Improvements in and connected with Gas and Hydrocarbon Engines.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with Gas and Hydrocarbon Engines.
We, ETIENNE PETRÉANO and JOSEPH BONNET, both of 95, Boulevard Beaumar-
chais, Paris, France, Engineers, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to gas and hydrocarbon engines, and its object is
to allow of working either backwards or forwards and of simply and rapidly
reversing such engines from forward to backward working and vice versa.
In the engines for which the present invention has been more especially
designed, the mode of regulation consists in principle in acting by means of
the governor so as to admit a variable volume of a previously produced explosive
mixture but with constant compression, and this while regulating by the governor,
not only the admission valve, but also the exhaust valve.
In engines of this type, when the normal speed of the motor increases, the
governor by the aid of appropriate cams closes the admission and opens
the exhaust during for example a fifth of the suction stroke of the piston; then the
exhaust closes, and at this moment the admission of the previously produced explo-
sive mixture opens during the other four-fifths of the stroke of the piston, so as
to fill the remaining space in the cylinder with the previously produced mixture,
after which the admission valve closes. If for any reason the speed of the engine
exceed the maximum, the governor, completely closing the admission of the mix-
ture, fully opens the exhaust.
It will be conceived that with this mode of regulation whatever be the charge
(empty, quarter, half, three-fourths, or full) the speed of the motor will remain
constant, because it is regulated by the governor.
According to the present invention, we obtain reversal of the engine as before
stated by simply adapting the cams which actuate the rollers of the valves, to be
displaced relatively to the shaft which carries them, all the other parts remaining
fixed and serving indifferently, in the same conditions, for the forward working
and for the backward working. The cams will be simply displaced, but they will
serve in both directions of working to actuate the rollers of the valves.
In four-time motors as is known, the four stages starting from the dead point
are the following:-

page_text: 3. Explosion and retention;
4. Exhaust.
By means of the improvements which we have produced in the method of regu-
lation above indicated, and by the simple displacement of the cams as described,
we are enabled to preserve the four stages in the same order both in forward
working and in backward working. This change of direction is impossibie in
nearly all motors hitherto constructed, and in those in which it is possible it
necessitates a fresh governor shaft as well as fresh rollers with the levers con-
trolling the valves. The change of governor shaft with its regulating cams
necessitates a partial dismounting of the motor, and consequently involves great
loss of time.
It is even necessary in this case to change the direction of the
governor.
By the present invention, the governor shaft, the governor, the rollers and the
levers which actuate the rollers of the admission and exhaust valves, as well as
the cams, serve in both cases, for forward working and backward working; we
thus add no part and we eliminate no part; all the parts preserve the same res-
pective positions in both directions of working except. the cams, which as before
stated we slightly displace relatively to their shaft. This is the only operation
which has to be effected to produce reversal of the engine, and it is an operation
which by reason of its simplicity can be effected by any workman almost instan-
taneously.
In carrying our invention into effect, we employ four cams, which for simplicity
we will call 1, 2, 3, 4, these cams being relatively situated in the order 1, 3, 2, 4.
The two cams 3 and 4 are mounted permanently upon a casing or tube which
surrounds the end of the governor shaft. The two other cams 1 and 2 are, mounted
loosely on this casing, but they can be made a fixture to the intermediately
situated cam 3 by means of two transverse pins adapted to engage in holes herein-
after described, said pins being so disposed that cams 1 and 2 may be simul-
taneously secured with the intermediate cam 3. The first or outermost of the said
pins penetrates in a constant manner into a hole formed in cam 1. If in conse-
quence of the rotation of cam 3, a hole in the said cam is presented behind the said
hole in cam 1 the first pin will be able to engage and secure cam 1 with cam 3,
but at this moment, in consequence of the immobility of cam 2 which does not
rotate and which is held by its roller, a hole formed in this cam will be behind
the said hole in cam 3 in such manner that the pin will render cams 1 and 2
simultaneously fixtures with cam 3. As we shall see later on, this position will
give us a position of cams 1 and 2 for one direction of working.
