongst other features of novelty a new mode of regulating the motion
of such engines.
The regulation of the motion of gas engines is effected at present in various
ways which may be generally reduced to two main types: The first method
which is the one most generally employed consists in altogether suppressing the
admission of gas. In this case, the air admission valve being automatic, the
piston draws in, compresses and expels air alone. The exhaust valve is only
open at the moment of expulsion of the burnt gases and closes immediately after-
wards. Or the air admission valve is closed at the same time as the gas inlet
valve, and the exhaust is completely open during the whole time occupied by the
engine in returning to its normal speed. In this case the piston draws in, and
expels the exhaust gases. The second method which is less usual, consists when
the speed of the engine tends to increase, in closing to a certain extent the admission
of gas alone without interfering with the admission of air, and the exhaust valve
is opened only for the expulsion of the burnt gases and is closed again immediately.
The last method is tantamount to varying the composition of the motive mixture
by causing it to be less rich in gas. Or again, the air inlet valve is closed to the
same amount as the gas inlet valve, and the exhaust opens only for the expulsion
of the burnt gases.
This method again is equivalent to varying the initial pressure
of the motive fluid in the compression chamber because as the admissions are
throttled, the piston draws in a less amount of mixture of gas and air than in the
normal working of the engine.
The methods hereinbefore described have the disadvantages of either causing
knocking or sudden jerks of the engine during the interval from the time at
which the supply of explosive mixture is entirely cut off, to the time at which
a complete charge of the explosive mixture is re-admitted, or else of causing
deposits arising from the miss-fires due either to the change in the composition of
the explosive mixture or else to the change in its compression.
A third method consists in acting by varying the compression and the expansion,
but this method has the disadvantages of entailing an excessive consumption of
gas, since the explosive mixture becomes richer in gas in proportion as the speed
of the engine increases or varies.
Now the method of regulation carried out according to this invention avoids all
those drawbacks:-The said method consists in principle in causing the governor
to admit a varying volume of previously produced mixture of gas or gaseous
vapor and air but with constant compression. Moreover in order to ensure that
the previously produced mixture shall retain the same composition during the
entire duration of the working of the engine, the governor may also be arranged
to act at the same time upon the valve controlling the admission of gas into the
apparatus (hereinafter called the mixer) in which the explosive mixture is pro-
duced externally of the engine cylinder and prior to its admission into the latter.
In order to effect the regulation in the conditions above stated I cause the exhaust
valve to be operated by the engine governor at the same time as the said governor
acts upon the valve for admitting the previously produced explosive mixture into
the engine cylinder.
If the normal speed of the engine increases, the governor closes the valve (herein-
after called the admission valve) for the admission of the previously prepared
explosive mixture and opens the exhaust valve during, say for instance, a fifth
part of the suction stroke of the piston. The exhaust valve is then closed and at
that moment the admission valve is opened during the remaining four-fifths of
the piston stroke, so as to fill the remaining space in the engine cylinder with the
explosive mixture, whereupon the admission valve closes.
There is therefore now in the cylinder a certain proportion of previously pre-

page_text: pared explosive mixture and a certain proportion of exhaust gases. These exhaus
gases are absolutely inert and do not take any active part in the explosion.
When the piston returns to compress the total volume, the explosive mixture
constituting a part only of the entire contents of the cylinder will be compressed
to exactly the same pressure as if the entire cylinder was filled with explosive
mixture, that is to say, to exactly the same pressure as in normal working. This
proportion of previously produced explosive mixture will therefore always be at
the most favorable pressure for exploding, although in smaller volume.
After the explosion which has thus been reduced in power but without possible miss-
fires, the gases will expand. During the next period the exhaust valve will open.
If from any cause the speed of the engine should exceed the predetermined
maximum limit, the governor will entirely close the admission valve and will
open the exhaust valve completely.
At the same time that the governor is acting upon the mixture-admission-valve
and upon the exhaust, I may also cause it to act upon the inlet of the gas into the
mixer in which the mixture of gas or gaseous vapor and air is previously effected.
This arrangement has for object to prevent the composition of the mixture from
becoming altered during the entire period of the fluctuations in the speed of the
engine. Then as the air enters the mixer only under atmospheric pressure at
each suction stroke of the piston, and if less mixture be drawn into the cylinder
and there is always the same inlet for the gas into the mixer, more gas will enter
in proportion than air.
In order to prevent this from happening the entry of the gas into the mixer must
be regulated in exactly the same manner as is the admission of mixture into the
engine cylinder and at exactly the same time.
In the accompanying illustrative drawings:-Figures, 1, 2, 2 are elevations,
partly in vertical section illustrating a suitable arrangement of mechanism for
effecting the regulation of the movements of the engine in accordance with the
present invention.
