Year: 1886

page_text: "I, Professor ENRICO BERNARDI, of Padua, in the Kingdom of Italy, 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 relates to gas engines or motors which can be made of very, small
dimensions, which are easily managed, which are very regular in operation; which
present no danger of explosion, and which are very economical.
The improved motors are adapted for domestic purposes generally, and especially
for driving sewing machines.
My improvements consist not only in the form and arrangement of parts which
are ordinarily found in a thermic motor, but also in certain altogether new arrange-
ments' viz.
1st The igniting apparatus.
2nd The apparatus for supplying the motor with combustible gas in cases where
ordinary lighting gas is not at 'disposal.
3rd The apparatus which automatically regulates the velocity of the engine.
For this reason I will give a brief description of the motor and its operation,
reserving till later the description of the details of the aforesaid three apparatuses
on which principally depend the possibility of constructing a gas motor fulfilling
the above-mentioned conditions.
DESCRIPTION OF THE MOTOR AND ITS OPERATION.
The cylinder is horizontal; and is open in front and closed at the rear. It is
surrounded by cold water taken from a reservoir at the side of the engine. The
piston transmits the motion to the driving shaft and fly-wheel by means of a
connecting-rod and crank. The connecting-rod, as in the Brotherhood three-
cylinder engines, is directly attached to the piston. This piston is made of metal,
without packing rings and hollow, and is very long, in order to increase the
wearing surface and consequently the durability.
.
>
A second crank-connected with the pin of the driving crank actuates. the
distributing slide through the medium of a connecting-rod, the said slide working;
between two surfaces in the ordinary. manner. This slide serves: exclusively for:
the introduction of the explosive mixture and for the discharge of the products.
of combustion, and has nothing to do with the ignition of the said mixture;ithis
being effected through a special opening in the bottom of the cylinder-The motor

page_text: is constructed on the Corliss-system; the guide for the cross-head however is
dispensed with, as the connecting rod is attached directly to the piston. The
piston moves to the bottom of the cylinder and during a quarter of its outward
stroke draws in the explosive mixture. The slide then closes the inlet for the
said mixture and a flame on entering through the hole in the cylinder ignites
the charge.
The expansion of the gases then acts against the piston for the remainder of its
strokę. At the same time the expanded gases are being cooled so that when the
piston arrives at the end of its stroke, their pressure has already descended below
the atmospheric pressure.
The slide continues to prevent any communication between the interior and
exterior of the cylinder until the piston has made half its return stroke. At this
point the slide opens the exhaust opening and the products of combustion which
at this moment reach a pressure which is nearly equal to that of the atmosphere,
are discharged by the piston during the completion of its in-stroke.
The phases of action of the motor accordingly are as follow:-
1st Suction of the explosive mixture during a quarter of the out stroke of the
piston.
2nd Explosion of the mixture and the propulsion of the piston through the
remaining three fourths of tits stroke owing to the excess of the internal pressure
over the external pressure.
3rd Cooling of the exploded gases and the propulsion of the piston during the
first half of its in stroke owing to the excess of the external pressure over the
internal pressure and
4th Discharge of the products of the combustion during the movement of the
piston through the second half of its back-stroke..
The drawing shows the application of my invention to a small motor suitable
for 'driving a sewing machine.
THE IGNITING APPARATUS.
A small, pair of bellows,draws in a mixture of combustible gas and air and
afterwards forces it through a nozzle arranged .obliquely with respect to the
bottom of the cylinder and against the open lighting hole in the said bottom..
A small flame always burns before this nozzle so that the gas: is; ignited on
leaving the said nozzle and is directed in this state towards the lighting opening.
This opening is provided externally with an obturator or slide which is displaced
and uncovers the said opening. at the same moment that the bellows force the jet of
flame towards it. The obturator closes the said opening again suddenly, immediately
after having opened it.
The opening and closing of the lighting hole is effected so rapidly by the motion
of the engine, that the "flame is communicated to the explosive substance enclosed
in the cylinder without any loss of gas through this hole at the moment of the
explosion.
