varying automatically the volume of mixture of gas and air, and its compression before ignition
Year: 1886

page_text: PAUL NIEL Engineer at W. C. Horne 5A Aldermanbury Postern, E.C. do hereby
declare the nature of this invention to be as follows:-
This invention is for improvements in gas engines, similar in principle to the engine
described in Letters Patent No. 3135 /83, viz: "varying automatically the volume of
mixture of gas and air, and its compression before ignition"; but by different methods
of construction, so that the charge of compressed mixture instead of being sent from
the pump into the working cylinder as a whole, and then parts of it being forced from
the working cylinder to the reservoir, the required volume to be exploded is alone
sent to the working cylinder and the excess is at the same time sent into the reservoir.
Or by another arrangement the excess of mixture is returned directly to the pump,
without using a reservoir.
In the first arrangement the working cylinder, the pump, and the reservoir, are
placed in the same manner as in the engine described in Letters Patent No. 3135 /83,
but in this case the pump is put in communication with the end of the working
cylinder through an oscillating cylindrical slide valve, instead of a flat one, this
cylindrical valve being at the same time a combustion chamber.
The suction of air and gas is made through the same port, communicating from the
pump to the oscillating valve. The mixture is in all cases homogeneous, the gas and
air being sucked in at the same time during the whole stroke of the pump. When
the mixture is forced by the pump, it may if necessary pass through a check valve
intercepting the communication between the pump and the oscillating valve. At the
beginning of the backward stroke, the communication between the oscillating valve
and the working cylinder is shut, and only remains open to the pump until the end of
the stroke. Before the stroke is quite completed, the valve in revolving opens
communication to the working cylinder, which until that moment has been exhausting
the products of the previous explosions. The mixture enters a small chamber left at
the end of the working cylinder, displaces what may remain of the burnt gases, and
sends them through the exhaust valve which is then closing. The backward stroke being
completed, the oscillating valve is shut from the pump, and is full open to the working
cylinder; in continuing its oscillations it uncovers a small port, through which the
the

page_text: igniting flame is introduced, the working piston is then forced outward by the
explosion, at the same time that the pump is sucking in a fresh charge for the next
stroke. The reservoir communicates with the main port by a pipe, through a regu-
lating valve, which is acted upon by the governor, so that when the engine is racing,
that valve is accordingly more or less opened. The charge forced from the pump goes
then partly to the oscillating valve, and partly to the reservoir, and when the pump
sucking it takes first what may be compressed in the reservoir, before sucking in any
fresh mixture.
In the other arrangement the pump is placed above the working cylinder in a
parallel line, or nearly so, and the heads of both pistons are connected with the same
crank, the centre of the crank shaft being between the axis of the cylinder and of the
pump. By this arrangement the working stroke is produced in less than half a
revolution of the crank, giving thus a greater speed to the piston when the com-
bustion takes place. And also the backward stroke of the working piston is completed
before the backward stroke of the pump, thus expelling the whole, or nearly the whole
of the burnt gases, before receiving the fresh charge. The pump is closed at both ends,
one end being employed to suck in the mixture of air and gas, the other end to
compress and force it through the oscillating valve, into the cylinder at the back of the
working piston.
Both ends of the pump are in communication by a port regulated by a valve, or the
piston is fitted with a valve opening from the suction side to the forcing side. The
valve placed in the port can always lift to let the charge pass from the suction side to
the forcing side, but can be prevented closing by the action of the governor, thus
when the compression takes place, only a part of the mixture is forced to the working
cylinder, and the other returned to the suction end of the pump, in consequence of the
valve being kept more or less open through the action of the governor, thus preventing
the suction of an equal volume of fresh mixture for the next stroke.
This arrangement can be produced as well by putting the pump by the side of the
cylinder, and both pistons connected to two different cranks on the same shaft, but at
different angles.
In both arrangements the oscillating valve is acted upon by a cam or eccentric
mounted on the crank shaft, and the exhaust valve in a similar manner by a cam on
the oscillating valve, or on the main shaft.

