Year: 1897

page_text: I, PIERRE JOSEPHI RAVEL, of 7, Rue Fromentin, Paris, in the Republic of France,
Engineer, do hereby declare the nature of this invention to be as follows:-
According to this invention two gas-motor cylinders, parallel and of the same
diameter have their pistons connected with one and the same crank; the fore part
of the cylinders and the fore part of the pistons constitute a duplex suction and
force pump body, the volume produced by this pump is thus twice that produced
by the downward thrust of one of the pistons. If then, at each revolution of the
machine, the volume of air or a mixture is conducted above, that is to say behind
one of the pistons, the vacuum produced by the descent of the receiving piston
will not only be completely filled, but there will also be an excess capable of
entirely discharging the residues of the previous combustions.
In this manner the maximum of useful effort or force is obtained from the
cylinders, thereby rendering it possible, 1st, to reduce, to the lowest possible limit,
the volume and weight of these cylinders, and 2nd, to impart a high speed to the
pistons and consequently make it practicable to apply motors of this type to the
different descriptions of motor vehicles.
The motor constructed according to this invention comprises two cylinders in
which are arranged pistons the connecting rods of which are attached to the pins
upon the three crank discs, the latter being rigidly fixed to the driving shaft.
The central crank disc is only an intermediate disc intended to fill as exactly
as possible the space between the outside discs. The crank pins or journals are
fixed at the same angle, forming thus a single crank and consequently the bottoms
of the two pistons work together parallel in the same plane.
The cylinders are mounted, and fixed upon a hermetically closed drum, or casing
which contains the crank discs. The faces of this drum likewise serve as bearings
for the driving shaft.
The admission chest contains a suction valve, and a force or delivery valve.
In the opening of this chest above the suction valve is provided a throttle valve
which is actuated by the centrifugal governor.
The lower part of the suction valve is in free communication with the atmo-
sphere, it is here that the air required for the explosive mixture is drawn in.

page_text: In this manner the front portion of the driving pistons form with the volume
of the drum and the chest, a suction and force pump the volume produced by which
is twice that produced by the descent or forward stroke of one of the pistons.
On the admission chest is arranged a cock provided with a small suction valve.
This cock is mounted upon the said chest above the suction valve. It is through
this cock that the gases forming the explosive mixtures are drawn; the cock thus
serves to regulate the admission of these gases.
Connected with the cylinders are the boxes containing the distributing valves.
The lower portion of these valves is in communication with the admission chest
by means of a pipe or conduit which opens above the force or delivery valve.
Connected also to the cylinders are the boxes containing the discharge valves.
The lower part of the discharge valves communicates freely with the atmosphere.
Upon the fore part of the driving shaft is mounted a pinion driving a train of
gear wheels imparting rotary motion to a cross shaft. This shaft should make
only one revolution whilst the driving shaft makes two revolutions. Upon this
shaft are mounted two cams actuating the discharge valves.
Upon the rear extremity of the cross shaft is mounted a double counter bent
crank intended to impart the same movement of rotation to a second cross shaft
on the opposite side upon which are mounted two distributing cams.
The ignition of the explosive mixture may either be effected by means of an
electric spark passing in the distributing boxes, or by means of incandescent tubes
terminating also in the distributing boxes, in either case in the usual manner.
In cases in which it is not desired to enclose the cranks and connecting rods
within a drum, it will suffice if the fore end of the cylinder is closed by plates
through which pass the piston rods, and if communication is provided at this
extremity between the cylinders in such a manner that the fore parts of the two
pistons and of the two cylinders always form a double pump body communicating
always with one or even two admission chests, according to the size of the motor.
The principle of the motor is not thereby affected in any way.
It will be understood that according to the different applications of this type of
motor, the cylinders may be either vertical, horizontal, or even oblique, but they
must invariably be parallel, and their pistons act in the manner described in this
specification.
