IMPROVEMENTS IN SINGLE AND DOUBLE ACTING COMPOUND AIR AND GAS MOTOR ENGINES
Year: 1881

page_text: LETTERS PATENT to George William Weatherhogg, Engineer, of No. 4, Bull
Ring, Birmingham, in the County of Warwick, for an Invention of
"IMPROVEMENTS IN SINGLE AND DOUBLE ACTING COMPOUND AIR AND GAS
MOTOR ENGINES,"
PROVISIONAL SPECIFICATION left by the said George William Weatherhogg
at the Office of the Commissioners of Patents on the 10th October 1881.
GEORGE WILLIAM WEATHERHOGG, Engineer, of No. 4, Bull Ring, Birmingham,
in the County of Warwick. "IMPROVEMENTS IN SINGLE AND DOUBLE ACTING
COMPOUND AIR AND GAS MOTOR ENGINES."
My Invention relates to what are commonly known as air and gas motor engines,
and has for its object certain improvements in the construction and mode of
operating such engines in order to more effectually economise the use of gas or
other inflammable vapours in gas motor engines than has hitherto been attained,
the compression and expansion of the combustible charges of gas or vapour being
effected in a compound cylinder, and two combustible charges fired and expanded
during the same stroke, giving two propulsions to the engine at different angles of
the crank, the engine being also capable of fireing the charges in both the out and
in-strokes, and the same cylinder being also available for pumping and compressing
atmospheric air or other fluids into a superheater or other receptacle for regene-
rating and utilising the waste gases and superabundant heat developed by the
explosions, such air or fluids being afterwards partially employed in the cylinder
for giving additional impetus to the crank.
The method upon which an engine works, according to my Invention, is by the
reciprocating motion of two working pistons in separate compartments of the
cylinder, each piston being coupled together by rods or a trunk, whereby the com-
pression and double expansion of the combustible charges are effected within the
same cylinder, or within two parts of such cylinder placed end to end so as to
work in line with each other, or placed alongside or concentrically around and
n

page_text: within each other, the parts of the cylinder being arranged so as to act conjointly
and simultaneously with each other, irrespective of position, at the times and for
the purposes hereinafter specified.
According to the present Invention I make the chamber of the compressing
pump to alternately act as a compressing reservoir and a second expansion chamber,
and I purposely fire each alternate combustible charge therein, by which means I
am enabled to obtain twice the number of explosions and about double the power
out of the same cylinder without materially increasing the weight of metal or cost
of production of the engine; and in a double-acting engine, where the combustible
charges are fired both ways, or on the in and out strokes, four times the number
of explosions with an equivalent increase of power is obtained out of a compound
cylinder, giving greater regularity of speed than when fireing the charges one way
of the strokes only.
In carrying out my Invention I may utalise the greater portion of the waste heat
generated from the explosions by reconverting it into motive power when required.
I form a jacket around the cylinder with an outer casing in the ordinary manner,
which is partly filled with water when I desire to collect the waste heat, and I
place an air vessel upon the outer casing communicating with the jacket of the
cylinder and a superheating chamber, the latter being preferably placed apart from
the cylinder, and arranged so that the exhaust products of combustion may come
into direct contact with a box or chamber which forms a part of the superheater.
I force diluted atmospheric air through the jacket and air vessel by a force pump
or other equivalent means into the superheating chamber, and I so proportion the
air and water or other fluids which dilutes the air that the heavier portions of the
fluid will lodge in the jacket space and absorb the superabundant heat developed
by the explosions. The air in its passage to the superheater takes up the heat
which rises through the fluid in the jacket as vapour, and is partly held in suspension
by the air, the vapory particles being forced along with the air into the superheater,
where they become regenerated and available for further use in the engine; and in
order to more clearly define the action of the regenerated fluid from the combustible
fluids I will hereafter call it the "working fluid." To the air vessel I connect the
air forcing pumps.
The pumps are first worked by hand or by turning the fly
wheel of the engine round by hand, so as to produce a pressure of air in the super-
heater and the air vessel without starting the engine to work, but when the engine
is started it gives motion to the pumps, and the preinduced pressure is maintained
in the air vessel and superheater. Should the heat in the superheater become too
great and the pumps continue to work, or the volumes in the superheater be greater
than the demand for the "working fluid" in the compressing reservoir or second
expansion chamber of the cylinder, the working fluid would be forced back into the
air vessel, from whence it would escape by a loaded valve into the atmosphere or
the exhaust pipe of the engine.
In a horizontal engine I sometimes place the air forcing pumps within the bed
plate of the engine, which I make into a water tank for keeping the pumps cool.
In another arrangement I am enabled to dispence with auxiliary air forcing pumps,
the air being forced into the air vessel and the superheater by one of the working
pistons of the cylinder. In some cases I place a water tank above the engine bed
and apart from the same, and let the water dribble into a basin or trough having a
perforated bottom, through which the water or other fluid is sucked into the
cylinder along with the air in the form of spray, so as to dilute the air in its
passage into the pumping compartment of the cylinder. I sometimes dispence with
the use of the working fluid entirely, the cylinder then being cooled by a circulation
of water in the ordinary manner, and when so arranged I form the chamber of the
compressing pump of sufficient size, whereby a larger and more highly explosive
mixture of air and gas is admitted therein than what is required to be passed
into the first explosion chamber for forming the combustible charge therein, this
strong charge on the outstroke of the pistons decreasing in pressure in the com-
pressing reservoir until fired by coming in contact with the burning gases of the

page_text: first combustible charge. The gases having by this time somewhat lost ther vitality,
will readily enter the second expansion chamber by the action of the slide valves,
and intimately mixing with the strong charge therein will readily burn together,
recuperating the first combustible charge and giving by increased expansion a
second impetus to the crank of the engine. When I employ the working fluid
before spoken of I mix it with this strong charge of air & gas in the compression
pump previous to the second fireing of the gases therein, and I arrange the passages
of the slide valves so that the working fluid enters the expansion compartment before
the pistons commence their out stroke, thereby giving another impulse to the crank,
and by the time of the admission of the burning gases into that compartment the
working fluid will have expanded somewhat with the strong charge, forming a
second combustible charge, the whole then intimately mixing and expanding
together to the termination of the stroke, as before. When the working fluid is
thus employed a greater economy in the consumption of gas is effected than when
working by the arrangement previously described, the waste heat being then
profitably re-employed in the engine.
