Improvements in Gas or Oil Engines.
Year: 1897

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TRUVIDIONAL
DI DUIFICATION.
Improvements in Gas or Oil Engines.
I, JOHN WILLIAM HUNTER of Eastdown Works, Dermody Road, Lewisham, in the
County of Kent, Engineer, do hereby declare the nature of this invention to be.as
follows:-
The object of my invention is to so design and arrange a motor of the internal
combustion type that it shall be very compact, shall run smoothly and without undue
vibration at a high rate of speed so as to develop great power in relation to its weight,
shall keep comparatively cool in the working parts, shall be capable of running for
long periods without special attention, and shall possess other incidental advantages.
The manner in which I carry into effect my invention is as follows:---
I provide, either in one casting or otherwise fitted together the body of the engine
consisting of a central drum or casing in which the cranks revolve, having projecting
on opposite sides of its circumference a cylinder fitted with a piston attached by means
of a connecting rod with a crank shaft. These projecting cylinders may either be in
line with each other, or may be set off so as to bring each piston in line with its own
crank, the cranks being either placed diametrically opposite to each other or slightly
inclined therefrom, the former position being preferred. The engine thus consists of
two cylinders opposite to one another, and acting simultaneously on a double-throw
crank. These cylinders, although they may be regarded as independent, are not so,
as they are connected at their outer ends by suitable passages with a central valve
box, open to both, and they thus act as one cylinder with two pistons, the outer end
of each piston receiving the impulse at the same time. An essential feature of this
invention is that there is no compression space or combustion chamber provided in
either of the cylinders, the cylinder ends being as close as possible to the pistons
when at the outward end of their stroke. The requisite space for compression and com-
bustion is placed quite outside the cylinders proper, and is provided for in the passages
which connect the two cylinders with the central valve box, which also acts as part of
the compression space, and where the charge is most conveniently fired. The result
of this arrangement is that a large proportion of the heat resulting from the explosions
is generated in the aforesaid chanels and their connections, which are not injured by
the heat, which latter is quickly dissipated by radiation, the cylinders and their
working parts being thus kept comparatively cool.
In addition to the arrangements already described for keeping the cylinders cool,
advantage is taken of the reciprocating movement of the pistons, by the application
of suitable inlet and outlet valves, to convert the closed drum in which the cranks
revolve into an air pump, and the air so acted on is forced through spiral or other
channels formed by cased in ribs or projections cast or otherwise fixed on the outer
surface of the cyclinders. A large quantity of cool air is thus positively forced over
the outer surfaces of the cylinders and the ribs attached thereto, which arrangement,
together with that for effecting the combustion outside the cylinders proper, renders

page_text: the motor to a large extent, and in the smaller sizes wholly self-cooling. In the
larger motors, however, the air blast herein described may be supplemented by a
water jacket.
I, JOHN WILLIAM HUNTER, of East down Works, Dermody Road, Lewisham, in the
County of Kent, 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 :-
This invention relates to gas or oil engines of the internal combustion type, and has
for its object the construction of a motor which shall be very compact; shall run
smoothly and without undue vibration at a high rate of speed; shall keep
comparatively cool in its working parts; and shall further contribute to efficiency by
allowing a high piston speed combined with a great reduction of heat waste, owing to
the fact that the portions of the motor in which the explosive charge is fired and
expanded in doing work on the pistons are for the most part maintained at a high
temperature, thus preventing absorption of heat from the expanding gases.
In the accompanying drawings Figure 1 is a side elevation, partly in section; ;
Fig. 2 is a plan view, also partly in section; and Fig. 3 is an end view.
The manner
in which my invention is carried into effect is as follows:-
I provide either in one casting or otherwise fitted together, the body of the engine
or motor, consisting of a central drum or casing, A, in which the cranks revolve,
having projecting therefrom on opposite sides of its circumference the cylinders, C
and C³, fitted with the pistons, c and c¹, acting by means of the connecting rods, c² and c³,
on the crank shaft, B. These projecting cylinders may either be in line with each
other, or may be set off so as to bring each piston in line with its own crank, as
shown in Figs. 2 and 3. The shaft is made with a double throw crank, the cranks
being placed either diametrically opposite to each other, or slightly inclined
therefrom, the former position being preferred. The cylinder ends are made to be
as close as possible to the pistons when the latter are at the outward end of their
stroke, and the cylinders thus fitted and arranged are connected at their outer ends
by means of suitable passages, D, with a central chamber, e, open to both, affording a
clear passage through from one to the other; and these channels or passages, together
with the central chamber into which they open, form the compression space and
combustion chamber into which the explosive charge is drawn, and in which it is
compressed and afterwards fired. The central fitting, E, consists of the chamber, e,
forming part of the aforesaid open communication between the outer ends of the two
cylinders; and of the two separate chambers, el and e², leading to the inlet and
exhaust passages, gand h, and opening respectively, by means of the valves, G and H,
into the compression space aforesaid. The valve, G, being held on its seat by a light
spring, allows the charge to be drawn in by the pistons, when not under compression;
the valve, H, also held on its seat by a spring, being positively opened at the right
moment to allow the waste products to escape through the discharge outlet, h. The
exhaust valve is operated by means of the tappet, I, the latter being controlled by
the cam, K, which is geared with the crank shaft, and travels at half its speed.
The firing of the explosive charge (may be effected by an electric spark, the fittings
for which are shown in the drawings, F, or by a hot tube, or by any other means;
but these arrangements, not being included in my claims, are not described in
detail.

