Improvements in Gas and Petroleum Engines.
Year: 1898

page_text: Date of Application, 26th Aug., 1898-Accepted, 22nd Oct., 1898
COMPLETE SPECIFICATION.
Improvements in Gas and Petroleum Engines.
ROBERT OWEN ALLSOP, 37, Norfolk Street, Strand, London, Architect, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following state-
ment:-
This invention refers to that class of gas and petroleum and the like internal
combustion engine, wherein a movable or adjustable piston or plunger, suitably
operated, slides at will in the compression or combustion space of such engines,
the use and purpose of the said adjustable plunger being to vary the clearance at
the back of the motor piston, and so vary the compression pressure; the ultimate
object of such varying of the cubical contents of the compression or combustion
space being to start, control, regulate and vary the speed and power of the engine.
I make reference to Letters Patent No. 26638 A.D. 1896 and No. 13092, A..D. 1897
granted to me. The present invention comprises certain improvements-as herein-
after specified-affecting the inventions as described by me in the specifications
of the above said Letters Patent.
The present invention comprises three improvements viz.:—
(1) A method of preventing leakage of the compressed gases past the adjustable
piston or plunger, where the engine is working with highest compression, at the
same time providing more effective water jacketting of the combustion chamber,
and preserving such chamber with a minimum of port space.
(2) An electric ignition device suitable to very high compression pressures and
to varying and low compression, and a means of protecting such electric ignition
device from the heat and shock of explosion when such device is used only for start-
ing engines.
(3) A method of forming the adjustable plunger whereby the ordinary ignition
tube without timing valve may be made applicable and practicable with varying
compression pressures.
Referring to the accompanying drawings comprising 5 sheets and twelve figures
Figs. 1, 2, 3, and 4 shew Improvement No. 1.
Figure 1 is a sectional plan Figure 2 a sectional elevation Fig. 3 a cross section
of an auxiliary compression space (looking towards the motor piston) and Fig. 4
a section of auxiliary compression space looking towards the reverse end of engine.
The figs, named shew the improvement as applied to an ordinary gas or petroleum
engine of the "Otto" four cycle type viz. with one motor stroke in every two
revolutions of the flywheel. Only a portion of such engine is shewn in the drawings
such portion comprising the cylinder and motor piston with a part of the bed and
a part of the connecting rod the combustion chamber and an extension of, or an
auxiliary combustion chamber and adjustable plunger with my improvement
adapted thereto.
The adjustable plunger is shown operated by a screwed rod and lever arms with
heavy weights after the nature of a fly press but the plunger may be advanced and
operated with any suitable means.

page_text: Figs. 1, 2, 3 and 4, are given in illustration of Improvement No. 1 A is the adjust-
able plunger; B³ B¹ respectively the combustion chamber and an extension of same;
C, is the cylinder and D) is the motor piston. E is the screwed rod working in the
back cover F and suitably secured to the plunger and to the operating lever and
weights G.
At H, J, & K, are respectively the ignition and exhaust and inlet valve ports.
In order to effectually prevent leakage of the compressed and exploded gases past
the plunger when the engine is working at its highest compression, I arrange that
the face or other suitable part of the plunger or any suitable projection on the same,
such as a plug stop or cap shall by action of the lever and screw be screwed tight
against any suitable ledge ring hole or opening communicating with the com-
bustion space proper (B 2).
As shewn in Figs. 1, 2, 3 and 4 the improvement is intended to be applied to
a engine using a high compression where it is advisable to keep the combustion
chamber as effectually water jacketted as possible.
To this end and purpose I make a comparatively small port or opening between
the combustion chamber and the auxiliary combustion chamber and thereby am
enabled to bring the cooling water well round to the back of the combustion
chamber as shewn at M, M, which are parts of the water jacket surrounding the
combustion chamber. I further in order to preserve a compact combustion space,
without unnecessary port surfaces, arrange a tapering plug or nose N, which being
carefully fitted and ground into the tapered opening L, makes the joint absolutely
gas tight and fills up the opening completely.
By this means therefore an engine may be started with low compression and
when running at high compression the highly compressed gases, and the gases
of explosion cannot leak past the plunger should the piston rings in such plunger
not be gas tight.
Improvement No. 2 is shewn in Figs. 5, 6 and 7 and comprises an improved
electric ignition device and means of protecting the same from the heat and shock
of explosion, when the electric ignition is only required for starting an engine,
and the engine subsequently runs with a hot ignition tube. Fig. 5 shews a com-
bustion chamber and auxiliary combustion chamber such as has been described
above and essentially similar to that shewn in the preceding figures, but also shew-
ing the electric ignition device and means of protecting the same from unnecessary
wear and tear. Fig. 6 is a cross section of an auxiliary combustion chamber shew-
ing the improved electric ignition device and at Fig. 7 one of the sparking points
and the improved method of mounting and securing the same is shewn.
The object of the improved ignition device is to prevent leakage through the
plugs at high compression with high explosive pressures and also to prevent the
short-circuiting that results from the condensation which takes place with certain
vapourised hydro-carbons particularly with engines using varied compression such
condensation disturbing the regularity of the sparking. This is especially so
where two wires pass through one plug with points that are close together.
In my improved ignition device I use two sparking points both insulated
absolutely from the walls of the combustion chamber. I connect these points in
any suitable manner with an electrical apparatus-preferably an accumulator or
secondary battery and a powerful induction coil. With suitable automatic or other
mechanism I make and break contact as required to produce a spark at a suitable
moment to fire the explosive charge in the engine.
Instead of placing my two wires or other conducting media in the same plug, I
place each in its own plug with separate insulators and separate means of adjust-
ment and I do not place the wires or conductors parallel to one another but I incline
the one to the other at a suitable angle but in the same plane.
By this means I am enabled to keep a considerable distance between the two
ignition plugs and gain by this greater distance, a greater immunity from the evil
effects of that short-circuiting which is caused by the deposition of a film of con-
densed petroleum.

