IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1884

page_text: I THOMAS BROWETT of Saint Simon Street Salford in the county of Lancaster
Engineer do hereby declare the nature of my invention for IMPROVEMENTS IN
GAS MOTOR ENGINES to be as follows:-
My invention relates to gas motor engines wherein power is obtained from the
explosion or combustion of an inflammable mixture of gas and air and consists of
arrangements of apparatus and a cycle of operations whereby certain conditions
are obtained which are favorable to the generation and utilisation of the power
developed by the explosion or combustion of the mixture of gas and air before
mentioned.
By my invention I am enabled to permit the heated gaseous mixture to be
expanded from the high temperature and pressure due to the ignition of such
gaseous mixture down to a lower temperature and pressure than has hitherto been
possible and I also effect this expansion rapidly so as to lose as little heat as possible
by the usual radiation and cooling due to the water jacket by which the cylinders
of gas motor engines are ordinarily surrounded.
In one method of carrying out my invention I employ an ignition or working
cylinder and a charge cylinder each of which I provide with a piston such pistons
being connected by means of suitable connecting rods to cranks of a crank shaft
such crank shaft being mounted in suitable bearings-The above mentioned cranks
I place at such an angle to each other that the piston of the charge cylinder
performs the latter portion about one third of its inward stroke while the piston of
the ignition cylinder is performing about the first one third of its outward stroke.
Similar results may however be obtained with various arrangements of the parts
above referred to without departing from the principle and objects of my
invention..
The cycle of operations is as follows:-The piston of the charge cylinder during
its outward stroke draws in a charge of combustible mixture of air and gas and
compresses such charge during about two thirds of the inward stroke of the above
mentioned piston when a valve placed in a port between the two above mentioned
cylinders permits communication between the said cylinders and the compressed
charge of gas and air is then displaced from the charge cylinder into the ignition
cylinder the piston of which is now advancing to make room in the ignition
cylinder for the charge-When the charge piston has discharged as much as

page_text: possible of the contents of the charge cylinder, into the ignition cylinder com-
munication between the two cylinders is cut off by the previously named valve
and the explosive mixture in the ignition cylinder is ignited-Instead of employing
the valve to shut off communication between the charge cylinder and ignition
cylinder the charge piston may be employed to close the port for that purpose.
Immediately after the ignition of the explosive mixture in the ignition cylinder
communication is reopened by means of the valve previously referred to or by the
charge piston receding and uncovering the port which it had previously closed, upon
which the pressure of the ignited mixture of gas and air will act upon both pistons
until the piston of the ignition cylinder has reached the end of its outward stroke
when an exhaust valve which may be situate at the back or inner end of the
ignition cylinder is opened-The charge piston having still a portion of its out-
ward stroke to perform I in some cases close the valve between the charge cylinder
and the ignition cylinder before the exhaust valve is opened and until the piston of
the charge cylinder has arrived at or about the end of its stroke when the before
named valve is reopened-As the piston of the ignition cylinder and the piston of
the charge cylinder make their inward strokes, the products of combustion will be
expelled from the charge and ignition cylinders, through the exhaust valve on the
ignition cylinder the valve between the two cylinders remaining open, or each of
the above cylinders may be provided with exhaust valves if required-The next
outward stroke of the ignition cylinder is made with the exhaust valve of such
cylinder open or a separate valve may be employed to admit air to the said cylinder
and so prevent a vacuum being formed in the said cylinder.
Upon the piston of the charge cylinder beginning to again recede, a fresh charge
of gas and air will be drawn into the charge cylinder in a manner similar to that
previously described the valve between the charge and ignition cylinders being
closed the piston in the ignition cylinder expels, the air which was last drawn
through the exhaust valve and the cycle of operations is then repeated.
The above described arrangement of gas motor engine makes one explosion for
every two revolutions of the crank shaft but I would have it understood that if
an additional charge cylinder in addition to that above referred to is employed an
explosion may be obtained for each revolution of the crank shaft.
In the above described arrangement of gas motor engine the piston in the
ignition cylinder is advancing when the explosion of the mixture of gas and air
takes place and the shock due to such explosion is lessened and the gases are
allowed to rapidly expand by such movement of this piston before mentioned-By
the above arrangements the heated gases are kept in contact with the cylinders of
the engine for a shorter time than heretofore and consequently there is less loss of
heat and an increase of power.
