IMPROVEMENTS IN MOTIVE POWER, ENGINES ACTUATED BY THE COMBUSTION OF A MIXTURE OF GAS AND MIXTURE OF 'GAS AND
Year: 1881

page_text: LETTERS PATENT to Edmund Edwards, of the Firin of Edwards and Co.,
Patent Agents and Engineers, of 40, Southampton Buildings, in the County
of Middlesex, for an Invention of "IMPROVEMENTS IN MOTIVE POWER,
ENGINES ACTUATED BY THE COMBUSTION OF A MIXTURE OF GAS AND
"
i
. I
PROVISIONAL SPECIFICATION left by the said, Edmund, Edwards, at,
Office of the Commissioners of Patents on the 23rd April 1881.
'
the
EDMUND EDWARDS, of the Firin of Edwards and Co., Patent Agents and
Engineers, of 40, Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN MOTIVE POWER ENGINES ACTUATED BY THE COMBUSTION OF
A MIXTURE OF 'GAS AND AIR."
My present Invention relates, firstly, to further improvements in the apparatus
for which I obtained Her Majesty's Royal Letters Patent, dated February, 20th,
A.D. 1880, and numbere1.760. In the Specification and Drawings of the said Letters
Patent I described and, showed novel methods of arrangements in which a mixture
of air and inflammable gas or vapour is drawn into, a cylinder and is then
ignited, a piston in the cylinder being actuated by the expansion of the air thus
caused..
In that form of such engine in which a valve, is described and shewn adinitting
the mixture of air and gas and closing by the action of the ignition, it is advisable
that the gas.should be thoroughly mixed with the entering air, and for this purpose
I make the inlet gas pipe communicate with numerous small perforations formed
in the face of the seat upon which the valve closes.
Another novel: method of arrangement for the purpose of mixing the air,and gas
consists in forming an inlet pipe for air at or near the bottom of the cylinder, the
outer end of such pipe being provided with a valve, preferably of india rubber,
asbestos.cloth, or other flexible material, opening inward.
At a suitable part of such inlet pipe, between the valve and, the cylinder I
arrange an internal concentric annular pipe into which gas is admitted and passes
ainto the air pipe, through a series of small hole:; or a recess may be formed inside
-D

page_text: the air pipe into which is fitted a ring. having an annular groove, preferably
excentric on its outer circumference, into which groove gas is admitted from a
supply pipe and passes into the air pipe through a series of small holes.
A small valve opening inward may be provided in the gas supply pipe to
prevent back pressure in the latter when the mixture of air and gas is
ignited.
I sometimes make the valve by which the heated air and products of combustion
can escape from the cylinder during the down stroke of the piston or plunger in the
form of a disc valve fitting upon a corresponding seat upon the botton of the
plunger, against which it is drawn up by a spring, the valve being provided with
a spindle passing up through a guide and actuated during the down stroke of the
plunger by a projecting arm upon the lower end of the connecting rod.
The valve seat described communicates with a vertical passage in the side of the
plunger and through it with the exbaust port in the side of the cylinder.
The exhaust port is preferably uncovered by the lower edge of the plunger at
the upper end of the stroke, as described in my former Specification already
referred to.
In order more completely to shut off the supply of gas after the mixture of air
and gas is ignited, I sometimes make the inlet gas passage communicate with an
opening in the side of the cylinder in the neighbourhood of a second similar
opening through which the gas is supplied from any convenient source.
In the plunger or piston I make a recess or passage which connects the two
openings when the piston is at the bottom of its stroke, but closes them either
gradually or suddenly when the piston has risen sufficiently far.
The position and shape of the recess in the piston may be varied so that the gas
is admitted and cut off at any desired points of the stroke.
I sometimes make another corresponding recess in the plunger or piston, which
admits gas at the proper time to the flame by which the mixture in the cylinder is
ignited, and cuts it nearly or entirely off during the time when such igniting flame
is not required. Instead of the method above described for cutting off the supply
of gas admitted with the air to the cylinder, I sometimes arrange a lever one end
of which enters an opening in the cylinder where it is actuated by the piston,
whilst its other end. is connected to the valve so that at the bottom of the stroke
of the piston the valve is opened, but when the former has travelled sufficiently far
it actuates the lever which closes the valve and retains it closed.
