Improvements in Gas Motors.
Year: 1891

page_text: Date of Application, 19th Aug., 1891-Accepted, 19th Dec., 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by JOHN STORER CONNELLY, of Plainfield, in the
County of Union, State of New Jersey, United States of America, Engineer.]
Improvements in Gas Motors.
I JOHN THOMSON KING of 4 Clayton Square, Liverpool, in the County of
Lancaster, Patent Agent, 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:-
Figure 1 is a side elevation of my improved gas-motor, showing the primary
cylinder and the charging cylinder in vertical central section.
Figure 2 is a cross section on the line II-II of Figure 3.
Figure 3 is a vertical section of the charging cylinder.
Figure 4 is a sectional view showing the igniting mechanism at the inner end of
the primary cylinder.
Fi
Figure 5 is an enlarged vertical section of the igniting mechanism.
Figure 51 is a vertical cross section on the line V¹Vi of Figure 5.
figure 6 is a sectional elevation on the line VI-VI of Figure 5.
Figure 7 is an elevation of the terminals of the igniting mechanism.
Like symbols of reference indicate like parts in each.
In the drawing, 2 represents the primary cylinder of the gas engine in which
the explosion of the charge is effected; 3 is the piston of this cylinder; 4 is the
secondary or charging cylinder the function and operation of which are hereinafter
explained; 5 is the piston of the cylinder 4. 6 is a pipe or channel connecting the
primary cylinder at ports 7 near its front end with the charging cylinder at a port
or ports 8 near its rear end. The pitmen 9 and 10 of the pistons of the two
cylinders are connected with a crank or cranks on the main shaft 11 of the engine,
and the charging cylinder is preferably set at an angle to the line of the primary
cylinder as shown. 12 is a port or series of ports connecting the rear part of the
cylinder 4 with an exhaust passage 13, which is controlled by a puppet valve 14
seating inwardly against a seat 15, and provided with a seating spring 16 of small
tension. 17 is a port or series of ports leading from a more advanced part of the
cylinder 4 and opening into an exhaust passage 18 which need not be controlled by
a valve. The trunk of the piston 5 is preferably provided with a passage 19
opening at a port 20, which at the back position of the piston (shown in Figure 1)
registers with the port 17 and at such back position the port 12 is covered and
closed by the piston.
In order to cushion the back stroke of the piston 5, I prefer to provide it with
a projection 21 which enters a cylindrical cavity 22 at the back end of the cylinder.
The piston of the primary cylinder 2 is adapted to control the port 7, to open it
hear the end of its outstroke. The admission of the explosive charge into the
primary cylinder is effected as follows:-23 is a valve of large area, preferably of
about the cross sectional area of the cylinder and situate at the rear end thereof
and adapted to open and close communication between the cylinder and a port 24
nto which air is admitted from a suitable inlet 25. In the middle of the valve 23
s a valve opening 26 communicating with a hollow stem 27, which stem is in com-
munication through a lateral opening with a gas inlet pipe 28. A valve 29 controls
the port 26, its stem 30 passes through the hollow stem 27, and is connected with
lever 31 pivoted to a post 32 which projects from the top of the stem 27. 33 is
a lever pivoted at.34 and connected by a rod 35 with the governor of the engine,

page_text: the construction being such that, if the speed of the engine should increase above
the desired limit, the governor will pull the lever 33 from beneath the lever 31 and
that otherwise when the engine is running at normal speed, the lever 33 stands
beneath the end of the lever 31 as shown. I do not claim broadly the use of the
lever or its connection with the governor.
The operation is as follows:-Suppose the parts be in the position shown in
Figure 1, with the primary piston on its outstroke and just about to uncover the
port and with the piston of the charging cylinder at the end of its instroke, but
before it has begun its outstroke. As the primary piston proceeds in its outstroke
it uncovers the port 7, and the nearly spent explosive gases from the cylinder 2
escape through the channel 6 and enter the rear of the cylinder 4, passing through
the passage 19 and escaping through the then connected ports 17, 20, to the exhaust
passage 18. As the piston 5 begins its outstroke, it closes the port 17 and the further
progress of the piston, creating a partial vacuum behind it in the cylinder 4. and in
the then connected cylinder 2 causes a suction on the valve 23 which unseats it
and admits air into the cylinder 2. Owing to the large area of the air valve, but
very little suction is required to open it. The inward motion of the stem 27 of the
air valve carries with it the post 32 and the lever 31, and the end of this lever
engaging the lever 33 causes the other end to have a downward motion and to
unseat the gas valve 29 so as to admit gas also into the cylinder. The motion of
the piston 5 not only causes the entrance of an explosive charge into the primary
cylinder as thus explained, but sucks out the spent gases of the preceding explosion.