The ignition of the mixture of gas and air in the ignition cylinder may be
accomplished by any well known method or by the following arrangement.
From the foregoing it will be seen that at the time the piston of the charge
cylinder commences to force the charge of gas and air into the ignition cylinder the
piston in this latter cylinder will be advancing at a slower speed than the piston of
the charge cylinder this will cause a temporary increase of pressure in the charge
cylinder and a portion of this more highly compressed charge may be led off by
suitable pipes or passages to the slide valve of the ignition cylinder-such slide
valve being provided with a port timed to open to a port in the ignition cylinder
after first passing the said mixture through a tube heated to redness and by reason
of this stored up mixture of gas and air being at a higher pressure than the
contents of the ignition cylinder will then be it will rush out through the port and
tube becoming ignited on its way and so firing the charge of gas and air in the
ignition cylinder-In some cases I propose to employ an igniter such as that
described in the Specification of Letters Patent N° 3568 dated July 20th 1883
granted to Christopher Thomas Wordsworth and Herbert Lindley.
I have described the pistons of the charge and ignition cylinders of engines
constructed according to my invention as having no clearance space between the

page_text: ends of such pistons before named and their respective cylinders when in their
extreme inward positions but one or both of such cylinders before referred to may
be provided with clearance without interfering with the cycle of operations
previously described-In all cases whatever the amount of such clearance may be
in the ignition cylinder the exhaust valve must be caused to close at such a point
in the instroke of the piston as will compress the contents of such cylinder to the
same pressure or thereabouts as that of the explosive charge at the time such
charge begins to be displaced from the charge cylinder into the ignition cylinder.
In some cases I propose to ignite that portion of the gaseous mixture which is
contained in the ignition cylinder before referred to when the two pistons are in
such position relative to each other that the mixture is at or about its greatest
pressure.
A further portion of my invention refers to gas motor engines generally and
consists in the employment of oil or other liquid of high boiling temperature for
increasing the efficiency of such gas motor engines and for keeping the cylinders or
other parts of such gas motor engines from becoming overheated-For this purpose
I surround the cylinder or other parts before referred to with a jacket casing or
cavity or jackets casings or cavities and I connect the said jacket casing or cavity
or jackets casings or cavities by means of pipes to a cistern or tank containing oil
or other liquid of high boiling temperature-By this portion of iny invention I am
enabled to prevent the cylinder or other part aforesaid from being overheated
without causing an undue loss of hoat.

page_text: I THOMAS BROWETT of Saint Simon Street Salford in the County of Lancaster
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
GAS MOTOR 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 gas motor engines wherein power is obtained from the
explosion or combustion of an inflammable mixture of gas and air and consists of
arrangements of apparatus and a cycle of operations whereby certain conditions are
obtained which are favorable to the generation and utilization of the power
developed by the explosion or combustion of the mixture of gas and air before
mentioned.
By my Invention I am enabled to permit the heated gaseous mixture to be
expanded from the high temperature and pressure due to the ignition of such
gaseous mixture down to a lower temperature and pressure than has hitherto been
possible and I also effect this expansion rapidly so as to lose as little as possible by
the usual radiation and cooling due to the water jacket by which cylinders of gas
motor engines are ordinarily surrounded.
In one method of carrying out my Invention I employ an ignition or working
cylinder and a charge cylinder each of which I provide with a piston such piston
being connected by means of suitable connecting rods to cranks of a crank shaft
such crank shaft being mounted in suitable bearings-The above mentioned cranks
I place at such an angle to cach other that the piston of the charge cylinder
perforins the latter portion (say about one third) of its inward stroke while the
piston of the ignition cylinder is performing about the first one third of its outward
stroke. Similar results may however be obtained with various arrangements of
the parts above referred to without departing from the principle and objects of my
Invention as hereinafter will appear.
