IMPROVEMENTS IN GAS MOTOR-
Year: 1881

page_text: LETTERS PATENT to James Shaw, of Hightown, Liversedge, in the County of
York, Cotton Spinner, for an Invention of
ENGINES.
"
44
IMPROVEMENTS IN GAS MOTOR-
PROVISIONAL SPECIFICATION left by the said James Shaw at the Office
of the Commissioners of Patents on the 26th November 1881.
15
JAMES SHAW, of Hightown, Liversedge, in the County of York, Cotton Spinner,
IMPROVEMENTS IN GAS-MOTOR ENGINES."
In gas motor engines of the horizontal type I attach to the rear end of the
working cylinder, or cast in one piece therewith, a vertical combustion chamber,
which I close at the top by a suitable cover; this combustion chamber extends
downwards about half way across the working cylinder and is open thereto.
Inside the said combustion chamber I place a pipe which reaches nearly to the
top thereof; this pipe is open at the bottom for the admission of air and has a
valve at the top.
Inside of this air pipe is another pipe for the admission of gas, leaving an
annular space around the same, which space forms the air passage. The valve at
the top of said air pipe is caused to open by the forward movement of the piston
in the working cylinder, which causes a partial vacuum in the combustion
chamber and around the air pipe; a simultaneous supply of both air and gas is
thus caused to enter the combustion chamber, where it forms in the upper part
thereof a combustible mixture or charge of air and gas, which by its buoyancy
remains located in said upper part of the combustion chamber, and is in a great
measure isolated from the products of combustion of a previously exploded charge.
Such products of combustion are expelled by the backward motion of the piston
through an exhaust pipe provided for that purpose at the rear end and in the
lower half or part of the working cylinder. At the outer end of the said exhaust
pipe is a valve within a casing; this valve, which by preference is a circular revolving
one (but which may be of any other suitable form), is actuated from the crank
shaft by suitably arranged gearing; it is hollow and open at its outer end. A port
or opening on one side of this valve communicates during its revolution and during

page_text: .
the backward stroke of the piston with the aforesaid exhaust pipe. On the outer
end of said valve casing is an escape or check valve, which opens outwards as the
products of combustion are being driven out of the working cylinder and through
said exhaust pipe, revolving valve and the escape or check valve, this latter valve
being closed automatically or by the atmospheric action immediately on the com-
mencement of the reverse motion of the piston and whenever there is a partial vacuum
in the cylinder, and thus preventing any air from entering the working cylinder by
or through the said exhaust pipe.
The admission of gas into the charge or combustion chamber is accomplished by
a valve actuated by a cam receiving its motion from the crank or other revolving
shaft, the quantity of gas for each charge being regulated by a suitable governor.
In order to ignite the charge of gas and air in the combustion chamber I employ
a hollow piston valve of cylindrical form, which has a reciprocating motion
imparted thereto by a suitably driven crank or eccentric.
This valve is surrounded by a cylindrical casing attached or connected to the
combustion chamber; this outer casing and the valve are each provided with an
⚫ opening for the admission of air at a required moment, which air in its passage to
the interior of the piston valve is caused to pass through a perforated diaphragmn
so as to regulate its speed of admission.
In the said casing of this hollow valve is a second opening, and in the valve
itself an elongated one corresponding therewith for the admission of a blue gas
flame or jet from a pipe having a tapered and contracted nozzle, the gas being
supplied to this contracted nozzle at properly timed intervals (by a valve arranged
and operated for the purpose) and ignited by a second gas jet which is continually
burning. On the blue flame being ignited and projected through the beforenamed
second opening in the valve casing, and into the cylindrical valve, and mixing with
the air previously admitted therein, it causes an explosion to take place within
the valve. The said explosion by means of an aperture or port having a hinged or
other suitable valve opening into the combustion chamber is communicated to the
charge therein, by the explosion of which the piston in the working cylinder is
propelled on its forward stroke. The last named valve immediately closes by the
action of the explosion and prevents any leakage backward through the said piston
valve.
In certain cases I modify the method of igniting the charge, and employ a
suitably formed retort of refractory material which I place in proximity to the
combustion chamber, the said retort being maintained at a red heat by a gas
flame or other equivalent means.
Attached to this retort is a pipe which forms a communication between the
combustion chamber and the cylinder, the point of communication with the
cylinder being immediately in front of the piston when in its back position.
In this position the combustion charge is under pressure, and a small jet of said
charge passes through said retort and communication, and out at the front of the
cylinder, and on the piston forming part of its movement forward through or by
the momentum of the fly wheel, and having so far advanced as to close the before
mentioned communication, a reaction of the said jet takes place through the red
hot retort into the combustion chamber and ignites and explodes the charge
therein, which thus propels and continues the piston in its forward movement.
In the said communication pipe I place a check valve between the cylinder and
the retort to prevent the formation of a current from behind the piston and back
into the combustion chamber.
My said improvements are equally applicable to gas-motor engines of the
vertical or other type.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Shaw in the Great Seal Patent Office on the 26th May
1882.
JAMES SHAW, of Hightown, Liversidge, in the County of York, Cotton Spinner,
"IMPROVEMENTS IN GAS MOTOR ENGINES."
In gas motor engines of the horizontal type I attach to the rear end of the
working cylinder or cast in one piece therewith a combustion chamber, which I
place in a vertical position and at a somewhat higher elevation than the said
working cylinder.
This combustion chamber I form by preference with a closed top, but it may be
closed by means of a separate cover. The lower part of said combustion chamber
is in communication with the working cylinder, and at that part I provide a foot
valve opening towards the said working cylinder for preventing the admission of
the products of combustion from the cylinder to the combustion chamber during
the backward stroke of the piston. Inside the said combustion chamber I place a
pipe, which reaches nearly to the top thereof, for the admission of air, and has a
valve at the top opening towards the combustion chamber. Inside of this air pipe
is another pipe for the admission of gas; this I prefer to introduce at one side of
the air pipe, and to turn it upwards more or less within the said air pipe. Around
the said gas pipe and within the air pipe an annular space is thus formed for the
passage of air. At the bottom of said air pipe and below the part at which the
gas pipe is introduced, I provide a check valve for preventing the waste of gas by
being driven out by the effect of the periodical explosions; such check valve allows
of the free admission of air at the required times. These valves in the air pipe are
caused to open by the forward motion of the piston in the working cylinder, which
causes a partial vacuum in the combustion chamber and around the air pipe, a
simultaneous supply of both air and gas is thus caused to enter the combustion
chamber where it forms a combustible mixture or charge, which by its buoyancy
remains located chiefly in the upper part thereof. And in order that such charge
of air and gas may be the better or more perfectly isolated from the products of
combustion of a previously exploded charge, and also become equally distributed
near the interior surface or walls of said combustion chamber, I place a disc of
metal or other suitable material around the top of the inlet pipe for directing such
charge and distributing it to the required position. The products of combustion
are expelled by the backward motion of the piston from the working cylinder
through an exhaust pipe provided for the purpose at the rear end and the lower
part thereof. At the outer part of the said exhaust pipe is a valve within a casing,
which by preference is a circular revolving one (but which may be of any suitable
form) actuated by gearing from the crank shaft; it is hollow and open at its outer
end; a port or opening on one side of this valve communicates during its revolution
and the backward stroke of the piston with the aforesaid exhaust pipe. On the
outer end of said valve casing is an escape or check valve, which opens outwards
as the products of combustion are being expelled from the working cylinder through
said exhaust pipe, this escape or check valve being automatically closed by the
atmospheric pressure immediately on the commencement of the outward stroke of
the piston, and whenever there is a partial vacuum in the cylinder, thus preventing
any air from entering the working cylinder by or through the said exhaust pipe.