What we have just stated as to the first or outermost pin applies absolutely to
the second or innermost pin, which is adapted to engage with three other holes
formed respectively at suitable points in cams 1, 3 and 2. When the second pin
passes through these three holes we have for cams 1 and 2 a new position which
corresponds to the other direction of working.
We will now proceed to explain how the pins may be caused to engage with
the different holes above referred to.
Each of the pins is under the action of a spring which tends to cause it to
become disengaged from the holes in the cams and to press the pins respectively
against two rings. These rings completely surround the casing on which the
cams are mounted but have no point of support thereon. They are respectively
carried by two bolts which can be moved in lateral slides disposed at each side of
the apparatus. The bolt which carries the ring which corresponds to the outer-
most pin is provided with a lever which permits the attendant of the motor to
more or less advance or draw back the said bolt so as to bring the said ring more
or less near to the first cam. The bolt which carries the ring corresponding with
the inner pin is fixed to a lever which permits of acting upon the said bolt to

page_text: bring the said ring towards cam 1. The effect of bringing the ring corresponding
with the outer pin towards cam 1 is, as will be understood, to push the outermost
pin towards cam 1, and this pin will engage with its holes as above described,
if these latter are at this moment opposite each other. In the same way the
bringing of the ring of the inner pin towards cam 1 has the effect of introducing
this pin into its holes as above described if these latter are also opposite each other.
In order to fix the two rings in the desired positions, their levers may be adapted
to be put over into notches formed in the edges of the slides in which the bolts
carrying the rings move. In order that the movement of the bolts may produce
the movements of their rings normally to the shaft, we secure each bolt to two dia-
metrically opposite points of the corresponding ring by bars, one of which bars, that
of the bolt corresponding to the outermost pin, is bent doubly,. and the other, that
of the other bolt, is an arc of a circle.
The penetration into the corresponding holes of cams 1, 3 and 2 of one or other
of the two pins produces working in the determined direction. Hence it follows
that it is indispensable that the two pins shall not be able to become inserted at
the same time, otherwise they would not produce the result desired. This simul-
taneous penetration of the two pins is rendered impossible by the relative posi-
tions of the two sets of holes formed in the different cams and by the different
distances of the pins from the axis of the governor shaft. We so adjust these
positions and distances that if the holes corresponding to the outermost pin are
opposite one another, the hole for the innermost pin in the intermediate cam (3)
will be diametrically opposite the hole for the same pin in the cam 1, and the
radius passing through the corresponding hole in cam 2 will form an angle with
the radius passing through the corresponding hole in cam 1. It will thus be seen
that if the outermost pin penetrates into its three holes, the innermost pin will
only be able to penetrate into the hole in cam 1, and that this pin will produce
no effect, but will be simply carried in the movement of rotation of the cam 1.
In the operation of the motor of the type in question it will be understood that
in consequence of the action of the governor, the four cams as a whole will partake
of a reciprocating movement parallel to the axis of the governor shaft. It is thus
necessary that the whole of the parts which allow of engagement of the pins with
the holes in the cams, shall participate, without opposing resistance, in these
reciprocating movements. To this end, the slides which support the operating
bolts are mounted at each side of a sleeve which has a shoulder adapted to slide
in a fixed slideway. This sleeve is thus enabled under the action of collars or
shoulders which surround it, to participate in the reciprocating movement of the
casing which carries the cams. Further this arrangement has for object, as will
be understood, to prevent the sleeve from participating in the movement of rota-
tion of the casing carrying the cams.
It will be understood that the said casing which is capable of displacement
parallel to the governor shaft, rotates at the same time as this shaft. This result
is attained by means of a key or wedge disposed the whole length of the casing.
