Improvements in Means for Igniting the Charges in the Cylinders of Explosion Engines.
Year: 1892

page_text: Date of Application, 18th May, 1892
Complete Specification Left, 20th Mar., 1893-Accepted, 22nd Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Means for Igniting the Charges in the Cylinders
of Explosion Engines.
I, PERCY JOHN OGLE, of 4, Bishopsgate Street Within, in the City of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to means for igniting the charges in the cylinders of
explosion engines.
One of the methods hitherto employed for effecting the ignition of such charges
consists in utilizing the heat produced by the explosions for heating some part
sufficiently to ignite the next charge which comes into contact with it. Owing, how-
ever, to the time which elapses between the successive explosions, to the cooling effect
produced by the expansion of the gases during the working stroke and also to the
contact with the part which is to serve as the igniter of the cool incoming charge
the said igniting part becomes more or less cooled so that it is only capable of
igniting a charge comparatively rich in vapour or gas, whereby an engine provided
with such an igniting apparatus does not work so economically as an engine
provided with an igniter such as a flame, an electric spark, or an externally
heated tube.
The object of my invention is to effect the ignition of the charges in explosion
engines by an igniting arrangement in which a proportion of the highly heated products
of combustion of the previous charge are retained in an igniting chamber until just
prior to the igniting of the next charge so that the said igniting chamber is kept at
a high degree of temperature, whereby my igniting arrangement may be used for
igniting relatively poor explosive mixtures without the application of any heat
except that due to the explosions in the igniting chamber itself.
In carrying out my invention I arrange in conjunction with the explosion
chamber of the engine a second chamber which I term my igniting chamber, and
in a communicating passage between the chambers I arrange a valve which normally
closes the said passage, but which is operated by the engine to open at the moment
when the charge in the explosion chamber is fully compressed and the piston of
the engine is in the proper position to receive the impulse due to an explosion and
to close immediately or very soon after the explosion has taken place. My
igniting chamber is preferably lined with fire-clay or other suitable refractory
material to retain the heat, but, at the starting of the engine, and until the igniting
chamber becomes sufficiently heated, I provide for igniting the charges by means
of a heated tube or other incandescent body passed into the igniting chamber, or
by an ordinary igniting tube, or by any other suitable means, after which the
igniting chamber will be maintained in a heated condition by the successive
explosions, the valve hereinbefore described serving to retain the igniting chamber
full of the heated products of combustion at a high temperature until just prior to
the operation of the said valve to again establish communication between the
explosion chamber and the igniting chamber. In conjunction with the igniting
chamber I arrange a second valve which is positively operated by the engine just
prior to the admission of a fresh charge into the igniting chamber for the purpose
of allowing the products of combustion therein to escape and to reduce the pressure
to that of the atmosphere.
Dated this 18th day of May 1900
.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Means for Igniting the Charges in the Cylinders
of Explosion Engines.
I, PERCY JOHN OGLE, of 4, Bishopsgate Street Within, in the City of London,
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 relates to means for igniting the charges in the cylinders of
explosion engines.
One of the methods hitherto employed for effecting the ignition of such charge
consists in utilising the heat produced by the explosions for heating some part
sufficiently to ignite the next charge which comes into contact with it. Owing,
however, to the time which elapses between the successive explosions, to the cooling
effect produced by the expansion of the gases during the working stroke and also
to the contact with the part which is to serve as the igniter of the cool incoming
charge, the said igniting part becomes more or less cooled so that it is only capable
of igniting a charge comparatively rich in vapour or gas, whereby an engine
provided with such an igniting apparatus does not work so economically as an
engine provided with an igniter such as a flame, an electric spark, or an externally
heated tube.
The object of my invention is to effect the ignition of the charges in explosion
engines by an igniting arrangement in which a portion of the highly heated
products of combustion of the previous charge are retained in an igniting chamber
until just prior to the igniting of the next charge so that the said igniting chamber
is kept at a high degree of temperature, whereby my igniting arrangement may be
used for igniting relatively poor explosive mixtures without the application of any
heat except that due to the explosions in the igniting chamber itself.
In carrying out my invention I arrange in conjunction with the explosion or
combustion chamber of the engine a second chamber which I term my igniting
chamber, and in a communicating passage between the said chambers 1 arrange a
valve which normally closes the said passage but which is operated by the engine
to open at the moment when the charge in the explosion chamber is fully com-
pressed and the piston of the engine is in the proper position to receive the impulse
due to an explosion and to close immediately or very soon after the explosion has
taken place. My igniting chamber is preferably lined with fire-clay or other
suitable refractory material to retain the heat, but, at the starting of the engine,
and until the igniting chamber becomes sufficiently heated, I provide for igniting
the charges by means of a heated tube or other incandescent body passed into the
igniting chamber, or by an ordinary igniting tube, or by any other suitable means,
after which the igniting chamber will be maintained in a heated condition by the
successive explosions, the valve hereinbefore described serving to retain the igniting
chamber full of the heated products of combustion at a high temperature until just
prior to the operation of the said valve to again establish communication between
the explosion chamber and the igniting chamber. In conjunction with the igniting
chumber I arrange a second valve which is positively operated by the engine just
prior to the admission of a fresh charge into the igniting chamber, for the purpose
of allowing the products of combustion therein to escape and to reduce the pressure
to that of the atmosphere.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which :-
Figure 1 is an elevation of my improved igniting apparatus; and,
Figures 2 and 3 are sections on the lines 2-2 and 3-3 respectively of
Figure 1:
Figure 4 is a plan with some of the parts removed.

