JN GAS MOTOR ENGINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Robert Skene at the Office
of the Commissioners of Patents on the 1st April 1882.
ROBERT SKENE, of Lambeth in the County of Surrey, Engineer, IMPROVEMENTS
JN GAS MOTOR ENGINES
My improvements relate to motor engines, operated by the explosion of any
convenient gases combustible by ignition with the atmosphere.
My invention is designed to effect greater convenience and economy in working,
and in the cost of construction, by dispensing with the water jacket or any cooling
medium, in or about the working cylinder, so as to retain and utilise the heat
generated by explosive combustion. Also by the use of explosion chambers of
special form attached to, but apart from, the working cylinders, by a piston rendered
nonconducting to heat, and by a simple and novel form of ignition valve, and
apparatus connected therewith, all as hereinafter more fully described.
The abstraction of heat by the usual water jacket deprives the exploding gases
of a certain proportion of their expanding energy and at the same time tends to
cause precipitation of carbon, in the solid form of soot, upon the comparatively cool
walls of the working cylinder.
Both these evils my improvements are designed to remedy.
My exploding chamber or chambers, apart from the working cylinder, but
communicating therewith, are preferably in the form of a tube or tubes of small
diameter, or they may be prolongations of comparatively small diameter connected
to the working cylinder. Their length and diameter will depend upon the desired
compression of the gases before ignition.
These tubes or chambers if more than one in number, unite on different sides of
a valve chamber, containing one or more conical or cylindrical valves which rotate
or oscillate at half speed of the engine to effect ignition in each explosion chamber
alternately.
This is done as follows:
A port at each side of the valve is pierced through it, so as to communicate with
a nipple placed in a pocket or recess in the valve

page_text: When these side ports are in juxta-position with either of the explosion
chambers charged at pressure with combustible gases, a small portion of the gas is
forced through the nipple, which is filled with wire gauze. The jet there comes
in contact with an external lighted gas jet, through a suitable hole in the casing,
catches light, and, by the oscillation or rotation of the valve, is carried round into
communication with, and so as to explode, the combustible charge in the explosion
chambers.
The working cylinder or cylinders are protected by a prolongation of non-
conducting material on the face toward the explosion, so as to protect the working
face.
I may use either the working cylinders to compress the explosive charge or a
distinct compressing cylinder in conjunction with working cylinders to which my
foregoing improvements may be adapted.
First: The working cylinder or cylinders draw in the charge of gas and air by
suction, compress the same into the explosion chambers on the return stroke; the
next is the working stroke by explosion, and the last the exhaust stroke. In this
case the fresh charge of mixed gas and air is drawn by the suction of the working
pistons through a suitable valve close to the igniting valve into the hot explosion
tubes or chambers, the valve port area being the same as that of the tube or
chamber. By this arrangement the incoming gas and air is exposed to an excep-
tionally large area of heated surface before explosion, and the smallness of the
tubes ensures proper separation of the fresh charge from the residuary gases of the
exploded charge
The exhaust exits may be placed in any convenient part of the explosion
chambers. The exhaust valve is opened at the commencement of the down stroke
and the time of its remaining open is determined by the governor, by means of
suitable cam gear. The space available for the incoming charge by the exhaust of
former products of combustion is thus determined by the governor and the speed
of the engine regulated.
Second A separate and distinct receiver for the compressed gases is employed
when a distinct charging cylinder is used. In such case the charge is admitted to
the explosion chambers, when required, by the ignition or other suitable valve.
I
may enclose the charging or compressing cylinder in a water jacket, to reduce
the bulk of the air or gas during compression, and I pass the exhaust from the
engine through the receiver, to communicate its heat to the compressed charge
therein.
The suction or inlet valve to the compressing cylinder may be regulated by any
excess of pressure in the receiver, so as to reduce thereby the amount of gas and
air drawn into the compressing cylinder. The charging passages to the explosion
chambers are packed with wire gauze to prevent risk of back explosion.
Such a receiver remaining charged with an explosive mixture would enable the
engine to be started at any moment.
The engine to which these improvements are adapted may be in a variety of
different forms of construction, but conveniently I may arrange two cylinders
closely side by side and supported on suitable framings, vertically below the crank
shaft, the two pistons operating on one crank
This particular arrangement has the advantage that if explosion be used only
on the under side of the pistons alternately, exhaust suction and compression strokes
intervening between each explosion, this explosive stroke will occur once in each
revolution of the crank.
The pistons may also be conveniently loaded by a downward prolongation of
non-conducting material or otherwise as before specified so that their weight,
together with that of the connecting and piston rods, may be utilised to aid the
downward or compression stroke.
This engine can be made to work at half power at any time by disconnecting
one of the pistons in which case an explosion will take place every second
revolution.

page_text: The exploding chambers may conveniently be attached to the underside of the
cylinders in the form of tubes meeting in the conical or cylindrical igniting valve.
The valve must be driven by suitable gear, so as to oscillate or rotate at half the
speed of the engine.
This engine may be made to explode twice every revolution by the addition of
a compressing cylinder which will compress into an intermediate receiver as before
described.
