Improvements in Starting Gear for Gas Engines..
Year: 1888

page_text: COMPLETE SPECIFICATION.
Improvements in Starting Gear for Gas Engines..
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention (which has been communi-
cated to me from abroad by Edouard Delamare-Deboutteville and Léon Paul Charles
Malandin of Fontaine le Bourg Seine Inférieure in the Republic of France Engineers)
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 improvements in starting gear for gas engines and it has
for its object overcoming the difficulty heretofore experienced in starting these motors
especially those of considerable power which difficulty has proved a serious obstacle to
the general use of these engines in practice. Many special methods have been proposed
with a view to facilitating the starting of the engines but have not been found to work
satisfactorily.
And in order that my said Invention may be fully understood 1 shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheet of drawings the saine letters of reference indicating
corresponding parts in all the figures.
Figure 1 of the accompanying drawings is an elevation partly in section illustrating
starting gear arranged according to this Invention and suitable for a motor of 25 H.P.
working with poor gas for example. This view shows the admission valve box and gas
chamber 9. It also represents in dotted lines an igniter which is connected with the
gas box
g by a three way cock k connected to a branch h by means of a rubber
tube i.
Figure 2 is a diagram illustrating the action of the cam or excentric.
. Figure 3 is a section of the three way cock & connected to the chamber of the
igniter ; which is also shown in section in this figure with the two insulated conducting
wires. The cock which should be as perpendicular as possible but may be horizontal
if necessary should not exceed an angle of 20° to work well.
Figures 4 and 5 are respectively views in section and elevation of the cock.
Figure 6 is an end view in elevation of the induction coil.
Figure 7 is a plan of a switch arrangement.
The diagram Figure 2 represents the four periods of the excle of operations nerfor ved

page_text: in working the engine the radial lines indicating the successive angular displacements
of the cam or excentric operating the valve or slide the said cam or excentric being
caused to describe one complete revolution to two revolutions of the crank shaft in the
usual manner.
The shaded segment between b and c represents the angle through which the cam or
excentric is caused to move during the first period that is to say the period during
which the gaseous mixture is drawn into the cylinder when the engine is working in
the usual manner the cam or excentric being rotated in the direction of the arrow.
The piston then returns and compresses the mixture whilst the cam moves from 6 to c.
The explosion takes place between c and d and the burned gases are expelled by the
second inward stroke of the piston whilst the cam moves from d to a and thus returns
to its original position in readiness for the next cycle.
The starting of the machine according to this invention is accomplished as
follows:-
The motor being at rest, the fly wheel is turned by hand so as to bring the connecting
rod to the dead point corresponding with position c (Figure 2) where the explosion
takes place when the engine is running. The strength of one man is enough to turn
the fly wheel for the one or two necessary revolutions if the motor does not exceed
25 horse power for a motor, exceeding this a winch or other suitable gear may be
employed to turn the fly wheel.
When the connecting rod is at the dead point corresponding with position c, a gas
cock Z placed on the valve box 9 (as indicated by the dotted lines in Figure 1) is
placed in the ordinary position for starting. Then the three way cock k is opened
to the position indicated in Figures 1, 3, 4 and 5. The fly wheel then is turned so
as to bring the connecting rod to a point a little beyond the angle of 90°, i.e. to
a position approximately corresponding with the point e (Figure 2). The fly wheel
must be turned slowly in order to give the gaseous mixture time to fill the cylinder.
The gas entering at o (Figures 3 and 4) mixes thoroughly with the air entering at n
filling the ignition chamber and passing on into the working cylinder of the motor.
It must be understood that during this time the vibration of the hammer or contact
maker of the coil is stopped so that the spark cannot pass between the two ends of the
platinum wire. The three way cock kis now shut, a small stop m preventing the
handle from being turned through more than about 45 degrees.
The fly wheel is then turned backwards to bring the connecting rod in a position
corresponding with the point e', a little in front of the position corresponding with the
point (Figure 2). This is done in order to slightly compress the mixture in the
cylinder thus facilitating combustion and giving a longer movement to the piston
which is thereby enabled to act more effectively. The cam being at e', a spark is
caused to pass as hereinafter explained, the mixture is thus exploded and the piston is
driven forward with such energy as to impart to the fly wheel the velocity necessary
to start the motor.
The hammer or contact maker of the induction coil is started as follows-when the
proper time has arrived for igniting the explosive mixture. In ordinary induction
coils the terminals & and figure 6 receive the wires coming from the battery and the
upper terminals a, y, carry the wires which conduct the current to the igniter. In the
present arrangement the terminals only is connected to one of the poles of the coil,
the terminal t being insulated and an auxiliary terminal u (Figures 6 and 7) introduced
in the place usually occupied by the terminal t. The hammer or contact maker having
been previously regulated to vibrate immediately on the passage of the two currents of
the battery, this current is interrupted by means of a switch which opens the circuit.
Then when the proper moment has arrived for igniting, it is simply necessary to set
this switch on the terminal u in order to close the circuit of the coil. The current
of the battery is then transmitted to the second pole of the coil and the hammer or
contact maker commences to vibrate establishing the electric current which produces
the spark in the igniter. This simple method of starting is equally applicable to
motors worked by town gas or poor gas, or petroleum vapour, or in fact to any motor
worked with explosive gas.

