Improvements in Gas Engines.
Year: 1891

page_text: Date of Application, 28th Sept., 1891
Complete Specification Left, 28th July, 1892-Accepted, 3rd Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in Gas Engines.
1, DUGALD CLERK, of Driffold Villa, Manor Hill, Sutton Coldfield, in the
County of Warwick, Engineer, do hereby declare the nature of this invention to be
as follows:-
-
My invention relates to improvements in the valve details of Otto cycle gas
engines and also to the construction of incandescent or hot surface igniters applicable
to other types of gas engine as well as to Otto cycle engines.
In carrying the first part of my invention into effect, I dispense with the two to
one gear usually employed and actuate the exhaust valve by means of an air com-
pressing piston directly connected to an eccentric or other arrangement moving with
every revolution of the crank shaft as described in my application for Patent
No. 12413 of 1891. And I adopt a rotating valve rotated by ratchet to cause the
air piston to compress, when it is required to open the exhaust valve, as there
described. In my present invention, however, I dispense with a separate gas valve
and arrange the gas cock and the rotating air valve to fit in one conical or other
aperture or shell. In the interior of the gas cock plug I place a rotating plug to.
control the supply of gas to the engine, and I cause this plug to be rotated by pawl
and ratchet driven from a reciprocating piece attached to the eccentric rod; the
plug rotates the separate air plug behind it by a flat and check, or other connection.
The apertures in the two plugs are preferably arranged so that when the air is
open and the exhaust valve keeps closed, then the gas plug remains shut so that
gas is shut off. A separate gas and air valve is also dispensed with, and one exhaust.
lift valve is made to serve the double purpose of inlet and exhaust, so that only one
lift valve opens to the engine cylinder and the pressure of the explosion is taken by
one valve only. To enable this to be done the air compressing piston which acts
on the exhaust valve through a separate piston, is also arranged to discharge
exhaust gases and feed air and gas. Suitable ports are arranged in it so that at
each revolution of the engine, on every back stroke the piston valve opens the space
below the lift valve herein before referred to, to the exhaust pipe. At every forward
stroke of the engine also the space below the said lift valve is opened by ports in
the piston valve to air and gas supply. The movement of the lift valve however,
determines whether the in stroke of the engine piston shall be an exhausting or a
compressing stroke, and also when the outward stroke of the piston shall be a
suction stroke or an explosion stroke. .
The rotation of the air plug and the gas plug is so arranged that every second
return stroke of the engine, the exhaust lift valve is held open and so the contents
of the cylinder are discharged through the lift valve and through the ports in the
piston valve. When the piston reaches the in end of its stroke and begins its next
out stroke, a charge of air is sucked in through the lift valve and the piston valve,
and with it a charge of gas by way of the rotating gas plug and the piston valve.
I prefer to pass the gas through a port or pocket in the piston valve, to a passage
surrounding the exhaust valve stem from which passage it streams through holes
immediately under the lift valve. The explosive mixture is thus formed immediately
below the lift valve and no mixture is wasted by filling the passage through which
the exhaust gases discharge.
By this arrangement I form a combination giving the necessary two to one action
on the exhaust lift valve, and I cause the said lift valve to perform the double
function of exhaust discharge and inlet for the combustible charge, the piston valve
serving to time the exhaust discharge, and the air and gas inlet. I preferably use

