IMPROVEMENTS IN GAS-ENGINES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office of
the Commissioners of Patents on the 9th January 1883. Communicated
to him from abroad by Hiram Stevens Maxim, of Brooklyn, New York,
United States of America, but at present residing at Paris, France.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and C, Patent Agents,
Southampton Buildings, London, IMPROVEMENTS IN GAS-ENGINES." [A communi-
cation to him from abroad by Hiram Stevens Maxim, of Brooklyn, New York,
United States of America, but at present residing at Paris, France,]
The object of this Invention is to provide an improved gas engine, simple in
construction, and capable of working with great regularity, the explosion of the
gases taking place at each revolution instead of at every alternate revolution as in
the gas engines usually employed.
In order that the said Invention may be more readily understood, I have illus-
trated in the accompanying Drawings, by way of example, a gas-engine constructed
according to the said Invention.
Figure 1 represents a plan of the engine, the excentric, the fly-wheel and the
governor being shewn in horizontal section.
Figure 2 represents a vertical longitudinal section of the engine.
Figure 3 is a transverse section on the line y y Figure 2.
Figure 4 is a transverse section through the plummer-blocks or bearings.
Figure 5 is a horizontal section of the bottom of the cylinder, the admission
valve and the gas-pump.
Figure 6 represents an end elevation of the same parts.
Figure 7 is a vertical section through the gas-chimney.
Figure 8 represents the front end of the cylinder with the admission valves.
Figure 9 is a transverse section on the line Figure 2.
Figure 10 is a transverse section on the line QQ Figure 2.
Figure 11 is a vertical longitudinal section of the gas-pump.
Figure 12 is a side elevation of the excentric and rod.
Figure 13 is a plan of one of the piston rings of the cylinder, and
Figure 14 is a side clevation of the same.
Figure 15 represents in plan the piston ring of the
Figure 16 is a side clevation of the saine.
gas-pump, and
Figure 17 is a diagrain illustrating the movement of the cam.

page_text: Figure 18 is a diagram of the performance of the machine shewing the com-
pression of the air and the pressure produced by the explosion.
Figure 19 is a rear elevation of the fly-wheel and governor.
Like letters indicate the same parts throughout the Drawings.
A represents a jacketted cylinder; B the piston; C the safety valve; D the
exhaust valve; E a spiral spring for keeping the valve D closed; F a spiral spring
holding the rod 10 in contact with the spindle of the valve D; Ga lover for
opening the exhaust; H the exhaust pipe; I the admission valve; J the piston of
the gas-pump; K the igniting flame; L the ignition slide-valve; M the ignition-
chamber; N the valve for the admission of the gas and air; O the gas inlet;
P the air inlet; R R apertures for the entrance of air; S the air-chamber; T holes
or ports for the passage of air; U the explosion-chamber; V the water chamber;
W the cam, and X a friction-roller.
a represents the gas-pump; b a strong spiral spring; c (Figure 5) a small
passage for gas; da small gas-chamber; e another small passage for gas; fan air
hole ga gas-burner; h a flat steel spring; i a steel spring; j the governor
weights; the governor arms; la lever pivotted at n; m a rocking shaft; pa
pin fixed in the cam W; r a screw for adjusting the spiral spring t; s the discharge
aperture of the safety valve; u the outlet for the hot water; the inlet for cold
water; w the key for the head of the piston rod; xa ring permitting the adjust-
ment of the head of the rod; 1, 1, 1, 1 screw-nuts for fixing the metal tube 2;
3 a conical joint; 4, 4, air valves; 5 a stuffing box; 6 the valve for the admission.
of gas and air combined; 7 a valve for the admission of air; 8 an oscillating lover
for actuating the gas-pump; 9 a key for holding the piston rod in the head; 10 a
sliding rod for opening the exhaust valve; 11 the piston rod.