page_text: I, PAUL NIEL, care of W. C. Horne, Esq, 6 Dowgate Hill, in the County of
Middlesex, 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 :-
My invention for improvements in gas engines has a similar object to that described
in Letters Patent No. 3135 of 1883, viz, to automatically vary the volume of the
mixture of gas and air and its compression in the working cylinder before ignition
according to the speed of the engine and also has for object to construct the supply
and ignition valve in such manner that it shall form part of the combustion chamber.
In an engine constructed according to the present invention-instead of the whole
of the charge of the compressed mixture being forced from the pump into the
working cylinder and then parts of it being forced from the working cylinder
to the reservoir as described in the above mentioned Letters Patent-the required
volume of the charge to be exploded is alone forced to the working cylinder and
the excess of the mixture in the pump over the charge is at the same time forced into
the reservoir; or, by another arrangement, the excess of the mixture is returned
directly to the pump, without using a reservoir.
In an engine constructed according to the first mentioned arrangement, the working
cylinder the pump and the reservoir are arranged in the same manner as described in
the before mentioned Letters Patent; but, according to my present invention, the
pump is put in communication with the end of the working cylinder through a hollow
oscillating cylindrical valve instead of a flat slide valve, this hollow valve forming also
a combustion chamber.
The gas and air are sucked in through the same port in definite proportions during
the whole forward stroke of the pump. During the first portion of the backward
stroke, the mixture is forced by the pump to the interior of the hollow valve, a check
valve being arranged in the passage if necessary. Before the end of the said back
stroke, the valve opens communication with the working cylinder which until then has
been exhausting the products of the previous explosion, and the pump forces the
mixture into a small chamber at the end of the working cylinder, thus displacing the
remaining products of the previous explosion, when the exhaust valve closes. At
the end of the backward stroke of the pump, the interior of the hollow valve is shut
off from the pump and fully open to the working cylinder and in continuing its
oscillation, it uncovers a small port through which the igniting flame is introduced
and the mixture in the hollow valve and in the end of the working cylinder exploded.
The working piston is thus caused to make its outward or working stroke, the pump
piston at the same time drawing in a fresh charge for the next stroke. The reservoir
communicates with the passage leading from the pump to the hollow valve through a
regulating valve acted upon by the governor so that more or less of the mixture in the

page_text: pump passes to the reservoir according to the speed of the engine. The pump piston
during its forward stroke first draws in the mixture previously compressed into the
reservoir.
In an engine constructed according to the second mentioned arrangement, the
pump cylinder is placed with its axis vertically above and parallel to the axis of the
working cylinder, or nearly so and the two pistons are connected to the same crank
on the main shaft, the axis of the main shaft being in a horizontal plane between the
axes of the two cylinders. By this arrangement, the working stroke is performed in
less than half a revolution of the crank shaft, thus giving a greater speed to the
working piston when acted on by the expanding gases and the backward stroke of
the working piston is completed before the backward stroke of the pump,
thus expelling the whole or nearly the whole of the products resulting from the
last explosion before receiving the fresh charge. The pump is closed at both ends,
one side of the piston drawing in the mixture of air and gas during the backward
stroke which during the next forward stroke passes through a valve in the piston or
through a valve in a passage connecting the two ends of the cylinder-to the other
side of the said piston. During the next backward stroke this mixture is forced to
the hollow valve described in the first mentioned arrangement and to the working
cylinder. It will readily be seen that, if the valve in the piston or in the passage
connecting the two ends of the cylinder be prevented by the governor from closing,
during this latter stroke, a portion of the mixture will pass back to the suction side of
the piston and thus prevent the suction of an equal volume of fresh mixture for the
next charge.
In a modification of this latter arrangement, the two cylinders are placed side by
side and their pistons are connected to separate cranks on the same shaft but making
an angle with one another.
The hollow valve in both arrangements is driven by a cam or eccentric on the main
shaft and the exhaust valve is driven by a cain on the hollow valve or on the main shaft.
In the accompanying sheet of drawings
Fig. 1 is a side elevation shewn partly in section of an engine constructed according
to the first arrangement; and
Fig. 2 is an end view from the back of the cylinder, with a part broken away at the
govering valve to shew the interior thereof, of the same; and
Fig. 3 is a side elevation shewn partly in section of an engine constructed according
to the second arrangement.
In all the figures, the same numerals denote corresponding parts.
Referring now to figs. 1 & 2, the working piston 2 is attached to the pump piston 3
working in the cylinder 4 which is of a larger diameter than the working cylinder.
In the forward motion of the pump piston the mixture of gas and air is drawn in
through the valve 5 which is shewn in cross section in Fig. 3, the air passing through
the port 9 and the gas through the port 10. The mixture enters the pump by the
port 11 and during the backward stroke is forced again through the port 11,
through the check valve 12-the valve 5 being closed by the pressure of the
mixture and through the port 13 to the interior of the hollow cylindrical valve 15
whose port 16 is then in communication with the port 13 but is closed to the port 14
leading to the working cylinder. When the backward stroke of the pump piston
is nearly completed, the valve 15 connects the ports 13 and 14 and during the
remainder of the stroke the mixture is forced into the small combustion chamber 1.
The valve 15 in continuing its motion closes the port 13 and then a small hole 18
in the valve 15 comes opposite a port leading to a red hot tube 19 exploding the
mixture in the valve 15 and in the combustion chamber 1. The working piston at
this moment is just beyond its dead point and is thus caused to perform its working
stroke. Just before the end of the working stroke, the exhaust valve 17 is raised by
means of the levers 20 and 21, the roller 23 and the cam 22 operated from an eccentric
on the main shaft and opens communication between the working cylinder and the
atmosphere thus allowing of the free escape of the products of the combustion. The