Having thus described our present improvements which permit of the reversal
of the engine under the conditions indicated in the opening portion of the present
specification, we will now explain the operation of the apparatus, and in order to
render our explanation as full as possible, we will describe the two cases which
may present themselves in practice, that is to say:-
1. Starting in either direction when the motor is stopped.
2. Reversing when the motor is working.
1. STARTING IN EITHER DIRECTION WHEN THE MOTOR IS STOPPED.
If the motor is stopped and we desire to start it.--In order to produce forward
working, always supposing that the two pins before described are absolutely
pushed by their springs outwardly of the cams, that is to say that they penetrate
respectively only into the holes formed to receive them in cam 1, the holes in the
cam 3 not being opposite the corresponding holes in cam 1,-one attendant actu-
ates the lever corresponding to the bolt and ring of the outermost pin so as to

page_text: bring pressure upon the head of this pin. During this time, another attendant
turns the flywheel of the motor to bring it to its starting position. In this move-
ment of rotation given to the flywheel, cam No. 3, being rigidly secured to the
casing carrying the cams, turns, and at the moment when its corresponding hole
is presented behind the hole for the outermost pin in cam 1, this pin will pene-
trate into the hole in cam 3 in consequence of the pressure exercised by the first
attendant upon the corresponding bolt. Under the action of this pressure the
pin likewise penetrates into the corresponding hole of cam 2 when in consequence
of the rotation of the two cams 1 and 3 the pin comes opposite the last named hole.
This coincidence will be produced, if not at the first rotation, yet certainly at the
second, because cam No. 2 being supported by the roller cannot turn.
The outermost pin will thus be pushed to the bottom of the three holes in ques-
tion and the parts will be ready for the forward working, which is immediately
produced, the cams acting as though they were all four keyed upon the casing.
We will now take the case in which, the motor being stopped, it is required to
produce backward working. Under these conditions, we effect the same operations
with the innermost pin and the corresponding set of holes in the cams as we have
just effected with the outermost pin and the first set of holes, and we shall then
obtain the position of the cams for backward working.
2. REVERSING WHEN THE MOTOR IS WORKING.
Let us suppose that the motor is working forward, the outermost pin rendering
the cams Nos. 1 and 2 a fixture with the intermediate cam No. 3. The operations
which should be effected to reverse will be as follows:-
At the moment when this change has to be effected, the lever of the bolt con-
trolling the outermost pin is actuated so as to draw back this bolt and consequently
to cause said pin to leave the holes of the cams. Cams Nos. 1 and now run
loose, since they are no longer driven by the fixed cam.3; they thus act no longer
upon the rollers and there is no longer admission or exhaust. The piston then
works in vacuo and the speed of the motor slackens pretty rapidly. When this
speed has become sufficiently slow to allow of noting the phases of the motor, the
lever is again actuated so as to again insert the outermost pin into the holes from
which it has just been withdrawn, and this insertion should be very rapid and
last only for the time necessary to produce an admission. This done, the said
pin is sharply withdrawn from cam 2..
Assuming the motor to be now running at a low speed, the explosion which is
going to be produced will be a forward explosion, and the motor will sharply
change its direction of working. In order that the following explosions shall be
produced in the desired direction of working it is necessary that as soon as the
outermost pin has been withdrawn for the second time by acting upon the cor-
responding lever, the other lever should be actuated so as to bring pressure upon
the innermost pin which will penetrate into its holes as soon as these latter come
opposite one another in consequence of the change of working. The explosions
will be produced in a regular manner and reversal of the engine has now been
effected. The same operations will have to be gone through, but in the contrary
direction if it be required to pass from backward working to forward working.
For entire certainty when the reversal takes place during the working of the
motor, we open to its full extent the cock which puts the explosion chamber in
communication with the atmospheric air, the opening of this cock facilitating the
change of working of the motor.

page_text: Improvements in ana connected with Gas and byurocarion
We, ETIENNE PETREANO and JOSEPH BONNET, both of 95, Boulevard Beaumar-
chais, Paris, France, Engineers, 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:
-
This invention has reference to gas and hydrocarbon engines, and its object is
to allow of working either backwards or forwards and of simply and rapidly
reversing such engines from forward to backward working and. vice versa.
