IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said Augustin Fiddes at the
Office of the Commissioners of Patents on the 13th December 1880.
AUGUSTIN FIDDES, of Bristol, in the County of Gloucester, Engineer.
"IMPROVEMENTS IN GAS MOTOR ENGINES."
This Invention consists,-
Firstly. In constructing a gas engine with a slide valve of peculiar constructing
working in the cylinder of the engine, by which the length of the cylinder is as it
were reduced internally at the time of firing, also fully compressing the charge and
maintaining such compression up to the time of firing.
Secondly. In admitting water to the charge at the time of firing which is
converted into steam, whereby an increases of power is obtained, and at the same
time such steam serving to cleanse the internal parts and pipes of the engine.
Thirdly. In a peculiar construction of valve arrangement for forcing the flame
into the charge so as to ensure the firing thereof.
Fourthly. In the employment of an oscillating cylinder in gas engines constructed
according to this Invention. In order to effect the above I construct a gas engine
substantially as follows:-
Into one end of a cylinder (which is open at both ends) is fitted a piston and rod
working in suitable guides, and at the other end the slide valve, which latter is
constructed similar to a hollow piston having suitable port holes corresponding to
those in the cylinder for the admission of the gases or other fluids for the exhaust.
To this slide valve is connected a rod having a T end working in a cam or cams
fixed at the back of cylinder so as to actuate the said slide valve at the proper
times as hereafter described. The gases are first admitted into the aforesaid
slide valve by the out stroke of the piston through the inlets in the cylinder
and slide valve contained therein, and immediately before the return or in stroke
the slide valve moves forward a short distance in the cylinder so as to cover the
inlets and partly compress the charge of air and gas contained in the said slide
valve. This movement of the slide valve is effected by means of a shaft and
suitable gearing connected to the crank shaft and shaft fixed at back of cylinder
Dries £21

page_text: connected to the aforesaid cam or cams and rod from the slide valve. When the
piston is at its return stroke, i.e., at the end of the in stroke, the aforesaid slide
valve moves forward to the piston, thus fully compressing the charge in the said
slide valve. On the next out stroke the slide valve with the compressed charge
therein follows the piston until the point of ignition is reached when the slide valve
will simultaneously uncover the inlet to admit a flame to fire the charge and water
which is immediately converted into steam. The peculiar construction of valve and
arrangement for firing the charge are as follows:-To the outside of the cylinder I
fix a small cylinder having a plunger working therein; this cylinder has a
transverse hole through which a flame is caused to burn to ignite the gas for firing
the charge; the other end of the cylinder is kept supplied with gas, and as the
ports are uncovered for firing the charge the plunger is forced in by means of a
suitable cam or excentric, so as to cut off the aforesaid flame, ignite the gas in the
cylinder and force a flame through the inlet to fire the charge. On the return
stroke the slide valve moves back sufficiently to allow the piston to move its full
stroke and open the exhaust port to expel the products of combustion, and imme-
diately upon the piston begining another out stroke the slide valve will move back
to its original position so as to close the exhaust and open the inlet for the gases,
and so on.
It is obvious that by altering the connecting shaft and working gear
I can fire at each stroke with half the charge or slower as required.
order to employ an oscillating cylinder the slide valve would be connected there-
with so that the oscillation of the said cylinder would actuate the slide valve, but
in this case the firing of the charge would take place at each stroke.
In
By constructing gas engines according to this Invention a considerable increase in
the power is obtained on account of the slide valve reducing as it were the length
of the cylinder at the time of firing, the charge being fully compressed at such
time, and further the additional force of the steam by the admission of water as
aforesaid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Augustin Fiddes in the Great Seal Patent Office on the
13th June 1881.
AUGUSTIN FIDDES, of Bristol, in the County of Gloucester. "IMPROVEMENTS
IN GAS MOTOR ENGINES."