In order to give greater prominence to the parts which "I a
.
am going to describe
in the figures which will be hereinafter referred to, I have omitted the supports
of the pivots upon which the arms acting upon the bellows and obturator turn;
and in figures. 1 and 3. I have: also omitted the small flame and the nozzle from
which the jet of flame is directed.
A (figure 1) represents the' exterior surface of the bottom of the cylinder, and a
the lighting hole. The obturator or slide.c consists of a small disc of steel, the
diameter of which is a little greater than that of the hole a, and which is provided
with a short stud which fits into a hole at the free,extremity of the arm.Ob. This
arm being pivotted at the-point. O causes the obturator to (slide upon the plane
surface of the cylinder so as ito cover, or uncover the hole, a. The small..disc.c
slides freely upon the cylinder A, because its stud can move freely in the end
of the arm Ob, and not only does this arm exert no pressure whatsoever upon
'

page_text: the said disc, but it permits it to recede slightly from the cylinder A. This
arrangement is important, because it always renders the closing of the obturator
certain and prompt, in spite of the burned oil and dust which condenses all around
the lighting hole.
j
When the small disc c bears upon the edges of the hole a and covers it, it must
be firmly pressed against the edges of the said hole in order to keep it hermetically
closed against the high pressure of the gases which explode in the cylinder. For
this purpose I fix a solid arm CC (Figures 2 and 3) upon the bottom of the
cylinder (this arm is not represented in Figure 1) which has a screw m n of steel,
provided at the point n with a shallow depression in the direction of its axis.
Into this depression one extremity of a steel pin n, vis introduced the other
extremity of which is placed into a similar depression formed in the stud of the
obturator c. The screw mn (Figure 3) is arranged slightly lower than the lighting
hole so that, if the obturator is placed in position to cover this aperture, the pin n v
remains slightly inclined from v to n. By regulating the length of this pin, and
of the screw mn, the said pin when the obturator covers the lighting hole, sustains
the said obturator and presses it against the hole and at the same time prevents it
from moving beyond the latter. This arrangement is advantageous, as it leaves
the motion of the obturator quite free while it covers and uncovers the lighting
hole and presses it forcibly upon the hole only when it completely covers the hole.
Moreover, the pin nv can be easily displaced by lifting the arm Ob until the
extremities of the pin pass freely from their depressions. As soon as the pin is
removed the arm Ob falls of itself, and leaves the surface around the lighting
hole free, and consequently permits the same to be easily and promptly cleaned of
oil and dust which in course of time collect there.
The bellows B (Figures 1 and 2) consist of a small bag of india rubber or the
like placed in the hollow of a wooden cup F which sustains it. Upon the box D
(Figure 2) from the nozzle of which the jet of flame passes are the valves of the
bellows which bellows are in communication with the said box through the medium
of the short pipe t, t of india-rubber.
The arm Ob which actuates the obturator is united to another arm Os (Figure 1)
which is nearly horizontal and at whose free extremity is fixed a knob e which
slightly enters the body of the bellows. It is easy to see that if the arms Ob
and Oe turn upon the point O from right to left the bellows are compressed, and
at the same time the obturator uncovers the lighting hole. The arms Ob and Oe
are fixed upon a small shaft Og (Figure 2) which runs parallel to the axis of the
cylinder as far as the driving shaft of the engine, and which carries a third arm q, s.
A tooth provided on the driving shaft, and which turns at the same time as this
arm, acts upon the extremity s of the said arm and after lowering it leaves it.
While the arm q, a descends, the arms Ob and Oe turn from right to left whereby
the bellows are compressed and the lighting hole opened. As soon as the arm 9, 8
is free from the aforesaid tooth the whole mechanism returns at once to the original
position owing to the action of the elasticity of the bellows, and without the
application of any spring. It is in this manner that I obtain the compression of
the bellows, and the instantaneous opening and closing of the lighting hole.
I will remark that in this apparatus I have applied for the first time the principle
of using the motion of the engine itself for rapidly opening and closing the lighting
hole without causing, at the moment of explosion, the least loss of gas through
the said hole. It is, upon this fact that the originality of this part of the invention
dependa
APPARATUS FOR FEEDING THE MOTOR WITH INFLAMMABLE GAS.

