Year: 1895

page_text: Date claimed for Patent under Sect. 103 of Act,
being date of first Foreign Application (in 8th Sept., 1894
France),
Date of Application (in United Kingdom), 25th Mar., 1895
Complete Specification Left, 20th Sept., 1895-Accepted, 26th Oct., 1895
I, OSCAR HENDRIK WILDT, of 54, Faubourg Montmartre, Paris, France,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to an improved explosive gas engine, the distinctive
feature of which has for object :
1st. To render engines operated by explosive mixtures more economical, to
reduce the temperature of the gases at the exhaust by a considerable prolongation
of the expansion, and by utilizing the partial vacuum which may be created by
cooling the products of combustion before allowing them to escape into the atmo-
sphere, as in the case of air engines. The volume of the burnt gases being greater
at the termination of the expansion than that of the explosive mixture admitted,
the contraction of the gases by cooling in a closed chamber must thus necessarily
create a partial vacuum.
2nd. To obtain greater regularity in the working of engines employing an
explosive mixture by producing an impulse upon one or both faces of the piston at
each revolution of the fly-wheel, while still retaining the advantage of inhaling
the explosive mixture into the working cylinder itself. The impulse may be varied,
according to the work to be done, by varying the volume of the mixture
admitted, whilst the proportions of the gases constituting the explosive mixture
may remain invariable, but the engine never misses fire during the working. To
effect the desired object the engine works upon the two-phase cycle principle,
that to say, considering one side of the piston only, it receives a working impulse
at each outward stroke (from the end of the cylinder to the most forward point)
while the exhaust of the burnt gases, the inhalation of a fresh mixture, and the
compression to a regular or variable extent of the mixture, are all effected during
the backward stroke.
In order that the invention may be more readily understood, I have represented
in an elementary manner, in the accompanying drawings, an example of my
improved system of engine, in which the piston receives the working impulse upon
one side only.
Figure 1 is a sectional view of the general arrangement of the engine.
Figure 2 is a plan of the distribution valve operating gear.
Figures 3 and 4 are also an elevation and plan of a modification of the distribu-
tion mechanism.
The same letters of reference denote like parts in all the figures.
My improved system of engine consists essentially of a working cylinder a in
which works a piston b which drives the shaft d through the connecting rod and
C

page_text: As
crank e. The shaft & carries a fly-wheel ƒ and cams g, g³, for operating the admis-
sion valve for the gaseous mixture and the exhaust valve A'.
For this purpose
the cams act upon rollers i, i, mounted on the ends of levers j, j', coupled by
means of link rods k, k', to bell crank levers 1,1; the latter by bearing against
collars mounted upon the valve stems m, m', determine the opening of said valves
by compressing the springa n, n', which serve to return the valves to their seats.
A spring n balances the weight of the admission valve. The crank e is also
coupled to the connecting rod o of a piston p working in an air pump cylinder q.
The interior of this cylinder may communicate by means of valves r, r¹, either with
the atmosphere through passages, or with the exhaust condenser t which is
enclosed in a cooling jacket u. As before mentioned, the engine works on the two-
phase cycle. The working stroke commences when the piston leaves the position
which it occupies in the drawing, the crank turning in the direction indicated by
the arrow; the stroke terminates. when the crank has arrived in a position
diametrically opposite to that in which it is shewn. This stroke is produced by the
thrust of the explosion of the detonating mixture giving an impulse to the fly-
wheel. During this stroke of the piston 6 the piston p of the air pump q expels
all the gases contained in the pump cylinder q through the discharge valve and
pipes into the open air. At this moment the cam g₁ strikes roller and through
lever j¹, connecting rod k¹, and bell crank lever l', opens valve ', whereby the gases
of combustion contained in cylinder a escape into condenser t. There, under the
action of the cooling jacket u, these gases acquire a temperature approaching that
of the cooling medium (water, ambient air, etc.,) and as they cannot diminish in
volume the pressure falls below the atmospheric pressure. The backward stroke
now commences, being at once an exhaust, inhaling, and compression stroke.