Various forms of cylinder may be employed so as to work in accordance with the
Invention.
In a single-acting engine one arrangement consists in making a compound
cylinder of two diameters, and somewhat similar to those described by me in a
previous Patent, No. 3972, 1878, the smaller diameter of the cylinder being the
first explosion and expansion chamber, the larger diameter of the cylinder con-
stituting what I term the compressing reservoir and second expansion chamber of
the engine. When a trunk is employed in this arrangement the larger chamber
forms an annulus around the trunk, which constitutes both the compressing
reservoir and the second expansion chamber before spoken of. The outer end of
the cylinder may or may not be closed by a cover according to the mode of
operating, and when closed the front end of the cylinder is employed for pumping
the working fluid; or it may be employed for other pumping purposes. Instead
of projecting the trunk or a rod through the outer cover for connecting to the
connecting rod, I preferably make the trunk of the pistons hollow, into which is
fitted a hollow cylindrical casing, the flange of this casing being bolted to the
outer end of the cylinder and forming the cover thereof. I fit ordinary piston
rings upon the inner end of this casing for keeping the front compartiment tight,
by which arrangement I save considerable space in the length of the engine. The
connecting rod working through this hollow casing is coupled to an abutment
within the trunk. I sometimes place within the larger part of the cylinder a ring
block containing internal springs, the block abutting against and is secured to the
end of the smaller chamber. I bore small holes through the block and turn
grooves in the same communicating with the jacket of the cylinder, so that water
or other lubricants may flow upon the trunk for cooling and lubricating the same;
or I may turn the grooves and drill the small holes through the smaller chamber of
the cylinder, thus dispensing with the ring box.
In another arrangement for a single acting engine I employ a parallel cylinder,
somewhat exceeding twice the length of the stroke, within which are two working
pistons coupled together by a trunk, the cylinder being divided in the centre by
a partition plate or plates through which works the trunk, internal rings or
packings being placed in the plates for keeping the joints tight; or the packings
may be externally adjusted.
This arrangement gives three working chambers, which with similar passages
and valve arrangements will operate precisely as in the form of cylinder previously
described, excepting that the pumping compartment is placed between the first and
second expansion chambers.
In another arrangement for a single acting engine I place the expansion
chambers concentrically around each other, which shortens the cylinder about one
half, the outer chamber forming an annulus into which is fitted a metallic piston,
the central chamber being fitted with a trunk piston working through an outer

page_text: cover, which arrangement gives a third chamber for the pumping of the working
fluid; the two pistons are coupled together, and the connecting rod is coupled to
the trunk piston direct. In this arrangement the supply and cut off valves work
upon one end of the cylinder, and instead of placing the first and second expansion
chambers within each other they may be placed alongside each other, the whole
being arranged so as to act in the manuer before described.
For operating an engine with either of the preceding forms of cylinder, valves of
various kinds may be employed, but I preferably employ two flat reciprocating
slide valves working upon the back of each other, which fully represents the
method of working the engine. The said valves work within a guide box or
casing which is held to the cylinder facing by a cover and set springs in the
ordinary manner. The valves have working passages formed therein, which
admits and ignites the combustible charges and the working fluid, and are driven
by cranks or eccentrics from a counter shaft travelling half the speed of the crank
shaft, the counter shaft in an horizontal engine being driven by spur gearing, the
shaft being placed either behind or below the main crank shaft, so that the upper
edges of the cylinder ports are about on a level with the centre line of the cylinder.