page_text: The admission of gas into the charge or combustion chamber is accomplished by a
circular or other form of valve actuated by a cam receiving its motion from the
crank or other revolving shaft ; but I prefer to impart the revolving motion direct
to the said valve, the quantity of gas for each charge being regulated by a suitable
governor. In order to ignite the charge of gas and air in the combustion chamber,
I employ a hollow piston valve of cylindrical form, which has a reciprocating
motion imparted thereto by a suitably driven crank, eccentric, or cam. This valve
is surrounded by a cylindrical casing attached or connected to the combustion
chamber; this outer casing and the valve are each provided with an opening for
the admission of air at the required moment, which air in its passage to the interior
of the piston valve is caused to pass through a perforated diaphragm, so as to
regulate its speed of admission. In the said casing of this hollow valve is a second
opening, and in the valve itself an elongated one corresponding there with for the
admission of a blue gas flame or jet from a pipe having an internally tapered or
contracted nozzle, the gas being supplied to this contracted nozzle at properly timed
intervals by a valve or cock actuated by mechanism in connection with the aforesaid
piston valve and ignited by a second gas jet, which I will call the permanent or
master gas jet, and which is continually burning. On the blue flame being projected
through the beforenamed second opening in the valve casing and into the said
cylindrical valve, and mixing with the air previously admitted therein it causes an
explosion to take place within the valve. The said explosion, by means of an
aperture or port having a hinged or other suitable valve opening into the combus-
tion chamber, is communicated to the charge therein, by the explosion of which
the piston in the working cylinder is propelled on its forward stroke. The last
named valve immediately closes by the action of the explosion, and prevents any
leakage backward through the said piston valve. The said piston valve is provided
with a cover or metallic plate for passing over and preventing the permanent or
master gas jet from being extinguished at the moment of ignition of the contents
within said valve. And in order to prevent the admission of air through the
aforesaid igniting aperture into the combustion chamber during the forward stroke
of the piston the said aperture is effectually closed by the said piston valve until
another explosion is required to take place.
In my Provisional Specification I propose a modification in the means for
igniting the charge of air and gas in the combustion chamber by the use of a
suitably formed retort of refractory material placed in proximity to the combustion
chamber, but to which I no longer attach any importance, and therefore I lay no
claim to it.
In the accompanying Sheet of Drawings the same letters refer to the same or
like parts wherever they occur. Fig. 1 is a plan of a gas motor engine according
to my Invention; Fig. 2 is a side elevation (partly in section); Fig. 3, an end
elevation (partly in section); Fig. 4 is a sectional elevation through the line 1, 1,
of Fig. 2; Fig. 5 is a detailed plan to an enlarged scale of the piston valve for
igniting the charge; Fig. 6, an elevation of the same to an enlarged scale; Fig. 7,
a back elevation of the said valve casing, also to an enlarged scale, looking at the
flange by which it is joined to the combustion chamber. A is the frame of the
engine; B, the working cylinder; C, the piston; D, the combustion chamber;
E, the air pipe within the combustion chamber; El is the gas feed pipe; F, the
pipe for conveying the gas to the combustion chamber, and enters the air pipe
at F1; G, a valve at the top of the air pipe; H, a valve at the bottom thereof for
the admission of air, and the prevention of the escape of gas during an explosion;
I is a disc of metal or other suitable material for distributing the charge of air and
gas in the combustion chamber as previously referred to; J is a foot valve between
the bottom of combustion chamber and the working cylinder; K is the exhaust
pipe conneted with the working cylinder, and having at the other end the rotating
valve L; L' is the port in the said valve communicating with the exhaust pipe K,
and receiving its motion from the crank shaft M by the gearing N, O; P is the

