GAS-MO
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Friedrich von Martini at
the Office of the Commissioners of Patents on the 27th February. 1883.
FRIEDRICH VON MARTINI, of Frauenfeld, in the Republic of Switzerland,
"A NEW GAS-MOTOR,
In gas engines with ordinary crank-motion and compression chamber in which
an ignition takes place after every second rotation of the crank-pin, the suction
stroke is equal to the expansion stroke of the piston.
The result of this is that the expanded gases are discharged with a tension of
still about 2 atmospheres.
The present construction has for its object to utilize the expansion as much as
possible, and for this purpose the engine works with a "specially arranged com-
pression and ignition chamber, in such a manner that the suction and compression
takes place during one rotation of the fly-wheel shaft with a small piston-stroke,
while a complete expansion occurs during the following revolution with large
piston stroke.
In the accompanying drawing which illustrates the invention Fig. I is a
longitudinal section of the cylinder showing also the compression chamber, and
(in diagram) the driving gear, valve gear, and governing mechanism.
Fig. II. serves to explain the governing-mechanism and Fig. III the igniting
mechanism.
The compression chamber 2 forms the continuation of the cylinder 1. Fig. I, and
both are cooled with water.
At the back wall of the compression chamber are situated the inlet-valve 51,
and the ignition valve 61: (Fig İ).
The arriving gases flow first into the mixing chamber m, and passing closely
to the ignition valve, enter the compression chamber through n.
The gases entering the latter are not free to expand over the whole space, but
are guided and kept separate by tubes.

page_text: They enter first the tube 49 (Fig. 1) which is enclosed by a tube 48. Both tubes
are fixed. Tube 48 has at its base several apertures 50. To the piston are attached
two tubes 45 and 46, adapted to move in the tubes 48 and 49 without friction.
The tube 46 is provided near the piston with apertures 47
In consequence of this arrangement the entering gases are compelled to pass first
through the interval tubes 49 and 46, then to pass through the openings 47 into
the outer tubes 45 and 48, from which they escape through the apertures 50.-
before reaching the cooled cylinder walls, the object being to keep the gases
separate instead of mixing them, and to produce a gradual combustion instead of
a sudden explosion.
The gases of combustion passing along the tubes serve to heat the latter and
thereby to heat the newly arriving gases. The heat of the gases of combustion
is also more utilized by expansion, and less heat is wasted for heating the cooling
water.
The driving mechanism connected with the piston consists kinematically of an
isosceles rotating double crank, the small crank 16 serving to turn the flywheel
shaft 17, while the large crank 14 drives the valve-gear-shaft 15.
The two cranks 14 and 16 are connected by the rod 13, the length of which
equals the radius of the larger crank 14.
The distance between the bearings of the two cranks equals the radius of the
smaller crank 16. In this mechanism the small crank 16 makes two revolutions
while the large crank 14 makes only one.
point of the
The novelty of the present construction consists in making a
coupling rod 13 the centre of the driving pin of the piston rod. This point 36
describes a curve called lemniscoid, which in this case resembles two different
circles joined together and placed one inside the other.
These circles being alternately described by the driving pin, may serve to
determine alternately a long and a short stroke of the piston.
The ratio of the diameters of these two circles depends on the position of the
point 36 on the coupling rod 13.
In Fig. I this lemniscoid is shown in dotted lines; the nearly circular portion
f, g, h corresponds to the suction stroke, h, f, i, to the compression stroke, i, k to
the expansion stroke; and k, f to the discharge or exhaust stroke. The rod 8
connects the pin 36 with the piston 7.
The lemniscoidal motion of the driving pin is also applicable to engines without
separate compressing chambers.
The axis of the cylinder may be placed at various angles to the line connecting
the two crank-centres. 17 and 15 of the cranks 14 and 16. If for instance the
cylinder is placed at B¹, of Fig. I in the direction of B-B¹, ẞ B', corresponds to
the suction stroke, 81 8 to the compression, and 3. 33 to the expansion stroke, the
compression chamber being formed by the difference of the strokes corresponding
to Band 3. The curve B³ B would correspond to the exhaust stroke.