In order to reduce the heat imparted to the cylinder by the ignition of the gas
in the latter I make its sides of great thickness, and circular or polygonal outside,
and I make a series of longitudinal perforations through them from end to end, the
upper ends of these perforations being open or connected to a pipe leading to the
open air or to a chimney, and their lower ends being open, preferably laterally, so
that they are closed below by a flange which attaches the cylinder to its base
plate. Air passing up these perforations through the sides of the cylinder keeps.
the latter comparatively cool.
In one of the perforations described I arrange a valve opposite to a flame by
which the ignition of the mixture in the cylinder is effected at the proper time.
An external opening may be provided opposite to the flame and may be closed by
a moveable door.
Instead of air water may be admitted and made to pass through the several
perforations.
The outer sides of the air spaces may be closed by separate plates; or the
lower part of the frame which carries the driving shaft and fly wheel may be
made hollow so as to embrace the cylinder, air or water being admitted between
them.
In order to regulate the admission of the air and gas or inflammable vapour to
the cylinder I sometimes use either a slide valve or disc valve actuated at the proper
times by the piston.
For this purpose I connect the valve to a lever upon a pivot, having its two ends

page_text: arranged so that they can enter corresponding openings in the cylinder, where they
are actuated alternately by the piston.
The latter has corresponding longitudinal recesses provided in it of such length
that their ends actuate the lever and through it the valve at the proper time, the
latter being opened when the piston reaches the bottom of its stroke, being closed
when the piston has risen sufficiently far, and either-remaining in its position until
the piston again descends or having its action reversed, so that whilst the air and
gas still remain cut off a passage is opened through which the products of combustion
escape during the down stroke of the piston.
Another part of my present Invention relates more particularly to engines in
which the mixture of air and gas or inflammable vapour is compressed before being
ignited.
In order to carry out this part of my Invention, I attach to the lower end of the
piston a second piston or plunger of less diameter, which fits and works with or
without the intervention of suitable packing, such as asbestos or metal rings, in a
lower cylinder concentric with the upper one. At the bottom of the lower smaller
cylinder I provide one or more valves opening inward, preferably of the kind
already described, by which the air and gas are mixed together. I make the lower
piston or plunger hollow and open below, and I make its hollow part communicate
with one or more transverse passages in the larger piston near its lower end, the
ends of these passages being situated when the piston is at the bottom of its stroke
just below an enlargement of the lower end of the cylinder, or coming opposite to
corresponding passages in the cylinder communicating with its lower end.
A ball or other check valve opening upward may be arranged, if desired, in the.
passage between the lower hollow piston and the transverse passages in the upper
one. The larger piston is recessed upward from its lower end round the smaller
piston or plunger, or it is arranged so as not to descend to the bottom of the
cylinder, so that in either case a considerable space is left below the upper piston
when at the bottom of its stroke, and an exhaust valve is arranged so as to be open
during the down stroke of the pistons, preferably of the kind already described,
in which the valve is actuated by a projection upon the lower end of the
connecting rod.
A firing valve, preferably of the kind hereinafter described, is arranged so as to
communicate with the interior of the cylinder soon after the piston has commenced
its up stroke.
The action of the apparatus constructed and arranged as described is as
follows:-
If the pistons be at the top of their stroke the lower cylinder will be filled with a
mixture of air and gas or imflammable vapour drawn in by the ascent of the lower
plunger, and when the piston descends the mixture is compressed into the hollow
ram untill the upper piston has nearly reached the bottom of its stroke, when the
compressed mixture expands through the transverse passages into the space below
a sufficient extent. The
the upper piston where it remains still compressed to
pistons then commence their ascent, the mixture below the upper piston being
almost immediately ignited and acting with great force to effect the ascent of the
pistons, which is aided during the first part of their stroke by the expansion of the
mixture remaining in the lower cylinder.
During the latter part of the stroke the lower piston or plunger draws in a
further supply of air and gas, which are compressed during the down stroke of the
pistons by the momentum obtained in the up stroke, and these operations are
continued at every stroke as long as desired.
In another method of arrangement I arrange a valve opening upward in the
lower extremity of the smaller plunger, the hollow space in which is of considerable
capacity. When the plungers are raised the mixed air and gas are drawn into
the smaller cylinder, and when the plungers are forced down the mixture is
compressed into the hollow plunger, from which at the lower end of the stroke a
sufficient quantity expands into the space below the larger plunger. As the

page_text: plungers rise the communication from the hollow plunger to the larger cylinder is
immediately shut off, and shortly after the mixture below the upper plunger is
ignited and the plungers forced up. The process is repeated continuously, a
compressed' mixture being admitted and ignited below the larger plunger at each
stroke. A safety valve held down by a strong spring may be arranged in the
larger plunger to prevent the pressure in the lower hollow plunger from becoming
too great in the event of accidental ignition in it.