page_text: check valve at the end of the exhaust outlet; Q is a valve for the admission of
gas into the combustion chamber through the beforenamed pipe F, the quantity
being regulated by the governor R actuating the valve S. The valve is by
preference made a rotating one, and receives its motion from the crank shaft
through the gearing N, O, T; U is the hollow piston valve by which the igniting
of the charge in the combustion chamber is effected, and which is shewn more
particularly in enlarged views in Figs. 8, 9, and 10; Fig. 8 is a vertical section on
the line 2, 2, of Fig. 7; Fig. 9 is a horizontal section on the line 3, 3, of Figs. 6
and 7; and Fig. 10 is a back view same as Fig. 7; U1 is the valve casing of said
piston valve; the opening V is the passage for supplying air to the said valve;
W is the igniting orifice into which the gas jet from the nozzle X is projected at
the proper moment, the said gas jet being itself ignited by the permanent or master
gas jet Y; Z is the vent hole which allows part of the exploded charge in the
piston valve to escape into the atmosphere during the time that the said valve is
stationary; a is the perforated diaphragm by which the passage of the air is
regulated; b is a finger attached to the valve U, for opening and closing the cock
or valve c by acting upon a bell crank d, d, in connection therewith; e is the pipe
for supplying gas to the nozzle X; g is the cover or metallic plate attached to and
forming part of the piston valve U, and by the reciprocating motion of which it is
interposed betwixt the master gas jet Y and the nozzle X; is the igniting port of
the combustion chamber, which is opened and closed by the piston valve U; and
j is a hinged valve for closing the said port inside said combustion chamber on the
explosion of the charge therein. The aforesaid valve U is actuated by the cam T1
on the wheel T, the stud n, and the rod p.
Having described the nature of the said Invention and the manner of carrying
the same into practical effect, I would have it understood that what I consider to
be novel and original, and therefore claim as secured to me by the Letters Patent
hereinbefore first in part recited is,―
1. In a gas motor engine the use of a separate combustion chamber in com-
bination with air and gas supply pipes or passages, and valves so arranged as to
deliver the combustible mixture to the upper part of the said combustion chamber,
substantially as and for the purposes herein before described.
2. In a gas motor engine the use in combination of a separate combustion
chamber air and gas supply valves, so arranged as to deliver the combustible
mixture to the upper part of the said combustion chamber, substantially as
described and shewn.
3. In a gas motor engine the use in combination with a separate combustion
chamber of an igniting arrangement comprising a valve casing provided with inlet
for air and ignited gas, a valve governing communication between the valve casing
and the abovenamed combustion chamber, and a cylindrical slide valve working
within the said valve casing, which valve is itself provided with inlet for air and
ignited gas; also with a perforated diaphragm for regulating the admission of air,
a vent hole for the escape of part of the products of the exploded charge from
within it, all substantially as hereinbefore set forth and illustrated.
4. In a gas motor engine the method of actuating a valve or cock that regulates
the intermittent supply of gas for the igniting jet, substantially as described and
shewn,
5. In a gas motor engine the use in combination of the governor and a rotating
valve Q, as shewn in section in Fig. 4, for the regulation of an intermittent supply
of gas for the explosive charge in the combustion chamber, substantially as herein-
before described and shewn.
6. In a gas motor engine the use in combination with an exhaust pipe of a
rotating valve L, as shewn in section in Fig. 4, and a check valve, such as P, Fig. 2,
substantially as and for the purposes hereinbefore described.

page_text: 7. The improved gas motor engine constructed, arranged, and operating, sub-
stantially as shewn in and described with reference to the Drawings.
In witness whereof, I, the said James Shaw, have hereunto set my hand and
seal, this Twenty-fourth day of May, in the year of our Lord One thousand
eight bundred and eighty two.
Witness to the signature of
the said James Shaw,
THO. E. CRAVEN, C.E.,
Patent Agent,
24, Victoria Chambers,
Leeds.
JAMES SHAW. (L.S.)