the piston b returns towards the bottom of the cylinder and expels the burnt gases
the piston p draws into the pump cylinder the burnt gases which have been
cooled in the condenser t. As the pump is of greater capacity than cylinder a the
vacuum goes on increasing, during the whole time the valve ¹ remains open. On
arriving at a certain point of the backward stroke the cam ' quits roller i¹ and
valve is closed on its seat by spring n'. At the same moment cam g meets
roller and by means of lever j, connecting link, and bell crank lever 1, com-
presses spring n, the stress of which is sufficient to prevent the valve from
opening under the action of the vacuum during the exhaust. By the compression
of spring n, the valve is released and remains held on its seat only by the weak
counterbalancing spring a. This spring yields to the atmospheric pressure and
valve opens and admits the explosive mixture to cylinler a, the air entering
through passage raul the gas through orifices a. The mixture is inhaled suddenly
by reason of the partial vacuum in cylinder a and immediately the pressure in this
cylinder approaches that of the atmosphere the spring n² closes valve h on its seat.
The inhaling of the fresh mixture thus takes place during a small fraction of the
backward stroke of piston b. During the remainder of the backward stroke the
explosive mixture is compressed in the chamber at the bottom end of cylinder a.
When the piston 6 has arrived at the bottom of the cylinder the compressed
explosive charge is ignited by any suitable means, e.g. by an electric spark, the
injection or transport of a flame, or an incandescent body, whereupon the explosion
takes place, the piston b is again driven forwards by the pressure created by the
combustion of the explosive mixture, the same operations being repeated
indefinitely.
The cam g is very short and the spring n resumes its normal position towards
the end of the backward stroke or at latest at the commencement of the next
forward stroke. This is necessary in order that the valve shall be held to its seat
from the moment when the expansion of the gases after the explosion causes the
pressure to fall below that of the place. The can may be formed in one
with shit das may also the cag wn in Figures 1 and 2 a. the drawings,
in which case the degree o
expan
able, as the
closing of the exhaust and the release of the a laission valve always takes place at
•

page_text: the same point of the backward stroke of piston b, so that the volume of the
explosive mixture inhaled is always the same. The engine may be adapted to work
with a variable degree of compression and expansion under the control of a centri-
fugal governor. In this case the cam which actuates the exhaust is made in two
parts sliding the oue in the other so that the exhaust always commences at the same
point but may terminate at points more or less advanced of the backward stroke of
piston b.
The shaft d in this case carries two collars (see Figure 4) one of which y
is fixed on the shaft and carries the cam g² which operates the exhaust while the other
collar y¹ which is movable, carries the cam g³ for acting on the exhaust and cam g
for operating the admission valve. The cam g³ in its ordinary position, that is to
say when the speed of the engine is normal exactly coincides with the cam g², the
engine then working as above described. The roller i is made of a breadth to bear
on both cams 92 and g³, and when the engine tends to exceed the normal speed, the
governor contained in the hollow disc z rotates the collar in the reverse direction
to that of the motion of the engine, so that the cams 93 and 9 occupy the positions
indicated in full and dotted lines in Figure 3. The exhaust thus always com-
mences at the same point, but the closing of the exhaust is retarded as is also
the moment of admission so that the piston b, being then nearer the bottom of
the cylinder the volume of the explosive mixture inhaled is diminished. Hence the
compression is less and the expansion prolonged. The governor thus regulates
the force developed at each explosion in direct relation to the work required of
the engine.
It is evident that the arrangement of certain of the parts of the engine may
be modified, without changing the mode of working. I may also modify the
distribution gear, according to circumstances; the cams may be replaced by
eccentrics for operating the valves or a plane or cylindrical slide valve. The
cylinders may be closed at both ends, like those of steam engines, the pressure
acting alternately on each side of the piston. The expansion may also be
effected in several cylinders but always in such manner that a partial vacuum
shall be created during the exhaust stroke in the first admission cylinder in
order that a fresh mixture shall be inhaled during the backward stroke of the
piston.
It will be evident that the engine may be made of all dimensions, according
to the purpose for which it is to be applied.