In this arrangement the cylinder should be connected to opposite cranks and
the ignition valve should rotate at the same speed as the engine.
Alternatively I may modify this form by the substitution for the compressing
cylinder and receiver, of a double acting displacement cylinder, in which case the
explosive charge will enter the explosion chambers during the exhaust stroke, and
the power be regulated by the admission of the said charge to the inlet port of the
displacement cylinder. In starting the engine the exhaust valve may be kept
open, avoiding compression until sufficient momentum of the fly wheel is
obtained.
Although the usual gas employed for such explosive engines is that known as
coal gas, I may use any gas capable of explosion with the atmosphere, notably that
obtainable by volatilisation from petroleum. The chief objection to the use of this
latter gas has been the deposition of solid unconsumed carbon upon the com-
paratively cool sides of the working cylinders. This defect the high temperature
of my improved explosion chambers and working cylinder is calculated to
prevent.
When such a liquid hydrocarbon is used I preferably compress pure atmospheric
air only, in the charging cylinder and receiver, and pass the explosion charge of
air or part of it when heated, over or through the liquid hydrocarbon. The heated
air charge will thus absorb sufficient volatile gas from the liquid hydrocarbon as
to be capable of ignition, and explosion, in the working cylinder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Skene in the Great Seal Patent Office on the
30th September 1882.
ROBERT SKENE, of Lambeth, in the County of Surrey, Engineer. IMPROVEMENTS
IN GAS MOTOR ENGINES.
My invention is designed to effect greater convenience and economy in working
and in the cost of construction; by dispensing with any excessive cooling of the
working cylinder so as to retain and utilize more fully the heat generated by
explosive combustion; by the use of explosion chambers of special form attached
to, but apart from, the working cylinders; by a piston shielded by a non-conducting
substance; and by. .a simple and novel form of ignition valve, and apparatus
connected therewith, all as hereinafter more fully described.
In order that my invention may be properly understood I now proceed to
describe the same with regard to the accompanying drawings in explanation thereof,
reference being had to the letters and figures marked thereon and in which like
letters refer to like parts throughout the figures."
Figure 1 is an elevation showing convenient arrangement of engine with two
single acting ram cylinders.
Figure 2 is a transverse section through the working cylinder.
Figure 3. is a horizontal section through the rocking plug explosion valve.
Figure 4. is a vertical section through said plug explosion valve and gas valvę.
Figure 5. is a vertical section through the exhaust and suction valves.
Figure 6. shows a detail of an automatic piston valve for regulating the charge of
air and gas when a separate receiver is used.
Figure 7 is a detail of the arrangement of gas nipples in the plug ignition valve,
showing one nipple filled with wire gauze and an alternative nipple with closed
pocket and pin-hole
.
In Figures 1 and 2 A indicates my chambers or tubes which are apart from the
working cylinders B, but communicate therewith and are of sinal diameter
compared with the working cylinder. Their exact length and diameter depending
upon the desired compression of the gases before ignition. The exact area of tubes
is not material, but to the area of the cylinder has been found in practice to
work well.
These tubes A communicate by the hollow girder or chamber C with a plug
valve D, shown in sectional detail in Figures 3 and 4, through which explosion is
effected. The tubes may be covered with a non-conducting material to prevent
radiation of heat This valve D oscillates, in the arrangement shown, by the
operation of a slot in the cam boss E on the rotating shaft F. The end of the plug
lever d, gears in this slot, and the rotating shaft F is driven at half speed of the
engine by the gearing f so as to effect explosion for one cylinder in each alternate
revolution
Alternatively this ignition valve may be rotated as hereinafter more fully
described.
Ignition is effected thus: A small port g is pierced through the plug so as to
make communication between the chamber containing the explosive compound and
a gas nipple G placed in a pocket or recess. The gas nipple may be either pierced
with a moderately large hole and filled with wire gauze to retard the escaping
jet, or the central hole in the nipple may be left unfilled, but closed at the bottom,
the side being pierced by a small pin hole to direct the entering jet downwards upon
the bottom of the nipple pocket. The jet is thus diffused and broken and caused
to burn quietly without the gauze at the mouth of the nipple,

page_text: When the side ports are in juxta-position with either of the explosion
chambers C charged at pressure with combustible gases, a small portion of the gas
is forced through the nipple and comes in contact with an external lighted gas
jet H through a suitable hole in the casing. The jet there catches light, and
by the oscillation or rotation of the plug valve is carried round into communication
with the combustible charge in the chamber C, so as to explode it.
The working cylinder or cylinders are protected by a prolongation K of the
ram or piston, preferably of non-conducting material, so as to protect the gland /
or working face. This gland may be surrounded by a water jacket if(found desirable
in large sizes and when working for a lengthened period without stopping.
