IMPROVEMENTS IN MOTIVE POWER ENGINES ACTUATED BY THE COMBUSTION OF A MIXTURE OF GAS AND AIR, OR BY THE PRESSURE OF STEAM OR OTHER ELASTIC FLUID, PARTS OF WHICH INVENTION ARE ALSO APPLICABLE TO OTHER PURPOSES
Year: 1880

page_text: 66
LETTERS PATENT to Edmund Edwards, of 40, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Engineer and Patent Agent,
for an Invention of IMPROVEMENTS IN MOTIVE POWER ENGINES ACTUATED
BY THE COMBUSTION OF A MIXTURE OF GAS AND AIR, OR BY THE PRESSURE
OF STEAM OR OTHER ELASTIC FLUID, PARTS OF WHICH INVENTION ARE ALSO
APPLICABLE TO OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said Edmund Edwards at the
Office of the Commissioners of Patents on the 20th February 1880..
EDMUND EDWARDS, of 40, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent. "IMPROVEMENTS IN MOTIVE POWER
ENGINES ACTUATED BY THE COMBUSTION OF A MIXTURE OF GAS AND AIR, OR BY
THE PRESSURE OF STEAM OR OTHER ELASTIC FLUID, PARTS OF WHICH INVENTION
ARE ALSO APPLICABLE TO OTHER PURPOSES."
This Invention relates to motive power engines in which the motive force is
obtained by the explosion in a cylinder of a mixture of gas and air in suitable
proportions, the expansion of which mixture by explosion actuates a piston in the
cylinder. It has for its objects improved methods of constructing and arranging
the several parts of the apparatus, so that it is simpler and cheaper than has
heretofore ordinarily been the case.
I take a cylinder of cast iron or other suitable material arranged in any
convenient position, but preferably vertically, upon a stand or base plate which
closes the lower end of the cylinder. In this cylinder I fit a hollow piston or trunk
capable of moving freely up and down in the cylinder, with or without the addition
of packing rings.
Near the lower end of this hollow trunk I arrange a transverse pin upon which
fits the lower end of a connecting rod, the upper end of which is fitted upon a crank
pin upon a crank or plate attached to a shaft, which revolves in a suitable bearing
formed in a standard which preferably forms a part of the cylinder, but may be
made separate. The revolving shaft is provided with a fly wheel and pulley or
other device, by which mechanism can be driven in the ordinary way.
At or near tho centre of the height of the cylinder I make an opening or port
through which an explosive mixture of gas and air can be admitted, and through
D .

page_text: the side of the plunger adjoining this port I make or cast a passage, the lower
end of which opens through the lower end of the plunger, whilst its upper end
enters a vertical opening at the side of the plunger, the upper edge of which
opening is so adjusted that it corresponds with the upper edge of the admission
port in the side of the cylinder, when the plunger is at the bottom of its stroke,
whilst its lower edge is adjusted so that when the plunger has risen to a sufficient
height, preferably from one third to one half of its stroke, it closes the adinission
port in the cylinder. Below the admission port I make a small aperture through
the cylinder, outside which a flame is kept burning, and a corresponding small
aperture is made laterally through the plunger into the vertical passage in the
latter. At another part of the circumference of the cylinder I make an exhaust
port or opening, which is uncovered by the lower edge of the plunger when the
latter is at the top of its stroke, but is reclosed as the plunger descends. The
action of the apparatus is as follows:-The plunger being at the bottom of its
stroke the fly wheel is turned round, and as the plunger rises mixed air and gas are 1
drawn through the admission port, and through the passage in the plungers into
the lower part of the cylinder. At the proper point the admission port is closed as
described, and immediately afterwards the small aperture in the plunger comes
opposite that in the cylinder, and the flame is drawn in and explodes the mixture,
the apertures being directly closed as the plunger rises. The expansion of the
exploded mixture forces up the plunger to the top of its stroke, at which point the
remaining gases escape through the exhaust port, leaving, if the quantities of the air
and gas are properly proportioned, a partial vacuum in the cylinder; the descent of
the plunger is then effected by the momentum of the fly wheel, as well as the
commencement of its re-ascent, when it draws in the mixture of air and gas as
already described, and the operations continue as long as may be desired.
It will be seen that the apparatus described is of great simplicity, consisting
essentially of a cylinder and plunger only.
I sometimes however use in addition a novel valve by which a free opening to
the exhaust passage is provided during the descent of the plunger, whilst any back
pressure against the inlet passage is prevented.
For this purpose I make a transverse dove tailed groove or recess across the
lower end of the plunger, and I fit into this recess a sliding plate or valve. On the
opposite side of the plunger I make a vertical passage through it similar to that for
the admission of the gas and air, as already described, the lower end of which
passage also opens through the lower end of the plunger, and I make the sliding
valve of such length that at one end of its stroke it covers the admission opening,
and at the other end the exhaust opening, whilst at the centre of its stroke .it
covers both openings. In order to actuate the sliding valve I make the central
hollow part of the plunger open through the lower end of the latter, and I provide
a projecting end or tail piece to the lower end of the connecting rod, which fits
into a corresponding recess in the sliding valve, so that as the connecting rod
oscillates it drives the valve backward and forward. 1 make the vertical exhaust
passage in the plunger communicate with an opening in the side of the latter, of
such length that it remains open to the exhaust port in the cylinder when the
plunger is at the bottom of its stroke, whilst its lower edge descends below the
exhaust port sooner or later, as may be desired during the down stroke of the
plunger.
By the arrangement described the admission opening at the bottom of the
plunger is closed during the descent of the plunger, whilst the exhaust opening is
closed during its ascent.
The revolving shaft may be provided with a second crank at its outer end,
arranged in a position opposite to the first one, and actuated by a second plunger
and cylinder; or two opposite cylinders may be arranged to drive the same crank
pin. In order to keep the cylinder cool I sometimes arrange a second cylinder of
greater diameter outside the first, and I allow a current of air to pass through the
concentric space between them.

page_text: The quantity of gas admitted may be regulated in the usual way by a governor
or by hand, and it may be made to pass through chambers filled with wire gauze
or other perforated or porous material, or through flexible bags or other chambers
of variable capacity by which its pressure is equalized.
Instead of a sliding plate or valve working in a dovetailed groove or recess
across the bottom of the plunger, as above described, I sometimes form the valve
of a bar preferably cylindrical, fitting and sliding in a transverse hole across the
plunger near the bottom of the latter.
The ports or passages above described pass out at the bottom of the plunger, but
the central opening need not pass through the latter. The sliding bar is worked in
the way already described by a projecting piece at the lower end of the connecting
rod fitting into a notch in the sliding bar. This arrangement is especially
applicable to engines driven by steam or other elastic fluid, in which cases the
openings for ignition are not required.
Instead of working the sliding valve or bar by means of the connecting rod,
I sometimes arrange it either vertically or horizontally, so that it is driven by a
separate connecting rod actuated by an eccentric upon the crank pin.
My improved apparatus may also be used as a pump for compressing air or other
elastic fluid.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edmund Edwards in the Great Seal Patent Office on the 20th August
1880.
EDMUND EDWARDS, of 40, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent. "IMPROVEMENTS IN MOTIVE POWER
ENGINES ACTUATED BY THE COMBUSTION OF A MIXTURE OF GAS AND AIR, OR BY
THE PRESSURE OF STEAM OR OTHER ELASTIC FLUID, PARTS OF WHICH INVENTION
ARE ALSO APPLICABLE TO OTHER PURPOSES."
My Invention relates more especially to motive power engines in which the
motive force is obtained by the explosion in a cylinder of a mixture of gas and air
in suitable proportions, the expansion of which mixture by the explosion actuates
a piston in the cylinder. It has for its objects improved methods of constructing
and arranging the several parts of the apparatus, so that it is simpler and cheaper
than has heretofore ordinarily been the case. The accompanying Drawings are in
illustration of my Invention. Figure 1 shows partly in section one form of my
improved apparatus. a is a cylinder of cast iron or other suitable material fixed
in any convenient position, but preferably vertically, upon a stand or base-plate b.
In the cylinder a is fitted a piston or trunk c, capable of moving freely from end
to end of the cylinder, with or without the addition of packing. Across the piston c
is arranged a pin d, upon which turns the lower end of the connecting rod e, the

page_text: upper end of which is fitted upon a crank pin f upon a crank or plate g fixed upon
the shaft i, which revolves in a bearing in the standard &, forming preferably a part
of the cylinder a, but which may be made separate. The shaft i is provided with
a fly wheel and pulley or other device, by which mechanism can be driven in the
ordinary way. In the side of the cylinder a I make an opening or port L,
through which a mixture of air and gas can be admitted, and through the side of
the plunger adjoining this port I make or cast a passage m, the lower end of which
opens through the bottom of the piston b, whilst its upper end enters a vertical
opening n at the side of the piston b, adjustod so that it corresponds with the upper
edge of the port when the piston bis at the bottom of its stroke, whilst its lower
edge is adjusted so that when the piston has risen to a sufficient height, preferably
from one third to one half of its stroke, it closes the port L. Below the level of the
port I make an opening o through the cylinder, as shown in Figures 2 and 3,
outside which a flame is kept burning, and a corresponding opening is made laterally
through the piston at p into the vertical passage m. At another point in the
circumference of the cylinder I make an exhaust port or opening 2, which is uncovered
by the lower edge of the piston b when the latter is at the top of its stroke, but is
re-closed as the piston b descends.
The action of the apparatus is as follows:-The plunger b being at the bottom
of its stroke the fly wheel is turned round, and as the plunger or piston b rises it
draws air and gas through the passage m into the lower part of the cylinder until
the lower edge of the opening n closes the admission port 1, and immediately after-
wards the aperture p in the piston comes opposite the opening o in the cylinder,
and the flame is drawn in and explodes the mixture, the apertures being directly
closed as the piston rises. The expansion of the exploded mixture forces up the
piston to the top of its stroke, at which point the remaining gases escape through
the exhaust port r, leaving (if the quantities of the air and gas are properly propor-
tioned) a partial vacuum in the cylinder. The descent of the piston b is effected by
the momentum of the By wheel, as well as the commencement of its re-ascent,
when it draws in the mixture of air and gas, as already described, and the operations
continue as long as may be desired. A valve opening inwards is shewn at 8 to
prevent any back pressure in the inlet pipe during the last part of the down stroke
of the piston b. In Figures 4 and 5 two passages m, m², are shewn in the piston c,
the air and gas being admitted through the openings, l', in the cylinder. The
passages for the admission of air should be made as large as possible, and sometimes
I make separate openings for the admission of the air and gas, which do not mix
until they reach the lower end of the cylinder, and in this case the explosion is
effected through a small opening in the side of the cylinder, which is uncovered at
the proper moment by the lower edge of the piston, and is provided with a valve
opening inward to prevent the escape of the gases after the explosion. In Figures 8
and 9 the passages for the air and gas are shewn separate, s being the inlet for the
air, and a¹ the inlet for the gas, corresponding openings being made in the piston c.
In Figures 12, 13, and 14 the separate air and gas passages & and 8' in the piston c
are shewn on a larger scale. The small opening and valve for exploding the mixture
are shown at p in Figures 6, 10, and 17. I sometimes use a novel arrangement of
slide valve, by which a free opening to the exhaust passage is provided during the
downstroke of the piston or plunger, whilst it also provents any back pressure
against the inlet passage. This arrangement is shewn in Figures 6 and 7, in which
a is the cylinder and 6 the piston; vis a cylindrical hole across the lower end of
the piston, and w is a sliding cylinder or valve fitting into the hole v. An exhaust
opening or passage x is made through the piston or plunger, and the valve wis of
such length that at one end of its stroke it covers the opening n, and at the other
end the opening ¤, whilst at half stroke it covers both openings. The valve w is
actuated by a projecting end or tail piece y upon the connecting rod e, which lits
into a corresponding recess in the valve, so that as the connecting rod oscillates
it drives the valve backward and forward. The passage x in the piston commu-
nicates above with the opening A, which is of such length that it remains open to

page_text: the exhaust port ? when the piston is at the bottom of its stroke, whilst its lower
edge descends below the ports 7 sooner or later (as may be desired) during the
downstroke of the piston. By this arrangement the admission opening m is closed
during the downstroke of the piston, and the exhaust opening during the upstroke.
Instead of a cylindrical sliding valve a flat sliding valve may be used, as shown on
a larger scale at win Figures 12, 13, and 14, and slightly modified in Figure 15.
The shaft i may be provided with a second crank at its outer end arranged in a
position opposite to the first one and actuated by a second piston and cylinder, or
two opposite cylinders may be arranged to drive the same crank pin; this
arrangement is shewn in side view at Figure 10 and in plan at Figure 11. The
cylinder may be kept cool if necessary by passing cold water round it, or by
arranging round it a second cylinder of larger diameter, air being allowed to pass
or circulate between them. Figure 16 shows a novel method which may be
adopted where it is desired to compress the mixture of air and gas before they are
exploded. For this purpose I allow a considerable space A between the bottom of
the piston C and the base plate b when the former is at the lower end of its stroke,
and I arrange the inlet passage s so that the air and gas are admitted during the
whole or the principal part of the up stroke of the piston. When the fly wheel
is turned round and the piston drawn up the space below it becomes filled
with the explosive mixture, and when the piston is then forced down it com.