In cases in which the motor is driven by gas already prepared, lighting gas for
example, the method of action is as follows:-
-
The two pistons rise together, drawing in through the admission chest the air
and gas forming the explosive mixture. Then the pistons in descending force this
mixture into one of the distributing boxes and consequently above the piston
corresponding to this box. This piston therefore receives the charge of the mixture
supplied by the pump.
In rising, this piston compresses the charge of the mixture which is ignited
either by means of an electric spark or incandescent tube.
The two pistons thus alternately receive above them the charge of explosive
mixture. There is therefore an explosion of the mixture for each revolution of the
machine.
The actuation of the discharge valves also takes place alternately, that is to say,
at each revolution of the engine one of the discharge valves rises in order to allow
the products of combustion to escape into the atmosphere.
When the motor is driven by means of hydrocarbons, the cock on the admission
chest with its valve is dispensed with and consequently the pump only sucks in
and forces atmospheric air. The force pipe or conduit may divide into two
portions, one of which conducting pure air, opens directly beneath the distributing
valves, the other portion of the conduit connects with a carburetor and in this case
the air is carburetted under slight pressure and not by suction.
It may nevertheless so happen that the carburetor employed is constructed in
such a manner that the air to be carburetted is drawn into it by suction. In this

page_text: case the outlet for the carburetted air would enter the admission chest passing
through the regulating cock.
The mixture will then be formed entirely in the pump body and the charge of
the mixture would pass as above described through the conduit entering the
distributing boxes alternately.
It should be remarked that in all cases, when the contents of the two cylinders
consisting of air or of explosive mixture produced by the front of the piston, that is to
say by the pump, are forced above one of the pistons, this latter performs its function
in the reverse direction, that is to say, the space situated above it increases in the
same proportion as the forcing of the air or mixture contained in the cylinder
which are supplied by the pump.
Owing to this fact there is no need of intermediate reservoirs and regularity in
the admission and distribution of the explosive mixture is obtained.
When the engine has a tendency to run at too great a speed, the centrifugal
governor closes to a greater or less extent the throttle valve; the suction then
becomes less strong and consequently the volume of air or of explosive mixture
which is drawn in decreases. The volume of the charge of the explosive mixture
thus varies according to the speed and the force employed.
Dated this 20th day of November 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings London, W.C.,
Agents for the Applicant.
I, PIERRE JOSEPH RAVEL, of 7, Rue Fromentin, Paris, in the Republic of France,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:-
According to this invention the motor comprises two cylinders which are arranged
parallel one with the other and of the same dimensions; the two pistons being
connected with the same crank. This latter rotates in a closed space forming the
front of the cylinders, the whole constituting a suction and force pump, the double
piston of which is formed by the front faces of the pistons.
The volume created by the action of this pump is thus double that formed by the
descending stroke of one of the pistons in one of the cylinders.
Consequently, if at each revolution of the motor, the gaseous volume filling the
front closed portion, that is to say the pump, is sent behind one of the pistons,
that is to say into the cylinder properly so called there will be not only a perfect
filling of the cylinder space, but also, owing to the excess supplied by the pump,
there will be gas in sufficient quantity to take the place of the residues of the
previous combustions and to discharge them.
In this manner the maximum of useful effort or force is obtained from the
cylinders, thereby rendering it possible; 1st, to reduce, to the lowest possible limit,
the volume and weight of these cylinders, and 2nd, to impart a high speed to the
pistons and consequently make it practicable to apply motors of this type to the
different descriptions of motor vehicles.
In the accompanying sheet of drawings
Figure 1 is a vertical section upon the axis of the two cylinders and of the
driving shaft.
Figure 2 is a vertical section upon the axis of one of the cylinders at right
angles to Figure 1.

page_text: Figure 3 is an elevation upon the transmitting side with the mechanism for
the rods of the exhaust and distributing valves.
Figure 3 is a detail section through the gearing.
Figure 4 is an elevation upon the opposite side to that shown in Figure 3.
