Year: 1886

page_text: Date of Application, 10th Mar., 1886.
Complete Left, 9th Dec., 1886.
Complete Accepted, 21st Jan., 1887.
I, JOHN FIELDING of The Atlas Works, in the City and County of Gloucester,
Engineer do hereby declare the nature of the said invention to be as follows:-
My invention relates to a construction of gas motor engine, in which two pistons
working either in two separate cylinders or in a single cylinder, control the charging,
ignition and exhaust ports.
For the sake of greater clearness, it will be convenient to describo first that
arrangement in which the pistons work in separate single acting cylinders which
are preferably equal in diameter and length of stroke, and placed parallel to each other
side by side.
They are in free and constant communication at their closed ends and their pistons
are connected to cranks in the usual manner.
One crank is placed about 45° in advance of the other. It will be convenient
to designate the first as the "leading" and the second as the "following" crank, the
same distinctive terms applying also to their respective cylinders and pistons.
Through the sides of the cylinders there are ports which are covered and
uncovered by the pistons, so as to operate in the following manner :-
Assuming that a combustible charge has been introduced and compressed ready for
ignition, the "following" crank, being then on the centre nearest to the cylinders,
while the "leading" crank is about 45° in advance, the "leading" piston at this
point uncovers the ignition port, the charge is ignited and its rapid expansion drives
the pistons forward until the "leading" piston uncovers a release port which permits
the final pressure of expansion to be reduced to that of the atmosphere. At about the
same moment, the same piston uncovers an admission port and a fresh charge of
gas and air is then drawn in through valves which are preferably worked by cams or
eccentrics.
The fresh charge continues to enter until the cranks have taken such a position that
the volume of the two cylinder spaces is a maximum.
.
At this point the admission valves are closed and, as the pistons return, waste
products of cumbustion are expelled through an exhaust port which is uncovered by
the "following" piston.

page_text: This exhaust port is again covered by the "following" piston at about the same
time that the "leading" piston covers the ignition port, and the pistons continuing
their instroke compress the charge until the cylinder space attains its minimum. The
"leading" piston, shortly after the commencement of its outstroke, then uncovers the
ignition port, and the charge is ignited, whereupon the cycle of movement is repeated.
The effect of the cycle of operations described is, that there is an extremely rapid
expansion of the ignited gases and a correspondingly brief exposure to loss of heat by
conduction. There is also a relatively long period during which the escape of the
waste products can take place.
The relative volumes which the charge occupies at the completion of each of the
three stages of admission, compression and expansion are approximately as four, one
and six respectively. Thus, as the ignited charge expands to a volume about one half
greater than the original volume which it occupied before compression, its expansion is
largely utilised for producing motive power.
Instead of placing the two cylinders side by side parallel to one another, they may
be arranged with their axes in one plane inclined about 45° to one another, both
pistons being connected to one crank. Also the engine may be arranged so that the
two pistons work in one cylinder, which, in this case, is open at both ends, the
rear piston being connected by side rods to a pair of cranks which are diametrically
opposite in position to the corresponding crank employed in the double cylinder
engine.
Obviously, instead of gas, inflammable vapour may be employed in this as in gas
motor engines generally.

page_text: I, JOHN FIELDING, of The Atlas Works in the City and County of Gloucester,
Engineer, do hereby declare the nature of this invention and in what manner the same
is to be performed to be particularly described and ascertained in and by the following
statement:
My invention relates to a construction of gas motor engine in which two pistons.
working in two separate cylinders, or in a single cylinder, by their movements cover
and uncover lateral ports thereby controlling the admission, compression and ignition
of the combustible charge and the expulsion of the products of combustion after they
have performed work.
Figure 1 of the accompanying drawings is a vertical section of one form of engine
according to my invention, having the two cylinders placed with their axes at an angle
of about 45° to one another and their pistons connected to one crank. Figs. 2, 3 and 4
are diagrams shewing successive positions of the pistons at various parts of a
revolution.
The one cylinder A has three lateral ports, I for admission of flame to ignite the
combustible charge, R for relief of pressure within the cylinder, and N for admission
of the combustible charge. The other cylinder B has four lateral ports, D for
admission of air, and F for communicating with N, also R' for rolief of pressure,
and E for exhaust which is governed by a valve worked by the engine. The ports R R¹
are to be understood as communicating with each other by an external channel or
pipe, as indicated by the dotted lines R. In the passage is situated a gas supply
valve G which is worked by the engine. The two cylinders A and B communicate
freely with each other at the bottom by a passage H. The piston of B is made with
cavities K and. L in its opposite sides. Both the pistons a and b are linked to one
crank C on a shaft S which revolves in the direction of the arrow.
When the pistons are in the positions shewn in Fig. 1, that is to say, bat the extreme
of its instroke, and a ascending, it is to be understood that the passage H and the
clearance spaces under both pistons are filled with a combustible charge in a_compressed
condition. When a ascends a little farther it uncovers the ignition port I and flame
is admitted igniting the compressed charge. By the increase of pressure and expansion
resulting from combustion of the charge both pistons are propelled upwards until,
as shewn in Fig. 2, a uncovers the port R and L puts R¹ in communication with E.
The exhaust valve in the passage E being_now opened, the expanded products of
combustion find a vent by R R R L and E, and the pressure in both cylinders is
therefore reduced to that of the atmosphere or nearly so. The pistons still ascending
to the position shewn in Fig. 3, air enters the cylinder A by D K F and N, and,
when the valve G is opened, mixed gas and air enter A by N. The pistons then
descend forcing out products of combustion by E from B until E becomes covered by 6
as shewn in Fig. 4. Continuing still their descent, the pistons compress the charge
below them until they attain again their position shewn in Fig. 1. The cycle of
movement is then repeated, that is to say ignition combustion and expansion of the