The cycle of operations is as follows:-The piston of the charge cylinder during
its outward stroke draws in a charge of combustible mixture of air and gas and
compresses such charge during about two thirds of the inward stroke of the above
mentioned piston when a transfer valve placed in a port between the two above
mentioned cylinders permits communication between the said cylinders and the
compressed charge of gas and air is then displaced from the charge cylinder into
the ignition cylinder the piston of which is now advancing to make room in the
ignition cylinder for the charge.-When the charge piston has discharged as much
as possible of the contents of the charge cylinder into the ignition cylinder commu-
nication between the two cylinders is cut off by the previously named valve and
the explosive mixture in the ignition cylinder is ignited.-Instead of employing
the valve to shut off communication between the charge cylinder and ignition
cylinder the charge piston may be employed to close the port for that purpose.-
Immediately after the ignition of the explosive mixture in the ignition cylinder
communication is reopened by means of the valve previously referred to or by the
charge piston receding and uncovering the port which it had previously closed
upon which the pressure of the ignited mixture of gas and air will act upon both

page_text: pistons until the piston of the ignition cylinder has reached the end of its outward
stroke when an exhaust valve which may be situate at the back or inner end of
the ignition cylinder is opened.-The charge piston having still a portion of its
outward stroke to perform I in some cases close the transfer valve between the
charge cylinder and the ignition cylinder before the exhaust valve is opened and
until the piston of the charge cylinder has arrived at about the end of its stroke
when the before named transfer valve is reopened-As the piston of the ignition
cylinder and the piston. of the charge cylinder make their inward strokes the
products of combustion will be expelled from the charge and ignition cylinders
through the exhaust valve on the ignition cylinder the valve between the two
cylinders remaining open or each of the above cylinders may be provided with
exhaust valves if required-The next outward stroke of the ignition cylinder is
made with the exhaust valve of such cylinder open or a separate valve may be
employed to admit air to the said cylinder and so prevent a vacuum being formed
in the said cylinder.
Upon the piston of the charge cylinder beginning to again recede a fresh charge
of gas and air will be drawn into the charge cylinder in a manner similar to that
previously described the valve between the charge and ignition cylinders being
closed the piston in the ignition cylinder expels the air which was last drawn
through the exhaust valve and the cycle of operations is then repeated.
The above described arrangement of gas motor engine makes one explosion for
every two revolutions of the crank shaft but I would have it understood that if an
additional charge cylinder in addition to that above referred to is employed an
explosion may be obtained for each revolution of the crank shaft.
In the above described arrangement of gas motor engine the piston in the
ignition cylinder is advancing when the explosion of the mixture of gas and air
takes place and the shock due to such explosion is loosened and the gases are
allowed rapidly to expand by such movement of this piston before mentioned By
the above arrangements the heated gases are kept in contact with the cylinders of
the engine for a shorter time than heretofore and consequently there is less loss of
heat and a corresponding increase of power. The ignition of the mixture of gas
and air in the ignition cylinder inay be accomplished by any well known method.
I am fully aware that several gas motor engines have been patented and mado
in which it has been sought to expand the heated gas in two or more cylinders but
this has been accomplished in one of two methods, namely, either by allowing the
heated gases to exhaust towards the end of the stroke of what may be designated
the first or high pressure piston through a hole port or passage leading to the
second or low pressure cylinder which may be of greater capacity than the first or
high pressure cylinder in which second or low pressure cylinder the said gases act
by further expansion, on the second or low pressure piston the communication
between the cylinders being closed during a portion of such second expansion-Or
the cubic content swept by the piston of the second cylinder being made larger
than that swept by the first piston the heated gases are admitted to the second
cylinder after being allowed to expand in the first cylinder the interiors of the two
cylinders being allowed to remain in free communication with each other during
the whole or a large portion of the strokes of their respective pistons the relativo
motions of the two pistons being so arranged that the volume of gases behind the
first or smaller piston decreases while the volume of gases behind the second or
larger increases a differential increase of volume of gases being thereby obtained as
is common in compound steam engines.-Such arrangements expose the heated
gases to a large cooling surface during a long period of time and conduce to a large
loss of heat by radiation and absorption and in neither case is the pressure of the
gases allowed to act on the second piston until it has been considerably reduced by
expansion behind the first piston.
In a gas motor engine constructed according to my Invention the defects which
exist in the arrangements of gas motor engines above described are in a great
measure-obviated chiefly by so urranging the parts and the cycle of operations that

page_text: the volume of the exploded or ignited gases is allowed to rapidly increase behind
a moving piston immediately after their ignition while the temperature is highest
and that both pistons receive the full initial pressure obtained by the explosion or
combustion of the gases or nearly so.
In order that the cycle of operations and the means which I propose to employ
in effecting the said cycle of operations may be fully understood I have appended
hereto one sheet of drawings which I will now proceed to fully describe and explain
The diagrams Figs. 1 to 7 inclusive illustrate the various noteworthy positions
occupied by certain of the parts of a gas motor engine constructed according to my
Invention at certain times in the cycle of operations.-In the diagrams Figs 1 to 7
inclusive A is the piston of the ignition cylinder, B is the piston of the chargo
cylinder, C is the transfer valve controlling the passage between the cylinders a b.-
1) is the gas and air inlet valve E is the exhaust valve and F is the igniting
apparatus The arrows in each figure indicate the direction of motion of the
pistons A B respectively at the times under consideration.
In Fig. 1 the piston B is at its extremo inward position in which position it may
just close the port leading to the transfer valve C and is about to draw in to the
cylinder b a charge of gas and air through the valve D the piston A is shown as
having advanced about one third along the cylinder whilst making the first
portion of its outstroke the exhaust valve E is open and the transfer valve C is
closed. In Fig. 2 the piston B is at the end of its first out stroke; the valve D
closes and the piston A has completed its outstroke and begun to return the
transfer valve C is closed and the exhaust valve E is open Fig. 3 shows the
piston A at the extreme end of its instroke and the exhaust valve E closed.-The
piston B now has performed about two thirds of its instroke.
The gas and air inlet valve D remains closed and the transfer valve C now opens
Fig. 4 shows the pistons A. B back in the positions in which they were originally
shown in Fig. 1 but now the space behind the piston A is filled with the compressed
combustible charge.-The valve C now closes momentarily or the piston B may be
caused to close the port leading to C by sliding on to or over such port.-The
charge of gas and air is now ignited and the port or valve C immediately reopened.
Fig. 5 shows the positions of the pistons A B when the crank shaft has performed
one quarter of a revolution after the mixture of gas and air lias been ignited By
Fig. 5 is clearly shown the great rapidity of the increase of the volume of the
heated gases. If the volume of the said gases at the time of ignition be taken as 1
it will now by the movement of the pistons A B have become about 44 This
expansion of the gases further continues until the pistons A B reach the positions
shown by Fig. 6 when the piston A. has completed its outstroke and the piston B
has performed about two thirds of its outstroke-The exhaust valve E now opens
and the transfer valve C being still open the products of combustion are expelled
from the cylinders a b during the next instroke of their respective pistons-The
transfer valve C might be closed before the exhaust valve E opens so as to allow
the piston B to complete its outstroke and after the piston B has completed its
outstroke the valve O must be reopened.
Fig. 7 shows the pistons and all the parts in the same position as they were at
the commencement of the cycle of operations the exhaust valve E being still open
so as to prevent the formation of a vacuum behind the piston A the transfer
valve C has just been closed and the cycle of operations is now completed.
In the accompanying diagrams (Figures 1 to 7) I have shown the piston A as
leading the piston B by rather more than 1th of a revolution (the exact fraction of
a revolution for the lead of on the piston A when B is at the beginning of its
stroke depending on the length of the connecting rod). The position of the
piston B relative to the piston A should be determined with reference to the amount
of compression which it is desired to give to the charge before ignition As shown
the charge will be compressed to a third of its volume at atmospheric pressure
which gives an initial pressure before ignition of about 30 lbs. above atmospheric
pressure With this relative position of cranks the final volume of the charge

page_text: prior to exhausting is about one and two third times the original volume of the
charge at atmospheric pressure The lead of piston A may be increased or
diminished according as a less or greater initial compression of charge is desired
but where the lead of piston A is increased the valve C should be closed before the
exhaust E is opened so as to get as much benefit as possible from the expansion in
cylinder b. In the foregoing description I have treated the capacities of the two
cylinders as equal and have assumed that there is no clearance space behind the
pistons when such pistons are in their extreme inward position but one piston
may have a longer stroke or a greater diameter or both a longer stroke and a
greater diameter than the other piston and either or both of such pistons may
have clearance space behind it or them when such piston or pistons is or are in
its or their extreme inward positions the angle between the cranks being varied
to correspond with the increase in diameter or stroke or diameter and stroke of
or clearance space allowed to each piston without altering the functions of the
parts or departing from the objects of my Invention In all cases the compressed
charge should be transferred to the ignition cylinder a by the piston B without
any great decrease of pressure an increase of pressure being preferable and
obtainable by making the volume swept by the charge piston B during the
period of transfer greater than the volume swept during the same time by the
ignition piston.