Instead of the air and gas being compressed into the hollow plunger, and
admitted thence to the cylinder through passages in the pistons, a separate pipe or
passage may be made to communicate from the bottom of the lower cylinder to a
suitable opening in the side of the upper cylinder, which opening is just uncovered
at the bottom of the stroke by a corresponding opening in the side of the piston
which communicates with the lower end of the latter."' Or instead of the lower
cylinder described the two cylinders may be arranged side by side; the smaller
plunger being actuated by a crank or cam, or by a cross-head connected to the
larger piston.
In order to ignite the mixture of air and gas or inflammable vapour, I prefer to
use a cylindrical or conical valve revolving in a corresponding case and actuated
by an excentric or cam.
The valve is closed at its ends, and has gas admitted into it through an opening
in the lower part of the case and through the valve, and this gas is ignited by a
flame kept burning outside a hole immediately adjoining the former.
At a higher level a third opening is made through the case and valve by which
the products of combustion pass away, the flame thus burning inside the valve.
When the valve is turned partly round the upper opening is first closed, then the
lower ones, and immediately afterwards a passage is opened communicating
between the inside of the valve and the cylinder, through which the air and gas
in the latter are ignited by the gas which remains for a short time burning in the
upper part of the valve. Instead of the arrangement described a slide valve may
be used.
In another method of arrangement for the same purpose I make the piston itself
serve the purpose of a valve, a recess in it being brought alternately opposite to a
flame by which gas admitted into it is ignited, and the gas being immediately
afterwards cut off, and the recess 'in it being brought opposite to a corresponding
recess or passage in the inside of the cylinder, which recess communicates at the
same time with a passage in the piston opening to the lower end of the latter.
+
A governor of any of the ordinary well known kinds may be used to regulate
the quantity of gas admitted to the supply pipe of the engines described, or to cut
the gas entirely off and allow air only to be admitted to the cylinders, if desired.
"
The different arrangements of engines described may be placed vertically,
horizontally, or in other convenient position.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edmund Edwards in the Great Seal Patent Office
22nd October 1881.
on the
EDMUND EDWARDS, of the Firm of Edwards and Co., Patent Agents and
Engineers, of 40, Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN MOTIVE POWER ENGINES ACTUATED BY THE COMBUSTION OF
A MIXTURE OF GAS AND AIR."
о
My present Invention relates, firstly, to further improvements in the apparatus
for which I obtained. Her Majesty's Royal Letters Patent, dated February 20th,
A.D: 1880, and numbered 760. The accompanying Drawings are in illustration of
my present Invention. In the Specification and Drawings accompanying the same
of the said Letters Patent I described and shewed methods of arrangement in
which a mixture of air and inflammable gas or vapour is drawn into a cylinder
and is then ignited, a piston or plunger in the cylinder being actuated by the
expansion of the air thus caused.
In that form of such engine in which a valve is described and shewn admitting
the combustible mixture of air and gas and closing by the force of the explosion
after ignition, it is advisable that the gas should be thoroughly mixed with the
entering air, and for this purpose I make the inlet gas pipe communicate with
numerous small perforations formed in the face of the seat upon which the valve
closes. Or, preferably, I form an inlet pipe for air at or near the bottom of the
cylinder, the outer end of such pipe being provided with a valve of indiarubber,
asbestos, or other flexible material, or of thin metal opening inward. At a suitable
part of such inlet pipe between the valve and the cylinder I arrange an internal
concentric annular pipe, into which gas is admitted and passes into the air pipe
through a series of small holes. This arrangement is shewn in Sheet. 1, at Figure 1,
in which a is the inlet air pipe (shewn broken off); b is the inlet gas pipe,
provided with a' valve at c to prevent back pressure in the pipe b when the
mixture of gas and air is ignited; and d is an annular pipe having an internal ring
C. Or the
of small perforations, and also an opening opposite to the valve
modified-arrangement shewn in Figures 2, 3, and 4 may be used, in which a is the
inlet air pipe provided with the inlet flexible valve at e; b is the inlet gas pipe
with the back pressure valve c; and d is an annular ring fitting into a recess in
the pipe a, and having round it a channel, preferably varying in sectional area,
from which small perforations communicate with the interior of the pipe, or
instead of perforations a sufficient number of fine grooves may be made in the
outer circumference and the upper or lower faces, or both, of the ring through
which the gas passes to the pipe a. In Figures 3 and 4 a method of arrangement *
is shewn by which the valve c is kept closed when the gas is shut off, f being a
spindle raised by a spring and having a conical cam which presses upon a
projection on the valve c and keeps the latter closed. The valve c is opened by
a light spring behind it, when the spindle f is forced down by the piston at the
lower end of its stroke, as shewn in Figure 3. When the valve is closed by the
explosion the spindle frises and keeps it closed until the piston again returns to
the bottom of its stroke. I prefer to make the exhaust valve by which the heated
air and products of combustion are allowed to escape during the down stroke of
the piston or plunger in the form of a disc valve fitting upon a. corresponding seat
upon the bottom of the plunger against which it is drawn up by a spring, as shewn
in Figure and other Figures; g being the exhaust valve fitting a seat in the
piston h, and, drawn up by the spring i. The vertical exhaust passage in the
side of the piston communicates with the exhaust pipe I, and the valve is opened

page_text: during the down stroke of the piston by a projection m upon the connecting rod n.
