Year: 1888

page_text: I, JOHN JAMES PURNELL, of Atlas Works, Webber Street, Lambeth, in the County
of Surrey, Engineer, do hereby declare the nature of this invention to be as
follows
My invention relates to a gas motor engine of simple and inexpensive construction,
one arrangement of which is as follows:-
On a hollow base stands a vertical cylinder open at the top and surrounded by a
water-casing. It is fitted with a trunk piston which is connected to a crank on a
flywheel shaft mounted in bearings overhead. In the cavity of the base are fitted two
valves opening upwards; the one valve is opened to discharge exhaust by a crank,
cam, or eccentric. on a countershaft driven from the flywheel shaft at half speed
working the valve by suitable levers and rods; the other valve which is the supply
valve is self acting, opening to admit air, and it has a hollow seating the annular
cavity of which is connected to a gas supply pipe and has numerous small perforations
opening to the face of the valve seating. From the cavity in the base a passage leads
to a vertical pipe which is kept heated by a gas burner. This pipe is made of
considerable height and is fitted at its top with a plunger that can be screwed more
or less deeply into the pipe so as to diminish or increase the height of the cavity
within the pipe. The action of the engine is as follows:-
:-
As the piston ascends it draws, by the opening of the supply valve, air mixed with
gas into the space below the piston; the piston then descending compresses this
mixture and, when the pressure is sufficient, a portion of the mixture being forced
into the heated pipe is ignited, the ignition is communicated to the charge and the
piston is propelled upwards; during the subsequent descent of the piston, the exhaust
valve is open and products of combustion are expelled.
By adjusting the plunger of the heated pipe, which after each ignition remains
charged with products of combustion, the volume of these products in the pipe can
be so regulated that their compression to the extent necessary to secure ignition of
the compressed charge takes place just as the piston reaches the end of its compressing
down stroke, thus dispensing with valve gear such as is usually employed to put the
igniting apparatus in communication with the charge.

page_text: The cylinder, instead of being vertical, may be horizontal or inclined, and two
horizontal cylinders may be arranged on a base opposite to one another their pistons
working one crank, and their exhaust valves being so timed that when the one piston
is compressing the charge in the one cylinder, the other piston is being propelled by
the combustion of the charge in the other cylinder.
I, JOHN JAMES PURNELL, of Atlas Works, Webber Street, Lambeth, in the County
of Surrey, 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 gas motor engine of simple and inexpensive construction
as I shal. describe referring to the accompanying drawings.
Fig. 1 is a front elevation with the valve case shewn in section and Fig. 2 is a side
elevation of a gas motor engine according to my invention.
On a hollow base A stands a vertical cylinder B which is open at the top and is
surrounded as usual with a water casing.
The cylinder has a trunk piston C connected to the crank on the flywheel shaft D
which is mounted in bearings carried overhead in brackets E extending up from and
in one piece with the cylinder B. In the cavity of the base A is a valve case
containing two valves F and G both opening upwards to a space H in free com-
munication with the interior of the cylinder B. The one valve F is kept closed by a
spring and is opened to discharge exhaust by an arm K of a' rocking shaft L which
has another arm M connected to a crank N or it might be an eccentric or cam on a
countershaft driven by gearing O from the shaft D at half the speed.
The other valve G is self acting opening to admit air by the pipe y, and it has a
hollow seating the annular cavity of which is connected to a gas supply pipe and has
numerous small perforations opening to the face of the valve seating. From the
space H a passage leads to a vertical pipe P which is kept heated by a gas burner,
and which has a cap p that can be screwed more or less down so as to diminish or
increase the interior capacity of the pipe P.

page_text: The action of the engine is as follows:-
As the piston C ascends the valve G rises admitting air mixed with gas into the
space below the piston, the valve F at this time remaining closed. The piston then
descending compresses the gaseous mixture and when the pressure is sufficient, a
portion of the mixture forced into the heated pipe P becomes ignited, the ignition is
communicated to the charge in the cylinder and the piston C is propelled upwards.
During the subsequent descent of the piston, the exhaust valve F is opened and the
products of combustion are expelled. By adjusting the cap p of the heated pipe P
which after each ignition remains charged with products of combustion, the volume
of the products contained in the pipe can be so regulated that their compression to
the extent necessary to secure ignition of the cylinder charge takes place just as the
piston C reaches the end of its compressing stroke, thus dispensing with valve gear
such as is usually employed to put the igniting apparatus in communication with the
charge. Obviously, instead of employing a cap p screwing on to the exterior of the
heated pipe P, a plunger might be screwed into its interior in order to regulate its
capacity for the purpose above stated.
Although I have described a vertical engine, the axis of the cylinder might obviously
be horizontal or inclined. Two horizontal cylinders may be arranged at opposite
ends of a base the pistons of both being connected to one crank on a transverse shaft
between them, and the working of their exhaust valves F being so timed that during
one pair of strokes, when the one piston is compressing the charge, the other piston
is being propelled by the combustion of the charge in the other cylinder, and during
another pair of strokes, the one piston is drawing in charge while the other is expelling
exhaust.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I claim is
--
.
A gas motor engine constructed and arranged substantially as herein described
with self-acting supply valve and with heated pipe for ignition adjustable in capacity
and always in free communication with the cylinder, thus dispensing with ignition
valve and gear.