Upon the shaft A of the engine governor there is mounted a sleeve B carrying
two sets of cams; one set a, b, c, d being designed to control the admission valve,
whilst the other set a¹, b, c, d is designed to control the exhaust valve.
The sleeve B is mounted with slight friction on the governor shaft A and is
actuated by a forked arm C of the
governor. The first mentioned set of cams a, b,
c, d acts upon the admission valve spindle F1 through the medium of a bent
lever D E fulcrumed on an axle 0, and the other set of cams a, b, c d acts upon
the exhaust valve spindle I' through the medium of a bent lever G H fulcrumed on
the same axle O,
Since the various cams are mounted on the same sleeve B, the admission valve F
and the exhaust valve I will be operated simultaneously, and the amount by
which the said valves are opened or closed will depend upon the shapes of the
respective cams.
Figures 3, 4, 5 and 6 are diagrams illustrating the respective shapes and
positions of the exhaust cams and the admission cams. Figure 3 illustrates the
shapes and positions corresponding to normal working of the engine.
a is the admission cam, and a¹ is the exhaust cam. In normal working the
admission valve F is opened during the first stroke (assuming the engine to have a
four-stroke cycle) and is then closed during the remaining three strokes. The
exhaust valve I is opened during the fourth stroke and is fully closed during the
first three strokes. On a first increase in the speed of the engine taking place
the respective shapes and positions of the cams coming into operation will be as illus-
trated in Figure 4, that is to say, the exhaust valve is opened by the action of
the cam b¹ during part of the admission stroke in order to allow of a certain
quantity of burnt gases entering the cylinder; the exhaust valve is then closed
during the remainder of the said stroke, as also during the compression stroke and
the explosion stroke, and it is then opened during the whole of the fourth or
exhaust stroke. The admission valve is closed by the operation of the cam 6

page_text: during the entrance of a certain volume of burnt gases into the cylinder, and it
is then opened until the end of the piston stroke for the purpose of filling the
remaining space in the cylinder with previously produced explosive mixture. The
admission valve is then closed during the second, third and fourth strokes.
Figure 5 illustrates the respective shapes and positions of the admission cam c
and the exhaust cam which come into operation on a greater increase in the
speed of the engine taking place, the exhaust valve is opened for a longer time
during a greater portion of the stroke in order to allow a larger volume of burnt
gas to enter the cylinder. It remains closed during the remainder of the stroke
and during the other two strokes, and is opened during the whole of the fourth
stroke. The admission valve is only opened immediately after the closing of the
exhaust valve during the remainder of the suction stroke, and it remains closed
during the second, third and fourth strokes.
Figure 6 illustrates the respective shapes and positions of the admission cam d
and the exhaust cam d¹ which come into operation, in the case of an increase of
the speed of the engine exceeding the predetermined maximum limit, the admission
valve is wholly closed and the exhaust valve is completely opened during the four
strokes.
Figure 7 is a sectional view of a suitable arrangement for regulating the entry
of gas into the mixer; it consists in connecting the end of the lever DE, that
actuates the admission valve F of the engine cylinder, by means of a rod K jointed
at N to a lever L fulcrumed at M, to the rod of a special valve R S (hereinafter
called gas inlet valve) controlling the gas inlet of the mixer. This valve which
is preferably a double valve constructed as hereinafter described, opens and closes
at each opening and closing of the admission valve. By means of this connection
on each admission of mixture into the cylinder exactly the same volume of gas
enters the mixer, so that the explosive mixture has always the same composition.
The double gas inlet valve above referred to consists of two valves R S arranged
one above the other, the one R for controlling the entry of the gas, and the other S
for controlling the entry of the air and gas together into the mixer; they are con-
nected together in the following manner:-The valve S is mounted on a hollow
spindle T in the interior of which is arranged a solid spindle V connected at its
upper end by means of a pin X which passes through a slot in the hollow spindle T,
to a sleeve forming one with the gas valve R.
The solid spindle V is screw-threaded at its lower portion and carries a nut B¹
and a lock nut C¹: The nut B₁ bears against a shoulder I on the end of the
hollow spindle T. The pipe union through which the gas enters is also formed
with a shoulder F. Between these two shoulders D and F¹ is fitted a spring Z
which tends to depress the hollow spindle T and also the solid spindle V through
the medium of the aforesaid pin X, that is to say, it has a tendency to move the
two valves R and S down upon their seats.
As there is no gas bag on the gas pipe, and as further it is not necessary in
this case because the suction produced by the piston has no effect whatever on
the entrance of the gas, there is need to regulate the entry of gas into the mixer
in accordance with the pressure of said gas, in order that there shall enter in the
mixer an amount of gas equal to that which is introduced into the cylinder.
To this end, when the pressure of the gas in the gas pipe is greater than the
normal pressure, the gas valve R must be arranged to have a shorter stroke or lift.
