IMPROVEMENTS IN GAS MOTORS
Year: 1884

page_text: TOLTITOO
SPECIFICATION.
I, EMIL CAPITAINE, of 89 Chancery Lane, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN GAS MOTORS" and in what manner the same is to be performed, to bo
particularly described and ascertained in and by the following statement :-
The construction of a gas motor in accordance with this Invention is somewhat
similar to that of a single acting steam engine. An explosion takes place upon
each revolution of the flywheel, this driving the fly wheel during one half of
a revolution, when the stored up active force resident in the same drives back the
piston of the motor during the other half revolution, the motor in the meanwhile
being charged afresh by means of mechanism arranged for the purpose as hereinafter
described.
I will describe the Invention (as communicated to me) with reference to the
accompanying Sheet of illustrative Drawings in which:
Fig. 1 is a side and part sectional elevation of my improved gas motor.
Fig. 2 is a part sectional plan thereof.
Fig. 3 is a view of valve arrangement drawn to a larger scale, and
Fig. 4 is an enlarged view of slide valve and igniting arrangement.
The method of operation is as follows:
Supposing the motor to be working and an explosion to have just taken place,
the working piston A is thereby driven forward and through the medium of the
piston and connecting rods gives off its power to the crank shaft. When the piston
has been driven through the whole of its forward stroke the expansive force of the
gases is nearly exhausted, and it is necessary during its return stroke to displace
the products of combustion from the space C, behind the piston, and to supply this
space with a fresh quantity of explosive mixture. This is done in the following
manner: When the piston has reached the extreme forward position indicated at B
the two valves a, b, are lifted by the rod D. The valve a effects a communication
of the inside of the cylinder with the outer atmosphere, and the valve b effects
a communication of the cylinder with an air reservoir E into which air at a low
pressure of about one tenth of an atmosphere has been previously pumped. Upon
the opening of the two valves a, b, of which a is the first to be opened the excess
pressure in the cylinder due to the preceding explosion disappears, and by reason

page_text: of the excess pressure in the air reservoir, fresh air flows into the cylinder past the
valve b, and expels the burnt gases or residues of combustion still remaining in
the same, the greater part passing past the valve a into the outer air. This
operation takes place whilst the piston is performing the first half of its stroke
backwards, from B to F. When it has reached the point F both of the valves a, b
are closed and the cylinder then filled with air at the atmospheric pressure. In
order however to perfect the charge for the purpose of the next explosion this air
must have added to it the requisite quantity of illuminating gas, and the mixture
compressed. This is effected during the second half of the piston stroke backwards
the illuminating gas being pressed into the working cylinder by the side gas
pump G, whilst the mixture of gas and air is compressed by the piston itself in its
backward motion. The gas is forced in during the movement of the piston from
B to H, and the mixture is ready to be exploded immediately before the working
piston has arrived at the dead point, and therefore just previous to the moment of
ignition.
The operation that takes place within the motor may be specified as follows:-
1. Expulsion of the burnt gases and charging the cylinder with fresh air, during
the time taken up by a quarter of a revolution of the fly wheel.
2. Compression of the air and forcing the illuminating gas into the same whilst
it is being compressed, during a quarter of a revolution.
3. Ignition and explosion of the gas mixture as also the transfer of the explosive
force to the fly wheel shaft, during half a revolution.
Such operation may be more particularly described under the several heads as
follows:-
1. The expulsion of the burnt gases and the charging of the cylinder with fresh
air commences when the piston is at the dead point B. and the expulsion is
concluded when the piston has arrived at F. A simple way of effecting this first
operation, is by arranging a lever in connection with a small crank or excentric on
the fly wheel shaft so as to have an oscillating motion communicated to it whereby
the valve a may be lifted during one quarter of a revolution, whilst the valve b
rises by reason of the pressure present in the air reservoir. The latter will only
rise when by the opening of the valve a the higher pressure in the working
cylinder shall have disappeared, and will at once close again as soon as the pressure
in the air reservoir has been lowered by the outflow of air. This form of valve
arrangement gives good results but it causes a blow to be given to the crank shaft
when the valve a is being lifted and also a sharp blow when the two valves a and b
are being closed. The valve a especially (which still retains a rather heavy load
due to the preceding explosion) is very suddenly operated by the oscillating lever
and as suddenly returned to its seating. Now to prevent these blows or shocks
and the speedy wear of the working parts due thereto I employ the method of
construction shewn in the accompanying Drawing.
Beneath both valves a, b, which are pressed down on their seatings by springs,
is mounted the lever c in such manner that when the same is moved outwards both
valves are simultaneously lifted. The lever c receives its motion from the cranked
lever & beneath it. This latter is mounted on the rod p. which has an oscillating
motion communicated to it from the crank shaft, the lever d consequently having
a corresponding oscillating motion, and only comes in contact with the lever c
during the time the valves are to be open, and so that the lifting operation is
commenced by the smallest radius of the lever d the larger radius then coming
into action and suddenly lifting the valves higher. Thus in the given short space
of time the desired stroke of the lever and valves is obtained, and the slightest
variation of speed in the lifting and falling of the valves avoided, the operation
being noiseless and without excessive wear in the working parts.
2. The compression of the air and forcing of the illuminating gas into the same,
whilst it is being compressed :-
The plunger of the aforesaid gas pump G is firmly connected to the crosshead of
the motor and has the same motion as the working piston. When the latter is.