page_text: a is my igniting chamber which is carried upon one side of the explosion chamber
and connected with the interior thereof by the passage b, and e is the valve which
is normally held against its seat by means of a spring a connected to the lower end
of the valve-stem.
e is the lining of refractory material within the chamber a, the said lining
having a central passage f and being introduced into the chamber a by removing
the cap g thereof.
h is the passage through which the products of combustion enclosed in the
chamber a can be exhausted, and is the valve in the said passage, which valve is
normally held against its seat by a spring d in the same manner as the valve c.
j, k are cams for operating the valves c, i, the said cans being mounted on the
shaft through the medium of which the engine valves are operated; which shaft
in the case of a two cycle or four stroke engine makes one revolution to two of
the crank-shaft. The projections j, k¹ of these cams j, k are designed to operate
against two levers m, m', respectively, pivotted to a bracket n, the said levers
respectively bearing against the lower ends of the stems of the valves c, i by means
of the projections o, o, which projections are on the adjacent sides of their levers,
as shewn most clearly in Figure 3, to enable them to actuate the valves.
The operation of the apparatus hereinbefore described is as follows:-Assume
the refractory lining e of the chamber a sufficiently heated to ignite the charges
and assume the said chamber to contain a quantity of heated gas under com-
pression due to the previous explosion and also that the pistou of the engine is
performing the compression stroke of the cycle. Just before this stroke is com-
pleted the projection of the cam k actuates the lever m' and lifts the valve i,
whereby the gases contained in the chamber a are allowed to escape sufficiently to
reduce their pressure to that of the atmosphere. Immediately after this has been
accomplished and by the time the piston reaches the end of its compression stroke
the projection of the cam operates against the lever n and lifts the valve c,
whereby a portion of the gases from the explosion or combustion chamber flow
through the passage into the igniting chamber a, where they are immediately
ignited, the flame passing back and igniting the charge in the said explosion
chamber. After the explosion the cam ; allows the valve c to close whereby the
gases contained in the igniting chamber a (which gases are at a high pressure due
to the explosion) are retained during the whole of the first outstroke under the
explosion, the next instroke by which the products of combustion are exhausted,
the next outstroke during which a fresh charge is drawn into the cylinder and
nearly the whole of the instroke during which the gases previously drawn in are
compressed, when, just before the end of such instroke, the projection ' acts
against the lever m¹ to open the valve i as herein before described.
It will be readily understood as the chamber a is lined as hereinbefore described
and as the products of combustion are retained from the time of one explosion
until just before the next explosion is to take place that the said igniting chamber
can be retained at the desired heat.
In practice I find it advantageous to surround that part of the apparatus con-
taining the valves with a water jacket to prevent it from becoming overheated.
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 :-
1. In igniting apparatus for explosion engines a chamber having a lining of
refractory material for retaining heat and communicating with the explosion
chamber, in combination with two valves, one of which controls the communi-
cation between the explosion chamber and the igniting chamber whilst the other
allows the gases contained by the igniting chamber to escape to the atmosphere,
the said valves being operated by cams in such a manner that the communication
between the cylinder and the igniting chamber is only opened when the charge is
to be ignited and between the igniting chamber and the atmosphere just prior to

page_text: the introduction of a new charge of gas into the igniting chamber, substantially as
. hereinbefore described.
2. The manufacture and use of the improved apparatus for igniting the charges
of explosion engines, substantially as herein before described and illustrated in the
accompanying drawing.
Dated this 20th day of March 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.