IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1883

page_text: LETTERS PATENT to Charles Henry Andrew of the firm of Messieurs
JE. H Andrew and Company Engineers of Stockport in the County of
Chester for an Invention of IMPROVEMENTS IN GAS MOTOR ENGINES
PROVISIONAL SPECIFICATION left by the said Charles Henry Andrew at
the Office of the Commissioners of Patents on the 20th June 1883.
CHARLES HENRY ANDREW of the firm of Messieurs J. E. H Androw and
Company, Engineers, of Stockport in the County of Chester. "IMPROVEMENTS
IN GAS MOTOR ENGINES
"
My invention relates to gas motor engines and the object of the Invention is to
produce an explosion at each revolution of the engine.
To effect this I prefer to employ two cylinders arranged tandem and to connect
the two pistons to the same piston rod: or the pistons may be cast in one piece
with the rod or frame which connects them. The crank shaft is placed centrally
between the two cylinders and it is actuated through the connecting rod. One of
the cylinders is for power and the other for mixing and compressing the charge
of gas and air.
The operation is as follows:-The fly-wheel is turned by hand or otherwise and
a, charge of mixed gas and air is drawn through a suitable valve into the com-
pressing or charging cylinder on the return stroke of the piston this charge is
forced through a suitable non-return valve into a pipe or reservoir connected. to
the slide valve of the working or power cylinder. When the piston of the charging
cylinder is about one inch from the end of its instroke the piston in the working
cylinder will be about one inch from the end of its out-stroke: Communication is
made at this point between the pipe or reservoir and the working cylinder through
a slide valve actuated by an eccentric attached to the crank shaft or in other
convenient manner: the compressed charge rushes into the combustion chamber
which is attached and open to the working cylinder and drives before it through
an exhaust opening or openings, any non-explosive vapour that may be contained
in both the chamber and cylinder. The exhaust openings are preferably one
Den 8,71

page_text: inch in width and are situated within about two inches of the out-stroke of the
working cylinder and are covered and uncovered by the piston in its stroke:
as the motion is continued, the working piston on its return stroke drives the
charge from the cylinder into the combustion chamber and compresses it ready for
explosion at the end of the stroke of the piston, the charge is ignited by means
of a flame carried by the slide valve. The result of the explosion is to propel the
working piston in the reverse direction until the edge of the exhaust openings is
uncovered when the products of combustion, being in a state of considerable
-tension,-will-rapidly-escape.during the traverse of the piston over the said openings
and be reduced to about atmospheric pressure then these products are further
expelled and replaced by the admission of the next charge and this operation is
continued.
As previously described, the, charge is ignited by a gas flame which is carried in
the slide valve: this valve is so formed that a small, chamber in its outer cover
receives and is filled by each explosive charge as the mixture is passing into the
combustion chamber and retained there at a pressure above that of the atmosphere:
a little before the piston in the working cylinder has completed its in-stroke the
slide-valve carries the flame to the small chamber and causes a preliminary explosion
therein which on the further traverso of the slide valve will expose the main
charge within the combustion chamber to this preliminary explosion, and cause the
main charge to be ignited or exploded at the commencement of each effective stroke
of the engine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Henry Andrew in the Great Seal Patent Office on the
20th December 1883.
CHARLES HENRY ANDREW of the firm of Messieurs. J. E. H. Andrew and'
Company, Engineers, of Stockport in the County of Chester. "IMPROVEMENTS
IN GAS-MOTOR ENGINES
"
My invention relates to gas-motor engines and the object of the Invention is to
produce at explosion at each revolution of the engine.
To effect this I prefer to employ two cylinders, arranged tandem, and to connect
the two pistons to the same piston rod or the pistons may be cast in one picco
with the rod or frame which connects them. The crank shaft is placed centrally
between the two cylinders and it is actuated through the connecting rod.
of the cylinders is for power and the other for mixing and compressing the charge
of gas and air.
One
1
The operation is as follows:-The fly-wheel is turned by hand or otherwiso and
a charge of mixed gas and air is drawn through a suitablo valve into the com-
pressing or charging cylinder: on the return stroke of the piston, this charge is
forced through a suitable non-return valve into a pipe or reservoir connected to
the slide valve of the working or power cylinder. When the piston of the charging
cylinder is about one inch from the end of its in-stroke the piston in the working
cylinder will be about one inch from the end of its out-stroke: communication is
made at this point between the pipe or reservoir and the working cylinder through
a slide valve actuated by an eccentric attached to the crank shaft or in other
convenient manner: the compressed charge rushes into the combustion chamber
which is attached and open to the working cylinder and drives before it through
an exhaust opening or openings any non-explosive vapour that may be contained,
in both the chamber and cylinder: The exhaust openings are preferably one inch
in width and are situated within about two inches of the out-stroke of the working
cylinder and are covered and uncovered by the piston in its stroke: as the motion
is continued, the working piston on its return stroke, drives the charge from the
cylinder into the combustion chamber and compresses it ready for explosion: at
the end of the stroke of the piston the charge is ignited by means of a flame carried
by the slide valve. The result of the explosion is to propel the working piston in
the reverse direction until the edge of the exhaust openings is uncovered, when the
products of combustion, being in a state of considerable tension, will rapidly escape
during the traverse of the piston over the said openings and be reduced to about
atmospheric pressure, then these products are further expelled and replaced by the.
admission of the next charge, and this operation is continued.
As previously described, the charge is ignited by a gas flame, which is carried
in the slide valve; this valve is so formed that a small chamber in its outer cover
receives and is filled by each explosive charge as the mixture is passing into the
combustion chamber and retained there at a pressure above that of the atmosphere:
a little before the piston in the working cylinder has completed its in-stroke, the
slide valve carries the flame to the small chamber and causes a preliminary
explosion therein, which on the further traverse of the slide valve will expose the
main charge within the combustion chamber to this preliminary explosion and
cause the main charge to be ignited or exploded at the commencement of each
effective stroke of the engine.