page_text: The operation of the motor is as follows:-the explosive charge, being drawn in
through the valve, G, as the pistons retire from the position shown in the drawings,
fills the outer ends of the two cylinders and the chamber and passages forming an
open communication between them, and the charge is then compressed by the return
of the pistons to their original position, and fired. The expansive force of the
exploded charge acts on both pistons at the same time, and when the pistons have
reached the other end of their stroke the exhaust valve, H, is opened by the means
already described, thus completing the cycle of operations.
The body of the motor need not necessarily be in the form shown, but may be of
any suitable design, either closed or open; but the type shown in the drawings is to
be preferred.
The cylinders may have cooling ribs or flanges, as shown, a, to assist in the
dissipation of heat from the working parts; or a partial or complete water jacket, or
both combined.
The passages forming the open communication between the ends of the two
cylinders may be of any shape or design, and may be carried over, under, at the sides,
or in any convenient position in relation to the body of the motor; and the shape
and position of the central chamber and valves may be modified, if desired, providing
the principle of the arrangement is adhered to.
As is usual with engines of this class, the motive power is derived from the
combustion of Gas, Vapour, Spirit, Oil, or any suitable Hydrocarbon; the motor being
adapted for the use of each or any of the various substances by the addition of
suitable spraying or vapourizing appliances.
In a motor arranged and constructed as aforesaid the shock of the explosion is
neutralized by acting on both pistons at the same time; and the recoil and vibration
of the parts having a reciprocating motion is reduced to a minimum by the
respective pistons and their connections being of practically the same weight and size,
and always travelling in opposite directions.
The firing of the explosive charge, being effected in the passages connecting the
two cylinders, which passages are always at a high temperature, there is very little
loss of efficiency through cooling of the expanding gases: and, further, a large
proportion of the heat generated is confined to the aforesaid passages, the result
being that the cylinders are kept relatively cool; and, in the smaller sizes, the motor
may be worked without a water jacket.
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. A Gas or Oil Engine constructed, arranged, and a lapted to operate substantially
as herein before described and illustrated.
2. In a Gas or Oil Engine of the internal combustion type, the combination of two'
or more cylinders mounted opposite to each other, with their pistons attached to the
crank shaft by means of connecting rods, in such a manner that the explosive charge
acts simultaneously on the outer ends of their respective pistons.
3. In a Gas or Oil Engine of the type specified in the preceding claims, connecting
the outer ends of the cylinders together by means of pipes or passages, as and for the
purpose set forth.
4. In a Gas or Oil Engine of the type specified in Claims 2 and 3, the combination
of a chamber or chambers in communication with the connecting pipes or passages,
adapted to form with the said pipes or passages a compression space and combustion
chamber, the said chamber or chambers being preferably provided with the inlet and
exhaust valves, and also the igniting device.