page_text: a forked port under the lift valve, one branch being opened for discharging exhaust
and closed when the exhaust is discharged, while the other branch is opened for air
and gas supply and closed when the charge is complete. The end of the piston
valve is used to compress air to work the separate exhaust valve piston, and it opens
at every forward stroke of the piston valve to the air ports and is so charged at
every stroke to make up for loss by leakage. The engine piston preferably passes
over an exhaust port in the side of the cylinder to discharge the pressure down to
atmosphere so as to reduce the pressure required to lift the exhaust valve and
diminish the volume of exhaust discharged through it.
The second part of my invention consists of a new arrangement of igniter tube
or chamber and is intended to enable the usual external heating of igniter tubes to
be dispensed with and replaced by the heat generated by the explosions.
I construct my tube or chamber of considerable internal capacity and I connect
it by a tube or connecting piece of relatively small section to the explosion chamber.
To start the engine I heat the exterior of the tube or chamber in the usual manner,
but when the engine is started I extinguish the external heating flame. The
considerable volume of mixture fired within the tube or chamber at each explosion
then supplies heat to make up for losses in the intervals between the explosions, and
the tube or chamber continues to fire regularly although the external heat supply is
withdrawn.
I prefer to make my tube or chamber of considerable internal capacity and the
aperture leading to the explosion space of larger diameter than is done at present
(I find a tinch aperture suitable) as I find that the inflammable gases can be
ignited while the hot surface is at a much lower temperature than with a small tube
and so I am enabled to greatly increase the life of the igniting chamber or tube and
dispense with the frequent renewals ordinarily required.
In arranging my internally heated tube I adjust the temperature so as to fire at
the desired period instead of adjusting the position of the ignited surface as is usual
with hot tube igniters open to the explosion space. I protect the tube or chamber
from direct loss of heat to the air by a suitable jacket.
The temperature of the hot tube or chamber is regulated according to the strength
of the combustible mixture employed, so as to produce explosion at the end of the
compression stroke, and the temperature of the tube or chamber is increased by
increasing the protection against the outer air, and diminished by allowing greater
access.
A timing valve is sometimes adopted.
Dated this 26th day of Santamber 1901
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Gas Engines.
1, DUGALD CLERK, of Driffold Villa, Manor Hill, Sutton Coldfield, in the
County of Warwick, 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 improvements in the valve details of Otto cycle gas
engines, and also to the construction of incandescent or hot surface igniters
applicable to other types of gas engine as well as to "Otto" cycle engines.
The accompanying drawings show my invention as carried into effect.
Figure 1 is a transverse section through valves and combustion space on the
liney Figures 2 and 3.
Figure 2 is an external elevation of my valve arrangements.

page_text: Figure 4 is a sectional plan of the cylinder showing front exhaust port.
Figure 5 is a section illustrating my improved igniter.
In carrying the first part of my invention into effect, I dispense with the two to
one gear usually employed and actuate the exhaust valve D by means of an air
compressing piston A directly connected by the rod A³ to an eccentric or other
arrangement moving with every revolution of the crank shaft as described in my
Specification to Patent No. 12413 of 1891. And I adopt a rotating valve B
rotated by ratchet wheel 132 and pawl to cause the air piston to compress when it is
required to open the exhaust valve, as there described. In my present invention,
however, I dispense with a separate gas valve and arrange the gas cock or valve
and the rotating air valve as one plug valve to fit in a conical or other aperture or
shell. This rotating gas and air control valve is shown at B Figure 1, where the
port a is the gas port and the port b the air control port whose position determines
whether air is, or is not compressed by the piston valve A and whether the exhaust
valve D is raised, or not, on the exhausting stroke.
In the interior or exterior of the gas cock plug I sometimes place a rotating plug
to control the supply of gas to the engine, and I cause this plug to be rotated by
pawl and ratchet, driven from a reciprocating piece attached to the eccentric rod;
the plug rotates the separate air plug behind it, by a flat and check, or other
connection. I prefer however to form the gas valve and air valve in one piece
as shown at B Figure 1. The apertures in the two plugs or combined plug are
preferably arranged so that when the air port bis open, and the exhaust valve D
therefore keeps closed, then the gas port a remains shut, so that gas is shut off.
A separate gas and air valve is thus dispensed with, and one exhaust lift valve D
made to serve the double purpose of inlet and exhaust, so that only one lift valve
opens to the engine cylinder and the pressure of the explosion is taken by one
valve only. To enable this to be done the air compressing piston A which acts
on the exhaust valve through a separate piston C, is also arranged to discharge
exhaust gases, and feed air and gas. Suitable ports as QS (Figure 3) are
arranged in it, so that at each revolution of the engine, on every back stroke the
piston valve port S opens the space I K below the lift valve D hereinbefore
referred to, to the exhaust pipe G (Figure 2). At every forward stroke of the
engine also the space IK below the said lift valve D is opened by a port or
ports Qin the piston valve A, to air and gas supply. H is the air pipe which
communicates by the air port M, shown in dotted lines in Figure 3, with the fork I
of the forked part I K, below the valve D, by way of the port Q in the piston
valve. Gas is supplied by the cock F to the rotating plug B by the passage a,
whence it passes through N Figure 1 to a hollow Q1 in the piston valve, and from
the hollow by the holes R to the air port Q, where it mixes with the air and
passes into the engine cylinder. The movement of the lift valve D, however,
determines whether the "in" stroke of the engine piston shall be an exhausting
or a compressing stroke, and also when the outward stroke of the piston shall be a
suction stroke or an explosion stroke.
The rotation of the air plug and the gas plug, or combined air and gas plug B
is so arranged, that at every second return stroke of the engine, the exhaust lift
valve D is held open by the compressed air accumulated under the piston C and so
the contents of the cylinder are discharged through the lift valve D, and through
the port S in the piston valve and L in the piston valve cylinder. When the
engine piston P (Figure 4) reaches the "in" end of its stroke and begins its
next "out" stroke, a charge of air is sucked in through the lift valve D, and the
piston valve A, and with it a charge of gas by way of the rotating gas plug B
and the piston valve A.
"
By this arrangement I form a combination giving the necessary two to one
action on the exhaust lift valve D, and I cause the said lift valve D to perform
the double function of exhaust discharge and inlet for the combustible charge, the
piston valve A serving to time the exhaust discharge, and the air and gas inlet.
preferably use a forked port 1 K under the lift valve, one branch K being
'