presses the mixture into the space A below the piston. The latter is made to
commence its second upward stroke, and immediately afterwards a small opening
at B is uncovered in the side of the cylinder and opposite a flame by which
the compressed mixture is exploded, the opening being instantly closed. The
expansion of the exploded mixture carries the piston to the top of its stroke
where the gases escape through the exhaust port, and the momentum of the fly
wheel is sufficient to carry on the piston through the same series of operations, the
explosion only taking place at every alternate stroke. I arrange a small slide or
other valve at D by which the opening for exploding the inixtures is opened and
closed at every alternate stroke, such valve being actuated by a cam or excentric
upon an axle driven at the proper speed by the main shaft, or it may be opened
and closed at every stroke, a valve opening outward being arranged at D, as shewn.
Another modified arrangement of apparatus is shewn in Figure 17, in which tho
air and gas which form the explosive mixture are drawn in through openings at
or near the bottom of the cylinder, these openings being provided with a valve or
valves opening inwards. A small opening provided with an inlet valve into the
cylinder for exploding the inixture is shown at p as in the arrangement previously
described, so that when the explosion takes place the several valves close and the
movement of the piston is continued by the expansion of the exploded mixture
which escapes during the downstroke of the piston, either through an exhaust
port uncovered by the piston or through a passage regulated by a slide valve, as
already described and shewn. In Figure 18 the air and gas are shewn mixed
together after passing through the slide valve w, the mixture passing through
openings E and thence passing down the pipe F attached to the bottom of the
piston, this pipe descending at the bottom of its stroke into a corresponding pipe G
in the base plate b under the cylinder. The passages for the air or for the
explosive mixture of air and gas should be made as large as possible. In Figures
12, 13, and 14 a circular sliding valve and ports are shewn fitted upon the bottom
of the piston and actuated in the way already described. Engines constructed in
the method described may be actuated by the pressure of steam, compressed air, or
other elastic fluid instead of gas. In such cases one inlet opening only is required,
and the devices for exploding the gas and air are not necessary. A mixture of
air with ordinary coal gas or with the vapour of inflammable hydro-carbon oils
may be used in the different arrangements of apparatus described. Instead of
actuating the sliding valve or bar by ineans of the connecting rod, as described and
shewn, I sometimes arrange the valve either vertically or horizontally, and arrange
it so that it is driven by a separate connecting rod actuated by an excentric upon

page_text: the crank pin. A form of this arrangement (the connecting rod being removed)
is shewn in Figuro 19, in which the piston c contains a cylindrical valve w actuated
by an excentric H upon the crank pin f. The admission port is at 8 and the
exhaust port at r, the communication with them through the passage I in the
piston being regulated by the passages in the valve w. In Figure 20 is illustrated
another method of arrangement in which a valve w is arranged to work in a
cylinder c outside the main cylinder a. Air is admitted at 8, and gas at 8², and r is
an exhaust passage. The valve w is shewn actuated by a properly proportioned
cam H or excentric upon the driving shaft i. The apparatus may be either vertical,
as shewn, or horizontal, as illustrated in Figure 21.
.
Having now described my Invention and the manner in which it is to be
performed, I claim :-The combination of the cylinder with a piston or plunger
having openings through it for the passage of the air and gas, and a valve opening
inwards in the inlet openings, substantially as described and shewn; also, the
combination of the cylinder and piston having openings for the passage of air and
gas with a valve in the piston operated by the connecting rod, substantially as
described and shewn; also, the combination with the cylinder and piston having
openings for the passage of air and gas, and a valvo actuated by the connecting
rod of a tube descending into the base of the engine, substantially as and for the
purpose described and shewn; also, the method of compressing the mixed air and
gns and exploding it at each alternate stroke by means of the cylinder having a
space below it, the piston having openings for the passage of air and gas, the valve
in the inlet passage and the valve actuated by an excentric or cam by which the
compressed mixture is exploded, substantially as described and shewn; also, the
combination of the cylinder and piston having passages for the air and gas with a
valve in the piston actuated by an excentric upon the crank pin, substantially as
described and shewn; also, the combination of the cylinder and piston with the
passages for air and gas, and a valve or valves by which such passages are closed
by the explosion, substantially as described and shewn; also, the combination
with the cylinder and piston of an external cylinder containing a double valve
actuated by a cam or excentric, substantially as described and shewn; also, the
general methods of arrangement of the apparatus, substantially as and for the
purposes described and shewn.
In witness whereof, I, the said Edmund Edwards, have hereunto set my
hand and seal this 20th day of August, in the year of our Lord 1880.
EDMIIND EDWARDS
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