The operation of the engine is as follows, that is to say-A suitable pipe for the
supply of gas being connected to the pipe O and to the burner g the machine is
turned one revolution by hand; the air is compressed in the chamber U and the
air and gas mixed in the chamber a enter equally in such a manner that there will
be in the space U a pressure of gas and air of about 4-20 kilogrammos per square
centimetre. As the machine continues to turn and the piston approaches the end
of its stroke, the slide-valve L is moved by the excentric into such a position that
the flame enters at K and causes the explosion of the charge. The explosion
impels the piston forward, and at the same time compresses the air on the opposite
side of the piston (Figure 2) into the chamber S. When the piston is about
25 millimetres from the other end of its stroke, the head of the rod comes in
contact with the small lever G, and thereby opens the large exhaust valve which
permits the residues of the explosion of gas and air to escape. As the piston
continues its forward movement, it passes the apertures T, and the air which has
been compressed into the space S passes through these apertures and forces out of
the cylinder, by the exhaust pipe, all the gaseous products of the explosion and
fills the cylinder with pure air. The expansion of the air by the heat sufficiently
augments its volume, not only to expel the gas residues, but also to cause a certain
quantity of pure air to flow through the exhaust aperture. On its return stroke,
the piston passes the holes T, draws in a fresh charge of air by the apertures R,
and when it has closed the holes T, the exhaust-valve D is closed; at this moment
the cam W is in contact with the friction roller X, the piston of the gas-pump is
impelled rapidly forward, and the contents of the chamber a are forced into the
cylinder. The piston B returning in the cylinder compresses the air and gas in the
chamber U, and the flame being brought into contact with the gas, the charge is
exploded and the piston performs its forward stroke as before. The piston of the
gas pump is caused to perform its outward stroke by the action of the spiral
spring 6 which holds the friction roller X against the cam. When, moreover, the
engine is working slowly and the cam occupies on the shaft such a position that
it is brought in contact with the friction roller X, the piston of the pump is
returned suddenly to the bottom of its cylinder at each return stroke of the
machine. But whenever the speed of the machine becomes sufficiently great for

page_text: the centrifugal force of the weights to move the spring i outward the cam W comes
into such a position that it no longer touches the roller X; this position is
represented in Figure 1. When the speed diminishes, the spring i by its pressure
upon the lever L, forces the pin p inward and causes the cam to slide upon the
shaft until it comes in contact with the roller ✗; a fresh charge of gas will thus
be forced into the cylinder.
In a gas engine, it is necessary, in order that no gas shall be lost, to regulate the
machine rather by the number of the explosions than by their force, bocause a less
proportion of gas would not produce an explosion. The proportion of air to gas
should be about ten to one. This quantity may, moreover, be varied from five to
fifteen, and if it is desired to obtain great regularity of the motor, the cam W may
be made of different layers or plates so that while doing less work, the machino
may be supplied with less gas. The capacity of the cylinder a is moreover,
considerably greater than is necessary whatever be the amount of gas employed;
so that there is a margin for the regulation of the machine. The cylinder of the
pump will be entirely filled at each stroke, but the entrance of gas can be regulated
by means of a cock, having an index, fixed on the pipe O. It is obvious that, with
a copious supply and a great pressure of gas in O, the air valvo P would not open,
and that the cylinder of the pump would be filled with gas only, at cach stroke.
If, moreover, the cock at O were partially closed, the gas could not enter rapidly
enough to fill the cylinder when the movement of the piston was offected rapidly
in such a manner that it would produce a sufficient suction to open the valve 7
which closes the air passage P: If air equal to half the amount of the charge is
sufficient to produce the maximum explosive effect, then the cock at O should be
sufficiently closed to allow the half of the contents of the pump to be drawn in at P.
In Figure 6 it will be observed that there are two valves placed one above the other,
and that in every case the aspiration causes the raising of the valve 6 and the
valve 7, if O is closed, but not if O is open. The mixture of air and gas will be
more effectual if a small quantity of air is mixed with the gas before it arrives in
the exploding cylinder.
When the piston moves forward and passes the holes T the air which has been
compressed in S passes into the cylinder, as above stated. As soon as the piston
has passed these holes on its return stroke, the compression commences in the
cylinder. At the same moment the gas and air are forced in at the other end, of
the cylinder and before the gas and air have time to become intimately mixed, they
are compressed and ignited. At the moment of the explosion there is a layer of
compressed gas and air at the left hand end of the space U (Figure 2) and a layer
of pure air against the piston B; the explosion at the left hand end forces the air
towards the right and produces a high pressure with a much smaller consumption
of gas than if the gas were mixed with the whole volume of air, because gas which
would produce an explosion while occupying only one-third of the space U would
not explode if mixed with the whole of the air contained in the cylinder. Great
economy is thus effected. By completely surrounding the cylinder by the air
space S, a large number of holes T may be made, so that the residues of the gas
may be completely expelled from the cylinder whilst the motor performs one-
twelfth part of its stroke. By giving to the connecting rod a relatively small
length, the time occupied by the piston for its return stroke is augmented so that
the exhaust valve remains open during a considerable time, whilst the machine only
makes one-twelfth of a stroke; the time during which air may enter is augmented
accordingly. The forward stroke of the machine is also rendered more rapid by
the employment of a short connecting rod in such a manner that the piston inoves
rapidly and does its work before the gas can cool and diminish its pressure. The
air necessary for expelling the foul gases from the cylinder is drawn in by the
apertures R. These apertures are closed by clack valves of ordinary construction
opening freely inwards but preventing any egress of air. The spaco S is of such
size that the pressure at the end of the stroke will not exceed 0-350 kilogramme
per square centimetre. The water casing is not cast with the cylinder A. The joint 3

page_text: which connects them is slightly conical in order to ensure its being tight. The
rocking shaft m is forged in one piece with the arms 8 and is held against its
bearing by the action of the spring h. If during the working of the machine, the
governor forces the cam Winward and it comes in front of the roller X this spring
yields and the shaft m is forced inward so that when the cam has passed tho
roller X; the spring forces back the shaft and causes the roller to engage with the
cam W.