The valves are coupled direct to the cranks or eccentrics upon the counter shaft,
by which means I am enabled to more effectually drain the cylinder from any
residuary products remaining therein. The slide valves and cylinder facings are
each arranged with double sets of passages in separate lines of travel for the
combustible gases and the working fluids. The inner slide I term the supply
valve, and the outer slide the cut-off valve. The supply valve has a peculiar
- shaped passage formed therein which is double the length of the others, it
extending and opening into both lines of travel at such times as is required for
admitting the air and gas and the working fluid supplies into the expansion com-
partments of the cylinder. The valve cover has passages cast therein for the air
supply to the expansion chamber, and for feeding a stationary burner placed
therein. The supply valve has an igniting chamber situated near one end of the
valve which is fed with combustible air and gas from the compressing or second
expansion chamber, it being also partly fed with pure gas, or air and gas, from an
independent source for maintaining a lighted flame within the igniting chamber, the
latter mode of feeding the flame being no part of this Invention. The light is inter-
mittently communicated from the stationary burner placed within the valve cover
through a passage in the cut-off valve which opens at suitable times for relighting
the flame in the igniting chamber, a separate passage in the cut off valve also
supplying air for supporting the igniting flame during a portion of the stroke of
the valve, the remaining portion being fed by the combustible mixture from the
second expansion chamber increasing the pressure of the flame in the igniting
chamber equal to the pressure of the gases remaining in the compressing or second
expansion chamber (as hereafter more fully explained). I form a chamber in the
cut-off valve which I term the "feeding chamber," partly through which the air
and gas supplies must pass from the second expansion chamber during compression
of the combustible charge into the first explosion chamber, after which by the
traverse action of the valves the feeding chamber closes with a fully compressed
and highly combustible mixture therein, when by the further traverse of the valves
the gas supplies for feeding the igniting flame being closed; the feeding chamber
then gradually opens into the igniting chamber, increasing the pressure of the
flame therein with the strong mixture, which by the time of the explosion is
considerably stronger and more explosive than the combustible charge in the first
explosion chamber, by which arrangement the compressed charge in the explosion
chamber is ignited owing to the positive and superior pressure of the igniting
flame. And in order to more fully insure certainty in the ignition of the com-
bustible charges I close the supply passage into the first explosion chamber some-
what before the pistons have terminated their stroke, when the compression will
be further increased in the compressing and feeding chambers oweing to the
remaining gases being prevented from escaping therefrom. I arrange for the

page_text: second expansion chamber to be either longer than the stroke of the pistons, or
provide an enlargement chamber in connection therewith for holding a sufficient
quantity of the explosive mixture so as to form the second combustible charge.
In a modification of the above mode of lighting the igniting flame in the supply
valve, instead of placing a burner in the valve cover I may employ a flame burning
in a chamber in the cut off valve, which is supplied by gas, or air and gas, taken
from an independent source, the said gas, or air and gas, flowing into a chamber or
reservoir formed within or connected to the supply valve, from which it again
flows through suitable grooves or passages into the lighting chamber in the
cut-off valve, a separate air passage being provided for maintaining the flame
therein.
The proper supply of gas necessary for forming the explosive compound in the
compressing reservoir is regulated by the supply and cut off valves, but the times
employ
of the supplies are regulated by the governors of the engine, and when
the working fluid in an horizontal engine I preferably make a casting with two
chambers in it, in which works two rocking valves which are coupled together and
connected by levers to the governor fork. One of the valves regulates the gas
supplies and the other the working fluid, both of which pass through separate
compartments of the valve box, the latter being placed to the outer casing of the
cylinder. The said regulating valves may be either round piston valves, or of
coned or spherical form, having the rocking motion imparted to them by the
governor levers. The valves when working in the same box are preferably above
each other. To the gas supply spindle is keyed a lever having a roller on its outer
end which freely turns thereon. The valves have suitable ports cut in them with
corresponding passages leading to and from the valve box into the compressing or
second expansion chamber. The supplies do not pass directly into the cylinder
but pass through suitable passages into the slide valves, from whence they repass
The valves are so set in
into the compressing and second expansion chamber.
relation to each other that the gas supply passage cannot be open for a charge of
gas unless the governors fall below a predetermined drop, by the action of which
the lever on the gas supply valve rises or falls (as may be arranged for), so that
during a certain portion of the stroke of the slide valves the roller on the gas
supply lever strikes an inclined projecting piece upon the cut off valve, which
raises or lowers the lever and turns the gas valve further round, opening the gas
supply passage, enabling a charge to be sucked into the compressing compartment
of the cylinder, and I instead of allowing the piston to suck in a charge of gas direct
from the main gas supply I sometimes form a charging chamber in the supply and
admission valve, which holds sufficient gas for a single charge, and I arrange the
passages in the slide valves so that this charging chamber gradually fills with gas
the slide valves, closing the communication with the main gas supply before the
charge is sucked into the cylinder, by which arrangement I am enabled to dispense
with the use of a gas bag or regulator, the gas being thereby prevented from
fluctuating in the pipes. Instead of operating the gas supplies by the means
described I sometimes work them by a cam or eccentric from the shaft which
operates the slide valves.
The mode of operating a single-acting compound engine with either of the
preceding forms of cylinder is as follows:-On an outstroke of the pistons a
strong explosive mixture of air and gas is drawn into the compressing reservoir or
second expansion chamber, and by the next instroke is partly driven into the first
explosion chamber, wherein is a volume of atmospheric air, or the working fluid
which intimately mixes with the explosive mixture as it is being compressed into
the first explosion chamber, forming a combustible charge therein, when on the
next outstroke the combustible charge is fired in the first explosion chamber which
propels the pistons outwards. Upon the fireing of this charge, and in some cases
before the pistons have made any advance (when the working fluid is employed)
by the action and lead of the slide valves, the working fluid passes from the super-
heater into the second expansion chamber, intimately mixing with the remaining

page_text: portion of the explosive mixture in the compressing reservoir or second expansion
chamber so as to form a second combustible charge therein, the working fluid
giving an impetus to the crank, and when the pistons have travelled from about
one fourth to, say, five eighths of the stroke, the passages in the slide valves open
to admit the burning mixtures into the second expansion chamber at this juncture,
which, intimately mixing with each other, burn and expand together, propelling
the pistons with accelerated force to the termination. of the stroke (as before
described), or about nine tenths of the same, when the exhaust valve opens, and
on the return stroke the expanded gases are simultaneously expelled from both the
first and second expansion chambers into the superheater or atmosphere as
desired.
In order to more fully insure the clearing of the passages of the slide valves and
the compressing reservoir from any residuary products of combustion I make small
openings in the valve passages, so that a portion of the working fluid may, during
a part of the exhaustion stroke, flow through the exhaust pipe, thereby causing
an induced current through the exhaust, which effectually clears both the valves
and the compressing reservoir after each expansive stroke of the engine.