This action continues until the piston 3 on its return stroke reaches and closes the
port 7 and cuts off communication between the two cylinders, and the remainder of
the instroke of the piston 3 is taken up by compression of the indrawn charge.
Immediately after the piston has closed the port 7, its pressure closes the air
valve 23. (The stem of this valve and the stem of the valve 29 are preferably
provided with springs 36 and 37 tending to lift them to their seats.) When the
piston 3 reaches and closes the port 7, the rear end of the piston 5 will have
uncovered the port 17, so that during the remainder of the out-stroke of the
piston 5 the opening of this port will permit its free motion without creation of a
retarding vacuum. On the instroke of the charging piston it expels the indrawn
gases until it comes to the port 17 after which it compresses the indrawn gases, and
such compression opening the valve 14 causes the gases to be expelled during the
remainder of the stroke through the port 12, and passage 13 into a suitable exhaust
channel, preferably constituted by the hollow bed plate of the engine. During
such backstroke, as the parts are pushed by the crank, their joints are held well
together, and at the conclusion of the stroke the entrance of the projection 21 into
the cylindrical cavity 22, creates an air cushion which further closes the joints and
holds them closed until the gases enter again from the primary cylinder. These
gases finding the parts pressed firmly together, operate on the piston without the
usual jarring mentioned above. If the speed of the engine should increase, so that
by operation of the governor the primary piston should make a stroke or several
strokes without explosion, it is obvious that this will not interfere with the motion
of the second cylinder by creating back pressure or suction thereon, since the
exhaust port 17 is open at the first and last part of the outstroke of the piston and
will then admit air freely to the cylinder, thus serving the function of the snifting
valve. At the end of the instroke of the piston 3, an igniting device ignites the
charge of gas in the cylinder 2 and propels the piston, the explosive force being
exerted thereon until the rear end of the piston reaches and uncovers the port 7;
thenceforward the cycle of operation of the engine is as described above.
In Figures 5, 6, and 7, I show in detail the electrical mechanism for igniting the
explosive charge in the primary cylinder. 34' is a shaft which extends through a
plug 35 set in the side of the primary cylinder, and at its inner end is fitted with
a wheel 36. 37 is a rod which also extends through the plug 351, and has at its
inner end a pawl 38, which bears against the periphery of the wheel 36. This

page_text: wheel has teeth formed as shown, with curved outer edges and abrupt ends, and the
pawl has its edge curved so as to be adapted to fit against the peripheries of the
teeth. When the wheel is rotated in the direction of the arrow, as hereinafter
described, the pawl will bear against the side of a tooth, until the end of the tooth
comes to the end of the pawl, whereupon the pawl, urged by suitable spring
pressure, will suddenly move inwardly upon the next tooth. The pawl and wheel
ferm the terminals of an electric circuit, and at the moment of separation of the
pawl from the tooth an electric spark is produced, which ignites the explosive
charge in the cylinder. The advantage of this construction of the pawl and wheel
is that all the wear by friction occurs at the periphery of the wheel, and not at the
ends of the teeth, and such wear will not disturb the adjustment of the parts, nor
change the moment when the spark occurs. In advance of the pawl and wheel is a
plug 39 having an oblong downwardly inclined slot 40 which affords communication
with the interior of the engine cylinder, and by reason of its inclination, prevents
the oil from the cylinder from getting access to the pawl and wheel and spoiling
their electrical action. The shaft 37 is preferably set in a bushing 41 surrounded
by a lining 42 of insulating material. At its outer end it is provided with a
spring 43 whose tension is regulable by means of a set nut 44. The dynamo, by
which the electric current is generated is not shown. It is driven by a belt from
one of the moving parts of the motor and its conductors are in electrical connection
with the pawl, and wheel of the igniting apparatus. There is a handwheel con-
nected with the dynamo and adapted to operate the dynamo for generation of
the electric current when the engine is first started. I shall now describe the
means which I employ for driving the shaft 34'. To rotate this shaft, I connect