Figure 5 is a side elevation upon the side on which are the distributing chests
and
Figure 6 is a side elevation upon the side on which are the exhaust valve
chests.
In the motor constructed according to this invention A and B are the cylinders
of the motor; in which are arranged pistons the connecting rods of which are
attached to the pins upon the three crank discs a be the latter c and a being rigidly
fixed to the driving shaft E EL.
The central crank disc b is only an intermediate disc intended to fill as nearly as
possible the space between the outside discs a and c. The crank pins or journals
are fixed at the same angle, forming thus a single crank and consequently the
bottoms of the two pistons work together parallel in the same plane.
The cylinders A and B are mounted and fixed upon an hermetically closed
drum For casing which contains the crank discs. The faces of this drum likewise
serve as bearings for the driving shaft E E¹.
G Figures 1, 3, and 5, is the admission chest containing a suction valve
force or delivery valve h.
and a
In the opening of this chest above the suction valve is provided a throttle
valve P which is actuated by the centrifugal governor H Figures 3 and 5.
The lower part of the suction valve is in free communication with the atmo-
sphere it is here that the air required for the explosive mixture is drawn in.
In this manner the front portion of the driving pistons C and D) form with the
volume of the drum F and the chest G, a suction and force pump the volume
produced by which is twice that produced by the descent or forward stroke of one
of the pistons.
On the admission chest is arranged a cock R provided with a small suction
valve l. This cock is mounted upon the said chest G above the suction valve g.
It is through this cock that the gases forming the explosive mixtures are drawn;
the cock R thus serves to regulate the admission of these gases.
Connected with the cylinders are the boxes K and K containing the distributing
valves m and m³ Figure 2. The lower portion of these valves is in communication
with the admission chest G by means of a pipe or conduit L Figures 3 and 4 which
opens above the force or delivery valve h.
Connected also to the cylinders are the boxes M & M containing the discharge
valves and Figure 2. The lower part of the discharge valves communicates
freely with the atmosphere.
The distributing and exhaust boxes are arranged symmetrically upon each side
of the cylinder thereby avoiding proximity to gaseous columns of pure mixture and
of the burned residues and assuring the presence in the distributing boxes where
ignition takes place of a mixture which is readily ignited.
Upon the fore part of the driving shaft is mounted a pinion N Figures 3
and 3 driving a train of gear wheels imparting rotary motion to the cross shaft 0.
This shaft O should make only one revolution whilst the driving shaft makes
two revolutions. Upon this shaft are mounted two cams p and p Figures 4
and 6 actuating the discharge valves.
Upon the rear extremity of the cross shaft is mounted a double counter bent
crank intended to impart the same movement of rotation to a second cross shaft ()¹
Figures 4 and 5 on the opposite side upon which are mounted two distributing
cams q and q¹.
The ignition of the explosive mixture may either be effected in the usual manner
by means of an electrical device in the distributing boxes, or by means of
incandescent tubes y terminating also in the distributing boxes.
In cases in which it is not desired to enclose the cranks and connecting rods

page_text: within a drum, it will suffice if the fore end of the cylinder is closed by plates
through which pass the piston rods, and if communication is provided at this
extremity between the cylinders in such a manner that the fore parts of the two
pistons and of the two cylinders always form a double pump body communicating
always with one or even two admission chests, according to the size of the motor.
The principle of the motor is not thereby affected in any way.
It will be understood that according to the different applications of this type of
motor, the cylinders may be either vertical, horizontal or even oblique, but they
must invariably be parallel, and their pistons act in the manner described in this
specification.
In cases in which the motor is driven by gas already prepared, lighting gas for
example, the method of action is as follows:
The closed space formed between the front portion of the pistons and the whole
of the recess of the crank box serves for sucking in a charge of gas corresponding
to the supply of one cylinder only.
If we suppose the motor to be in motion when the two pistons C and D rise, they
draw in through the admission chest G a certain quantity of explosive mixture;
when the two pistons descend this volume of gas is sent to one of the cylinders, A for
example within the space which is formed behind the piston C owing to its forward
displacement. Upon the two pistons C and D again rising, the gas is compressed
with the cylinder in question A and at the end of the stroke ignition is effected,
the explosion takes place and the pistons are driven forward. When this last
movement of rise and descent takes place, a fresh charge of gas is drawn into the
space formed in front of the pistons and then forced into the other cylinder B
owing to appropriate action of distributing valves; the piston rising in the first
cylinder A the expulsion of the gases is effected whilst in the second cylinder B
the gaseous mixture is compressed. When the two pistons again descend the first
cylinder A receives a charge of gas whilst in the second cylinder B and explosion
takes place and so on in succession. There is thus an explosion for each revolution
of the engine. The distributing cams are of course adjusted so as to send the
charge of gas either into one or other of the cylinders according to the phase of the
rotation.
When the motor is driven by means of hydrocarbons, the cock on the admission
chest with its valve is dispensed with and consequently the pump only sucks in
and forces atmospheric air. The force pipe or conduit L may divide into two
portions, one of which conducting pure air, opens directly beneath the distributing
valves m and m¹; the other portion of the conduit L connects with a carburetor
and in this case the air is carbureted under slight pressure and not by suction.
It may nevertheless so happen that the carburetor employed is constructed in
such a manner that the air to be carbureted is drawn into it by suction. In this
case the outlet for the carbureted air would enter the admission chest G passing
through the regulating cock R.
The mixture would then be formed entirely in the pump body and the charge
of the mixture would pass as above described through the conduit L entering the
distributing boxes K and K alternately.
It should be remarked that in all cases, when the contents of the two cylinders,
consisting of air or of explosive mixture produced by the front of the piston, that
is to say by the pump, are forced above one of the pistons, this latter performs its
function in the reverse direction, that is to say the space situated above it increases
in the same proportion as the forcing of the air or mixture contained in the
cylinders which are supplied by the pump.
This relation between the forcing of the gas by the front portion of
rear portion of this latter,
the piston and its admission through the
that is to say into the cylinder, always remains constant since it is the same part
(the piston) which causes by its displacement the variation of the volume of the
two spaces the cylinder properly so called and the crank box; this relation cannot

page_text: exist with the same certainty when separate gas pumps are employed, as is some-
times the case.
Owing to this fact there is no need of intermediate reservoirs and regularity
in the admission and distribution of the explosive mixture is obtained.
When the engine has a tendency to run at too great a speed the centrifugal
governor H closes to a greater or less extent the throttle valve P; the suction then
becomes weaker and consequently the volume of air or of explosive mixture which is
drawn in decreases. The volume of the charge of the explosive mixture thus varies
according to the speed and the force employed.
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 arrangement of two equal cylinders, the pistons of which, actuated by the
same crank arranged in a drum, form a pump body.
2. The method of admitting the air or explosive mixture consisting in the
suction of a double charge of air or mixture, forcing it above, that is to say behind,
one of the pistons in such a manner as to obtain the maximum of pure mixture for
the explosion.
3. The arrangement of distributing and exhaust boxes characterised by the
symmetrical disposition of the same upon each side of the cylinder, thereby avoid-
ing proximity to gaseous columns of pure mixture and of the burned residues and
assuring the presence in the distributing boxes where ignition takes place of a
mixture readily ignited, substantially as described with reference to the drawing.
4. In the motor described in Claims 1 and 2 the modification which, in cases in
which it is not desired to enclose the connecting rods and the cranks in an envelope
into which the cylinders open, consists in closing the front of these latter and
establishing communication between them upon this side in order to form a double
pump body, communicating with the admission box or boxes.
5. The improved gas or like engine substantially as hereinbefore described and
shown in the drawing.
Dated this 20th day of d 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.