Dated this 25th day of March 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
I, OSCAR HENDRIK WILDT, of 54, Faubourg Montmartre, Paris, 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 :-
This invention relates to an improved explosive gas engine specially arranged
with a view :—
1st. To render engines operated by explosive mixtures more economical, to
reduce the temperature of the gases at the exhaust by a considerable prolongation
of the expansion, and by utilizing the partial vacuum which may be created by
cooling the products of combustion before allowing them to escape into the atmos-
phere, as in the case of air engines. The volume of the burnt gases being greater
at the termination of the expansion than that of the explosive mixture admitted,

page_text: the contraction of the gases by cooling in a closed chamber must thus necessarily
create a partial vacuum.
2nd. To obtain greater regularity in the working of engines employing an
explosive mixture by producing an impulse upon one or both faces of the piston at
each revolution of the fly-wheel, while still retaining the advantage of inhaling the
explosive mixture into the working cylinder itself. The intensity of the impulse
may be varied, according to the work to be done, by varying the volume of the
mixture admitted, whilst the proportions of the gases constituting the explosive
mixture may remain invariable, but the engine never misses fire during the
working.
To effect the desired object the engine works upon the two-phase cycle principle,
that is to say considering one side of the piston only it receives a working impulse
at each outward stroke (from the end of the cylinder to the most forward point)
while the exhaust of the burnt gases, the inhalation of a fresh mixture, and the
compression to a regular or variable extent of the mixture, are all effected during
the backward stroke.
In order that the invention may be more readily understood I have represented
in an elementary manner in the drawings accompanying my Provisional Specification
an example of my improved gas engine, in which the piston receives the working
impulse upon one side only.
Figure 1 is a sectional view of the general arrangement of the engine.
Figure 2 is a plan of the distribution valve operating gear.
Figures 3 and 4 are also an elevation and plan of a modification of the distribution
mechanism.
The same letters of reference denote like parts in all the figures.
My improved system of engine consists essentially of a working cylinder a in
which works a piston b, which drives the shaft d through the connecting rod c and
crank e.
The shaft d carries a fly-wheel f and cams 9, g¹, for operating the
admission valve for the gaseous mixture and the exhaust valve h¹. For this
purpose the cams act upon rollers i, i¹, mounted on the ends of levers j, j³, coupled
by means of link rods k, k¹, to bell crank levers 1, 1; the latter by bearing against
collars mounted upon the valve stems m, m', determine the opening of said valves
by compressing the springs n, n', which return the valves to their seats. A spring n²
balances the weight of the admission valve. The crank e is also coupled to the
connecting rod o of a piston p working in an air pump cylinder q. The interior of
this cylinder may communicate by means of valves r, r, either with the atmosphere
through passages or with the exhaust condenser t which is enclosed in a cooling
jacket u.
As before mentioned, the engine works on the two-phase cycle. The working
stroke commences when the piston leaves the position which it occupies in the
drawing, the crank turning in the direction indicated by the arrow; the stroke
terminates when the crank has arrived in a position diametrically opposite to that
in which it is shewn. This stroke is produced by the thrust of the explosion of
the detonating mixture giving an impulse to the fly-wheel f. During this stroke
of the piston b the piston pexpels all the gases contained in the air pump cylinder q
through the discharge valve r and pipe s into the open air. At this moment the
cam gstrikes roller and through lever j¹, connecting rod k¹, and bell crank
lever, opens valve h¹, and allows the gases of combustion contained in cylinder a
to escape into condenser t, where under the action of the cooling jacket u the said
gases acquire a temperature approaching that of the cooling medium (water,
ambient air, etc.,) and as they cannot diminish in volume the pressure falls below
the atmospheric pressure. The backward stroke now commences, being at once an
exhaust, inhaling, and compression stroke. As the piston returns towards the
bottom of the cylinder and expels the burnt gases the piston p draws into the
pump cylinder the burnt gases which have been cooled in the condenser t and as
the pump is of greater capacity than cylinder a, the vacuum goes on increasing
during the whole time the valve remains open. On arriving at a certain point
q

page_text: of the backward stroke the cam ¹ quits roller and valve h¹ is closed on its seat
by spring n. At the same moment cam 9 meets roller i and by means of lever j,
connecting link k, and bell crank lever 1, compresses spring n, the stress of which
was sufficient to prevent the valve h from opening under the action of the vacuum
during the exhaust. By the compression of spring n, the valve his free to open,
being held to its seat only by the weak counterbalancing spring n². This spring
yields to the atmospheric pressure and valve opens and admits the explosive
mixture to cylinder a, the air entering through passage and the gas through
orifices x. The mixture is inhaled suddenly by reason of the partial vacuum in
cylinder a and immediately the pressure in this cylinder approaches that of the
atmosphere the spring n² closes valve h on its seat. The inhaling of the fresh
mixture thus takes place during a small fraction of the backward stroke of piston b.