it with a gear-wheel 52 on a shaft 53 which is driven by gearing 54 from the engine
shaft by means of a pinion 55 which is set on the igniting shaft and is so connected
therewith that it shall transmit motion to the latter shaft when the engine is
running forward, but not when it is reversed. This is effected by the device shown
in Figures 5 and 51. 55 is a wheel set against the hub of the pinion 55 and
having a flange which encircles said hub, and is adapted to be fixed thereto by a
set screw 56¹. Inside the hub of the wheel 55' the shaft is provided with a
peripheral notch or groove 56 tapering in depth and terminating in a shoulder, the
depth of the groove increasing in the direction of motion of the pinion produced by
forward motion of the engine. 57 is a spring-actuated pawl or dog set in a hole in
the hub of the wheel 55¹ and pressed by its spring 58 into contact with the
periphery of the shaft. So long as the pinion is fixed to the wheel 55¹ and rotates
in the direction of the arrow shown in Figure 51, the engagement of the pawl with
the shoulder at the end of the groove will transmit rotary motion to the igniting
shaft, but if the engine should be reversed, the pinion would revolve in the opposite
direction to that above described, and as the pawl cannot then catch on said
shoulder, ne rotation will be transmitted to the igniting shaft. The means used to
permit rotation of the igniting shaft in one direction only is important, because it
prevents injury to the igniter, which would otherwise occur in case-through any
cause, the motion of the engine should be reversed.
-
In the operation of the engine it is necessary that the spark should be made after
the admission and compression of the charge and at the beginning of the outstroke
of the primary piston when the engine crank is at its up centre. The parts should
be adjusted so that the time of this ignition should occur very accurately, and it is
for this purpose that I employ the wheel 55' detachably fixed to the pinion. To
set the igniter-shaft so that the explosion shall occur at the proper moment, I place
the engine crank on its up centre, then loosen the set screw 56 and turn the
wheel 55 (turning with it the shaft 341 within the pinion 55) until the igniter
pawl 38 drops on one of the teeth of the wheel 36. I then tighten the set screw 56¹
so as to connect the wheel 55' and the pinion, and thenceforth the spark will be
produced exactly at the same point in the cycle of action of the engine.
It will be understood that it is possible to get the benefit of part of my
invention

page_text: by making the wheel 55' and the pinion of one integral piece, and I intend to
cover such construction in the claims. In this case the advantage of preventing
reverse motion of the igniter shaft would be secured, without securing adjustability
of the igniting mechanism.
It will be understood that when the speed of the engine exceeds the normal, so
that the lever 33 is pulled away from the path of the lever 31, the opening of the
air valve will not open the gas valve, and the engine will proceed to revolve without
explosion until the speed again is reduced to the normal degree.
In the use of engines having a primary cylinder and second or charging cylinder,
the action of the second cylinder and piston is noisy, so much so as to unfit the
engines for use for many purposes. The reason for this I have found to be as
follows: It impossible to make the connection between the piston and piston
rod of the second cylinder, and between the piston rod and crank so exact that
there shall be no loose motion of the parts, and when the piston is being started on
its outstroke by revolution of the main shaft, the joints of the parts are separated
to the fullest extent. It has been the practice heretofore not to admit the charge
into the second cylinder until after the piston has thus commenced its out-
stroke, and the effect of the sudden force exerted on the piston by the entrance
of the gases is to force the parts quickly together with a jarring and disagreeable
noise.
One object of the invention above described is to obviate this difficulty, and I
accomplish it by so relating the positions of the cylinders with reference to their
crank or cranks, and the location of the exhaust port of the primary cylinder, that
the exhaust from the primary cylinder into the second cylinder shall occur just as
the second piston is at the end of its instroke, and before the parts have been
separated or loosened by the draft of the crank on the piston. The exhaust then
on entering the second cylinder, finds the joints of the parts all closed together, by
the pushing of the crank on the piston, and therefore operated without any jar.