I would here point out that whatever amount of clearance is employed in the
ignition cylinder A the exhaust valve E must close at such a point on the instroke
of the ignition piston as will cause the air contained therein to be compressed
to a pressure the same or nearly the same as that of the next incoming charge
at the time when the transfer valve C opens and so long as these conditions are
fulfilled the transfer valve C may in practice be caused to open any time after
the exhaust, valve E has closed-The considerations above referred to limit the
amount of clearance which it is desirable to use.-But it must be borne in mind
that by increasing the clearance in cylinder a the ratio of the volume of the
ignited charge before exhaust to the volume at atmospheric pressure before
ignition is diminished so that less expansion is obtained. Hence any considerable
ainount of clearance is undesirable. In like manner if the capacity of the charge
cylinder be made greater than that of the ignition cylinder the ultimate total
volume of the heated gases after such gases have been allowed to expand will .
Le proportionately reduced.
The charge drawn into the charge cylinder may either be a uniform com-
bustible mixture of gas and air or more advantageously the portion first drawn
in may be air only and the remaining portion an inflammable mixture of air
and gas so that when each charge is transferred from the charge cylinder to the
ignition cylinder the portion of the charge which fills any clearance space in the
charge cylinder and the ports or passages and valve cases may be chiefly air so
that there may be no actual ignition in such ports or passages and valve cases 80
that the loss of heat which might arise from the mixture being ignited while
in contact with the increased surface is minimized.
It will be also advisable to employ cylinders the internal diameters of which are
large in proportion to the strokes of their respective pistons so as to expose the
heated gases to a cooling surface as small as possible in proportion to their
volume. The limit of this is of course reached when the internal diameter of
the cylinder equals the stroke of the piston of such cylinder.
I have above stated that the port or passage which connects the two cylinders
is closed just at the inoment of ignition which arrangement I prefer to adopt but
if both cylinders were in free communication at the moment of ignition similar
results would be obtained.-It will be seen from the foregoing description that
in gas motor engines of the arrangement above described the efforts obtained in
the two cylinders are simultaneous and that the crank shaft therefore receives all
the power transmitted to it during not more than one half revolution out of two
complete revolutions of the said crank shaft.

page_text: I will now describe certain arrangements and means whereby the force acting
upon the pistons of gas motor engines constructed according to my Invention
may be more uniformly distributed.-In one method of accomplishing the object
above stated I make either piston preferably that of the charge cylinder similar to
that of an ordinary steam engine that is double acting for which purpose I
provide the said piston with a piston rod working through a stuffing box or
gland in the cylinder cover at the end of the cylinder which is opposite to the end
at which the charge of inflammable gas and air enters.
It will be readily understood that if a clearance space be provided in front of
the piston above mentioned and a suitable air inlet valve be provided in connection
with such clearance space air may be compressed by the outward stroke of the
piston above mentioned and the greater portion of the power thus absorbed would.
be given back on the expansion of the compressed air on the next instroke of
the piston above referred to.-Instead of the arrangement above described the
air drawn in and compressed as above described may be conducted by means of
suitable passages and a valve or valves to a reservoir preferably formed as an
annular chamber around a portion of the ignition cylinder in which reservoir it
will be further heated by being in contact with the heated metal of the said
ignition cylinder a valve controlling a port or passage leading from the said
reservoir to the ignition cylinder may be opened at the time when the transfer
valve C closes and the ignition piston has performed a portion of what would
otherwise have been its idle stroke the exhaust valve E or an air inlet valve which
was before opened to prevent a vacuum from being formed having been closed at
such a point in the previous instroke of the ignition piston as will cause the
contents of the two cylinders to be compressed to about the same pressure as the
compressed heated air in the reservoir above referred to and such valvo E being
kept closed during the outstroke of the ignition piston so that the above mentioned
compressed heated air may when admitted propel the ignition piston and power be
imparted to the crank with which this piston is connected at every revolution of
the crank shaft of the engine on the first outstroke of this piston by the combustion
or explosion of the charge of gas and air and on its second outstroke by the
expansion of the air compressed by the outward stroke of the charge piston and
stored in the reservoir as above described.
'
When desired the charge piston may be provided with a trunk or enlarged piston
rod to reduce the volume of the air to be compressed By means of the arrangement
above described I am enabled to obtain a more even and uniform rotation of the
crank shaft by distributing the impulses imparted to the said crank shaft.-
This arrangement is shewn in Fig 15, 16, and 17, of the drawing hereunto
annexed.