In the engines for which the present invention has been more especially
designed, the mode of regulation consists in principle in acting by means of
the movements of their rings normally to the shaft, we secure each bolt to two dia-
metrically opposite points of the corresponding ring by bars, one of which bars, that
not only the admission valve, but also the exhaust valve.
opens
In engines of this type, when the normal speed of the engine increases, the
cams closes the admission and
governor by the aid of appropriate
the exhaust during for example a fifth of the suction stroke of the piston; then the
exhaust closes, and at this moment the admission of the previously produced explo-
sive mixture opens during the other four-fifths of the stroke of the piston, so as
to fill the remaining space in the cylinder with the previously produced mixture,
after which the admission valve closes. If for any reason the speed of the engine
exceed the maximum, the governor, completely closing the admission of the mix-
ture, fully open's the exhaust.
It will be understood that with this mode of regulation whatever be the charge
(empty, quarter, half or three-fourths or quite full) the speed of the engine will
remain constant, because it is regulated by the governor.
According to the present invention, we obtain reversal of an engine of the kind
above referred to by simply adapting the cams which actuate the rollers of the
valves, so that they can be displaced relatively to the shaft which carries them,
all the other parts remaining fixed and serving indifferently, in the same condi-
tions, for the forward working and for the backward working. The cams will be
simply displaced, but they will serve in both directions of working to actuate the
rollers of the valves.
In four-stroke cycle engines as is. known, the four stages starting from the
dead point are the following:
1 Admission.

page_text: levers which actuate the rollers of the admission and exhaust valves, as well as
the cams, serve in both cases, for forward working and backward working; we
thus add no part and we eliminate no part; all the parts preserve the same re-
spective positions in both directions of working except the cams, which as before
stated we slightly displace relatively to their shaft. This is the only operation 5
which has to be effected to produce reversal of the engine, and it is an operation
which by reason of its simplicity can be effected by any workman almost instan-
taneously.
For the purpose of enabling our invention to be more clearly understood we
shall now proceed to describe by way of example a convenient arrangement of l
apparatus illustrating its application, with reference to the accompanying drawings
in which
Figure is a side elevation of the cam mechanism of a gas engine of the type
hereinbefore referred to, only so much being shown as is necessary for the under-
standing of our invention.
Figure 2 is an end view of Figure 1.
Figure 3 is a partial longitudinal section of Figure 1.
Figure 4 shows diagrammatically the positions of the movable admission and
exhaust cams 1 and 2 for forward working.
Figure 4" shows diagrammatically the positions of the same cams for backward 2
working.
Figure 5 is a side elevation of the movable exhaust cam 1.
Figure 5 is a side elevation of the disc 3.
Figure 5 is a side elevation of the movable admission cam 2.
and
In carrying our invention into effect, we employ two movable cams 1,
a fixed disc 3, relatively situated in the order 1, 3, 2. The disc 3 is mounted
permanently upon a sleeve or tube 11 which surrounds the end of the cam shaft 12.
The exhaust cam 1 and the admission cam 2 are mounted loosely on this sleeve,
but they can be made a fixture to the intermediately situated disc 3 by means of
two pins 13 and 14 adapted to engage in holes provided as hereinafter described
in the three parts 1, 2, 3 in such a manner that cams 1 and 2 may be simultane-
ously secured to the intermediate disc 3. The pin 13 penetrates constantly a
hole 5 formed in cam 1. When in consequence of the rotation of disc 3, a hole 10
in the said disc is presented behind the said hole 5 in cam 1, the pin 13 will be
able to engage therein and thus secure cam 1 with disc 3, but at this moment,
in consequence of the immobility of cam 2 which does not rotate and which is
held by its roller, a hole 7 formed in the cam 2 will be behind the hole 10 in
disc 3 in such manner that the pin 13 will render cams 1 and 2 simultaneously
fixtures with disc 3. As we shall see later on, this position will give us a position
of cams 1 and 2 for one direction of working.
What we have just stated as to the pin 13 applies similarly to pin 14, which is
adapted to engage with three other holes 6, 9 and 8 formed respectively in the
parts 1, 3 and 2.
When the pin 14 passes through these three holes we have for
cams 1 and 2 a new position which corresponds to the other direction of working.
We will now proceed to explain how the pins may be caused to engage with
the different holes above referred to.
.