One cycle of operations having now been gone through, it will be seen that the
engine has made four strokes or two revolutions, during which time there would
have been three propulsions imparted to the engine, viz., one from the ignition of
the first combustible charge, one from the ignition of the second combustible
charge, and one from the expansion of the working fluid.
Various arrangements with the preceding and other forms of cylinders may be
employed to obtain double action effects in both the in and out-strokes of the
pistons of a compound cylinder with similar valve arrangements, whereby double
the number of propulsions may be given to the engine in the same number of
revolutions, thus: In one arrangement I employ a parallel cylinder twice the
length of the stroke, in which are two pistons coupled by a rod or trunk, and with
a central partition as before described, but with both ends of the cylinder closed
by a cover, a rod or trunk passing through the cover for coupling to the connecting
rod. By one arrangement for operating the engine I employ two sets of the slide
and cut off valves before described, they being placed on the opposite sides of the
cylinder, and I arrange them so as to work conjointly or alternately with each
other, each acting as before described, by which means one half of the cylinder
may be inoperative when required. Or I may duplicate the passages in one pair
of valves so as to enable the engine to work constantly in both the in and out
strokes.
In another arrangement with the same form of cylinder and valves as last
described I fix a solid partition in the centre of the cylinder, dividing the chambers
in two halves as before, but, as it were, cutting the trunk in two halves, each
piston working in the separate compartments with each part of the trunk working
through suitable stuffing boxes in the outer covers; the pistons may be connected
together by trailing rods and cross-heads, to which is connected the connecting
rods in the usual manner; or I may place the crank shaft near the centre of the
cylinder, the pistons being connected by levers to a rocking shaft at each end of the
cylinder, which imparts the power to the cranks by other rods and levers in a
manner well known.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George William Weatherhogg in the Great Seal Patent Office on
the 10th April 1882.
GEORGE WILLIAM WEATHERHOGG, Engineer, of No. 4, Bull Ring, Birmingham,
in the County of Warwick. "IMPROVEMENTS IN SINGLE AND DOUBLE-ACTING
COMPOUND AIR AND GAS MOTOR ENGINES."
My Invention relates to what are commonly known as air and gas motor engines,
and has for its object certain improvements in the construction and mode of
operating such engines in order to more effectually economise the use of gas or
other inflammable vapours in gas motor engines than has hitherto been attained.
The compression and expansion of the combustible charges of gas or vapour being
effected in a compound cylinder and two combustible charges fired and expanded
during the same stroke, giving two propulsions to the engine at different angles of
the crank. The engine being capable of firing the charges in both the out and in
strokes, and available for pumping and compressing atmospheric air or other fluids
into a superheater or other receptacle for regenerating and utilising the waste
gases and superabundant heat developed by the explosions, such air or fluids being
afterwards partially employed in the cylinder for giving additional impetus to the
crank.
The method upon which an engine works according to my Invention is by the
reciprocating motion of two working pistons in separate compartments of the
cylinder, the pistons being coupled together by rods or a trunk, whereby the com-
pression and double expansion of the combustible charges are effected within the
same cylinder, or within two parts of such cylinder placed end to end so as to
work in line with each other, or placed alongside or concentrically one within
the other, the parts of the cylinder being used conjointly and simultaneously,
irrespectively of position at the times and for the purposes hereinafter specified.
According to my present Invention I make the chamber of the compressing
pumps to act alternately as a compressing reservoir and a second expansion chamber,
and I purposely fire each alternate combustible charge therein (except in certain
cases hereinafter described), by which means I am enabled to obtain twice the
number of the explosions and about double the power out of the cylinder without
materially increasing the cost of production of the engine; and in a double acting
engine where the combustible charges are fired both ways, or on the out and in
strokes, the number of the explosions are again doubled with an equivalent increase
of power, giving greater regularity of speed than when firing the charges one way
of the strokes only. In carrying out my Invention I may, when desired, utilise
the greater portion of the waste heat generated from the explosions by reconverting
it into motive power. I form a jacket around the cylinder with an outer casing
When I desire to
in the ordinary manner, which is partly filled with water.
collect the waste heat I place an air vessel upon the outer casing with the
jacket of the cylinder and a superheating chamber, the latter being preferably
placed apart from the cylinder, and arranged so that the exhaust-products of
combustion may come into direct contact with a box or chamber which forms part
of the superheater. I force water or diluted atmospheric air through the jacket
and air vessel by a force pump or other equivalent means into the superheating
chamber, and I so proportion the air or other fluid spaces that the heavier portions
of the fluid will lodge in the jacket space and absorb the superabundant heat
developed by the explosions. The water or air in its passage to the superheater

page_text: takes up the heat which rises through the fluid as vapour of steam, the vapory
particles being forced along with the air into the superheater, where they become
regenerated and available for further use in the engine. And in order to more
clearly define the action of the regenerated fluid from the combustible fluids I will
hereafter call it the working fluid. To the air vessel I connect the air forcing
pumps which are first worked by hand or by turning the fly wheel of the engine
round by hand so as to produce a pressure of air in the air vessel prior to starting the
engine to work, but when the engine is started it gives motion to the pumps, and
the preinduced pressure is maintained in the air vessel and superheater. Should
the heat in the superheater become too great and the pumps continue to work, or
the volumns in the superheater be greater than the demand for the working fluid in
the cylinders, the working fluid would be then forced back into the air vessel, from
whence it would escape by a loaded valve into the atmosphere or the exhaust pipe
of the engine. In a horizontal engine I sometimes place the air forcing pumps
within the bed plate of the engine, which I make into a water tank for keeping the
pumps cool.