If a sufficiently large clearance space be provided in the ignition cylinder it would
be possible to cause the cranks to move exactly together but I prefer to let the crank
of the ignition cylinder lead the crank of the charge cylinder so that one of the
cranks shall have passed its "dead centre" at the time that the charge of gas and
air is ignited in order to obtain the advantages arising from the more rapid increase
in the volume of the ignited gases immediately after ignition by means of which
the loss of heat during the period of highest temperature of the ignited charge is
considerably reduced.
Gas motor engines constructed according to my Invention may be governed either
by causing the gas inlet valve to remain entirely closed when the speed of the engine
exceeds the desired speed so that no explosion or ignition takes place during one or
more revolutions of the crank shaft or the gas inlet valve may be caused to open
during a portion only of the stroke during which the charge is being drawn in
In the former case it will be necessary to open only the air inlet valve during the
outstroke and also to reopen it or allow it to reopen automatically on the next
outstroke at a time when the compressed air has expanded to atmospheric pressure
or thereabouts. This may be conveniently accomplished by providing two air inlet
cams and mounting the cams for actuating the air and gas inlet valves on a sleeve

page_text: or sliding tube actuated by the governor such cams being made of a configuration
necessary to give the required motion to the valves either the one or other of the
air inlet cams being brought into action as required. In those cases in which the
air and gas inlet valves are both actuated by a forked lever operated by the same
cam when a combustible charge is being drawn in, a contact or filling piece may be
arranged so as to be capable of being interposed between or withdrawn from
between the said lever and the gas inlet valve by the governor the said governor
also actuating the sleeve or sliding tube before mentioned so as to bring into action
the proper air cam.
In some cases I dispense with the use of a water jacket or apply a water jacket
to portions only of one or both cylinders of gas motor engines constructed
according to my invention.
In the modification of my invention described in reference to Figures 15. 16.
and 17 in which modification air is compressed by the charge piston and conducted
to a reservoir which reservoir may be formed as an annular chamber around a
portion of the ignition cylinder such portion may or may not be provided with
a water jacket.
In the foregoing description of my invention I would have it understood that
I have used the expression "outstroke" to signify that motion of either piston
during which it is moving towards the crank shaft in an engine in which the parts
are arranged as in the drawing hereunto annexed.
Having now clearly described the objects of my Invention and the arrangements
to be employed in carrying it into effect I will now proceed to describe a gas motor
engine constructed according to my said Invention.
Figures 8. 9 and 10 shew a gas motor engine constructed according to my
Invention, similar letters of reference being employed to indicate corresponding
parts throughout the three figures Fig. 8 is a side elevation Fig. 9 is a plan and
Fig. 10 is an end elevation looking from the back of the gas motor engine. The
charge cylinder 1 is provided with a suitable piston 2. The charge cylinder 1
communicates by means of a port or passage with the ignition cylinder 3 which
ignition cylinder 3 is provided with a suitable piston 4 The port or passage
between the charge cylinder 1 and the ignition cylinder 3 may be opened or closed
by means of the transfer valve 5.-The pistons 2 and 4 are respectively connected
by means of connecting rods 6 and 7 to the cranks 8 and 9 of a double throw
crank shaft 10 mounted in suitable bearings 11 formed on the frame 12.-The
cylinders 1 and 3 are shown in the drawing as being surrounded with a jacket or
casing common to both of such cylinders which jacket or casing is for the reception
of water or other cooling liquid. The charge cylinder 1 is fitted with a gas and
air inlet valve 13 (shewn more clearly in Fig. 12) the air and gas valves of which
are actuated by means of a forked lever 14 which derives its action from a cam 15
mounted fast upon the shaft 16. The ignition cylinder 3 is provided with an
exhaust valve 17 details of which are shown in Fig. 11 which exhaust valve 17 is.
operated by a lever 18 which lever 18 is actuated by a cam 19 mounted fast upon
the shaft 16. The transfer valve 5 is operated when required by a lever 20
actuated by a cam 21 mounted fast upon the shaft 16.-As these three cams 15.