page_text: And in order that my Invention may be fully understood and readily carried
into effect I will proceed to describe the accompanying three Sheets of Drawings
reference being had to the Figures and letters marked thereon.
Figure 1 is a side elevation. Fig. 2 a plan and Fig. 3 an end elevation, all
partly in section, of a gas motor engine, to which my Improvements are applied.
Fig. 4 is a detached view of the governor and eccentrics and the valve which
regulates the supply of gas to the engine. Fig. 5 is a sectional elovation through
the line A B Fig. 1. Fig. 6 is a plan view of the valve cover and Fig. 7 a plan
-view-of-the-valve-cover_and_of_the_slide valve of the working cylinder and Fig. S
is a plan view of the slide valve and Fig. 9 is a dingram of cycle of operations-of-
the pistons in the power and charging cylinders
Similar letters refer to similar parts throughout the several views.
a is the working and 6 the charging cylinder with pistons a' and b' respectively
shown cast in one piece with the web or frame c: to the crank shaft d is secured
the crank which is connected by the rod d to the piston a' in the working
cylinder.
с
The admission of gas to the engine is controlled by a valve e shown composed of
two cones on one spindle and regulated by the governor (see Fig. 4) the gas
passes through the valvo e along the pipe c', through the gas bags e², past the
conical regulating valve into a chamber e* where it remains under pressure
until the diaphragm is depressed (in the manner hereinafter explained) and the
mushroom valve opened, when the gas in the chamber c and pipe e' passes
through the valve e into the pipef: this pipe f intercepts or passes through the
air supply pipe g and the gas passes through perforations in the pipe f, and mixes
with the air in the pipe g at this point as shown at Fig. 2; during the out-stroke
of the piston bl a charge of gas-and air is drawn through the passage f" and port h
in the slide valve h and so through the passage i into the compressing cylinder b,
and when the charge has been coinpressed during the in-stroke of the piston b₁ it
is driven from the cylinder 6 through the passage i and port 2 in the slide valve h
through the passage into the pipe or reservoir j. The pipe j conducts the com-
pressed charge to a combustion chamber a attached to and forming part of the
working cylinder a: a part of the charge passes from tho passage il down a small
pipe into a chamber above the diaphragm e²: the pressure of the charge
depresses the diaphragm e and opens the mushroom valve of and admits a fresh
supply of gas as previously described. The slide valve h controls the admission
through the port h' and discharge through the port of gas and air to and from
the cylinder : the valve h has a cover h³ and is connected by a rod h* and lever h
to a short shaft he connected to a slotted lever : a bowl on the strap of the
eccentric ³ takes into the slot in the lever hand so operates the slide valve h as
the crank shaft à revolves. The admission of the charge of gas and air to the
combustion chamber a² is controlled by the slide valve k: this valve has a cover l
and is traversed by a rod connected to an eccentric on the crank shaft d.
The operation is as follows-To start the engine the fly wheel is turned by
hand or otherwise and during the outstroke of the piston b'a charge of gas and
air is drawn from the point where they mix through the passage, port h¹ and
passage i into the charging cylinder b on the return or instroke of the piston b¹
the slide valve h will have moved sufficiently to close the port ¹ and open the
port and the charge is driven or forced through the passage i port h³ and
passage into the pipe or reservoir j.
:
The explosive charge is conducted through the pipe j and admitted to the
combustion chamber a³ of the working cylinder a through the slide valve k in the
following manner-When the piston b' of the charging cylinder b is about one
inch from the end of its in-stroke, the piston al in the working cylinder a will be
about one inch from the end of its out-stroke (i.c. near the exhaust openings a³):
at this time the ports and in the slide valve will be over the small
chamber in the valve cover thus opening a communication between the