In another arrangement I dispence with auxiliary air forcing
pumps, the air or air and water being forced into the air vessel and the super-
heater by one of the working pistons of the engine. And in some cases I place
a water tank above the engine bed, and let the water dribble into a basin or
trough having a perforated bottom through which the water or other fluid is
sucked into the air pumps or the cylinder in the form of spray. I sometimes
dispence with the use of the working fluid entirely, the cylinders being then cooled
by a circulation of water in the ordinary manner, and when so arranged I form the
chamber of the compressing pump of sufficient size to hold two combustible charges,
one of which is passed into the first explosion chamber, forming a combustible
charge therein, the stronger and more highly compressed charge preferably
remaining in the reservoir, which on the outstroke of the pistons decreases in pressure
until fired, by coming in contact with the burning gases of the first combustible
charge, the gases having by this time somewhat lost their vitality will readily
enter the reservoir and second expansion chamber by the action of the slide valves,
and intimately mixing with the strong charge therein will rapidly burn together,
recuperating the first combustible charge, and giving by increased expansion a
second impetus to the crank of the engine, rapidly propelling the same over the
dead centre. Various forms of cylinder may be employed so as to act in accordance
with the Invention, thus:-In a single acting engine one arrangement consists in
making a compound cylinder of two diameters, and somewhat similar in form to
those described by me in a previous Patent No. 3972, 1878. The smaller diameter
of the cylinder being preferably the first explosion chamber, the larger diameter
constituting what I term the compressing reservoir and second expansion
chamber. When a trunk is employed, as in this arrangement, the larger chamber
forms an annulus around the trunk, constituting both the compressing reservoir
and second expansion chamber before spoken of. The outer end of the cylinder
may or may not be closed by a cover according to the mode of operating, and when
closed the front end of the cylinder is used for the working fluid, or it may be
employed for other pumping purposes. Instead of projecting a trunk or rod
through the outer cover for coupling to the connecting rod, I preferably make the
trunk of the pistons hollow, into which is fitted a hollow cylindrical casing, the
flange of this casing being bolted to the outer end of the cylinder forming the cover
thereof. I fit ordinary piston rings upon this casing for keeping the front
compartment light, by which arrangement I save considerable space in the length
of the engine. I sometimes place within the larger part of the cylinder a ring box
containing internal spring rings; I bore small holes through this block and turn
grooves in the same, communicating with the jacket of the cylinders, so that water
or other lubricants may flow upon the trunk for cooling and lubricating the same.
In another arrangement for a single-acting engine I employ a parallel cylinder, or
two cylinders, somewhat exceeding twice the length of the stroke, within which are

page_text: two working pistons coupled together by a rod or a trunk, the cylinders being
divided in the centre by a partition plate or plates fitted with packing rings
through which works the rods or trunks. The cylinders may be either be bolted
together or placed sufficient distance apart to admit of the packing rings being
externally adjusted. This arrangement gives three working chambers which with
suitable passages and valve arrangements will operate as in the form of cylinder
last described, excepting that the pumping compartment is placed between the first
and second expansion chambers. In another arrangement for a single acting
engine I place the expansion chambers concentrically with each other, which
shortens the cylinder about one half, the outer chamber forming an annulus into
which is fitted a metallic piston, the central chamber being fitted with a trunk
piston working through an outer cover, which arrangement also gives a third
chamber for pumping the working fluid.
According to another arrangement I employ two separate cylinders placed
alongside each other and within one water jacket; the cylinders have a separate
piston in each chamber, and are coupled by connecting rods to independant cranks
which are set somewhat in advance of each other, each cylinder being operated by
valves so as to work in conjunction with each other. For operating an engine
with either of the preceding forms of cylinder, valves of various forms may be
employed, such as rotary, semi-rotary, lift valves, or flat faced sliding valves, either
of which I adopt according to the class of engine required; but in most cases I
preferably employ two flat reciprocating slide valves working one upon the back of
the other, and upon the cylinder facing, they being held to the cylinder facing by
a cover and set screws in the ordinary manner. They are also partly equilibriated
In the accompanying Drawings Fig. 1 shews elevation of a horizontal single acting
compound engine having two cylinders bolted end to end, and fitted with
appliances for collecting and utilising the superabundant heat evolved by the
explosions; Fig. 2 being a plan of the same with the cylinders and slide valves
shewn in section; Fig. 3 shews end view; Fig. 4 transverse sections through the
first explosion cylinder (2) and water jacket, also the supply and cut-off valves,
the valve box cover, the gas igniting chambers, the gas regulating valves, the
exhaust box, and the working fluid passages; Fig. 5 shews the cylinder facing and
gas and working fluid ports of cylinder (2); Fig. 6 shews inside facing of valve
box cover and position of lubricating chamber. In these and following Drawings
the same reference numerals are used to mark the same or like parts wherever
they are repeated. The engine is here shewn provided with an auxiliary air and
water pump, and as arranged (1) is the second explosion or expansion chamber;
(2) is the first explosion chamber; (4) and (5) are the cylinder transmission
passages; (6) working fluid passages; (7) and (8) are gas passages; (9) is the
supply, and (10) the cut off valve, which are driven by gearing, such as cranks or
eccentrics, placed upon the second motion shaft (11), the latter travelling half the
speed of the crank shaft. The gearing as here shewn is arranged to give a
continuous reciprocating motion to the valves, but it may be arranged to impart
an intermittent motion to the valves producing similar results; (13) is the air
vessel; (14) are the air and water pumps, which are coupled to the neck of the
air vessel by piping, as shewn; (15) is the suction pipe for water, and (16) the
air suction pipe; (17) is the loaded relief valve for regulating the pressure of
the working fluid; (18) is a ball cock for regulating the height of water in the
tank; (19) is the superheater, shewn partly in section, and connected to the
cylinder by piping, as shewn. The working fluid passing through the heater by
circuitous routes through a coil of piping, or a series of trays, or other obstructions
placed within the heater for the purpose of retarding the flow of the working

page_text: fluid therein when it becomes dried or superheated for further use in the engine.