•
It will be seen that when the machine is not charged or is working lightly, the
action of the governor will cause the said machine to lose a stroke, that is to say,
to make one stroke without effecting any work. The gas not entering, no explosion
will occur.
The flame which causes the explosion of the charge is admitted to the cylinder
in the following manner, that is to say:-The action of the excentric moves the
slide-valve L forward until the space M coincides with the aperture f. The draught
of the chimney then draws in air at f whilst discharging at M all the gases which
have been exploded.
The lower extremity of the chimney is reduced in diameter to produce a draught
at this point. When the chamber M coincides with the aperture fa part of the
gas contained in the chamber M is drawn into the chimney; this portion of the
gas is ignited and the excentric pushes back the slide-valve and closes the aperture f.
In order to ensure that the gas in the chamber M shall not be extinguished, the
chamber dis employed which not only supplies gas to M but augments the pressure
at this point in such a manner that when it is opened to K the flow of the gas is
not so rapid as it would otherwise be.
There is a small hole c through the slide-valve L and another hole c, and the
space between these holes is a little greater than the hole communicating with the
chamber d. When the hole c passes d the explosive gas flows through c and
filla d with gas at the same pressure as that in K. When the slide-valve is moved
forward it closes c and opens c the gas compressed into & then enters through the
port e into M, and as it is of an explosive nature it does not require oxygen to be
supplied to the flame, before this flaine is extinguished, the alide valve L moves
forward until M is in communication with K and the explosive gas entering is
ignited and the explosion occurs. If necessary, a small groove may be cut in the
slide-valve L so that a small quantity of gas may escape from K in to M, whilst M
is in communication with fand the chimney.
Oil may be supplied to the cylinder with the gas and air through the admission
valve I. The oil-cup may be of the kind usually employed in steam engines and
may be connected with the passage between 6 and 1. The metal tube 2 is rendered
tight at its extremities by means of screw-nuts. The long screw-thread at one of
its extremities permits of its insertion.
The slide of the head of the piston rod is provided with a key having the form
of a wedge held in position by means of a bolt. When it is necessary to adjust
the same, the ring is removed and reduced in thickness to permit the said wedge
to be shifted further under the head. In all cases, the screw should be firmly
fastened. The weight of the governor is connected to the rim of the fly-wheel by
a very thin piece of steel. This arrangement is better than a hinge or a pivot
and works equally well. The piston B is made of a single piece and is firmly
rivetted to the rod. There are three rings which are preferably made of cast iron
and should have a thickness on one side of about 5 millimetres and on the other
side of about 1, millimetres, they should be turned about 3 millimetres larger
than the diameter of the cylinder, cut at their thinnest part and one end made to
overlap the other as shewn in the Drawings about 10 millimetres. The piston ring
of the pump is made in a similar manner, but smaller in proportion.
The spiral spring should have considerable elastic force and should be compressed
by the screw so that a pressure of about 6-30 kilogrammes in S will be necessary
to open the valve. The object of employing a safety valve upon this engine is to
prevent too great pressure in the cylinder in case an accidental explesion in the

page_text: cylinder should take place whilst the charge is being compressed and the piston is
moving against the charge instead of in the other direction.
The standards are of cast iron and are provided with bearings of anti-frictional
metal; the admission valve I has a long rod which extends through the bottom of
the cylinder; this valve is kept closed by a spiral spring . Leakage around the
rod of this valve is prevented by means of a cap which completely encloses the
spring and the valve.
Brass should not be employed for the heated parts of this engine, they should
either be made of cast iron or of steel, the double stop valve should, however, be of
brass. The friction roller should be of steel connected to the arm by means of a
steel pin and the arm should be firmly keyed to the rocking shaft m. The spring F
should be of considerably less strength than the spring E in order to allow the
valve D to be closed.