page_text: Moreover by the fact of the two spark conductors being inclined to each other in
the same plane I am enabled with great facility to adjust the distance of the spark-
ing points for by screwing or otherwise advancing or withdrawing one or both of
the plugs in the wall of the combustion chamber I can adjust them at the required
distance and set them in position by suitable lock nuts.
In the construction of each individual plug in order to prevent any leakage
through and between any of the component parts of such plug I form the porcelain
or other suitable nonconducting plug or insulator tapered externally and with a
tapered hole internally and I grind and carefully fit around the porcelain plug a
suitably screwed sleeve-piece or nipple with tapered hole and I carefully fit and
grind into the centre of plug a tapered length of soft iron or other suitable con-
ducting material with suitable platinum or other sparking points. The result of
this method of forming the plug is that the more forcible the explosion pressure
the harder and more gas tight is the conductor driven into the porcelain plug and
the porcelain plug driven into the sleeve or other suitable holder.
Fig. 7 shews a section of one of the plugs employed in this electric ignition
device. A is a tapered conducting core of soft iron or other suitable material
ground into, or otherwise carefully fitted and set with plaster of Paris or other
suitable cement in a tapered hole in B, which is the insulating plug of porcelain
or other suitable material. The outside face of the porcelain plug is also tapered
and is carefully grooved in or otherwise fitted to a metal or other suitable sleeve C
such sleeve having a thread cut on it and being screwed a suitable distance into
the wall of the combustion chamber D and set in the required position by the lock-
nut E¹.
At F is a sparking point of platinum or other suitable material screwed or suit-
able fixed in the soft iron core A¹. At the other end of the conducting core a screw-
thread is cut and a nut G¹ screwed on which keeps the tapered core tight against
porcelain plug and a lock nut H, may be used as a terminal to secure the wire from
induction coil.
A lock nut or a cap below or above could be employed to further secure the
plug in the sleeve but I find that with a carefully fitted taper joint with a suitable
cement, such as plaster of Paris the explosion pressure keeps the plug device hard
and gas-tight in the sleeve.
At Fig. 6, the plugs are shewn inclined together in accordance with the inven-
tion as explained above. In cases where, as in an engine permanently run by
electric firing, I place this electric ignition device in the actual combustion chamber
of gas and petroleum engines I preferably place one plug on either side of the
inlet valve port at a suitably inclined angle and in the same plane so that the spark-
ing points may be kept cool and clean by the rush of fresh air and so that the spark
may occur in a part rich in fresh explosive mixture and freest from exhaust
products.
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In Fig. 5 is shewn the method of protecting the electric plugs from the explosion
in cases where such may be desirable as in internal combustion engines started
in the manner described in Letters Patent 13092, A.D. 1897 granted to me; A is
the adjustable plunger B₁ the auxiliary combustion chamber 132 the combustion
chamber proper;
Ğ the screwed rod operated by suitable means. At the end
the plunger has a longer nose or plug than that shewn in Figs. 1, 2, 3 and 4 the
object being to seal the tapered opening connecting the auxiliary explosion chamber
and the explosive chamber proper and yet to leave the annular space E into which
the electric plugs protrude. The engine being started by operating the plunger
and drawing in & firing a charge by an electric spark, the communication between
the two combustion chambers is kept open and the engine continues running by
means of electrical sparking, until the ignition tube being sufficiently hot, the
lunger nose is advanced to seal up the taper hole of communication.
compression pressure then causes the ignition tube to fire the charge regularly and
the electric plugs are cut off and remain protected from the heat and explosion
until again required for starting the engine.
The increased