page_text: °
contain 'and 'the spongy substances which they usually enclose, and which are
saturated with hydrocarbon are completely renewed.
Moreover, the continual evaporation of the bydrocarbon cools it, and at the
same time cools the entire apparatus. It is accordingly necessary to find means
1st for easily separating the heavier oils which collect in the apparatus and, if
possible, utilizing them and 2nd for compensating the loss of heat which the hydro-
carbon continually undergoes by reason of its evaporation. The description of the
apparatus is as follows.
:
The hydrocarbon is introduced into the reservoir A (Figure 4) through the
pipe u, u the lower opening of which is provided with one or more partitions of
wire gauze or the like for preventing the flame from being transmitted from the
exterior to the interior of the said reservoir A. The horizontal dimensions of
this reservoir are very large relatively to its height, for the purpose of causing only.
a slight lowering of the level of the hydrocarbon even if a large quantity thereof
is consumed.
BB is a cylindrical receptacle provided with a cover, and C is another receptacle
likewise cylindrical, concentric with the receptacle B, and closed. The space
between these two receptacles is divided into two annular compartments m and n
by the cylindrical diaphragm S. The compartment m is in communication with
the reservoir A through the medium of the pipe 6, e. The interior of the recep-
tacle C is traversed by the hot gases which are discharged from the cylinder of the
engine by means of a pipe, and introduced, through the opening z and discharged
from the opposite side. In this manner the receptacle C is heated and the heat is
proportional to the work done by the engine, and consequently to the quantity of
hydrocarbon evaporated. All around the diaphragm S and over the same are
arranged rovings formed of slightly twisted strong cotton yarn, the suspended ends
of these rovings fill the compartment m and n their extremities extending to the
bottoms of these compartments.
i
..
1
11;
The hydrocarbon proceeding, from the reservoir A passes through the pipe e, e
and enters the compartment m; by reason of the capilarity of the yarn it, rises,
afterwards through the same and descends into the compartment 'n so that, in a
short time the liquid is at the same level in the reservoir A and in the compart
ments m and n.
+
A hollow cylinder x, x having thin sides open at the two ends, and a diameter
a little larger than the exterior of the receptacle C..passes through and hermetically.
closes the cover of the. receptacle B B and encloses the receptacle C. The cylin-
der x, a, does not extend to the bottom of the compartment n, but terminates
a little above the level of the hydrocarbon, in the compartment...
1.
The cover which, hermetically closes the receptacle B, B has a pipe h, h through
which the motor. draws the inflammable gas necessary for its operation. When the
engine is drawing gas through the pipe h, h, the only passage open to the external
air to the interior of the receptacle B, B. is between the sides of the cylinder x, x
and the hot sides of the receptacle C; consequently the air passing through the
barrow annular space formed by these two walls is heated. The air descends,
nearly to the level of the hydrocarbon, it then, bends upward and passes through
a number of openings between the cotton threads which fill the compartment n;
it.finally enters, charged with inflammable vapour, into the pipe h, h through which
it is drawn into the engine.
14
'
From..this arrangement, it results that the air is heated before it reaches the
hydrocarbon; and the latter, and the rovings in the compartment n are also hot,,
being in communication with the hot sides of the receptacle C.
As the hydrocarbon continually evaporates in the compartiment its level tends
to lower and consequently a continuous current of fresh hydrocarbon proceeding
from the compartment m passes through the rovings in the direction m Sn, while
the heavier oils tend to collect upon the bottom of the heated, compartment n.
If the engine is large, these heavy oils must from time to time be removed
through the medium of a small pipe v, which traverses the compartment-n. -In

page_text: small engines, for instance such as those which are applied for driving sewing
machines, the said oils are conducted to the wick of the flame p (Figure 2) of the
igniting apparatus which has already been described, and in such a manner that,
when feeding this flame they are utilized without interruption and without its
being necessary to remove them.