During the remainder of the backward stroke the explosive mixture is compressed
in the chamber at the bottom end of cylinder a. When the piston 6 has arrived at
the bottom of the cylinder the compressed explosive charge is ignited by any
suitable means, e.g. by an electric spark, the injection or transport of a flame, or an
incandescent body, whereupon the explosion takes place and the piston 6 is again
driven forwards by the pressure created by the combustion of the explosive
mixture, the same operations being repeated indefinitely.
The cam g is very short and the spring n resumes its normal position towards
the end of the backward stroke or at latest at the commencement of the next
forward stroke. This is necessary in order that the valve shall be held to its seat
from the moment when the expansion of the gases after the explosion causes the
pressure to fall below that of the atmosphere. The cam g may be formed in one
with shaft d as may also the cam g¹ as shewn in Figures 1 and 2 of the drawings,
in which case the degree of compression and expansion would be invariable, as the
closing of the exhaust and the release of the admission valve always take place at
the same point of the backward stroke of piston b, so that the volume of the
explosive mixture inhaled is always the same.
The engine may be adapted to work with a variable degree of compression and
expansion under the control of a centrifugal governor. For this purpose the cam
which actuates the exhaust is made in two parts sliding the one in the other so that
the exhaust always commences at the same point but may terminate at points more
or less advanced of the backward stroke of piston b. The shaft din this case
carries two collars (see Figure 4) one of which y is fixed on the shaft and carries
the cam g, which operates the exhaust, while the other collar y', which is movable,
carries the cam g³ for acting on the exhaust and cam g₁ for operating the admission
valve. The cam g³ in its ordinary position, that is to say when the speed of the
engine is normal, exactly coincides with the cam g², the engine then working as
above described. The roller is made of a breadth to bear on both cams g² and g³,
and when the engine tends to exceed the normal speed the governor contained in
the hollow disc rotates the collar in the reverse direction to that of the motion of
the engine so that the cams 93 and 9 occupy the positions indicated in full and
dotted lines in Figure 3.
The exhaust thus always commences at the same point, but the closing of the
exhaust is retarded as is also the moment of admission so that the piston b, being
then nearer the bottom of the cylinder the volume of the explosive mixture inhaled
is diminished. Hence the compression is less and the expansion prolonged. The
governor thus regulates the force developed at each explosion in direct relation to
the work required of the engine.
It is evident that the arrangement of certain of the parts of the engine may be
modified, without changing the mode of working. The distribution gear may also
be modified according to circumstances; thus the cams for operating the valves
may be replaced by eccentrics, or a plane or cylindrical slide valve may be used.
The cylinders may be closed at both ends, the pressure acting alternately on each
side of the piston. The expansion may also be effected in several cylinders but
always in such manner that a partial vacuum shall be created during the exhaust

page_text: stroke in the first admission cylinder in order that a fresh mixture shall be inhaled
during the backward stroke of the piston.
It will be evident that the engine may be made of all dimensions, according to
the purpose for which it is to be applied.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. The herein described gas engine constructed and arranged for operation,
substantially as specified.
2nd. In a gas engine, the employment of a condenser for the exhaust gases in
combination with an air pump for creating a partial vacuum in said condenser and
in the working cylinder during the period of exhaust, as specified.
3rd. In a gas engine provided with a condenser and air pump, as specified, the
arrangement of distribution gear whereby during the same return stroke of the
piston the discharge of the burnt gases are exhausted, a fresh explosive mixture is
inhaled and compressed by the exhaust being opened to the condenser at the
beginning of the stroke (or with a slight lead) and closed at a certain point before
the completion of said stroke, the closing of the exhaust being immediately followed
by an inhalation through a valve which is permitted to open at the exact moment
of closing the exhaust, the said valve closing automatically immediately the
cylinder is filled with explosive mixture at atmospheric pressure, as specified.
Dated this 20th day of September 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.