page_text: charge, relief of pressure by discharge of products, indraught of fresh charge,
expulsion of products, and compression of charge as above described. Instead of
placing the two cylinders. at an angle to each other with their pistons linked to one
crank, they may be placed side by side parallel to one another with their pistons
linked to two cranks on one shaft, one of these cranks being about 45° in advance of
the other. Figs. 5 and 6 are vertical sections of two cylinders thus arranged.
Figs. 7 and 8 being elevations of opposite sides. Figs. 7a is a part elevation
corresponding with Fig. 7, with cover removed to shew connection of ports F and N
with the central gas inlet. Fig. 9 is a plan and Fig. 9a a sectional plan. The piston a
of the one cylinder A is linked to a crank C which is about 45° in advance of
the crank to which the piston of the cylinder B is linked, both cranks being on
the same shaft S. The ports governed by the pistons are arranged as already
described with reference to Fig. I and are marked by corresponding letters, but in the
figures 5 to 9 and 9ª inclusive are shewn certain details which will now be described.
The air inlet D opens from a cavity D¹ faced with wire gauze. The ignition port I is
shewn in Fig. 5 as communicating with a heated tube T, but it is to be understood
that any other known means of ignition may be applied. For the purpose of working
the exhaust and gas valves, I drive by oblique or helical gear on the shaft S, a
vertical counter shaft U on which there are two cams the one e, which through a
spring lever e opens at the proper times the exhaust valve M, and the other cam g which
through a lever opens at the proper time the gas valve G in opposition to a spring
which tends to close it. In order to regulate the engine a centrifugal governor
may be employed in the following manner. When the governor which revolves with the
vertical countershaft U revolves too quickly, it raises an internal rod within the tubular
shaft U and thus raises the cam g which is free to slide along the shaft U at the same
time raising one end of the lever g¹. This lever having a swivelled fulcrum g² its
other end is thus moved downwards so as to escape the stem g³ of the gas valve G,..
and consequently no gas is admitted to the cylinder A until the speed of the engine
becomes moderated. While the governor revolves at a speed not exceeding that for
which the engine is arranged the lever g¹ remains in such an attitude that at every
revolution of the cam g it is caused to strike the stem g³ of the gas valve G, and
consequently to open that valve for admission of gas along with air to the cylinder A.
Instead of employing two cylinders, a single cylinder may be arranged with two
pistons as shewn in the longitudinal section Fig. 10, sectional plan Fig. 11, and part.
transverse section Fig. 12. In this case the front part A of the cylinder has its
piston a connected to the crank C, and the hinder part B of the cylinder has its
piston connected by a crosshead and side rods to two cranks (2 which are at an
angle of about 225° behind the crank C². The ports INRE correspond with those
marked by similar letters in Fig. 1. G is the gas inlet, the gas supply to which
may be controlled as already described by a governor acting on a stem g³. The air
inlet D and the outlets from the ports Rand are provided with check valves. The
cycle of operation is similar to that already described. By linking the pistons of two
parallel cylinders to a guided T connecting rod, that is to say a cross-head rigidly
fixed at right angles to a connecting rod that has one end guided in a rectilineal path
and has its other end jointed to a single crank, the movements of the two pistons very
nearly correspond to those engines arranged as already described and effect a similar
cycle of operations as will be understood from the diagrams Figs. 13 to 16 inclusive.
In these diagrams the two pistons a and b are linked to a cross-head X which has
rigidly fixed at right angles to it the connecting rod Z, having its lower end guided
and its upper end jointed to the one crank C on the shaft S. The ports are marked.
by the same letters as in Figs. 1 to 4 inclusive, and the movement of the
pistons a and b cover and uncover these ports so as to effect the same cycle of
operations as in the engines shewn in Figs. 1 to 4. Thus the position of the ports in
Fig. 13 corresponds with that in Fig. 1, Fig. 14 with Fig. 2, Fig. 14 shews a little
farther advance of the moving parts, Fig. 15 corresponds with Fig. 3, and Fig. 16 with
Fig. 4.

page_text: Having now particularly described and ascertained the nature of my said invention.
and in what manner the same is to be performed I declare that what I claim is :-
1. In a gas motor engine, two pistons connected to a crank or cranks on one shaft
in such manner that the one piston is about one eighth of a revolution in advance of
the other, these pistons moving over lateral ports for admission and for ignition of
charge, for release of pressure and for discharge of exhaust arranged so that at every
revolution of the crank-shaft there is ignition and combustion of charge, followed
after a time by relief of pressure, by admission of fresh charge, by expulsion of exhaust
and finally by compression of charge, substantially as herein described.
2. The arrangement, substantially as herein described, with reference to Figs. 1 to 4
inclusive, of two cylinders inclined to one another having their pistons connected
to one crank, and operating in the manner referred to in the first claim.
3. The arrangement, substantially as herein described, with reference to Figs. 5 to 9
and 9 inclusive, of two parallel cylinders having their pistons connected to separate
cranks on one shaft, and operating in the manner referred to in the first claim.
to
4. The arrangement, substantially as herein described, with reference
Figs. 10, 11 and 12 of a single cylinder having two pistons connected to separate
cranks on one shaft, and operating in the manner referred to in the first claim.
5. The arrangement, substantially as herein described, with reference to Figs. 13
to 16 inclusive, of two cylinders having their pistons linked to a guided T connecting
rod jointed to one crank and operating in the manner referred to in the first claim.
ABEL & IMRAY,
Agents for the Applicant.