This Invention relates to, firstly, a method of constructing a gas engine with a
slide valve working in the cylinder of the engine, by which the length of the
cylinder is as it were reduced internally at the time of firing, also fully compressing
the charge and maintaining such compression up to the time of firing.
Secondly, to a method of admitting water to the charge at the time of firing,
which is converted into steam, whereby an increase of power is obtained, and at
the same time such steam serving to cleanse the internal parts and pipes of the
engine.
Thirdly. To a peculiar construction of valve arrangement for forcing the flame
into the charge so as to ensure the firing thereof. And in order to explain my said
Invention more fully, I will now proceed to describe the same with reference to
the accompanying Drawings
Figure 1 shews an elevation partly in section of an engine constructed according
to my said Invention, the piston and piston slide or compressor valve being in the
position they would assume at time of firing the charge.
Figure 2 shews plan partly in section of Figure 1.
Figures 3, 4, 5, and 6, are detached views hereafter referred to. In each of the
Figures the same letters are employed to denote the same parts. A shews the
cylinder; B, piston proper; C, connecting rod connected to the crank E for
working the main shaft; a, a, are two guide rods; F is the slide or piston valve to
which is connected the cross levers b; to these levers are connected pins c, c, having
friction collars thereon which form T ends, one end of each of these pins works in
the slot d, and the other ends in the right and left handed cams e, e, (shewn detached
at Figure 6) formed on the back shaft G; these cams are arranged so as to operate
as hereafter described. To this shaft G is connected a cam f which acts against
the piece g fixed to the arm h at the proper time, as hereafter described; this arm
is free to work in the slot i. The piece g is kept against the cam f by means of
the spring k. To the other end of the arm h is connected the plunger in connection
with the arrangement for firing the charge, all of which is hereafter described with
reference to Figure 4. is the exhaust, into which is fitted a valve m, which is
acted upon at the proper time, as hereafter described by the arm n, which latter
is actuated by the projection o formed on the cam e, to open the exhaust port in
order to expel the products of combustion. p is an endless chain passing over the
toothed wheels q, r, for actuating the back shaft G. A¹ shews bed of engine
having a well 8, to allow for the action of the crank. H, H, are fly wheels; t is the
water jacket kept supplied by means of the circulating pipes u, v. Figure 3 is
section through line A, B, Figure 2. Figure 4 is a detached view drawn to an
enlarged scale, shewing the arrangement for firing the charge and for admitting a
small quantity of water (by means of pipe ', as shewn at Figure 3) to be converted
into steam by the firing of the charge. I is a cylinder cast in the water jacket t of
the main cylinder A (as shewn at Figure 2); K is the plunger connected to the
arm h, also shewn at Figure 2. L is a check valve through which a small quantity
of gas is supplied to the cylinder I. M is a pipe communicating with the cylinders I

page_text: gas
and A by means of the hole N and passage o formed in the plunger K. The end of the
of
plunger is made concave, as shewn at X, in order to facilitate the passage and
air through the hole P communicating with the chamber R in the plunger. . There is
also an air hole formed in the cylinder I communiating with chamber R, in order
that the gas may burn in the said chamber, as shewn in port s. The hole S is
for establishing a communication with the flame in the chimney T and chamber R.