Each of the pins is under the action of a spring which tends to cause it to
become disengaged from the holes in the cams and the disc and to press the pins
respectively against two rings 15 and 16. These rings 15 and 16 completely
surround the sleeve 11 on which the cams and the disc are mounted but have no
point of support thereon. The rings 15 and 16 are respectively carried by two
bolts 17 and 18 which can be moved in lateral slides 19 and 20 disposed at each
side of the apparatus. The bolt 17 which carries the ring 15 is provided with a
lever 21 which permits the attendant of the engine to more or less advance or draw
back the bolt 17 so as to bring the ring 15 more or less near to the first cam.
The bolt 18 which carries the ring 16 is fixed to a lever 22 which permits of acting
upon the bolt 18 to bring the ring 16 towards cam 1. The effect of bringing
4

page_text: the ring 15 towards cam 1 is, as will be understood upon examination of Figure 1,
to push the pin 13 towards cam 1, and this pin will engage with its holes as above
described, if these latter are at this moment opposite each other. In the same
way the bringing of the ring 16 towards cam 1 has the effect of introducing the
pin 14 into its holes as above described if these latter are also opposite each other.
In order to fix the two rings 15 and 16 in the desired positions, their levers 21
and 22 may be adapted as shown in Figure 2 to be put over into notches formed
in the edges of the slides in which the bolts carrying the rings move.
In order
that the movement of the bolts may produce the movements of their rings 15
and 16 askew relatively to the shaft 12, we secure each bolt to two diametrically
opposite points of the corresponding ring by bars, one of which bars, namely the
bar. 23 of the bolt 19, is bent doubly & the other namely the bar 24 of the bolt 18,
is an arc of a circle as shown in Figure 2.
The penetration into the corresponding holes of the parts 1, 3 and 2 of one or
other of the two pins 13, 14 produces working in the determined direction. Hence
it follows that it is indispensable that the two pins shall not be able to become
inserted at the same time, otherwise they would not produce the result desired.
This simultaneous penetration of the two pins is rendered impossible by the rela-
tive positions of the holes formed in the different cams and disc and by the
different distances of the pins from the axis of the shaft 12. We so adjust these
positions and distances that as indicated by Figures 5, 5º, 5º, if the holes 5, 10
and 7 are opposite one another, the hole 9 in the intermediate disc (3) will be
diametrically opposite the hole 6 for the same pin in the cam 1. It will thus be
seen that if the pin 13 penetrates into the three holes 5, 10 and 7 the pin 14 will
only be able to penetrate into the hole 6 in cam 1, and that this pin 14 will produce
no effect, but will be simply carried in the movement of rotation of the cam 1.
In the operation of the motor of the type in question it will be understood that
in consequence of the action of the governor, the cams and disc as a whole_will
partake of a reciprocating movement parallel to the axis of the shaft 12. It is
thus necessary that the whole of the parts which allow of engagement of the pins
with the holes in the cams and disc shall participate, without opposing resistance,
in these reciprocating movements. To this end, the slides 19 and 20 which sup-
port the operating bolts are mounted at each side of a bearing 30 (Figure 3) which
has a foot 31 adapted to slide in a fixed slideway 32. This bearing 30 is thus
enabled under the action of collars or shoulders 33, 34 which surround it, to
participate in the reciprocating movement of the sleeve 11 which carries the cams
and disc. Further this arrangement has for object, as will be understood, to pre-
vent the bearing 30 from participating in the movement of rotation of the
sleeve 11.
It will be understood that the said sleeve 11, which is capable of displacement
parallel to the cam shaft 12 rotates at the same time as this shaft. This result
is attained by means of a feather key (not shown) disposed the whole length of
the sleeve.