In the arrangement shown the working cylinder or cylinders draw in the charge
of gas and air by suction valves L, the gas being admitted through the valve
box. The charge is compressed on the return stroke into the explosion tube A,
the explosion upstroke follows, and finally the exhaust is driven out on the down
stroke through the valve M. In this case the fresh charge of mixed gas and air is
drawn by the suction of the working pistons through the valve L' into the hot
explosion tubes, the valve port area being the same as that of the tube or
chamber A. By this arrangement the incoming gas and air is exposed to an
exceptionally large area of heated surface before explosion, and the smallness of
the tubes insures proper separation of the fresh charge from the residuary gases of
the exploded charge.
The exhaust exits M may be placed in any convenient part of the explosion
chambers. The exhaust valve M is opened at the commencement of the down
stroke and the time of its remaining open may be determined by the governor N,
which operates a sliding barn, which may move the cams m, so as to vary their
time of keeping the valve M open. In this case the space available for the
incoming charge by the exhaust of former products of combustion is thus
determined by the governor and the speed of the engine regulated,
Alternatively the exhaust valves may remain fully or partially opened through-
out the stroke without alteration, and the proportion or frequency of the gas
charge may be regulated by the valve , which is lifted by a cam O upon the
shaft F, such cam being regulated as to its lift, or thrown out of gear, by the
governor N, by means of the sliding bar n, so as to regulate the speed of the
engine and the consumption of gas, or the sliding bar can be dispensed with and
the gas valve regulated by a cam or lever direct from the governor. A pocket at
the back of the valve in the valve box is provided for water to circulate, to protect
the valve from being overheated.
I may use an alternative arrangement of a gas engine to which my before
detailed improvements are applied, but to which is adapted a distinct compressing
or charging cylinder in conjunction with one working cylinder now exploding once
every revolution and with or without a receiving vessel.
In this case the charge is admitted to the explosion chamber by a rotating
ignition valve D provided with a special port for this purpose and one igniting
nipple similar in construction to that previously described. It is rotated by a
bevil gear from any convenient rotating shaft.
I may enclose the charging or compressing cylinder in a water jacket, to reduce
the bulk of the air or gas during compression, and I may pass the exhaust from
the engine through the receiver to communicate its heat to the compressed charge
therein.
The suction or inlet R, Figure 6, to the compressing cylinder, may be regulated
by the equilibrium piston valve S, which is operated by any excess of pressure in
the receiver. The inverted syphon pipe » contains any suitable liquid, such as oil,
and causes the piston valve to float on its surface. Any rise of pressure in the
receiver raises the level of the liquid in the outside pipe, forcing up the valve S
against the resistance of a spiral spring T, so as to close the passage of the suction
pipe R, aud to reduce thereby the amount of gas and air drawn into the

page_text: compressing cylinder. The charging passages to the explosion chambers are
packed with wire gauze, to prevent the risk of back explosion.
Such a receiver remaining charged with an explosive mixture would enable the
engine to be started at any time.
The engine to which my above described improvements of detail can be applied,
may be of various arrangements, other than those shown, nor do I confine my
invention to single acting plungers rather than to double acting piston cylinders.
In the latter arrangement two working cylinders may be employed in
conjunction with one compressing or charging cylinder, in which case the cylinders
are connected to opposite cranks and the ignition valve or valves should rotate at
the same speed as the engine.
The single acting compressing or charging cylinder may be made a double
acting piston cylinder, instead of a single acting plunger.
In starting the engine, the exhaust valve may be kept open, avoiding
compression until sufficient momentum of the fly wheel is obtained.
Although the usual gas employed for such explosive engines is that known as
coal gas, I may use any gas capable of explosion with the atmosphere, notably
that obtainable by volatilisation of petroleum. The chief objection to the use of
this latter gas has been the deposition of solid unconsumed carbon upon the
comparatively cool sides of the working cylinders. This defect the high
temperature of my improved explosion chambers and working cylinder is calculated
to prevent
When such a liquid hydro-carbon is used I preferably compress pure atmospheric
air only, in the charging cylinder and receiver, and I may pass the explosion
charge of air when heated, over or through the liquid hydro-carbon. The heated
air-charge will thus absorb sufficient volatile gas from the liquid hydro-carbon to
be capable of ignition and explosion in the working cylinder.
And having now described and ascertained the nature of my said invention be
it known that what I consider novel and desire to protect by letters patent is.
1st In a gas engine the use and construction of elongated explosion tubes or
chambers independent of, or apart from, the working cylinder, and of smaller
sectional area than the cylinders, substantially as and for the purposes described.
2nd In a gas engine the use and construction of a plug cylindrical ignition
valve oscillated to ignite the charge for two cylinders with one valve, or rotated,
as and for the purposes substantially as described.
3rd In a gas engine the use and construction of an independent compressing
cylinder and receiver for the compressed charge, in combination with an automatic
inlet valve operated by the variable pressure in the receiver, substantially as and
for the purposes specified
4th The general construction and combination of parts in a gas engine,
substantially as and for the purposes described.
In witness whereof I the said Robert Skene have hereunto set my hand
and seal this twenty-ninth day of September in the year of our Lord
One thousand eight hundred and eighty-two.
Witness
S. P. WILDING.
23 Rood Lane, London. E.C,
Patent Agent.
ROBERT SKENE. (L.S.)