The heater is provided with an outer annular casing, through which the exhaust
products of combustion play, said casing being provided with an exhaust opening
in which is fitted a loose swinging or lift valve which is for the purpose of
retaining a portion of the heated products in the exhaust chamber, said products
being afterwards condensed with fresh air in the exhaust chamber, which becomes
heated therein, and is afterwards passed through the cylinder (2) as hereafter more
fully explained. I sometimes place an atmospheric gas burner or stove within the
heater when it is necessary to further superheat or increase the working fluid.
When I employ a chamber of the working cylinders to feed the jacket with air or
water, I arrange the admission valves so that the working fluid enters the pumping
compartment each or each alternate in-stroke of the pistons as desired, and I admit
the fluid when the piston is about to return inwards, thus imparting an impulse
to the crank on the return stroke. The fluid being expanded is on the termination
of the in-stroke open to a special exhaust valve, and after which a little water is
sprayed into the pumping chamber, which on the next out stroke is along with
the atmospheric air forced into the jacket for maintaining the supply therein.
Figs. 16 and 17 shew modifications of compound; Figs. 18, 19 shewing the
arrangement in which the cylinders are placed alongside each other, and which
may be arranged to work either as single or double-acting engines, if single
preferably with cranks set at an angle of about 60° to 70°, but if double preferably
at about 120° to 140°, two sets of similar valves in the latter case being employed,
each cylinder being used alternately for compression and explosion. In the former
case the explosion always takes place in one of the cylinders and the compression
in the other, but in the latter case each cylinder is alternately used for explosion
and compression, care being taken that the explosions take place on the side of
the piston opposite to that to which the trunks or piston rods are attached, the
compression and second expansion in each case taking place on the trunk or piston
rod side of the pistons. Both of these arrangements are specially applicable when
the working fluid is expansively employed in the cylinders. The valves may
either be placed upon a facing piece across the ends or sides of the cylinders,
and when the former loose facings with passages are used, the exhausts
are formed in the sides of the cylinders. Other things being equal the cylinders
produce results similar to those previously described. The construction and mode
of working the gases and the working fluid of the supply and cut-off valves will
be understood by referring to Figs. 2, 7, 8, 9, 10, 11, 12, and 15, of which Figs. 2-12
and 15 represent longitudinal sections of the slides, cylinder passages, and valve
cover through the upper line of passages X, X, Fig. 15 shewing a longitudinal
section of the slides through the lower line of passages Y, Y. These sections shew
the valves in different positions of travel, Fig. 11 being a transverse section through
line Z, Z, of the supply valve shewing the working fluid passages (21), which
opens into both lines of travel at such times as is required for admitting the working
fluid into the second expansion chamber; Figs. 7, 8, 9, and 10 shew the valve
facings and working passages. The valve cover, Fig. 6, has a passage (22) for
supplying atinospheric air to the second expansion chamber. This passage has an
outer cover with small openings formed therein, through which the air is first
sucked into the cylinder. (23) is an ordinary gas burner within the cover having
an opening (24) for admitting a lighted flame to the gases in the cut-off valve
chamber (25). The supply valve has an igniting chamber (26), which is partly
fed with combustible air and gas from the second expansion chamber and partly
from the main gas supply, or from a reservoir formed in the supply valve which is
in connection with the main gas supply, as hereinafter more fully explained. The
flame is intermittently communicated from the burner (23) through the passage (25),
which opens at suitable times for relighting the gases in the igniting chamber; a
separate passage (27) in the cut off valve supplies atmospheric air for supporting
the flames in the chambers (24) and (26). I term the chambers (28) in the cut-off

page_text: valve now referred to the feeding chamber, partly through which the combustible
air and gas must pass during compression or simple transmission of the charge into
the first explosion chamber, and by the traverse action of the valves the feeding
chamber closes with a fully compressed and highly combustible mixture therein,
when by the further traverse of the valves, the gas for feeding the igniting flame
being cut off, this feeding chamber then gradually opens into the igniting chamber,
increasing the pressure of the flame therein with the strong mixture, which by
the time of the explosion is considerably stronger and more explosive than the
combustible charge in the first explosion chamber, by which arrangement the
combustible charge in the first explosion chamber is rapidly ignited owing to
the positive and superior pressure of the igniting flame.
In a modification of the above mode of lighting the igniting flame in the supply
valve, instead of placing a burner in the valve cover I may employ a flame burning
in a chamber in the cut-off valve, which is supplied by gas or air and gas taken
from the source previously described. Fig. 20 shews an enlarged sectional elevation
of the lubricating chamber before referred to and the feeding arrangement of the
game. The chamber (50) is formed in the valve cover and near to the air inlet
port (22), as shewn. Within this chamber is screwed a hollow brass casting (51),
said casting being closed at the top and bored out to fit a round conical headed
plug (52), which has a recess formed upon the same near to the cone head which
communicates with small openings (53) drilled in the tube casting. This casting is
surrounded with an outer casing formed upon the cover which holds the lubricants.