:
The bydrocarbon vapour forming the jet of flame which ignites the explosive
mixture enclosed in the cylinder of the motor; proceeds directly from the reservoir 'A
(Figure 4) through a pipe y, y of small diameter, applied to the top of the reservoir'
itself. When the motor is in operation, the pipe u, u is left open, in order that
the external air can replace that saturated with combustible vapour which is
always drawn through the pipe y, y by the bellows of the lighting apparatus.
1
The motor operates either with vapour of benzine, or with any other volatile oil,
or with lighting gas. In the latter case the apparatus which I have just described
is dispensed with, and the lighting gas is conducted to the engine in the usual
manner. In each case two cocks having micrometric screws are provided to
regulate the proportions of the inflammable gas and air forming the explosive
mixture which must afterwards be drawn into the cylinder of the engine, and into
the bellows of the lighting apparatus.
APPARATUS FOR AUTOMATICALLY REGULATING THE VELOCITY OF THE ENGINE.
For automatically regulating the velocity of the motor,, an ordinary centrifugal
governor may be arranged so as to cause a change in the quantity of combustible
gas drawn into the cylinder according to the changes in the resistances offered to
the motion of the engine. Such a regulator however is very delicate, especially if
it is constructed of small dimensions, as it must be for small engines. Also it
would complicate the engine and would greatly increase the price thereof.
For these reasons I employ the following very simple apparatus by which the
object is completely attained.
The pipe R R (Figure 5) through which the mixture is drawn, which explodes
in the cylinder is in communication with a small cylindrical chamber S. This
chamber is arranged so that the axis is vertical, and it is always closed above. At
its lower end it carries a screw-threaded ring ee which at its upper extremity
has the form of a truncated cone, and over the opening of which is placed a
valve which opens from the outside inwards, and which consists of a simple
metallic disc.
A pin. which is fixed to the top of the said chamber prevents the valve from
being lifted too much or being turned over.
When the velocity of the motor increases, the suction of the explosive mixture
becomes more and more violent and consequently during the suction the pressure
in the pipe R R is lowered below the atmospheric pressure. The valve z z remains
closed while the velocity of the motor does not exceed a certain limit, but it opens
when this limit is exceeded. By the lifting of the said valve cold air is allowed to
enter the pipe R R, which air dilutes the explosive mixture, thus rendering the
explosion less violent, weakening the impulse of the piston and diminishing the
velocity of the driving shaft, thereby bringing it nearer and nearer to the normal
velocity.
This velocity can be regulated by making the valve of a suitable weight.
It can also be made variable at liberty by making the valve of little weight and
compressing it in its place by means of a spring, the pressure of which can be
regulated by turning a suitably placed screw.
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 :-
First. The apparatus, by means of which the ignition of the explosive mixture
in the cylinder is obtained, the said ignition being effected by a jet of flame at a

page_text: very elevated temperature, directed into an opening in the cylinder, which opening
is rapidly opened and closed upon the outside: by means of an obturator or slide
operated by the engine itself.
י
Second.. The apparatus for the production of the combustible gas, the said
apparatus comprizing two compartments communicating with one another by
means of cotton threads which are constantly saturated with liquid hydrocarbon,
the first of which compartments receives the fresh hydrocarbon whilst in the
second, which is heated by the hot gases discharged from the cylinder, is effected
the evaporation of the hydrocarbon and consequently the generation of inflammable
gas or vapour which feeds the motor, the, most volatile portions of the hydrocarbon
being evaporated in the first compartment, while the heaviest and least volatile
oils enter the second compartment so that the apparatus, in addition to pro-
ducing inflammable vapour, at the same time separates the heavy oils from the
hydrocarbon used.
Third. The automatic apparatus for regulating the velocity of the engine, the
said apparatus consisting of a valve which opens inwardly, and which is maintained
in its place by gravity, or a spring, or by any other suitable means; the con-
struction of the said apparatus being based. upon the fact that, when the velocity
of the motor increases, the pressure in the gas suction pipe is lowered so that when.
the velocity of the engine reaches a certain limit, the said. valve is lifted thereby
admitting atmospheric air, which latter dilutes the explosive mixture and con-
sequently diminishes the force of the explosion and the velocity of the motor.
Dated this 24th day of April 1886.