page_text: passage lending from the reservoir j and the passage a leading to the com-
bustion chamber a²: the chargo under pressure rushes from the pipo j, through the
passage j port into the small chamber and through the port and passage a
into the combustion chamber a*: the charge drives before it through the exhaust
openings a³ any non-explosive vapour that may be contained both in the chamber as
and cylinder a the piston a¹ on its return or in-stroke drives the charge before it
from the cylinder a into the combustion chamber a² and compresses it ready for
explosion while at the same time the piston b' is drawing a fresh charge of gas
and air into the cylinder b. During the in-stroke of the piston a¹ the pocket n in
the slide valvo comes over the passage o' in the valve cover leading from the gas
supply pipe o and receives a supply of gas through the slot n' previous to reaching
the master light m, where the gas in the pocket 2 is ignited. The master light m
is kept constantly burning in the chimney m in a division of or near the com-
bustion chamber a³: an opening m³ in the valve cover admits a current of air
which causes the gas in the pocket n to be ignited. When the piston al has
compressed the charge into the combustion chamber a and begins its reverse or
out-stroke in the position shown in Figs. 1 and 2 the slide valve k will have moved
in the right hand direction and as the valve continuos its traverse the flame in the
pocket n ignites and explodes the mixture under pressure in the small chamber (
a moment in advance of uncovering the passage a leading into the combustion
chamber a this preliminary explosion in the chamber and pocket n instantly
ignites and explodes the main charge in the combustion chamber a
The result of the explosion of the main charge is to propel the working piston a¹
outward until the edge of the exhaust openings a³ is uncovered when the products
of combustion, being in a state of considerable tension, will rapidly escape
during the traverse of the piston over the said openings a³ and be reduced to
about atmospheric pressure and before the openings a³ are again covered by the
piston a' on its inward stroke the remaining products of the previous explosion
will have been expelled through the openings a³ by the next charge of gas and air
admitted to the combustion chamber a through the valve kas already described.
A small portion of the effective stroke of the piston a' is thus sacrificed for the
purpose of expelling the remaining products of combustion by the inrush of a fresh
charge of explosive mixture.
When the slide valve k again moves in the left hand direction, the waste gases
in the ignition pocket n escape through the opening m³ in the valve cover
previous to the pocket n receiving a fresh supply of gas which is ignited at the
master light mas already described and as the slide valve k moves in the right
hand direction the flame in the pocket n again causes a preliminary explosion in
the chamber and so in this manner explodes the main charge in the combustion
chamber a² at the commencement of each effective stroke of the engine.
My improvements are shown applied to a horizontal gas engine only, but it is
obvious that they are equally applicable to gas engines of a vertical type.
Having stated the nature of my Invention and described the manner of
performing the same
I declare that I claim
1. In a gas motor engine, the peculiar construction, arrangement, and com-
bination of the power cylinder a and charging cylinder b with their respective
pistons a and b, and the other parts whereby one effective stroke of the working
piston a¹ is obtained for each revolution of the crank shaft, all substantially as
herein shown and described.
2. The combination of the small chamber charged with explosive mixture at
a pressure exceeding that of the atmosphero with the pocket and the ports and
passages in the slide valve k for the purpose of causing a preliminary explosion and
thus igniting the main charge in the combustion chamber a³, substantially in the
manner and for the purposes herein shown and described.

page_text: 3. Expelling the remaining products of a previous explosion from the working
cylinder of a gas motor engine by the inrush of the next charge of explosive
mixture in the manner herein described.
In witness whereof I the said Charles Henry Andrew have hereunto set my
hand and seal this eighteenth day of December Une thousand eight hundred and
eighty-three
CHARLES HENRY ANDREW. (L.S.)