page_text: Improvement No. 3 is shewn in Figs. 8, 9, 10, 11, & 12. The object of the
improved device is to cause an engine having varied compression to fire at the right
moment, viz. at, or shortly before, the consummation of the compression pressure.
In the case of an engine having varied compression pressures, and an ordinary
ignition tube without timing valve there will be a degree (determined by the
position and intensity, of the Bunsen flame) of compression at which the engine will
fire most suitably and regularly. If the compression be decreased to any extent
the engine will miss fire more or less regularly at every other working stroke and
with still less compression the engine will only fire occasionally and with very
marked irregularity.
On the other hand if the compression be increased the engine will fire too soon
and this fact will become more pronounced as the compression increases, so that
the engine will begin to lose power and were the compression still further increased
and the speed kept low by a suitable load would tend to stop the engine.
To remedy this I have devised the form of adjustable plunger shewn in Figs. 8,
9, 10, 11 or 12. The figures shew a combustion chamber B with valve ports C, C,
a suitable ignition tube D screwed in combustion chamber and heated by the
Bunsen burner, for example say at the level E. The adjustable plunger is suitably
secured to the screwed rod E' and operated by any suitable means. The plunger
is shewn with piston rings and the end towards the valve ports is turned down
slightly, say to about the depth of the diameter of the ignition tube. The annular
space thus formed by the reduction of the diameter of the plunger constitutes
when the plunger is advanced anywhere beyond its position at lowest compression,
virtually an extension of the ignition tube. Thus when the plunger is in position
as shewn at Fig. 8 the mouth of the ignition tube is freely exposed to the com-
bustion chamber; and as a consequence the incombustible products of combustion
which fill the tube after each explosion have only to be forced back the distance
of the mouth of the tube from the heated portion. On the other hand in Fig. 10,
with the engine working at highest compression, the narrow annular space
surrounding the plunger in its reduced portion will be filled after explosion with
the products of combustion and the fresh gases must be forced back first into the
annular space and then up the ignition tube. At Fig. 9 the plunger is shewn in
its middle position and the engine working with middle compression and the
distance from the open part of the combustion chamber down the annular space
and up the ignition tube is also at its medium.
There is therefore with this improvement a virtual variation of the length of
ignition tube in exact ratio to the variation of the compression pressures; since
as the plunger is advanced and compression increased, the distance from the face
of plunger to the heated part of ignition tube is increased and vice versa.
Fig. 11 is a cross section of plunger and the combustion chamber cutting through
and shewing the circular space caused by the slight reduction of the diameter of
the plunger.
The adjustable plunger A shewn in Figs. 8, 9, 10, 11 rotates as it advances. In
a plunger that is advanced without revolving, I make the whole of the plunger
a good fit to the bored combustion chamber and cut a groove in a line with the
ignition tube as shewn at X in Fig. 12. The groove then serves the purpose of
the annular space in Figures 8, 9, 10 & 11.
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 and petroleum engines having compression varied by means of a
plunger sliding into the combustion space or in an auxiliary combustion space,
the act of preventing leakage of the compressed gases and of the gases of explosion
past the adjustable plunger by means of the plunger abutting against a ring or
other suitable annular or other stop or shoulder in the combustion chamber, or by
a plug, nose or cap fitting gas-tight against or closing or sealing in any way a hole

page_text: or opening connected with a combustion chamber operating in the manner hereto-
fore stated and for the purpose and objects herein before set forth.
(2) The use of and the act of using an electric ignition device for gas and
petroleum engines, comprising two separate and distinct plugs with tapered con-
ducting media and tapered insulating media, the said plugs being inclined at an
angle to one another and in the same plane substantially as described and specified
herein.
(3) The use of and the act of using a moveable plunger sliding in the combustion
chamber, or the equivalent of such combustion chamber of gas and petroleum
engines, formed as herein before described for the purpose of protecting an electric
igniting device in the manner hereinbefore stated.
(4) The use of and the act of using a plunger sliding in the combustion space
of gas and petroleum engines the said plunger being formed and operated so as to
form, in combination with an ordinary ignition tube virtually an ignition tube of
differentially varying length, substantially as described above for the purpose of
regulating the firing of gas and petroleum engines using variable compression.
(5) The combination a suitable gas or petroleum engine with the improvement
or improvements hereinbefore described and specified.
(6) The apparatus comprising a moveable plunger sliding in a combustion
chamber, for application to gas and petroleum engines, such plunger being formed
and operated for the several purposes herein before specified.'
(7) The apparatus comprising an improved electric igniting device for gas and
petroleum engines substantially as described.
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