The exhaust port may be uncovered by the lower edge of the piston itself at
the upper end of its stroke, as described in my former Specification already
referred to..
In Figures 8, 9, 12, 13, 16, & 20 the piston is shewn formed with a hollow trunk
of smaller diameter, the outer end of which works in a guide at the outer end of
the cylinder, and the passage in the piston opened by the exhaust valve
communicates with the space between this trunk and the cylinder, the exhaust.
pipe opening into the cylinder at its outer, end, and by this method of construction
the cylinder can be made of less length.
In order more completely to shut off the supply of gas after, the mixture of gas
and air has been ignited, I sometimes adopt the method of arrangement shewn in
Figures 2, 5, and 6, in which the inlet gas passage o opens into the side of the
cylinder in the neighbourhood of a second similar opening through which the gas
is supplied by the pipe b. In the plunger or piston I make a recess or passage p,
which connects the two openings when the piston is at the bottom of its stroke,
but closes them either gradually or suddenly when the piston has risen sufficiently
far. The position and shape of the recess p may be varied so that the gas
admitted and cut off at any desired point of the stroke.
I sometimes make another corresponding recess in the plunger which admits gas
at the proper time to the flame by which the mixture in the cylinder is ignited, and
cuts it nearly or entirely off during the time when such igniting flame is not
required, and the consumption of gas is thus economized.
Instead of the methods above described and shewn for cutting off the supply of
gas admitted with the air to the cylinder, I sometimes arrange a lever, one end of
which enters an opening in the cylinders, where it is actuated by the piston itself,
whilst its other end is connected to a valve, so that at the bottom of the stroke of
the piston the valve is opened, but when the former has travelled sufficiently far
it actuates the lever, which closes the valve and retains it closed. And I sometimes
use a somewhat similar method of arrangement in order to regulate the admission
of the air and gas or inflammable vapour to the cylinder, in which either a slide
valve or disc valve is actuated at the proper times by the piston. For this purpose
I connect the valve to a lever upon a pivot, having its two ends arranged so that
they can enter corresponding openings in the cylinder, where they are actuated
alternately by the piston. The latter has corresponding longitudinal recesses
provided in it of such length that their ends actuate the lever, and through it the
valves at the proper times, the valve being opened when the piston reaches the
bottom of its stroke, being closed when the piston has risen sufficiently far, and
either remaining in its position until the piston again descends, or having its
action reversed, so that whilst the air and gas still remain cut off a passage is
opened through which the products of combustion escape during the down stroke
of the piston. In Figure 26 on Sheet 9 a separate cylindrical exhaust valve g is
shewn actuated by an excentric m, the inlet air and gas valves being similar to
those already described and shewn.
Engines constructed according to my Invention may be made with their cylinders
vertical or in other convenient position, but I prefer to arrange them diagonally, as
shewn in Sheets 2, 3, 4, 5, 6, and 8 of the Drawings; and in order to reduce the
heat imparted to the cylinder by the ignition of the gas I prefer to adopt the
method of arrangement shewn in Sheet 2, at Figures 8, 9, 10, and 11, and in
Sheet 3, at Figure 12, in which a is the cylinder having a piston b and hollow
trunk c working in a guide d; as already described, e heing the exhaust valve
actuated by the connecting rod f, and allowing the hot air and gases to pass to the
exhaust pipe g through the space h between the trunk c and the cylinder. The
flexible air valve i opens outward, the end of the air pipe as well as the valve i
being covered by the cap k and the perforations at 1, through which air is drawn,
opening into a space between the cylinder a and an outer casing m.
