IMPROVEMENTS IN GAS ENGINES
Year: 1883

page_text: LETTERS PATENT to Charles Henry Andrew of the firm of Messieurs J E
H Andrew and Company of Stockport in the County of Chester Engineer
for an Invention of "IMPROVEMENTS IN GAS ENGINES
"
PROVISIONAL SPECIFICATION left by the said Charles Henry Andrew at
the Office of the Commissioners of Patents on the 6th September 1883.
CHARLES HENRY ANDREW of the firm of Messieurs J. E. H. Andrew and
Company of Stockport in the County of Chester. Engineer "IMPROVEMENTS IN
GAS ENGINES.".
My Invention relates to those engines in which the combustible charge of gas.
and air is exploded under considerable pressure and the object is to relieve the
slide valve of the pressure due to the compression and explosion of the charge.
In applying my improvements to a gas engine I fit or arrange a check valve in
the passage between the combustion chamber and the slide valve: the combustiblė
charge passes under this check valve to enter the combustion chamber: directly the
charge is compressed the check valve closes and severs the connection between
the main charge and a portion of the charge left in the passage at atmospheric
pressure:
When the light is introduced by the slide valve, the portion of the charge in the
passage is in the best and most favourable condition for igniting; the expansion
caused by this preliminary explosion raises the check valve and the flame meets the
compressed charge in the combustion chambers and fires it: the check valve is
instantly closed and the slide valve is relieved from the pressure of the explosion.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Henry Andrew in the Patent Office on the 4th March 1884.
CHARLES HENRY ANDREW, of the Firm of Messieurs J. E. H. Andrew and
Company, of Stockport in the County of Chester, Engineer. "IMPROVEMENTS IN
GAS ENGINES.
"
My invention relates to those engines in which the combustible charge of gas
and air is exploded when under considerable pressure and the object is to relieve
the slide valve of the pressure due to the compression and explosion of the charge.
In applying my Improvements to a gas engine I fit or arrange a check valve in
the passage between the combustion chamber and the slide valve, the combustible
charge passes under this check valve to enter the combustion chamber; directly
the charge is compressed the check valve closes and severs the connection between
the main charge and a portion of the charge left in the passage at atmospheric
pressure,
When the light is introduced by the slide valve the portion of the charge in the
passage is in the best and most favourable condition for igniting; the expansion
.caused by this preliminary explosion raises the check valve and the flame meets
the compressed charge, in the combustion chamber, and fires it: the check valve is
instantly closed, and the slide valve is relieved from the pressure of the explosion.
And in order that my Invention may be fully understood and readily carried
into effect I will proceed to describe the accompanying Sheet of Drawings reference
being had to the figures and letters marked thereon.
Figure 1 is a side sectional elevation through the line D E Fig. 2 and Fig. 2
an end sectional elevation through the line A. B. Fig. 1 of the slide valve and
combustion chamber of the power cylinder of a gas engine fitted with my
Improvements. Fig. 3 is a plan view of the valve cover. Fig. 4 is a plan view
of the valve cover and of the slide valve and Fig. 5 is a plan view of the slide
valve.
Similar letters refer to similar parts throughout the several views.
In these views a is the combustion chamber of the power cylinder a¹ of a gas
engine the explosive charge of gas and air mixed is conducted under pressure
from the charging or compressing cylinder (not shown in the drawings), when a
separate charging cylinder is employed, or, when only a single cylinder is employed,
is drawn through the pipe, reservoir or passage b, and passage 61, to the slide
valve c, and is admitted through the passage and space a³ to the combustion
chamber a, and so to the power cylinder a¹ in the following manner:-the slide
valve c is formed with a port c¹ and when the piston (not shown in the drawings)
in the power cylinder a¹ is near the end of its outstroke, one end of this port c¹
comes opposite the passage b¹ and the other end of the port comes opposite the
passage a thus opening a communication between the pipe or passage 6 and the
passage a leading to the combustion chamber a: the charge is drawn, or, if under
pressure, rushes from the pipe or passage b, through the passage b¹, port c¹, and
passage a, lifts the mushroom check valve d and passes into the combustion
chamber a: the spring d' on the valve spindle is used to assist in closing the
mushroom check valve d, as soon as the charge has passed into the chamber a and
cylinder a and thus the main charge in the combustion chamber a is shut off from
a portion of the charge left in the passage and space a³
During the in-stroke of the piston in the power cylinder a' and while the
compression of the charge is taking place, the hole e¹ in the slide valve c comes
over the passage f in the valve cover g and gas is thus allowed to pass from the
supply pipe f¹, through the passage and the hole e¹, along the slot e², into the

page_text: pocket e where it is ignited at the master light / by means of a current of air
admitted through the opening h' in the valve cover g. The master light h is kept
constantly burning in the chimney h¹ in a division of or near the combustion
chamber a
When the piston in the power cylinder a' has compressed the main charge into
the combustion chamber a and a moment before the piston begins its reverse or
out-stroke, the slide valve c will have moved in the right hand direction and be in
the position shown in Figs. 1 and 2 and as the valve continues its traverse, the
explosive mixture in the passage and space a³, between the underside of the
mushroom check valve d, and the slide valve c is ignited and exploded by the flame
in the pocket e; this preliminary explosion raises the mushroom valve d and
explodes the main charge in the combustion chamber a: the mushroom check
valve d is instantly closed by the force of the explosion and thus relieves the slide
valve c of all pressure from and protects it from any injury by the explosion in the
combustion chamber a.
When the slide valve c again moves in the left hand direction the waste gases in
the ignition pocket e escape through a small pipe f'in the valve cover g previous
to the pocket e receiving a fresh supply of gas.
I have described and shown a mushroom check valve, but any suitable kind of
check valve may be employed.
Having stated the nature of my Invention and described the manner of
performing the same
I declare that what I claim is-
1. The use and application of a check valve between the combustion chamber of
the power cylinder and the slide valve of a gas engine, substantially in the manner
and for the purposes herein shown and described.
2. In a gas engine, the combination with the slide valve c, provided with the
ignition pocket e and the port c¹ communicating with the pipe or passage b by
means of the passage 61, and with the combustion chamber a by means of the
passage a², of the check valve d, substantially in the manner and for the purposes
herein set forth,
3. In a gas engine, the combination with the slide valve c, provided with an
ignition pocket e, having slots e¹ and e8, of the valve cover 9 provided with the
passage f, leading from the gas supply pipe f¹, substantially as and for the purpose
herein set forth.
In witness whereof I the said Charles Henry Andrew have hereunto set my
hand and seal this twenty eighth day of February One thousand eight hundred
and eighty four.
CHARLES HENRY ANDREW (L.S.)