In the present example the lemniscoid is not situated symmetrically to the axis
of the cylinder, but so, that at the end of the compression the power piston has
entered the cylinder a little further than at the end of the exhaust-stroke.
The object of this unsymmetrical position is to produce the ignition of the
charge by the stroke of the piston.
The igniting valve illustrated by Fig. III consists of a conical valve 62 with
cylindrical extension 64 and piston valve 61.
The latter moves in the cylinder 80, which allows the escaping gases to be
ignited by the permanently burning flame 60, through the slot 81.
The flame is protected by the hood 59.
At the end of the compression stroke a projection of the tube 45 comes in
contact with the lever 63, thereby opening the igniting valve. As soon as the flame
has entered the valve chamber, the piston 61 closes the slot 81, and the ignition
valve opens completely, so as to ignite the charge in the compression chamber.
The motion of the inlet and outlet valve is effected from a point 41 of the
.

page_text: connecting rod 8. The outlet-valve 11 is situated at the lower part of the
compression chamber, between the latter and a blow-off pot. On the valve-
spindle reaching down into the blow-off pot is mounted a fixed disc 70 (Fig. I)
serving to open the valve. The valve is kept closed by a weight or a spring.
'
The point 41 of the connecting rod 8 is connected with two parallel levers 10
and 10 by a rod. 9. These levers have their fulcrum at 42 on the piece containing
the outlet valve.
The point 41 describes a curve corresponding to the lemniscoid, but consisting
of two nearly elliptical curves a, b, c d joined together, the direction during the
exhaust period being indicated by an arrow (from d to a).
A piece placed between the two levers 10 and 10% comes during the exhaust
period in contact with the disc 70 of the valve-spindle, therby opening and
closing the outlet valve. The latter remains closed, while the point 41 travels
through the other parts of the curve.
The inlet valve. 51 constructed as a mixing valve is also controlled by an
extension of the lever 10 beyond 42, from a point 75 situated directly under the
inlet valve. 54. (Fig. I).
The air-suction valve 51 is combined with a gas-inlet-valve. 52 and a cock for
controlling the admission of gas.
After this stop-cock has been opened, the gas flows through the conduit 58.
to the gas inlet valve 56, and then into the annular space 52, from which small
holes. 55 lead to the seat of the valve 51.
Consequently when this valve is closed, air and gas are simultaneously shut off.
By opening the valve 54 while the gas valve 56 is closed, air alone is drawn in,
and if the valve 56 is open, an explosive mixture of gas and air, which are then
more completely mixed in the mixing chamber m.
The motion of the inlet valve takes place during the admission period, during
which the point 41 moves from a to b, thereby lifting the point 75 and causing
the arm. 25 to act on the valve 54. To prevent the inlet valve from being further
opened during the expansion period a vertical oscillating motion is also imparted
to the arm. 25 by means of an eccentric. 21 mounted on the valve-gear shaft. 75,
which motion is transmitted by means of rods. 22 and 24, lever 23 and hinged
joint. 26.
During the suction stroke the arm 25 remains nearly vertical, and during the
other periods it moves side-ways
The regulation of the speed is effected by means of a pendulum 27 having
its fulcrum in 29. The period of oscillation may be regulated by shifting the
weight 28.
The pendulum receives motion from the laterally swinging arm 25 which may
have at 26 a roller coming in contact with the adjustable face. y of the pendulum.
(Figs I and II). As the point 26 recedes rapidly the pendulum is allowed to fall
freely, thereby meeting with its button 57 the head of the gas-inlet valve 56,
so as to open the same.
-
a, Fig. II indicates another position of the ball 27.