page_text: cam 22 closes the valve 17 just after the ports 13 and 14 have been put in com-
munication so that a part of the compressed mixture enters the cylinder and forces
out the remaining products of combustion of the previous charge. The valve 15 is
operated by means of a link, attached to the cam or eccentric on the main shaft, the
arrangement being shown by an interrupted centre line and the small circles 24
and 25.
In order to regulate the speed of the engine a port 6 is formed in the passage
leading from the port 11. to the check valve 12 and communicates with the reservoir 7
through a small valve 26, port 29 and pipe 8. The valve 26 is operated from the
governor by means of a rack on the governor spindle 28, the rack gearing with a
pinion 27 on the valve spindle. The governor-which is not shown-is operated by
the belt 30 shown in interrupted lines. The valve is capable of a radial movement on
its spindle as clearly shown, it being kept up to its face by the pressure of the
mixture when this pressure exceeds the pressure in the reservoir. It will thus be
seen that according to the position of the valve 26 more or less of the mixture passes
to the reservoir instead of to the working cylinder and so regulates the speed of the
engine. The mixture forced into the reservoir, is, at the next forward stroke, again
drawn through the valve 26 into the pump cylinder; the valve 26 then acting as an
ordinary suction valve.
Referring to fig. 3, the diameter of the pump cylinder 4 is approximately equal to
the diameter of the working cylinder or it may be varied to correspond with the
desired degree of compression. The two pistons 2 and 3 are connected to the same
crank a.
During the backward motion of the pump piston 3, a charge of gas and air is
drawn in through the valve 5, as described above and during the next forward stroke
of the piston 3, this charge passes through the valve 12 (shown in interrupted lines)
in the piston to the other side of the piston and during the next backward stroke this
charge is compressed. During this compression the valve 26 which is arranged in a
passage connecting the two ends of the cylinder is more or less open according to the
speed of the engine, the valve being controlled by the governor as above described
with reference to figs. 1 and 2, and thus allows more or less of the charge to pass to
the other or suction side of the piston which is drawing in a fresh charge during this
period. During this compression stroke the charge is forced to the hollow valve 15
and to the combustion chamber 1 as described above with reference to figs. 1 & 2.
The valve 17 is also operated as described above with reference to figs. 1 & 2.
If desired the cylindrical valve 15 may be oscillated in the direction of its length
instead of circumferentially, the ports being cut transversely to the axis of the valve
instead of longitudinally.
The arrangement for lubricating the cylinders is shown in Fig. 1. The spindle of
the valve 5 passes through an oil cup and when moving downward, the small quantity
of oil in the recess 31 in the said spindle is brought to a small passage controlled by
a small set screw and allowed to drop on the suction valve. The oil is thus sucked in
with the mixture of gas and air and is blown in a spray on the body of the piston and
on the sides of the cylinder.
When the governor has fully opened the valve 26, any further motion of the
governor arising from an increase of the speed of the engine may be arranged to lock
the suction valve.
It will be evident that the construction and arrangement of the engine may be
modified in various ways without departing from the nature of my said invention.
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 :-
1. In gas engines automatically varying or regulating the volume of the explosive
mixture forced into and its compression in the hollow cylindrical valve and in the
working cylinder according to the speed of the engine in the manner and by the means
substantially as hereinbefore described.

page_text: 2. In gas engines, the employment in combination with the governor of a valve
automatically varying the proportion of the volumes of the explosive mixture
respectively forced into the combustion chamber and returned to the pump directly or
through a reservoir to be used at the following stroke substantially in the manner
hereinbefore described and illustrated.
3. In gas engines the arrangement and construction of the hollow cylindrical valve
acting as a supply and ignition valve and forming part of the combustion chamber
substantially in the manner hereinbefore described and illustrated.
4. The general construction and arrangement of gas engines substantially as
hereinbefore described and illustrated.
WHEATLEY & MACKENZIE,
156, Strand, London, W.C.,
Agents for the Applicant.