Within the inner tube or casting is placed a small spiral spring, which closes the
oil passages by forcing down the plug and bringing its recess inte mmunication
with the chamber (50), when the suction of the air pump draws out the few drops
of oil through the slide passages into the second expansion chamber, and during the
transmission or compression of the gases from that chamber the pressure lifts the
valve, and the recess automatically refils with oil for another charge. The proper
supply of gas necessary for forming the explosive compound in the compressing
reservoir is regulated by the supply and cut-off valves, but the times of the supplies
are regulated by the governors of the engine. When the working fluid is employed
in a horizontal engine I make a casting (30) with two chambers in it, in which
work two regulating valves, which are coupled together by two segments of
wheels (31), and connected by levers to the govenor folk.
The valves are pre-
ferably placed one above the other, (32) being the gas supply, and (33) for the working
fluid supply (when flat sliding valves are employed), both of which pass through
separate passages into the chambers, and are fitted with covers and glands, as shewn.
Said regulating valves may be either flat, cylindrical, or of conical forın, having a
rocking motion imparted to them by the governor levers (or by a cam on the second
motion shaft). To the gas supply spindle is keyed a lever (32) having a roller on
its outer end which freely turns thereon. The gas supply does not pass directly
into the cylinder, but comes through passage (8) into the slide valves, whence it
passes along with the air into the compressing reservoir and second expansion
chamber, as shewn in Fig. 12, by the action of which they mix into one homo-
genious mass previous to explosion. Upon the slide valve (10) is fixed a lifting
wedge (34), which is arranged to raise or pass the lever (32) during the period of
taking in the combustible charge before referred to, and by the raising of the
lever (32) the valves turn and open the gas supply, and when the governors exceed
their normal speed the wedge passes the lever, and no gas is then passed into the
valves or cylinder.
Instead of allowing the piston to suck in a charge of gas through the valves
direct from the main gas supply, I sometimes form a charging chamber in the
supply valve, which holds sufficient gas for a single charge and also for feeding
the igniting flame, and I arrange the passages in the slide valves so that this
charging chamber gradually fills with gas, the supply valve closing the commu-
nication with the main gas supply before the charge is sucked into the cylinder, by

page_text: which arrangement the gas is prevented from fluctuating, which otherwise has a
tendency to weaken the power of the engine. The mode of operating a single-
acting compound engine constructed with either of the preceding forms of cylinder,
and working with or without the working fluid will be understood by the following
description, reference being had to the diagram shewn in Fig. 13, which shews
diagrammatically the action of the pistons and slide valves upon the crank path,
reference being also had to Figs. 2, 12, and 15, the arrows of which indicating the
movement of the valves at those particular periods of the travel, of which
Fig. 12 represents the period when on an out stroke of the pistons atmospheric air
is about to be drawn through passage (22) and gas from the supply (8). The air
and gas mingling together passes through the valve chambers and passage (5) into
the compressing reservoir and second expansion chamber in cylinder (1) as indi-
cated by the arrows, forming the combustible charge therein; atmospheric air or
vapour of steam is simultaneously admitted through the exhaust valve (12), it
being held open during the out and also the greater part of the next in-stroke by
the cam on the second motion shaft, said air or vapour being on the in-stroke
repassed into the exhaust chamber, which action prevents a vacuum being formed
in the cylinder, and also to some extent cleans the cylinder from any residuum
remaining therein. On the commencement of this charging stroke the crank
would have moved from zero and on the return stroke would again return there,
during which time the combustible mixture would have been retained in the
reservoir and valve passages, and on the closure of the exhaust would be either
wholly or in part simply transferred from the second to the first explosion chamber.
When working in conjunction with the working fluid I transfer nearly the whole
of the charge into the first explosion chamber. The valves valves will then be in the
position as shewn in Fig. 2, it which it will be observed that the working fluid
passage (21) has a slight lead of the crank for propelling the pistons outwards.
When the crank has arrived at point 1 on diagram the ignition of the combustible
charge takes place, which further assists in propelling the engine outwards, and
when the crank has arrived at or between the points 4 or 5 (as may be arranged for)
the slide valves will be in the position to open, admitting the burning mixture
into the second expansion chamber, which at this juncture intimately mixing with
each other burn and rapidly expand together, propelling the pistons with great
accelerated force to the termination of the stroke or to point 6. When the exhaust
valve opens and on the return stroke the products are simultaneously expelled
from both cylinders through the exhaust into the superheater or atmosphere as
desired; and in order to more fully ensure the clearing of the slide valves the
compressing reservoir and expansion chambers from any residuary products of
combustion I make small openings (44) in the valve passages, so that a portion of
the working fluid may, during part of the exhausting stroke conveniently between
points 7 and 8 flow through the exhaust pipe, thereby causing an induced current
through the exhaust, which, acting for the time as an ejector, creates a partial
vacuum both in the valve passages, the compressing reservoir, and the expansion
chambers, thereby effectually cleaning those chambers after an explosion.
action of the working fluid and the relative position of the slide valves when used
for ejecting the products will be fully understood on referring to Fig. 15, which
shews a section of the valves through the lower line of passages Y, Y, the arrows
indicating the fluid passing from chamber (6) through openings (44) in the valves
and passage (4) into the exhaust chamber. It will be obvious on referring to
Figs. 11 and 8 that by stopping up the port opening of the passage (21) leading
into the upper line of passages X, X, the working fluid could not then pass into
the cylinder during the expansive stroke of the pistons, which arrangement I
adopt when the working fluid is not expansively employed in the engine, and
when so arranged I dispence with the superheating apparatus, the fluid being
simply pumped into the air vessel or its equivalent, and acting in the manner now
described. It will be evident on referring to the Drawings that I may considerably
The

page_text: vary the size or volumes of the charges in the first and second expansion chambers,
the mixtures therein being stronger or weaker as the pressure of the combustible
charges are higher or lower, by which means the engine may be worked with
the combustible charges either at atmospheric pressure or compressed to any
required degree according to the dynamic effect required to be produced upon
the pistons. The requisite proportions of air and gas or other vapour for forming
an efficient explosive mixture, being well known to engineers, chemists, and
others.