page_text: opened for discharging exhaust, and closed when the exhaust is discharged, while
the other branch I is opened for air and gas supply, and closed when the charge
is complete. The end A³ of the piston valve A is used to compress air to work the
separate exhaust valve piston, and it opens at every forward stroke of the said piston
valve to the air port M, and is so charged at every stroke to make up for loss by
leakage. Communication is made between the space at the end of the compressing
part of the piston, that is A³, and the piston C, by a passage T controlled by the
port in the plug B, and further regulated by the pin C in the cover C. D¹ is
the port leading to the combustion space E and serving both as inlet and exhaust
port. E is an igniter tube leading into D. B' is the link actuating the pawl,
operating the ratchet wheel B, preferably connected as shown to the rod A³.
The engine piston P (Figure 4) preferably passes over an exhaust port O in
the side of the cylinder, to discharge the pressure down to the atmosphere, so as to
reduce the pressure required to lift the exhaust valve D, and diminish the volume
of exhaust discharged through it.
•
The second part of my invention consists of a new arrangement of igniter tube
or chamber shown at Figure 5, and is intended to enable the usual external heating
of igniter tubes to be dispensed with, and replaced by the heat generated by the
explosions.
I construct my tube or chamber d of considerable internal capacity, and I connect
it by a tube or connecting piece e of relatively small section, to the explosion
chamber. To start the engine I heat the exterior of the tube or chamber in the
usual manner by the burner y, but when the engine is started I extinguish the
external heating flame of y. The considerable volume of mixture fired within
the tube or chamber d at each explosion, then supplies heat to make up for the
losses in the intervals between the explosions, and the tube or chamber & continues
to fire regularly although the external heat supply is withdrawn.
I prefer to make my tube or chamber of considerable internal capacity, and
the aperture e leading to the explosion space of larger diameter than is done at
present (I find a inch aperture suitable) as I find that the inflammable gases can
be ignited while the hot surface is at a much lower temperature than with a small
tube, and so I am enabled to greatly increase the life of the igniting chamber or
tube and dispense with the frequent renewals ordinarily required.
In arranging my internally heated tube I adjust the temperature so as to fire
at the desired period instead of adjusting the position of the ignited surface as is
usual with bot tube igniters open to the explosion space. I protect the tube or
chamber from direct loss of heat to the air by a suitable jacket f of ordinary
construction.
The temperature of the hot tube or chamber is regulated according to the
strength of the combustible mixture employed, so as to produce explosion at the
end of the compression stroke; and the temperature of the tube or chamber is
increased by increasing the protection against the outer air, and diminished by
allowing greater access.
A timing valve is sometimes adopted.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In a gas or like engine the combination of a small air cylinder and piston,
a pawl and ratchet wheel or other means of rotation, rotating or actuating a plug
or valve and a piston operated exhaust valve to obtain the alternate action of the
exhaust valve, operating pneumatically; the said air compressing piston being
arranged as a fluid control valve and the said piston operated exhaust valve serving
the double purpose of charging and discharging the engine cylinder substantially
as and for the purposes herein before described and illustrated in the drawings.
2. In a gas or like engine the valve gear hereinbefore described with reference
to Figures 1, 2, 3, and of the accompanying drawings comprising combined piston

page_text: valve and compressing piston, as A, piston operated lift valve as D, rotating plug
as B, and suitable air inlet and exhaust discharge ports substantially as arranged in
the valve casing A¹ for the purposes described.
3. In a gas or like engine an igniter tube or chamber as hereinbefore described
5 with reference to Figure 5 of the drawings in which the said tube chamber is of
sufficient volume or capacity to keep hot by the explosions in the cylinder,
substantially as hereinbefore described.
Dated thi. 07th 1 of T1 1900
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicant.