IMPROVEMENTS IN GAS ENGINES
Year: 1884

page_text: I, JOHN MºⱭILLIVRAY, of 24 Richmond Street Glasgow, in the County of
Lanark, Engineer, do hereby declare the nature of my said Invention for
"IMPROVEMENTS IN GAS ENGINES," to be as follows:-
This Invention of improvements in gas engines consists of a novel construction
and arrangement of the valves through which the charge of combustible gas is
supplied, is ignited and is exhausted..
The improved valve arrangement comprises a hollow piston or plunger which is
reciprocated and oscillated by the combined action of a cam or eccentric on the
crank shaft and a pin working in a groove in the side of the piston, and which is
fitted within a cylindrical or tubular casing formed or fitted on the side of the
engine cylinder. A gas supply pipe and an air pipe or opening are formed in the
valve casing and in the hollow piston, such openings in the casing and in the piston
being arranged to come opposite each other during the reciprocation in one direc-
tion of the piston in order to admit a charge of gas and air into the hollow piston;
and to pass cach other to cut off the supply, while the movement of the piston also
brings a third port or opening formed in it opposite to an admission port connecting
the valve casing and the end of the engine cylinder. The forward stroke of the
piston valve closes the inlet ports and brings an ignition port in the hollow piston
opposite an opening in the casing communicating with a tube in which a jet of gas
is kept burning, whereby the combustible charge within the piston and within the
cylinder is fired, and a stroke of the piston of the engine effected. The ignition
port communicates with an ignition chamber within the piston valve in which is
a separate port on the side next the cylinder, and the two ports are so placed in
relation to each other that the outer one, through which ignition of the charge
within the ignition chamber takes place, closes or is nearly closed by the time the
inner port opens to fire the charge within the cylinder. The opening and closing
of these ports is effected by an oscillating motion imparted to the piston valvo by
the action of the pin and groove before referred to, and the object of so forming
and operating the ignition ports is to prevent blowing back of the exploding
combustible charge from the cylinder.
"
The exhaust of the exploded combustible takes place through an exhaust port
in the same valve, which is brought opposite the port forming the inlet and outlet
in the cylinder when the engine commences its in-stroke. The admission of the
combustible charge is effected, and the operation of igniting the charge and
exhausting the spent gases, are repeated at each stroke of the engine, and the
engine may be made double-acting, by duplicating the valve mechanism.
Dated this Fighth dow of No

page_text: .
Improvements in Gas Engines.
I JOHN MCGILLIVRAY of 24 Richmond Street Glasgow in the county of
Lanark Engineer do hereby declare the nature of my invention for "IMPROVEMENTS
IN GAS ENGINES and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :—
"
This invention of improvements in gas engines consists of a novel construction
and arrangement of the valves through which the charge of combustible gas is
supplied is ignited and is exhausted. In the accompanying drawings figure 1 is a
sectional side elevation and figure 2 is a sectional plan of a gas engine embodying
my improvements.
The improved valve arrangement comprises a hollow piston or plunger A which
is reciprocated and oscillated by the combined action of a cam or eccentric B on
the crank shaft C and a pin or roller D working in a groove E in the side of the
piston or plunger A and which is fitted within a cylindrical or tubular case. F
formed or fitted on the side of the engine cylinder G. A gas supply pipo H. and
an air pipe or opening I are formed in the valve casing and corresponding pass-
ages H¹ and I are provided in the hollow piston A such openings in the casing
and in the piston being arranged to come opposite each other during the recipro-
cation in one direction of the piston in order to admit a charge of gas and air into
the hollow piston A and to pass each other to cut off the supply and the movement
of the piston which opens the admission ports also brings a third port or opening J
formed in it opposite to an admission port K connecting the valve casing and the
end of the engine cylinder. The forward stroke of the piston valve' closes the
inlet ports H. and I and brings an ignition port 7 in the hollow piston A opposite
an opening L in the casing communicating with a tubo M in which a jet of gas
from a burner m is kept burning whereby the combustible charge within the
piston A and within the cylinder G is fired and a stroke of the piston of the engine
effected. The ignition port communicates with an ignition chamber N. within
the piston valve A in which is a separate port n on the side next the cylinder in
which is a small port n¹ and the two ports and n are so placed in relation to each
other that the outer one through which ignition of the charge within the ignition
chamber takes place closes or is nearly closed by the time the inner port n opons to
fire the charge within the cylinder G. A separate orifice l' is provided in the
casing F for charging the ignition chamber N with gas previous to firing the charge.
The opening and closing of these ports is effected by the oscillating motion
imparted to the piston valve by the action of the pin D. and groove E before
referred to and the object of so forming and operating the ignition ports is to
prevent blowing back of the exploding combustible charge from the cylinder.
เ
The exhaust of the exploded combustible takes place through an exhaust port O
in the same valve which is brought opposite the port K forming the inlet and
outlet in the cylinder when the engine commences its in stroke. The admission of
the combustible charge is effected and the operation of igniting the charge and
exhausting the spent gases are repeated at each stroke of the engine and the engine
may be made double acting by duplicating the valve mechanism.

page_text: Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed I declare that what I claim is
1st In a gas engine the improved construction of piston valve provided with
admission ignition and exhaust ports and operated substantially in the manner
herein described.
2nd The arrangement in a reciprocating gas engine valve of a groove and pin
serving to control the movement of the valve and effect a rapid closing of the
ignition port substantially as set forth.