By this method of operating tortional strains resulting from a violent explosion
are obviated, partly owing to the combustible charges being fired at different
intervals for imparting the dynamic force to the pistons at different angles of
the crank, and partly because of the means provided for doubly expanding the
gases.
The following table denotes the action of the pistons in each working compart-
ment of a compound single acting engine, when the working fluid is expansively
employed in each working compartiment, the pumping chamber being in the
front end.
By the above table it will be observed that by my improved method of working
there would be four propulsions imparted to the crank in the two revolutions.
I will now describe how with the compounded cylinders the propulsions are
imparted to the crank in both the in and out strokes of the pistons.
In one arrangement I employ a parallel cylinder similar in form to those
described by me in my previous Patent before referred to, but the cylinder
passages are arranged to suit valves constructed to work according to my present
method of working. In this and the preceding arrangement, which I am about to
describe, although not absolutely necessary it is preferable to employ two separate
sets of supply and cut off valves for operating, similar in form to those kinds
herein before described or which might be employed therefor, they being operated
by similar means. According to the present arrangement each chamber of the
cylinder communicates by the valves with the chamber beyond the partition or
outer cover for forming the first and second explosion, or expansion chambers, and
I arrange the gearing of the valves so that either set may work independently of
the other, by which means one half of the cylinder may be inoperative when
required.
According to another arrangement I construct a compound cylinder, as shown in
Figs. 16 and 17, which shew elevation and a longitudinal plan view partly in
section. The cylinder which may either be made in one piece somewhat exceeding

page_text: twice the length of the stroke, as shewn, or in two halves, has a partition (60)
fixed in the centre through which water circulates for cooling the walls of the
cylinder. Working pistons (61) are placed in each part of the cylinder with
trunks working through packings (62) placed within the covers, as shewn. In
this, as in the preceding arrangement, each chamber of the cylinder communicates
by the valves with the chamber beyond the partition (60), thus forming the first
and second explosion or expansion chambers, the engine being worked by similar
valve arrangements, the central chambers forming the first explosion chambers.
The pistons may be connected together by trailing rods and cross heads direct to
one crank, but preferably to separate cranks set in advance one of the other upon
the same shaft, the shaft being placed either in the centre or beyond one end of
the cylinder, and coupled up by levers and connecting rods or simply by connecting
rods. Or the cylinder may be placed between two separate crank shafts, the
pistons being coupled by connecting rods direct to their respective cranks,
a separate force pump being employed for the working fluid. The valves shewn
are circular in form and have a reciprocating motion, the passages being suitably
arranged.
The action of the pistons in each working compartment of a double action
compound engine with the cylinders constructed to work in line with each other
and the explosions taking place in the central chambers, is shewn in the diagram,
Fig. 14, denoting the points of or position of the crank when taking in the
combustible charges, the working fluid charges, also the points of compression,
explosion, second expansion, exhaust, and heated air or vapour of steam, relief, and
scavenging charges upon the crank path.
Having thus particularly described my said Invention, and the manner of
performing the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is,-
First. The construction and mode of working two cylinders or chambers with
pistons acting in combination with each other and in which the explosions are
successively made, substantially as and for the purposes described.
Second. The use of a working fluid for propelling the piston of one cylinder
previously to the explosion in the other cylinder, and afterwards mixing the
contents of both cylinders.
Thirdly. The arrangement by which the products of the waste heat of gas engines
are used so that they can be worked at any pressure less or greater than the
explosion mixture, substantially as and for the purposes described.
Fourth. The method of clearing out the cylinders and passages by means of an
induced current produced by compressed air or steam.
Fifth. The mode of supplying the gas from a separate charging chamber instead
of direct from the gas main.
Sixth. The mode described of working two cylinders in combination so as to get
an equivalent of one explosion or propulsion for each revolution.
Seventh. The mode described of duplicating the parts so as to obtain two
explosions or propulsions for each revolution.
Eigth. The mode of working engines, as described, by which one half of the
engine may be made inoperative when reduced power is required.
Ninth. The mode described by which a charging chamber in the cut off valve is
supplied with fluid from the compression reservoir and for a time confined therein,
said chamber gradually opening into the igniting chamber raising the pressure of
the flame previous to ignition.
Tenth. The employment of a pumping chamber in the cylinder of an air and gas
engine other than that required for working the engine, substantially as and for
the purposes described.
Eleventh. The admission of air or steam into the first explosion chamber and

page_text: subsequently ejecting the same, substantially as and for the purposes bereinbefore
described.
In witness whereof, I, the said George William Weatherhogg, have hereunto
set my hand and seal, this Tenth day of April, in the year of our Lord One
thousand eight hundred and eighty two.
Witness,
EDW. E. ALLERY, C. E.,
Cheyne Walk,
Chelsea.
GEO. W. WEATHERHOGG. (L.S.)