The upper
end of the cylinder and of its cover d have perforations through them, as shewn at

page_text: ,.through which all the air used by the engine is drawn, and the cylinder is thus
kept cool, and the sound of the explosion is completely deadened; or an outer
casing may be arranged outside the cylinder, through which water or air circulates,
as shewn in Figure 7; or the sides of the cylinder may themselves be of great
thickness, and either circular or polygonal outside, a series of perforations. being
made through them from end to end, the upper ends of these perforations being
open or connected to a pipe leading to the open air or to a chimney, and the lower
ends being open preferably laterally. Air passing through these perforations in
the sides of the cylinder keeps the latter sufficiently cool; or instead of air water
may be made to circulate round the cylinder. The outer sides of the spaces or
perforations may be closed by separate plates.
The arrangement shewn in Figures 8, 9, 10, 11, and 12, in which the air which
supplies the engine is drawn through an outer casing which surrounds the cylinder,
is shewn on Sheet 4 at Figures 13 and 14, and on Sheet 5 at Figure 15. These
Figures also show a separate valve for the purpose of cutting off the supply of gas
at each stroke. o is a small cylinder containing a plunger or piston p actuated by
an excentric r upon the driving shaft of the engine. A transverse passage across
the cylinder o admits gas from the supply pipe s, the inner end of which is
provided with a back pressure valve at t similar to those already described, by
which the gas is admitted preferably through a series of perforations, as shewn,
into the air pipe v. The plunger has a transverse opening through it, so arranged
that the gas is entirely cut off at the proper time. A similar plunger may also be
used to force the gas into the cylinder. The mixture of gas and air is ignited at
the proper moment by a flame, which is admitted through an opening uncovered
at the proper time by the lower edge of the piston, a small valve being arranged, as
shewn on Sheet 5 at Figure 17, to close the opening at the moment of the explosion.
And in order to ensure the more certain ignition of the air and gas in the cylinder
by lessening the quantity of air which is drawn in with the flame, I sometimes
use the novel method of arrangement shewn on Sheet 5 in Figure 18, in which the
flame is shewn turned back and directed outward through a tube w, a small
flame being kept constantly burning at in order to relight the flame in case of
its accidental extinguishment. And sometimes I adopt the method shewn in
Figure 19, in which a supply of unburned gas is admitted through a supply pipe y
and a second valve into the cylinder in front of the flame when the latter is
drawn in, being thus itself ignited, and securing the ignition of the combustible
mixture in the cylinder.
Where it is desired that the stroke of the piston in the cylinder should be of
greater relative length than in the method of arrangement already described and
shewn, I sometimes use the arrangement shewn in Sheet 6 at Figure 20, in which
a is the cylinder fitted with the piston b and bollow trunk c working in the
guide d, the exhaust valve e being of the same kind and actuated in the same way
as those already described and shewn, and the methods of admitting the air and
gas, which are not shewn in the Drawing, being also similar to those already
described and shewn. The outer end of the connecting rod f is shewn connected
to the upper end of a bar g, the lower end of which is jointed to a vibrating radius
link h (or is arranged to work in a straight guide), whilst an intermediate point in
its length is fitted upon the crankpin at i. By this method of arrangement, whilst
the piston has a long stroke relatively to the crank (as shewn in dotted lines), its
transverse oscillation is not too great to allow it to actuate the exhaust valve e in
the method already described. Instead of the method shewn at Figure 20, methods
of a similar kind, as indicated in dotted lines in Sheet 7 at Figures 21 and 22,
may be used for the same purpose, the dotted lines f representing the connecting
rod, g the connecting bar, the vibrating link, and i the crank pin.
On Sheet 8 Figure 23, 24, and 25 represent another method of arrangement,
in which a novel form of apparatus is shewn for the purpose of admitting and
cutting off the gas, and also for actuating the exhaust valve; a is the cylinder

page_text: fitted with the external casing m, as in the arrangements already shewn, through
which air is drawn to the air valve in the cap k. The piston b is connected by
& tubular rod c to the bollow slide d which works in the guide e, through which
openings are made at n for the admission of air, as already described. The con-
necting rod f is jointed to the hollow slide d, and also to a pin in the fly wheel g,
which works in a suitably formed recess in the frame h. The air inlet pipe 7 has
fitted within it a tubular valve m capable of moving for a sufficient distance in the
direction of its length. A slot is formed in the side of the pipe l, in which, fits and
works a pin n attached to the valve m, and actuated preferably by the excentric
rod o, which passes through the space between the cylinder and the casing m.