The construction of the engine may easily be modified so as to draw back hot
gases of combustion from the blow-off pot, when the speed of the engine is too
great, instead of admitting cold air, until the explosive charge commences to enter,
for which purpose the exhaust-valve must be adapted to perform the function of
a suction valve, and the opening of the air and of the gas-inlet valve must be
effected simultaneously by the governor.
Instead of the valves described, slide valves may be employed and the
construction correspondingly modified..

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Friedrich von Martini in the Great Seal Patent Office on the
27th August 1883.
FRIEDRICH VON MARTINI, of Frauenfeld, in the Republic of Switzerland,
"A NEW GAS-MOTOR,"
.
In gas engines with ordinary crank-motion and compression chamber, in which
an ignition takes place after every second rotation of the crank-pin, the suction
stroke is equal to the expansion stroke of the piston.
In consequence of this arrangement the expanded gases are discharged with a
tension of about 2 atmospheres.
The present construction has for its object to utilize the expansion as much
as possible, and for this purpose the engine works with a specially arranged
compression chamber and an ignition chamber, in such a manner that a suction
and a compression take place during one rotation of the axle with a small piston-
stroke, while a complete expansion occurs during the following revolution with.
large piston stroke.
In the accompanying drawings which illustrate the invention Fig. I is a
longitudinal section, Fig. II a side view, Fig. III a front view, Fig IV a back view
and Fig. V a horizontal section of a gas engine embodying my invention and in
which the axle 17 serves as a fly wheel-shaft, while Fig. VI shows a modified
construction, in which the fly-wheel is on the axle 15. Fig. VII is a section across
the outlet-valve.
In the first sheet of the drawings (Figs I to VII) the details of the compression
chamber are omitted, for the sake of clearness. Fig. VIII is a longitudinal section
of the cylinder on a larger scale, showing the details of the compression chamber,
valve gear and governor. Fig. 1X explains the action of the governor.. Fig. X
shows the igniting arrangement. Fig. XI shows various positions of the piston for
the purpose of explaining the functions of the compression chamber.
The compression chamber 2 forms the continuation of the cylinder 1 (Figs I, V,
and VIII), and both are cooled with water.
At the back wall of the compression chamber are situated side by side the inlet-
valve 51, and the ignition valve 61 (Figs IV and V).
The arriving gases, flow first into the mixing chamber m (Fig. VIII) and passing
closely to the ignition valve (Fig. V) enter the compression chamber through the
orifice n (Fig. VIII).
The gases entering the latter are not free to expand over the whole space, but
are guided and kept separate by tubes. They enter first the tube 49 (Fig VIII)
which is enclosed by a tube 48. Both tubes are fixed. Tube 48 has at its base
several apertures 50. To the piston are attached two tubes 45 and 46, adapted to
move in the tubes 48 and 49 freely, but with as little clearance as possible. In
Figs I and V the tubes 48 and 49 are omitted, in order to avoid crowding.
The tube 46 is provided near the piston with apertures 47. In consequence of
this arrangement the entering gases are compelled to pass first through the internal
tubes 49 and 46 and then through the openings 47 into the outer tubes 45, and 48,
from which they escape through the apertures 50 before reaching the cooled
cylinder walls.
The distribution of the gases will therefore take place as illustrated by Fig. XI.
In Fig. XI a the piston begins its sucking action, all spaces are filled with gaseous
products of combustion and are of such a size, that at the end of the suction stroke
these gases form a jacket for the explosive charge, which has been drawn in, as

page_text: indicated by Fig. XI, B, Ŏ and d. The usual so-called waste space is purposely
enlarged into a compression and separation chamber. The dotted vertical lines in
Fig. XI indicate gases of combustion, produced by the preceding operation, while
the dotted lines running from the upper left hand corner towards the lower right
hand corner represent a small quantity of air between the products of combustion
and the explosive charge (Fig. XI B and 6); the dotted lines running from the
upper right hand corner towards the lower left hand corner represent the explosive
charge (Fig. XI; B, Ŏ) and the horizontally dotted lines the products of the
combustion which has just taken place, (Fig XI X);
At the beginning of the stroke of the piston only a small quantity of atmospheric
air is allowed to enter, and immediately afterwards the full explosive charge. At
the end of the suction stroke, Fig. XI ẞ, all incombustible gases will have been
displaced towards the cylinder walls, while the combustible gases are, strictly
separated from the others, inside the tube.