page_text: The system of starting hereinbefore described can also be applied to gas motors
whose explosion is produced by a gas jet or otherwise in place of an electric spark. In
this case the apparatus is arranged as illustrated in Figure 8 for example being screwed
into the cylinder o of the motor or into one of the sides of the compression chamber.
The gas inlet represented at a is put in communication with the admission cock of the
gas as herein before described with reference to Figure 1.
E
In order to start the engine with this arrangement a stop cock and a threeway
cock B corresponding to the cock marked k in Figures 3 and 4 are opened, the fly
wheel is turned as hereinbefore described to draw in and compress the explosive
mixture. Then the cock ẞ is shut and the spark caused to pass in an igniter 8. The
explosion then takes place the piston is driven forward and the fly wheel acquires
sufficient velocity to start the engine.
The starting being thus effected the cock & is shut immediately after the first
explosion. It must be understood that in the first instance the parts must be placed
in the positions for starting the engine in the ordinary way: A stopper r enables the
points of the platinum wires in the igniter to be adjusted without removing the igniter
itself. As a single electric spark suffices for the explosion in this special case it is
possible so to arrange the coil that the spark is only produced between the points of
the wire for the short period of time sufficient for igniting the gaseous mixture.
It is evident that the construction of the parts hereinbefore described with reference
to the accompanying drawings may be modified in various ways without departing
from the principle of the invention.
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 :-
1. An improved starting gear for gas engines consisting of a cock k supplying
explosive gaseous mixture the said cock being connected to the igniting chamber and
a gas pipe h connecting the said cock with the gas supply chamber g all operating as
and for the purpose hereinbefore described with reference to Figures 1, 3, 4 and 5 of
the accompanying drawings.
2. In starting gear constructed or arranged as hereinbefore described with reference
to the accompanying drawings or otherwise excluding the gaseous mixture until the
cam or excentric is on the point c that is to say has reached the point at which the
ignition normally takes place the admission afterwards continuing until the can or
excentric has reached a point e after which the mixture is compressed by bringing the
cain or excentric back to a point el substantially as hereinbefore described with reference
to Figure 2 of the accompanying drawings.
3. In combination with starting gear for gas engines arranged and operating as
hereinbefore described and claimed a circuit opener or switch v arranged in the circuit
of the induction coil in the manner and for the purpose substantially as hereinbefore
described with reference to Figures 6 and 7 of the accompanying drawings.
4. In combination with a gas engine provided with an electric igniter the combina-
tions and arrangements of parts constituting the improved starting gear substantially
as hereinbefore described an illustrated in Figures 1 to 7 of the accompanying
drawings.
5. In combination with a gas engine in which the ignition is effected by a jet or
otherwise, the combinations and arrangements of parts constituting the improved
starting gear substantially as hereinbefore described and illustrated in Figure 8 of the
accompanying drawings.
Dated this 24th dove of February 1888