As a useful auxiliary to this part of my invention, I prefer to employ the cushioning
device, 21, 22, at the inner end of the second cylinder, which, as the piston reaches
the end of its stroke, ensures the closing together of the joints and holds them
together until the charge has acted on the piston with its outward propulsion.
The parts of my invention above indicated are of use even when the engine is so
used, as above described (opening of the exhaust valve at the moment of the escape
of the gases from the primary cylinder), that no effective power is transmitted to
the second cylinder, which is used only for the indraught of the next explosive
charge. In such case, the escape of the gases from the primary cylinder produces
a blow on the piston of the second cylinder, which though not sufficient to act
appreciably to propel it, is enough to make the disagreeable noise above referred
to if my improvements were not employed. They are also of material use when
the parts are so constructed and arranged that the exhaust valve in the second
cylinder is closed at the time of admission of the charge from the primary cylinder
in which case the charge will act propulsively on the piston of said second cylinder.
Both such constructions are within the scope of my invention.
Another feature of my invention relates to the exhaust valve, through which the
exploded gases are discharged from the cylinders. Heretofore it has been the
practice to employ an exhaust valve communicating with the primary and second
cylinders, and operated mechanically, so that it shall be closed at the time when
the discharge from the primary cylinder to the second cylinder occurs, and that it
shall be open during the back stroke of the second piston. This would answer
well enough if there were an explosion at every outstroke of the primary piston,
but it is the general practice in operating gas engines to employ a governor, so
constructed and geared with the valve which admits the gas for the explosive
charge, that when the engine runs above its normal speed the valve shall be closed
temporarily. The primary piston may thus make two or three successive strokes
without explosions, and in such case, if no special device be employed to prevent

page_text: it, the second piston must of necessity on its outstroke create a vacuum which
would seriously retard the motion of the engine. To prevent this it has been
common to employ a snifting valve located at the rear of the second cylinder and
adapted to open when a partial vacuum is produced by the cause above mentioned.
There are however serious objections to the use of a snifting valve. If it is made
to open easily, there is danger that it will open when suction is created in the
cylinders by the normal action of the piston at the end of its stroke in drawing in
the explosive charge of gas and air, and this, of course, would interfere with the
indraught of the charge. If it is made difficult to open, so as to overcome the
danger last indicated, it is at the serious loss of power of the engine, which on idle
strokes must part with considerable energy in overcoming the suction which must
occur before the valve opens. Besides this, snifting valves in any case are
objectionable, because it is practically impossible to provide efficient and noiseless
means for closing them with sufficient rapidity. These matters which are of great
importance in gas engines, I provide for, by employing an exhaust valve which is
open in the first and last parts of the outstroke of the second piston. Of course by
this construction, power is lost by reason of the partial escape of the exploded
gases while still under tension, but this is much more than overbalanced by the
great saving of power which arises from the prevention of the difficulties incident
to snifting valves as above mentioned.
Other advantages of my improvement are that the operation of charging the
engine with an explosive mixture is effected by the action of the pistons, and the
use of specially constructed cams and mechanism for operating the valves is.
dispensed with, the exhaust mechanism is extremely simple, the engine operates
with little noise, and the expulsion of the exploded gases, and the indraught of the
explosive gases is effected accurately and thoroughly.
It will be understood by those skilled in the art, that the engine is capable of
modification in various ways within the scope of my invention, and, as before
indicated, it may be modified to serve as a compound engine in which the gases act
first on the primary piston, and subsequently on the second piston.
The purpose of the passage 19 is to permit a preliminary exhaust of the gases
and to cause the cylinder 4 to act solely as a charging cylinder, not as a motive
cylinder. With suitable modification, however, this passage may be dispensed
with.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
First. A gas engine having a primary cylinder and a second charging cylinder,
each provided with a piston and being connected, and the primary cylinder being
provided with a suction operated valve for the inlet of the explosive charge, and
the piston of said cylinder being adapted to open and close communication between
the two cylinders, whereby when said communication is established, a suction is
created and the valve opened thereby; substantially as and for the purposes
described.
Second. In a gas engine the combination of the primary cylinder and a second
exhaust and charging cylinder connected therewith, and provided with a valve
opened by outward pressure for the expulsion of the exhaust, said cylinders
having pistons, and an inwardly acting suction valve in the primary cylinder
for the admission of the explosive charge; substantially as and for the purposes
described.