This separation remains unaltered at the close of the compression, at the
beginning of the ignition, Fig. XI. ɣ, and till the end of the expansion, Fig XI §.
The object is to avoid a mixture of the gases.
By this construction of the compression chamber the following advantages are
obtained:
1.) An almost perfect separation of the charge from the other gases as already
mentioned.
2) A successive combustion of the charge instead of an instantaneous explosion,
the combustion being caused to proceed like a rocket along the tubes.
P
3). As the combustion takes place only inside the tubes, the latter are heated to a
high degree, and serve for the preliminary heating of the gases newly
introduced.
4.) The heat produced by the explosion or combustion of the gases may be
utilized by expansion, instead of being wasted by heating the cooling water.
Less cooling water is required.
5) The flame is prevented from touching the walls of the cylinder.
6) The sliding parts of the piston move only. in incombustible gases, in consequence
of which less lubrication is required.
The driving mechanism connected with the piston consists kinematically of an
isosceles rotating double crank, the small crank 16 (Figs I, II, V, VI, VIII) serving
to turn the shaft 17, while the large crank 14 drives the shaft 15.
-
The two cranks 14 and 16 are connected by the arm 13, the length of which
equals the radius of the larger crank 14.
The distance between the bearings of the two cranks equals the radius of the
smaller crank 16. In this mechanism the small crank 16 makes two revolutions;
while the large crank 14 makes only one.
The novelty of the present construction consists in making a point of the coupling
rod 13 the centre of the driving pin of the piston rod. This point 36. (Fig. V
and VIII.) describes a curve called lemniscoid, which in this case closely resembles
two unequal circles joined together and placed one inside the other.
These circles, being alternately described by the driving pin, may serve to
determine alternately a long and a short stroke of the piston.
The ratio of the diameters of these two circles depends on the position of the
point 36 on the coupling rod 13.
?
In Figs I and VIII this lemniscoid is shown in dotted lines; the nearly circular
portion f-g-h corresponds to the suction stroke; h-fi to the compression
stroke; -k to the expansion stroke and k-f to the discharge or exhaust stroke,
The rod 8 connects the pin 36 with the piston 7.
The lemnoscoidal motion of the driving pin is also applicable to engines
without separate compressing chambers, in which engines the gases of combustion
are completely discharged from the cylinder after the expansion and the
compression have been obtained by altering the stroke of the piston. In the
present construction the stroke may be altered by placing the axis of the cylinder

page_text: at various angles to the line connecting the two crank centres 17 and 15 of the
cranks 14 and 16 (Fig. V and. VIII). If for instance in Fig VIII the cylinder is
placed at B, in the direction of B-B¹, the line ẞ B¹, corresponds to the suction
stroke, B B to the compression stroke, the compression chamber being formed by
the difference of the strokes represented by the line ẞ 32. The curve B³ B would
correspond to the exhaust stroke. By the choice of the point 36 on 13, as well as
by the choice of the position of the cylinder axis. B B', the ratios between
suction, compression and expansion-strokes may be varied within wide limits.
In the example shown by the drawing the lemniscoid is not situated symmetrically
to the axis of the cylinder, but so, that at the end of the compression the power
piston has entered the cylinder a little further than at the end of the exhaust-
stroke.