An inlet gas pipe p and back pressure valve t admit gas to the pipe l, the admission
and cut off being regulated by the port through the valve m.
A second port
at n through the valve m regulates the opening and closing of the passage to the
exhaust pipe v.
At
Another part of my present Invention relates more particularly to that form of
engine in which a mixture of air and gas or inflammable vapour is compressed
before being ignited. In order to carry out this part of my Invention, I attach to
the lower end of the piston, constructed and working in a cylinder in a way similar
to those already described, a second piston or plunger of smaller diameter, which
fits and works with or without the intervention of suitable packing, such as
asbestos or metallic rings, in a lower cylinder concentric with the upper one.
the lower or outer end of the smaller cylinder I provide one or more valves opening
inward, preferably of the kind already described and shewn, by which air and gas
in suitable proportions are admitted and mixed together. I make the lower piston
or plunger hollow and open at its lower end, and I make its hollow part com-
municate with one or more small transverse passages in the larger piston near the
lower end of the latter, the outer ends of these passages being situated, when the
pistons are at the bottom of their stroke, just below an enlargement of the lower
end of the bore of the larger cylinder, or opposite to corresponding passages in the
larger cylinder communicating with its lower end. A ball valve or other check
valve opening upward may be arranged, if desired, at the upper end of the passage
in the smaller hollow piston or plunger, and the larger piston is recessed upward at
its lower end round the smaller piston or plunger, or it may be so arranged as not
to descend to the bottom of the cylinder at the lower end of its stroke, so that in
either case a sufficient space is left below the upper piston when at the bottom of
its stroke. An exhaust valve is arranged so as to open during the down stroke
of the pistons, preferably of the kind already described, in which the valve is
actuated by a projection at the lower end of the connecting rod, but arranged so
that the valve closes before the small transverse openings in the larger piston
descends low enough to communicate with the space below such lower piston, as
already described.
In Sheet 9 of the accompanying Drawings Figure 27 is in illustration of an
engine constructed according to the novel method just described. The Drawing
shows the cylinders in a vertical position, but it is to be understood that they may
be arranged in a horizontal or preferably in a diagonal position; a is the larger
cylinder, in which is fitted and works the piston b, having the hollow trunk c
working in the gvide d, and having the exhaust valve e actuated by the connecting
rod f, as in the arrangements already described; is the smaller cylinder in which
fits the hollow plunger or piston h, which is packed with asbestos or other packing
at i, as shewn.
One or more transverse passages j are made through the piston b; so that at the
bottom of the stroke they open into corresponding grooves at k, or an equivalent
enlargement of the cylinder. The piston bis recessed up, as shewn at 6, the exhaust
valve c being situated at the top of the recess. Inlet valves for air at m and for
gas at n are provided of a kind preferably similar to those already described, and o
is a valve opening upward at the upper end of the hollow plunger h. A firing

page_text: valve, preferably of the kind hereinafter described, actuated by an excentric or
cam, is arranged so that it communicates with the lower end of the larger cylinder
shortly after the pistons have cominenced their up stroke.
.
The action of the apparatus constructed and arranged as described and shewn is
as follows:-It the pistons be at the top of their stroke the lower cylinder g will be
filled with a mixture of air and gas or inflammable vapour drawn in by the ascent
of the lower hollow plunger h, and when the pistons descend the mixture is
compressed into the hollow plunger until the larger piston has reached the
bottom of the stroke when the compressed mixture expands through the transverse
passages j, first forcing any products of combustion remaining in the cylinder into
the upper part of the recess l, and filling the remainder of the space itself whilst
still remaining sufficiently compressed. The pistons then commence their ascent,
the mixture in the bottom of the cylinder a being almost immediately ignited and
acting with great force to effect the ascent of the pistons, which is aided during the
first part of their stroke by the expansion of the mixture remaining in the lower
cylinder g. During the latter part of the stroke the lower hollow piston h draws
in a fresh supply of air and gas through the valves m and n, which mixture is
compressed during the downstroke of the pistons by the momentum obtained
during their upstroke, and these operations are continued as long as desired. In
a modified arrangement I make a valve opening upward at the lower end of the
smaller plunger, the hollow part of which is preferably of small area, and I make
the communication with the larger cylinder open at some distance from the
bottom of the stroke, preferably before the point at which the exhaust is also
closed. The mixture is partly compressed in the small cylinder, and when the
communication is opened it expands into the larger cylinder, expelling the products
of combustion through the exhaust. The mixture is compressed both by the
smaller and the larger pistons during the remainder of the stroke. Another
modified arrangement is shewn on Sheet 9 at Figure 29, in which a valve opening
upward is fitted at the bottom of the lower piston c, the rod of which his reduced
in diameter so that the air and gas during the down stroke are compressed
through small openings into the space round it at i. An exhaust valve is
not essential, part of the products of combustion escaping through the exhaust
port e at the top of the stroke, and the remainder being compressed below' the
piston b.