Third. In a gas engine, the combination of the primary cylinder and a second
exhaust and charging cylinder connected therewith, and provided with a valve
opened by outward pressure for the expulsion of the exhaust, said cylinders having
pistons, said valve communicating with the charging cylinder through a port at its
rear portion, and a second port situate at a more forward portion of the charging

page_text: cylinder and adapted to be opened by the piston thereof; substantially as and
the purposes described.
Fourth. In a gas engine, the combination of the primary cylinder and a second
exhaust and charging cylinder connected therewith, and provided with a valve
opened by outward pressure for the expulsion of the exhaust, said cylinders having
pistons, and said valve communicating with the charging cylinder through a port
at its rear portion, and a second port situate at a more forward portion of the
charging cylinder and adapted to be opened by the piston thereof, and a passage 19
extending through the trunk of the piston, and adapted to register with said
forward port at a portion of the stroke of the piston and at a time when the valve
controlled port is closed by said piston; substantially as and for the purposes
described.
Fifth. A gas engine having a primary cylinder and a second charging cylinder,
each provided with a piston and being connected, and the primary cylinder being
provided with a suction operated valve of substantially the cross sectional area of
the primary cylinder for the inlet of the explosive charge and the piston of said
cylinder being adapted to open and close communication between the two cylinders,
whereby when said communication is established a suction is created and the valve
opened thereby substantially as and for the purposes described.
;
Sixth. The combination with the explosion chamber of a rotatory igniting shaft,
gearing connecting the same with the driven parts of the engine, and an
intermediate ratchet and deteut connection, whereby motion of the igniting
shaft in one direction only is possible; substantially as and for the purposes
described.
Seventh. The combination with the explosion, chamber, of a rotatory wheel
having a tooth with curved periphery and abruptly terminating end, and a pawl
whose side is shaped to fit against the periphery of the wheel, said wheel and pawl
forming the terminals of electric circuit; substantially as and for the purposes
described.
Eighth. The combination with the explosion chamber of a gas engine cylinder,
of electric igniting terminals, and a plug having an inclined slot separating the
terminals from the cylinder; substantially as and for the purposes described.
Ninth. In a gas engine, the combination of the primary cylinder and the
secondary cylinder, the pistons of which are connected with a crank and the said
cylinders being set with their axial lines at an oblique angle to each other and a
passage connecting the cylinders, said parts being so related in position that the
discharge shall occur when the piston of the secondary cylinder is at the end of its
instroke before it begins its outstroke; substantially as and for the
described.
purposes
Tenth. In a gas engine, the combination of the primary cylinder and the
secondary cylinder, a passage connecting them and adapted to discharge the
partially spent gases from the primary cylinder to the secondary cylinder, said
parts being so related in position that the discharge shall occur when the piston of
the secondary cylinder is at the end of its instroke, and an air cushion chamber for
the secondary cylinder; substantially as and for the purposes described.
Eleventh. In a gas engine, the combination with the connected primary and
secondary cylinders and their pistons, of an exhaust mechanism so timed that the
exhaust valve shall be open at or about the beginning of the stroke of the
secondary cylinder; substantially as and for the purposes described.
Twelfth. In a gas engine, the combination with the connected primary and
secondary cylinders and their pistons, of an exhaust mechanism so timed it shall be
open at or about the beginning of the stroke of the secondary cylinder, that it
shall then close to create a suction for drawing in the explosive charge, and that
it shall then open and shall remain open during the instroke of the secondary
cylinder; substantially as and for the purposes described.
Thirteenth. In a gas engine, the combination with the explosion chamber, of a

page_text: rotatory igniting shaft, a driving pinion not directly fixed to the shaft, and a
detachable connexion, such as a set screw, adapted to fix the driving pinion to the
shaft substantially as and for the purposes described.
Fourteenth. In a gas engine, the combination with the explosion chamber, of a
rotatory igniting shaft, a driving pinion not directly fixed to the shaft, a wheel 55¹
set on the shaft and connected therewith by a ratchet and detent connection, and a
detachable connection, such as a set screw, adapted to fix the wheel to the driving
pinion; substantially as and for the purposes described.
Dated the 18th day of August 1891.