Having thus described our present improvements which permit of the reversal
of the engine under the conditions indicated in the opening portion of the present
specification, we will now explain the operation of the apparatus, and in order to
render our explanation as full as possible, we will describe the two cases which
may present themselves in practice, that is to say:-
1. Starting in either direction when the engine is stopped.
2. Reversing when the engine is working.
1. STARTING IN EITHER DIRECTION WHEN THE ENGINE IS STOPPED.
If the engine is stopped and we desire to start it. In order to produce forward
working (Figure 4), always supposing that the two pins 13 and 14 are pushed
by their springs outwardly of the cams and disc, that is to say, that they pene-
trate respectively only into the holes 5 and 6 formed to receive them in cam 1,
the holes and 10 in the disc 3 not being opposite the corresponding holes 5 and 6
in cam 1, one attendant actuates the lever 21 so as to bring pressure by means of

page_text: the bolt 17 and the ring 15 upon the head of the pin 13. During this time,
another attendant turns the flywheel of the engine to bring it to its starting posi-
tion. In this movement of rotation given to the flywheel, the disc 3, being rigidly
secured to the sleeve 11, turns, and at the moment when its corresponding hole 10
is presented behind the hole 5 the pin 13 will penetrate into the hole 10 in disc 3
in consequence of the pressure exercised by the first attendant upon the corres-
ponding bolt 17.
Under the action of this pressure the pin likewise penetrates
into the corresponding hole 7 of cam 2 when in consequence of the rotation of
cam 1 and disc 3, the pin 13 comes opposite the hole 7. This coincidence will
be produced, if not at the first rotation, yet certainly at the second, because cam 2,
being supported by the roller cannot turn.
The pin 13 will thus be pushed to the bottom of the three holes 5, 10 and 7
and the parts will be ready for the forward working, which is immediately pro-
duced, the cams and the disc acting as though they were all three keyed upon the
casing as indicated in Figure 4.
We will now take the case in which, the engine being stopped, it is required to
produce backward working. Under these conditions, we effect the same operations
with the pin 14 and the corresponding set of holes 6, 9 and 8 in the cams and disc
as we have just effected with the pin 13 and the first set of holes 5, 10 and 7 and
we shall then obtain the position of the cams for backward working as indicated
in Figure 4. .
2. REVERSING WHEN THE ENGINE IS WORKING.
Let us suppose that the engine is working forward, the pin 13 rendering the
cams 1 and 2 a fixture with the disc 3. The operations which should be effected
to reverse will be as follows:
At the moment when this change has to be effected, the lever 21 is actuated so
as to draw back the bolt 17 and consequently to cause the pin 13 to leave the
holes of the parts 1, 3, 2. Cams 1 and 2 now run loose, since they are no longer
driven by the fixed disc 3; they thus act no longer upon the rollers and there is
no longer admission or exhaust. The piston then works in vacuo and the speed
of the engine slackens pretty rapidly. When this speed has become sufficiently
slow to allow of noting the phases of the motor; the lever 21 is again actuated so as
to again insert the pin 13 into the holes 5, 10 and 7 from which it has just been
withdrawn, and this insertion should be very rapid and last only for the time
necessary to produce an admission. This done, the said pin 13 is sharply with-
drawn from cam 2.
Assuming the engine to be now running at a low speed, the explosion which is
going to be produced will be a forward explosion, and the engine will sharply
change its direction of working. In order that the following explosions shall be
produced in the desired direction of working it is necessary that as soon as the
pin 13 has been withdrawn for the second time by acting upon the corresponding
lever 21, the other lever 22 should be actuated so as to bring pressure upon the
pin 14 which will penetrate into its holes as soon as these latter come opposite
one another in consequence of the change of working. The explosions will be
produced in a regular manner, and reversal of the engine has now been effected.
The same operations will have to be gone through, but in the contrary direction,
if it be required to change from backward working to forward working.
For entire certainty when the reversal takes place during the working of the
engine, we open to its full extent the cock which puts the explosion chamber in
communication with the atmosphere, the opening of this cock facilitating the
change of working of the engine.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
-
1. The means whereby a gas or hydrocarbon engine of the kind herein referred
to may be started in either direction or be reversed when in motion which meana

page_text: consist in mounting the admission and exhaust cams loosely upon their shaft in
such a manner as to allow of changing the angular position of said cams on said
shaft so as to suit the direction in which the engine is desired to run, substantially
as herein before described.
2. For carrying out the method of reversing specified in the preceding claim,
the construction and arrangement of parts substantially as described and shown.
Dated this 15th day of March 1898.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.