If an exhaust valve be used I arrange it so that it closes, when the
pistons have descended so far that all the products of combustion have escaped.
I prefer to make the gas inlet at a short distance from the bottom of the
smaller cylinder, as shewn, so that the latter contains air only at the bottom.
Another nodified arrangement is shewn at Figure 28, in which packing is
introduced. round the lower plunger at the upper end of the smaller cylinder g
instead of at the lower end of the plunger itself. A valve held down by an
adjustable spring is indicated in dotted lines at r, Figure 27, to prevent the pressure
in the lower hollow plunger h from becoming too great in the event of accidental
ignition in it.
In another method of arrangement I make a valve opening upward in the lower
extremity of the smaller plunger. When the plungers are raised the mixed air and
gas are drawn into the smaller cylinder, and when the plungers are forced down
the mixture is compressed into the hollow plunger, from which at the lower end of
the stroke a sufficient quantity expands into the space below the larger piston.
As the pistons rise the communication from the hollow plunger to the larger
cylinder is cut off, and shortly after the mixture below the upper plunger is ignited
and the. pistons forced up. This process is repeated continuously, a compressed
mixture being admitted and ignited below the larger piston at each stroke.
A space, of capacity preferably adjustable, is left below the bottom of the lower
piston when at the bottom of its stroke, so that the quantity of air and gas drawn
in at each stroke is determined. Instead of air and gas being compressed into the
hollow plunger, and admitted thence to the cylinder through passages in the
larger piston, as shewn, one or more separate pipes or passages may be made to

page_text: communicate from the bottom of the lower cylinder to a suitable opening in the side
of the larger cylinder, which opening is uncovered at the bottom of the stroke by
a corresponding opening in the side of the piston which communicates with the
space below the lower end of the latter. Or instead of the lower cylinder described
the two cylinders may be arranged side by side, the secondary piston or plunger
being actuated by a crank, or cain, or by a crosshead connected to the principal
piston.
.
In order to ignite the compressed mixture of air and gas or inflammable vapour,
any convenient form of apparatus or device may be used, but I prefer to use a
cylindrical or conical valve of the kind shewn in Sheet 5 at Figure 29, in which
the valve is shewn in several different positions.
The cylindrical valve a is fitted in a corresponding case b, its ends being closed,
and a lever being fixed upon it at c by which it can be actuated as desired
by an excentric or cam. Gas is admitted into it through an opening d through the
lower part of the case and through the valve, and this gas is ignited by a flame
kept burning outside a hole e immediately adjoining it.. At a higher level a third
opening is made through the case and valve by which the products of combustion
pass away, the flame thus burning inside the valve when the latter is in the
position shewn at A. When the valve is turned partly round, as shewn at B, the
opening is closed, the lower openings d and e are next closed, as shewn at C, and
immediately afterward the passage g opens to a corresponding passage into the
cylinder, in which the compressed air and gas are ignited by the gas, which
remains burning for a certain time in the valve. A cylindrical or flat slide valve
may be used in the same way instead of a cylindrical valve.
Another novel inethod of arrangement for the same purpose is shewn on Sheet 5
at Figures 31 and 32, in which the piston itself serves the purpose of a valve.
a is the piston in the cylinder b, and c is a recess in the piston, which by the
movement of the latter is alternately brought opposite to an opening d in the
cylinder where a flame is kept burning and then opposite to a corresponding recess
or passage e inside the cylinder, which recess communicates at the saine time with
a passage in the piston communicating with the bottom of the latter. Gas is
admitted from a supply pipe g which communicates (except at the bottom of the
stroke) with a vertical recess in the side of the piston at h, and this recess
communicates by a passage i with the recess c. In Figures 30 and 31, a
valve is shewn at k through which air is drawn, and at through which gas is
drawn during the upstroke of the piston, the gas being mixed with the air through
the small perforations at m, and the valves k and closing during the descent of
the piston when the mixture is compressed into the hollow piston.