This is effected by screwing the nut B' and the lock nut C₁ along the solid spindle V
so as to cause the shoulder I)' on the hollow spindle T and consequently the hollow
spindle T to rise again. The spring Z being more compressed acts through the
medium of the shoulder D' and of the nut B¹ upon the solid spindle V so as to
keep the gas valve R pressed down with greater force upon its seat. Further, as
the lever K L operates the valve by bearing by means of a roller E' upon the lock-
nut C¹ and as further the said lock-nut has been raised by screwing it along the
solid spindle V at the same time as the nut B¹ the roller E will rise idly to a cor-
responding extent before it strikes the nut C¹, and the stroke of the valve It will

page_text: therefore be shorter. It is to be noted that the function of the valve S is not
really to regulate the entrance of air into the mixer, but merely to cause the air
and gas to spread out in a thin layer or sheet and to be mixed and stirred up
together at their entry into the mixer in order that the friction between the mole-
cules may facilitate their diffusion.
The gas entering under pressure and being lighter than the air will flow in more
rapidly than the latter, and consequently the amount of air entering the mixer
will be the difference between the volumes of mixture to be replaced in the mixer
and the volume of gas that has entered.
When the pressure of the gas in the pipe is less than the normal pressure, the
stroke of the gas valve should be longer. This is effected by turning the nut B¹
and lock nut C in a direction the reverse of that in the previous case. By this
means there is produced between the upper face of the nut B1 and the shoulder D¹
an interval of distance which allows of the gas valve R being opened to a cor-
responding extent in advance of the valve S which latter valve remains on its
seat until raised by the nut B₁ striking the shoulder D¹, whereupon both valves
rise together. The gas enters below the valve S into the tubular union which allows
of the entry of air whence it enters the mixer at the suction stroke.
In the mode of regulation just described, the essential feature is the introducing
into the cylinder of a smaller volume of explosive mixture, the remaining space
being filled with exhaust gases. It is to be noted that a regulation of the same
kind might be effected by filling the remaining space of the cylinder, not with
exhaust gases, but with air only. For that purpose it would be sufficient to have
a supplementary valve controlled by the governor by means of special cams which
in normal working, would keep it always closed, and which in the case of an
increase in speed would keep it open only during a longer or shorter fraction of
the admission stroke. In this case the governor would act upon the exhaust valve
in the ordinary manner, that is to say, would open it only at the fourth stroke.
The first mentioned arrangement is however prefered because the result is
better. In fact by thus sending supplementary air into the cylinder, the previously
produced mixture diffuses much more quickly in that air, than in burnt gases and
consequently the composition of the mixture would tend to vary. By using the
exhaust gases I avoid this diffusion, and consequently the variations in the com-
position of the previously produced explosive mixture.
Figure 8 is a sectional view of an improved construction of piston which I prefer
to employ in my improved engine. In this construction I apply to the working
face of the piston of the engine a disc U of less diameter than the piston. This
disc U which is connected to the piston by means of a stem u, has for object to
prevent (with the mode of regulation hereinbefore described) the previously pro-
duced mixture from impinging with too great velocity against the exhaust gases
introduced into the cylinder during a fraction of the admission stroke, and causing
a kind of mixing of the previously produced mixture with the said exhaust
gases. The disc U allows to a certain extent of the separation in the interior of
the cylinder, of the total volume into two parts, one, nearest the piston consisting
of burnt gases, and the other furthest away from the piston, consisting of previously
produced mixture.
Further this disc U being also at a high temperature since it is exposed to the
heat of explosion in the compression space, promotes the instantaneous ignition of
the previously produced active mixture.
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 improved mode of regulating the speed of gas and hydrocarbon engines
worked by an explosive mixture produced externally of the engine cylinder and

page_text: to admit a varying volume of said explosive mixture with constant compression,
the arrangement being such that the said explosive mixture is caused to retain
the same composition during the entire duration of the working of the engine,
substantially as described.
2. For carrying out the improved mode of regulating the speed of gas and
hydrocarbon engines specified in Claim 1, arranging the engine governor to act
simultaneously upon the valve controlling the admission of gas into the apparatus
(mixer) in which the explosive mixture is produced and upon the exhaust valve
of the engine cylinder, substantially as described and for the purpose specified.
3. The arrangement of mechanism for carrying out the improved mode of regu-
lation specified in Claims 1 and 2, substantially as described with reference to
Figures 1 to 7 inclusive of the accompanying drawings.
4. The improved construction of engine piston, arranged and operating sub-
stantially as described with reference to Figure 8 of the accompanying drawings.
1000
Daleu
frn mor STU
1030.
J. C. MEWBURN & ELLIS,
55, and 56, Chancery Lane, London, Chartered Patent Agents.