19. 21 each require to perform any given function but once in every two revolutions
of the crank shaft 10 the shaft 16 by which the cams 15. 19. 21 are rotated may
conveniently be caused to rotate once during every two revolutions of the crank
shaft 10 and in the engine shewn in the drawing the rotation of the shaft 16
I cause by mounting fast upon the crank shaft 10 a pinion 22 gearing into a toothed
wheel 23 of a diameter equal to twice that of the pinion 22. which toothed wheel 33
is mounted fast upon a suitable spindle 24 which spindle 24 carries a mitre wheel 25
which mitre wheel 25 gears into a similar mitre wheel 26 which mitre wheel 26 is
mounted fast upon the shaft 16 which shaft 16 is mounted in suitable bearings 27. 28.
In the drawings the pinion 22 toothed wheel 23 and the mitre wheels 25 and 26 are
represented by lines shewing their pitch diameters in order that confusion may be
avoided. The ignition cylinder 3 is provided with a slide 29 which slide 29 in

page_text: moved by a lever or link 31 which is actuated by an excentric or cam 30. The
slide 29 is shewn detached in Fig. 13 and the action of such slide 29 will be
described hereinafter.
A governor 32 of ordinary construction is shewn in the drawing as being driven
by a belt 33 and pulley 34 which pulley 34 is secured upon the crank shaft 10.-
The governor 32 operates a lever 35 which lever 35 carries a taper or stepped
contact or falling piece 36 which taper or stepped contact or filling piece 36 is
interposed or withdrawn from between the end of the forked lever 14 by which
forked lever 14 the gas inlet valve is operated so as to cause such gas inlet valve to
be opened to any required extent or not opened at all when the engine exceeds its
normal speed.
From the foregoing description and the drawing hereunto annexed the con-
struction and positions of and the methods of operating the essential parts of a gas
motor engine constructed according to my invention may be readily understood.
Fig. 11 of the drawing hereunto annexed shews a section taken through the
exhaust valve casing in which Figure 1 is the port leading to the ignition cylinder
2 is the exhaust valve and 3 is the exhaust outlet.-The valve 2 is kept upon its sent
by a spring as shown in Fig. 10 which spring also serves to keep the lever 18
(shewn in Figures 9 and 10) in contact with the cam 15 by which such lever 18 is
actuated. The cam shown on the left hand side of Fig. 11 is of a configuration
suitable for actuating the valve which valve is open during of each revolution of
the cam shaft. Fig. 12 of the drawing hereunto annexed shews a section through
the casing containing the gas inlet valve 1 and the air inlet valve 2 The air enters
by the port 3 and the gas enters by the port 4 and when admitted by the valve 1
to the interior of the perforated pipe 5 the gas issuing through the perforations
will mix with the incoming air and the combustible or inflammable mixture of gas
and air so obtained passes by the valve 2 and port 6 to the charge cylinder.
The valve 6 must be made sufficiently strong to be capable of withstanding the
pressure due to the compression and ignition of the charge.
The valves 1 and 2 are kept in contact with their seats by suitable springs 7, 8
respectively as shewn in the drawing. The spindles 9, 10 of the valves 1, 2. are
prolonged and arranged so as to be capable of being actuated by the lever 14 and
cam 15 (shewn in Figures 8 and 9) The cam 11 shewn on the left hand side of
Fig. 12 is of a configuration suitable for actuating the valves 1, 2 which valves
require to be opened during of each revolution of the cam shaft.
Figures 13 and 14 of the drawing, which Figures are combined in the said
drawing represent a transverse vertical section taken through the cylinders, transfer
valve and igniting slide The charge cylinder and the ignition cylinder 1, 3 are
connected by a port or passage 2 and the plug 4 has formed through it a port or
passage similar to that above mentioned so that when the said plug 4 is in one
position there will be an open thoroughfare or passage between the two cylinders 1
and 3. The plug valve 4 is attached to a vertical spindle 11 passing through a
gland or stuffing box 12 which spindle 11 is provided with a toothod bevil wheel
or toothed bevil segment 13 into which toothed bevil wheel or toothed bevil
segment 13 gears another toothed bevil wheel or toothed bevil segment 14. Of
the toothed bevil wheels or toothed bevil segments 13 and 14 the pitch lines only
are shown.—The toothed bevel wheel or toothed bevil segment 14 is secured to the
lever 15 which lever 15 is provided at its lower end with a roller which roller is
adapted to roll against the periphery of a cam mounted fast upon the shaft 16 as
herein before described. By means of this combination of mechanism the plug
valve 4 is turned through a portion of a revolution sufficient to cause the port
thoroughfare or passage 2 to be opened and closed. The configuration of the cam
is made suitable for giving the required motion to the valve that is causing such
valve 4 to be open during of each revolution of the cam shaft. The figures
and which I have employed in the following descriptions of the cams for
operating the air and gas inlet valves and the exhaust valves and the transfer
valve respectively refer to what may be called the simple cycle illustrated in the

page_text: diagrams Figures 1 to 7 inclusive, but I would have it understood that I do not
confine myself to the said figures, and as they may in practice be con-
siderably varied and will be necessarily affected by the amount of clearance allowed
in the cylinders and by the pressure desired and by the relative capacities of the
two cylinders as above described.