The exhaust valve, which may be of the kind already described and shewn, is
not shewn on the Figures. In the different arrangements of engines described,
the cylinders and pistons may be kept cool by the injection or admission otherwise
of a small quantity of water.
Having now described my Invention and the manner in which it is to be
performed, I claim,-The methods of admitting gas and mixing it with air,
substantially as described and shewn in Figures 1, 2, 3, and 4.
. . Also, the method of keeping the gas check valve closed and releasing it when
necessary, substantially as described and shewn in Figures 3 and 4.
Also, the disc exhaust valve in combination with the spring for keeping it in its
seat and the projection upon the connecting rod by which it is actuated,
substantially as described and shewn in the Drawings.
Also, the combination with such exhaust valve so actuated, of the piston formed
with hollow trunk working through a guide and an exhaust port opening into the
space round such trunk, substantially as described and shewn in the Drawings.
Also, for the purpose of admitting and cutting off the gas from the inlet valve,
the recess in the plunger in combination with passages communicating with the
gas supply pipe and inlet valve, substantially as described and shewn in Figures 2, 5,
and 6.

page_text: Also, for the purpose of so admitting and cutting off the supply of gas from the
inlet valve, a lever, one end of which is connected to a valve and the other end is
actuated by the piston through an opening in the cylinder, substantially as
described.
Also, for the same purpose, the lever turning upon a centre, and connected with
a valve, its ends alternately entering openings in the cylinder, and being actuated
by the piston or plunger, substantially as described.
Also, for the purpose of keeping cool the cylinders of gas engines, the openings
through the cylinder cover in combination with the external casing, so that the air
admitted to the cylinder is first drawn through the space between the cylinder and
the casing, substantially as described and shewn in Figures 8, 9, 10, 11, 12, 13, 14,
15, 23, and 24.
Also, for the purpose of keeping the cylinders cool, the perforations through its
solid sides, through which water or air is circulated, substantially as described.
Also, in combination with the cylinder piston, hollow trunk working through a
guide, inlet air valve, and disc exhaust valve actuated as described, the separate
valve actuated by an excentric or cam, for the purpose of supplying and regulating
the admission of gas, substantially as described and shewn in Figures 13, 14,
and 15.
Also, for the purpose of igniting the mixture of air and gas in the cylinder
through a suspended valve, the horizontal tube containing the igniting flame
directed outward, substantially as described and shewn in Figure 18.
Also, for the purpose of rendering the ignition of the mixture of air and gas in
the cylinder more certain, the second separate passage provided with a separate
and independent suspended valve, admitting unburned gas into the cylinder,
substantially as described and shewn in Figure 19.
Also, for the purpose of increasing the length of stroke of the piston or plunger
of the engine without increasing the transverse movement of the connecting rod by
which the exhaust valve is actuated, the combination of the connecting rod, bar,
and radius link, arranged in the manners described and shewn in Figures 20, 21,
and 22.
Also, for the purpose of regulating the admission and discharge of air and gas in
the cylinder, the concentric pipe provided with air and gas valves, and containing
a tubular slide valve actuated by an excentric or cam, substantially as described
and shewn in Figures 23, 24, and 25.
Also, in engines actuated by the combustion of a compressed mixture of air and
gas, the combination of the working cylinder and piston with the compressing
cylinder and piston or plunger, and the passage or passages communicating with a
space beneath the working piston, or round the lower piston rod, substantially as
and for the purpose described and shewn in Figures 27, 28, and 29.
Also, in combination with such engine, arranged substantially as described and
shewn in the Figures, the valve for firing the compressed mixture of gas and air in
the cylinder, consisting of a hollow plug fitted in a case actuated by an excentric or
cam, gas being admitted to the hollow plug and alternately ignited by an external
flame, and igniting the mixture in the cylinder, substantially as describe anḍ
shewn in Figure 29.
Also the general arrangement of apparatus, substantially as and for the purposes
described and shewn in the several Figures.
In witness whereof, I, the said Edmund Edwards, have hereunto set my hand
11001
EDMUND EDWARDS. (L.S.)