:
The object of this unsymmetrical position is to automatically produce the
ignition of the charge by the stroke of the piston. The igniting apparatus is
illustrated by Fig X. It consists of a conical valve 62 with cylindrical
extension 64 and piston valve 61. The latter moves tightly in the cylinder 80,
to which the permanently burning igniting flame 60 has access through the
slot 81. The flame 60 is protected by the hood 59. (Fig. X shows 59, 60
and 81 turned 90 degrees out of their actual position for the purpose of better
illustration.
The cylindrical extension below the ignition valve enters with slight clearance a
cylindrical bore below the seat of the ignition valve. At the end of the com.
pression stroke a protuberance of the pipe 45. attached to the piston strikes the
lever 63 and opens the ignition valve.
The compressed explosive gases enter the cylinder 80 with low tension, owing
to their having been throttled by the cylindrical extension 64, and are ignited by
the flame 60. As soon as the flame has struck into the chamber of the ignition
valve, the piston 61 closes the slot 81, and the ignition valve opens entirely, after
which the ignition takes place in the compression chamber.
The motion of the inlet and of the discharge valve is effected from a point 41
of the connecting rod 8 (Figs. I and VIII.).. The discharge valve 11 is below the
compression chamber in an intermediate piece 3 situated between the compression
chamber and the blow-off-pot 4.
The spent gases pass directly from 2 through 3 into 4, as shown in Fig VII.
On the valve spindle, which extends down into the blow-off-pot, is fixed a disc 70,
Figs VII and VIII, serving to open the valve. This valve is kept closed by a
weight or spring 12, Fig. L
The point 41 of the connecting rod 8.is connected with two parallel levers 10
and 10° by means of a rod. 9.
These levers have their fulcrum at 42 on the piece 3 containing the outlet valve
(Figs. I and VIII).
The point 41 describes a curve corresponding to the lemniscoid but consisting of
two nearly elliptical curves a-b-c-d joined together, the travel during the
exhaust period (in the direction indicated by an arrow) being from d to a. This
part of the curve being the highest, the levers 10 and 10* are lifted up to their
highest position.
An intermediate piece 20 between these levers (Figs VII and VIII), which
comes in contact with the disc 70 of the valve rod, controls the opening and
closing of the discharge valve. The proportions of 10 and 9 and the position of
the point 41 are such, that the discharge-valve remains closed, while the point 41
passes through the other portions of its travel.
The inlet valve 51, constructed as a mixing valve, is also controlled by an
extension of the lever 10 beyond 42, from a point 75 situated directly under the
inlet valve 54 (Fig VIII). The air suction valve 51 is combined with a gas-
inlet-valve 52, and a stop-cock. 53 (Figs II, IV. & V.)-In Figs VIII and IX the
gas-inlet-valve is drawn in a different position, for the sake of clearness. After
the stop-cock has been opened, the gas flows through the conduit 58 to the gas

page_text: inlet valve 56, and then into the annular space 52, from which small holes 55 lead
to the seat of the valve 51.
Consequently, when this valve is closed, air and gas are simultaneously shut off.
By opening the valve 54, while the gas valve 56. is closed, air alone is drawn in,
and if the valve 56 is open, an explosive mixture of gas and air, which are then
more completely mixed in the mixing chamber m.
The action of the valve gear on the inlet valve takes place during the admission
period, during which the point 41 of the connecting rod 8 moves from a to b,
thereby lifting the point 75 of the rod 10° and causing the arm 25 to act on the
valve 54, (Fig VIII) so as to open the same when required.
To prevent the inlet valve 54 from being further opened during the expansion
period corresponding to the curve c-d an oscillating motion in a vertical plane is
also imparted to the arm 25 by means of an eccentric 21 mounted on the valve-
gear shaft 15. This eccentric is connected with the arm 25 by means of rods 22
and 24, lever 23 and hinge joint 26, and it is set at such an angle that during the
suction stroke the arm 25 remains nearly vertical, while during the other periods
the arm 25 moves side-ways to the left, and therefore the inlet valve remains closed
when the point 75 occupies its highest position (Fig. IX).