page_text: driven forward the pump plunger also goes forward and draws in illuminating gas
from the gas conduit through an ordinary pump valve arranged in front of the
pump. This illuminating gas however is not forced into the working cylinder
immediately on the backward stroke of the pump plunger, because, as before
described, during the first half of the backward stroke of the working piston the
valve a is open, and thus a considerable portion of the inflowing gas would escape
with the exhausting burnt gases. For this reason an ordinary valve arrangement
is unsuitable and in lieu thereof the valve arrangement shewn in the Drawing is
applied. It consists substantially of a valve f with piston g. This piston is of the
same cross sectional area as the valve opening, so that the valve cannot open by
the pressure of the gas forced into the pump cylinder. In addition a spiral spring
mounted outside keeps the valve to its seating until the lever h worked from the
fly wheel shaft presses against the piston g and opens the valve which opening
commences when the plunger e has made half its stroke backwards, the working
piston A having arrived at the point F, and the two valves a and b are again
closed. The valve f again closes when the piston and plunger have arrived at the
end of their stroke, when the explosion takes place, driving the working piston to
the other end of the cylinder, and thus the operation is repeated continuously.
In order to maintain a constant excess pressure in the air reservoir E the
working cylinder in front of the piston is utilised as an air pump and upon each
stroke the cylinder receives a full charge and presses it into the air reservoir. This
air upon the opening of the valves a and b flows into the cylinder; it escapes to
the extent of one half with the burnt gases, the other half remaining in the
cylinder whereby a fairly pure air is obtained.
3. Ignition.
In
The flame burning within a slide arrangement is in the case of motors that work
with compression extinguished at the moment it should effect ignition, that is to
say, when it comes in contact with the compressed gas mixture of the working
cylinder, before ignition can take place. In order to avoid this drawback the
construction shewn in the Drawing is employed:-Air is supplied through the
piper and illuminating gas through the pipe 8. When the slide moves to the right
the passagen is put in communication with the pipes r and 8.
A mixture of gas
and air flows into the chamber m so proportioned and regulated that it forms an
explosive compound. This mixture flows through the orifice o in the passage / and
thence into the space k where it is ignited by a continuously burning flame.
order to guard against the ignition striking back into the chamber m, an additional
gas supply passage is made to open into the orifice o and through which the
outflowing mixture is supplied with gas to such an extent that from this point it
is no longer explosive. Thus the chamber m is filled with an explosive. gas
mixture whilst only combustible gas flows out of the orifice o. When the slide
moves to the left the air and gas supply is completely cut off at the moment that
the passage comes into communication with the port a leading into the cylinder,
and the passage is cut off from the outer atmosphere. The flame burning through
the orifice o strikes back towards the chamber m, the mixture present in the same
is ignited and in turn ignites the mixture in the working cylinder through the
port x.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. In gas motors, in which an explosion takes place upon each revolution, the
application of an air reservoir, in which is a pressure in excess of that of the outer
atmosphere, and by the expansion of the contents of which, during the first half
of the backward stroke of the working piston the burnt gases are driven out of
the working cylinder, substantially as described and illustrated.
2. For the purpose of replacing the burnt gases in the working cylinder of a gas
motor by atmospheric air, the arrangement of the inlet and outlet valves a and b
being both simultaneously operated by a lever in such manner that the speed at

page_text: which the valves commence to rise and finish falling is extremely slow, substantially
as described and illustrated.
3. The forcing of the illuminating gas into the working cylinder through the
valve by the pump G the opening and closing of the valve being operated at the
proper time independently of the motion of the pump plunger, and by outside
mechanism only, substantially as described and illustrated.
4. In gas motors, operating the ignition by means of an explosive mixture in
the chamber m of an igniting slide, in such manner that the said explosive mixture
is by means of a supply of gas through the orifice o rendered only capable of
burning when in contact with the ordinary outside flame and is exploded at the
moment of contact with the cylinder contents by shutting off this particular
supply of gas.