In Fig. 13 the slide 5 is provided with a small hole or port so that when the
slide is moved into the position shewn in the drawing a portion of the compressed
combustible mixture of gas and air contained in the cylinder 3 may pass by the
port 8 through the port in the slide 5 and through a port formed in the back plate
or cover 6 into the interior of the tube 7 which tube is closed at its other end and
is kept heated so as to be incandescent by the gas flame issuing from a suitable
burner 9 and by means of a muffle 10 In passing into the tube 7 the combustible
mixture above mentioned will become ignited and will afterwards ignite the
combustible charge in the cylinder 3.-The form of igniter above described is well
known but I would have it understood that I do not confine myself to the use of
such form of igniter as other forms of igniter may be employed if desired.
Figures 15. 16. and 17 are respectively a vertical section, plan and horizontal
section showing the additions and modifications necessary to be used when it is
desired to distribute more equally the work produced by the ignition of each
charge. In this arrangement an air inlet valve 1 communicates by means of a port
with the annular space around the trunk of the piston 2. At 3 is a back pressure
valve also communicating with the annular space and opening into the pipe 4
which pipe leads to the reservoir 5 which reservoir is formed as an annular
chamber around the ignition cylinder. The transfer valve 7 is modified by the
formation therein of a cavity 8 as shewn in Fig. 17 which cavity 8 serves to put
the reservoir 5 into communication with the ignition cylinder by means of the
port 9 The reservoir 5 is required to be put in communication with the ignition
cylinder just at the time when the valve 7 must close the port thoroughfare or
passage connecting the two cylinders so that if the plug 7 be caused to turn
through a slightly larger angle than is required for the purpose of opening and
closing the port thoroughfare or passage such plug valve 7 may in this modification
serve both for the purpose of opening and closing the said port thoroughfare or
passage and for putting when required to do so the reservoir 5 into communication
with the ignition cylinder.
The air inlet valve 1 (Fig. 16) may be actuated by a cam mounted fast upon the
shaft 16 which cam must be of a configuration such that it will close the valve 1
during one quarter of each revolution of the cam shaft 16.
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. A gas motor engine having two cylinders one of which is used to compress
the charge whilst both are acted upon simultaneously by the ignited charge
substantially as described.
2. A gas motor engine having two cylinders communicating by a port or passage
controlled by a valve one of which serves as a charge cylinder and the other as an
ignition cylinder and arranged so as to employ the cycle of operations bereinbefore
described wherein the combustible charge after being drawn into the charge
cylinder is compressed and transferred to the other cylinder where it is ignited
and the pressure so obtained is allowed to act at or immediately after ignition
simultaneously on both pistons in the manner and for the purposes hereinbefore
described and illustrated in Figures 1 to 7.
3. A gas motor engine having two cylinders arranged so that both pistons
receive the full pressure (or thereabouts) due to the ignition of the charge and the
ignited charge is allowed to expand in the cylinders to a volume greater than the
volume which it originally occupied at atinospheric pressure substantially as
hereinbefore described.

page_text: 4. A gas motor engine having two cylinders constructed arranged and operating
in such a manner that a combustible charge drawn in during one instroke of one
of the pistons may be compressed by one or by both pistons conjointly and ignited
and that the increased pressure due to ignition may act at or immediately after
ignition on both pistons substantially as described.
5. A gas motor engine arranged so that the ignition of the charge takes place
behind a piston which is moving forward and has already advanced some distance
along the cylinder at the moment of ignition whilst by means of a second piston
operated upon simultaneously with the first the required expansion of the ignited
charge is secured substantially as described.
6. The general construction and arrangement of a gas motor engine substantially
as herein before described and illustrated by the drawings.
The following clerical errors in the original Specification having been
amended by the Patentee, with the consent of the Comptroller, the. Printed
Specification will now read as shown below:-
Page 5, line 27.
For loosened." read lessened.