The regulation of the speed is effected by means of a pendulum 27 having its
fulcrum in 29. The period of oscillation may be altered by shifting the
weight 28.
The pendulum receives motion from the laterally swinging arm 25, which.
,may have at 26 a roller adapted to come in contact during its oscillation with the
adjustable face y of the pendulum (Figs VIII and IX), so as to impart to the same
a speed depending also on the position of the face y. As the point 26 recedes
rapidly, the pendulum is allowed to fall freely, thereby meeting with its button 57
the head of the gas-inlet valve 56, so as to open the same and to control the
explosive charge of the engine. As with equal angles of oscillation the periods of
oscillation remain the same, the engine will always receive an equal charge during
its normal action. In the drawing a represents the highest position of the
pendulum with normal speed of engine. If now the speed of the engine increases
the following circumstances operate to retard the gas-inlet. The pendulum is
acted upon more rapidly by 26, whereby the angle of oscillation increases (see 2
Fig. IX), and the pendulum begins its receding motion later.
With the oscillating angle increases also the period of oscillation. Conse-
quently the engine is charged later, and therefore with a smaller quantity of
explosive gas.
•
With too slow oscillations the effects are the reverse of those just mentioned.
By suitably adjusting the period of oscillation, the engine may be charged with
explosive mixture during the whole of its suction stroke, in order to obtain the
maximum power. If less power is required, more or less air is first admitted before
the explosive charge begins to enter, and owing to the peculiar construction of the
compression chamber these charges are kept separate as much as possible. The
construction of the engine may easily be modified, so as to draw back hot gases of
combustion from the blow off pot, when the speed of the engine is too great, instead
of admitting cold air, until the explosive charge commences to enter; for which
purpose the exhaust-valve must be adapted to perform the function of a suction
valve, and the opening of the air and of the gas inlet valve must be effected
simultaneously by the governor. The engine is mounted on a stand 4, serving also
as a blow-off-pot, and on a stand 6 which serves as a gas reservoir and may be
provided with a gas pressure regulator. Instead of the valves described slide-
valves may be employed and set in motion from the shaft 15, which makes only
one half of the number of revolutions of the shaft 17.
As an advantage of the lemniscoid motion may be mentioned, that the piston
possesses the greatest speed during the period of expansion, because the pin 36
travels through the two lemniscoidal circles in equal periode.
Having now described my invention, and the best manner, known to me, of

page_text: rying the same into practical effect, I wish it to be understood, that I do not
it myself to the exact details shown by the drawings, as the same may be
ered without departing from my invention, but that what I claim is:
In gas engines, a compression chamber 2 containing fixed tubes, and movable
- tubes attached to the power piston, the said tubes being adapted to slide in
each other and constructed or arranged substantially as described, for the
purpose of keeping the gases separate.
The lemniscoidal motion of the driving pin of gas engines, substantially as
described and for the purposes set forth.
Producing or controlling the motion of the inlet and outlet valves from a
point 41 of the connecting rod 8 guided in a lemniscoid, by means of
mechanism adapted to open the inlet and outlet valves according to the
elevation of the point 41, and from the valve gear shaft 15 by means of
mechanism adapted to periodically disconnect the spindle 25 from the inlet
valve, substantially as described.
The igniting apparatus consisting essentially of the conical valve, the cylindrical
throttle valve and piston valve, and mechanism for operating the same set in
motion by the power-piston of the engine, the whole combined and adapted
to operate, substantially as described.
A pendulum governor, made adjustable by moving a weight, and adapted to be
lifted more or less according to the intensity of periodical impulses depending
on the speed of the engine, so as to open a gas-inlet valve sooner or later by
coming in contact with the valve or its connection sooner or later, substantially
as described.
The general arrangement of the engine, substantially as described and
illustrated.
In witness whereof I, the said Friedrich von Martini, have hereunto set my
ad and seal this 20th day of August A.D. 1883.