U is the hole communicating with the main cylinder A; v', Figure 3, is the pipe
to supply a small quantity of water to the chamber R to be converted into steam
by the explosion; Figure 5 shews detached view drawn to an enlarged scale of the
valve arrangement for admitting air and gas, and for preventing the charge from
escaping when the slide or piston valve passes over the inlet port; V is a valve box
bolted to the cylinder A and having a moveable cover W in order to drop the
valves X, X, into their seats; Y is the inlet for gas, and Z is the inlet for air; lis
the port to cylinder A. The stems V, VI, are actuated by means of the cams S¹ on
the back shaft G Figure 2, which act upon levers U₁, having their fulcrum at R¹
(shewn at Figure 2) so as to open and close the valves X, X, as required for the
admission of gas and air. The operation of a machine constructed as above is as
follows, the cams being arranged accordingly:-Supposing the engine to be in the
position shewn in the Drawing, that is at the time of firing the charge (or
thereabouts), the piston B would then be forced out by the explosion of the
charge, and upon the return stroke the slide or piston valve F will be drawn back
(sufficiently to allow the piston B to complete the in stroke) by the action of the
right and left handed canis e, e, on the levers b (the said cams being arranged
accordingly), by which action the exhaust will be uncovered by the port in the
piston valve F to expel the products of combustion, and the projection o will
simultaneously act on the tail of the lever n so as to open the exhaust valve m and
retain it open until the completion of the in stroke. On the next out stroke of the
piston B, the valves X, X, will open so as to admit the air and gas to the cylinder A
through the inlet port (shewn at Figures 3 and 5), and remain open until the
completion of the stroke by the action of the cams s¹ on the levers U¹, the slide or
piston valve F remaining still during this time. On the next in stroke of the
piston B (when the charge is in the cylinder) the slide or piston valve F will be
drawn entirely back by the action of the cams e, e, the valves X, X, being now
shut so that the charge may not escape, and on the next out stroke the slide or
piston valve F will be forced after the piston B, but will travel at a greater speed
so that the charge may be fully compressed at time of firing; this extra speed
being obtained by the action of the cross levers b, produced by the pins or
rollers c, c, acting in the cams e, e, and during this time the plunger K is forced
forward by the action of the cam f against the piece g, and during its transit the
pipe (shewn at Figure 3) will be uncovered to admit a small quantity of water
to the compressed charge in piston valve F through chamber R, which is converted
into steam by the firing of the charge and adds to the force, communication now
being established between the chamber R and the compressed charge in the piston
valve F, by means of the holes N and U and two corresponding ports in the piston
valve F, so that the flame is also forced into the piston valve to fire the charge, or
instead of admitting water in this way, I may in some cases find it advantageous
to make the air pipe connected to the inlet Z dip in or over water, so as to draw a
kind of spray through the cylinder and thus form a part of the charge.
By constructing gas motor engines as above described, the force employed for
compressing the charge is exerted on the piston instead of being partially lost as
in engines of ordinary construction, and in addition extra power is obtained by
reducing the internal capacity of the cylinder at the time of firing.
Instead of employing my improved arrangement of slide or piston valve, two
pistons may be used and operated precisely in the same way, so that the power for
compressing the charge may not be lost, but in this case an additional slide valve
would be required or a telescopic cylinder would answer the purpose.
Having thus described and ascertained the nature and object of my said

page_text: Invention, and the manner of carrying the same into practical effect, I would
remark in conclusion that what I claim as my Invention is,―
First. The use substantially as described of a slide or piston valve made to work
in the cylinder, in such a manner as to fully compress the charge by travelling in
the same direction as the piston proper, and to maintain the charge so compressed
up to time of firing, substantially as hereinbefore set forth.
Secondly. The arrangement herein described of ports in the cylinder, in com-
bination with the slide or piston valve working therein, whereby the slide or piston
valve is made to admit the gas and air at the proper time for acting on the piston
proper, so that the engine may be worked without a separate external slide valve,
substantially as set forth.
Thirdly. The admission and employment of a small quantity of water in the
cylinder at time of firing, so as to be converted into steam and act expansively,
substantially as and for the purpose set forth.
Fourthly. The combination of parts shewn on the Drawing at Figure 4 and
employed for firing the charge substantially as described.
Fifthly. The respective combinations of parts constituting improvements in my
gas motor engine, substantially as set forth and as shewn in Figures 1, 2, 3, 5,
and 6.
In witness whereof, I, the said Augustin Fiddes, have hereto set my
hand and seal, this Eleventh day of June, in the year of our Lord One
thousand eight hundred and eighty one.
AUGUSTIN FIDDES. (L.S.)