Year: 1885

page_text: I, JOSEPH SOUTHALL, of the firm of Hardy & Padmore of Worcester Foundry in
the County of Worcester, Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention applies to Gas Motor Engines of that kind in which there is a
cycle of four piston strokes, one outstroke drawing into the cylinder a combustible
charge, one instroke compressing the charge in the cylinder, one outstroke effected
by expansion of the ignited charge, and one instroke discharging the products of
combustion. The object which I have in view is to equalise the action of such
engines by providing that during every stroke of the cycle there is development of
propelling power. For this purpose, I divide the cylinder by a middle partition
into two lengths, each of which operates as a double acting cylinder provided with
a piston; and, by means of a reciprocating or rotary slide governing ports leading
to the ends of each of these two cylinders, I time the action of their pistons so that,
during every stroke, the one or the other of the two pistons is being propelled in
the one or the other direction by the expansion of an ignited charge. The two
pistons may be on one rod which passes through packing in the middle partition,
or they may be on separate rods passing through the covers at the ends of the
cylinders, and connected externally by side rods to one set of cranks.
At each end
of the cylinder, and on each side of the middle partition, a movable end may be
placed, consisting of a piston pressed inwards against fixed stops by a spring, which
allows this end to retreat during the compressing stroke, giving space for the
compressed charge, but, which, during the discharging stroke, causes the end to
advance so as more completely to clear the cylinder of the products of combustion.
When these movable ends are employed, the middle partition may be dispensed
with.

page_text: I, JOSEPH SOUTHALL of the Firm of Hardy and Padmore of Worcester Foundry
in the County of Worcester, 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 applies to Gas Motor Engines of that kind in which there is a
cycle of four piston strokes, one outstroke drawing into the cylinder a combustible
charge, one instroke compressing the charge in the cylinder, one outstroke effected
by expansion of the ignited charge, and one instroke discharging the products of
combustion. The object which I have in view is to equalise the action of such
engines by providing that during every stroke of the cycle there is development of
propelling power. For this purpose, I divide the cylinder by a middle partition
into two lengths, each of which operates as a double acting cylinder provided with
a piston; and, by means of a reciprocating or rotary slide governing ports leading
to each of these two cylinders, I time the action of their pistons so that, during
every stroke, the pistons are propelled in the one or the other direction by the
pressure of an ignited charge acting directly upon the one or the other of them.
The two pistons may be on one rod which passes through packing in the middle
partition, or they may be on separate rods passing through the covers at the ends
of the cylinders, and connected externally by side rods to one set of cranks. At
each end of the cylinder and on each side of the middle partition a movable end
may be placed consisting of a piston pressed inwards against fixed stops by a
spring, which allows this end to retreat during the compressing stroke giving space
for the compressed charge, but, which, during the discharging stroke, causes the
end to advance so as more completely to clear the cylinder of the products of
combustion. When these movable ends are employed, the middle partition may be
dispensed with.
.
Fig. 1 of the accompanying drawings is a side view, Fig. 2 is a plan shewing
the cylinder in section and Fig. 3 is a transverse section of the cylinder of a gas
motor engine according to my invention. Fig. 4 shows to an enlarged scale
transverse sections at four different parts of the length of a rotary slide valve S
that may be used to govern the admission and ignition of the combustible charges
and the discharge of the expanded products of combustion after they have
performed work in the four separate compartments of the cylinder. The cylinder C
which may be water cased as usual is divided by a middle partition D into two
parts each fitted with a piston P¹ P. Both pistons are fixed on one rod which is
connected in the usual way to a crank on the fly-wheel shaft A From this shaft
is caused to rotate by mitre gear the spindle B of the valve S which revolves with
it. The valve S has cavities and ports so arranged as shown in Fig. 4 relatively
to the four ports O that open into the cylinder C, that in each of the four compart-
ments into which the cylinder is divided by its partition D and its pistons P¹ P³,
the cycle of action recurs in regular rotation. Thus, for example, when the pistons
are making their forward stroke, one of them, say P¹, is being propelled by the
expansion of the ignited charge behind it, while P is drawing in behind it a fresh

page_text: charge, at the same time P¹, is expelling the exhaust in front of it and P is
compressing in front of it a fresh charge. Again, in making the back stroke,
while P' is being propelled by the ignited charge in front of it and is compressing
the charge behind it, P¹ is drawing in a fresh charge in front of it and expelling
the discharge behind it. And thus in rotation the four strokes of the cycle recur
in each of the four compartments of the cylinder. As shewn diagrammatically by
Fig. 5 instead of passing the one piston rod through the partition D, each of the
pistons P1 P2 may have its separate rod connected to a crosshead E, the two
crossheads being joined by side rods F. Or, as shewn by Fig. 6, the crank shaft A
may pass through the partition, the crossheads E E being linked to the cranks by
the side rods F. Fig. 7 is a sectional plan of the cylinder provided with movable
ends H H formed as pistons, and two such pistons H H constituting the middle
partition. Each of the pistons H¹H' is pressed away from the end of the cylinder
by a spring towards a stop ring K, and the two middle pistons H* H* are pressed
apart by a spring between them also towards stop rings K. Thus when the
pressure in any one of the compartments of the cylinder is relieved during the
discharge of exhaust, the spring piston at the end of that compartment is advanced
by its spring so as to be brought close or nearly close up to the working piston at
the end of its stroke, thus leaving little or no space occupied by residual products
of combustion, and when the charge in any one of the compartments is compressed,
the spring piston yields, giving space for the compressed charge.
Although I have described a single rotating valve S for governing the admission,
ignition and emission of the successive cylinder charges, this might obviously be
effected by a longitudinally reciprocating slide valve worked by a cam or eccentric
on the main shaft, or there might be separate slides or valves for each of the four
compartments of the cylinder, each operating as in ordinary gas motor engines
having a cycle of strokes like that herein referred to.
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 gas motor engines working with a cycle of four strokes, the use of a
cylinder divided by a partition and two connected pistons into four compartments
having their ports so governed that the four operations performed successively in
each compartment, namely charging, compressing the charge, firing the charge and
expelling the exhaust, are being simultaneously performed in the four compartments,
substantially as and for the purpose herein set forth.
2. In a gas motor engine of the kind referred to in the preceding claim, the use
in each of the four compartments of an end movable as a piston urged inwards by
a spring, substantially as described.
ABEL & IMRAY,
Agents for the Applicant.