IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1883

page_text: LETTERS PATENT to Thomas Miller Williamson, James Malam and William
Allerston Ireland; all of Southport in the county of Lancaster, for an
Invention of IMPROVEMENTS IN GAS MOTOR ENGINES
PROVISIONAL SPECIFICATION left by the said Thomas Miller Williamson,
James Malam, and William Allerston Ireland at the Office of the Commissioners
of Patents on the 10th October 1883.
THOMAS MILLER WILLIAMSON JAMES MALAM and WILLIAM ALLERSTON IRELAND,
all of Southport in the county of Lancaster IMPROVEMENTS IN GAS MOTOR
ENGINES
This invention relates chiefly to Gas Motor Engines of the type described in the
Specifications of Letters Patent No 1692 and N° 3685. 1880 granted to Hugh
Williams and James Malam and No 5456 1881 granted to Hugh Williams but is
in part applicable to Gas Motor Engines of other types
The first part of our invention relates to improvements in the suction exhaust
and terminal pressure valves.
The second part of our invention relates to certain means and methods of
actuating the exhaust or terminal pressure valve
The third part of our invention relates to certain means and methods of
actuating the pump for compressing the gas or gases and introducing the same into
the working or power cylinder
The fourth part of our invention relates to means and methods of reducing the
temperature of the products of combustion after leaving the power cylinder and
before entering the vacuum cylinder
The fifth part of our invention relates to certain means and methods of igniting
the charge of combustible mixture while under compression in the power cylinder
The sixth part of our invention relates to certain arrangements of the terminal
pressure & vacuum ports
The seventh part of our invention relates to Gas Motor Engines having the
power and vacuum cylinders arranged parallel to each other and in which the
piston of the power cylinder acts as the terminal pressure valve and at the proper

page_text: moment opens communication between the vacuum cylinder and the power
cylinder
The eighth part of our invention consists in certain means and methods of
regulating the speed of the engine
The ninth part of our invention relates to certain means and methods of
regulating the opening of the admission or suction valve
The tenth part of our invention relates to certain methods of flushing the
ignition port
In carrying out the first part of our invention we employ metallic valves of the
mushroom type having either flat or conical seats. Secured to the body of the
valve we use asbestos millboard or other suitable material which we cover with a
cap of thin sheet metal secured in such a manner as to protect the asbestos or
other material from the outrush of hot gases and the beating of the valve on its
seat The thin metallic covering forms a seating and the shock of metallic contact
is lessened by the yeilding material between the body of the valve and the seating
Referring to the second part of our invention it has been found that in engines
of the type wherein a vacuum is used it is necessary to reduce the pressure of the
burnt gases (by exhaustion) to that of the atmosphere before the vacuum cylinder
is put into communication with the power cylinder. Difficulties have been
experienced in closing the terminal pressure or exhaust valve quickly enough, it
has been done previously by cams or eccentrics in our invention we carry it out
as follows. We employ a small cylinder fitted with a piston or a diaphragm which
is connected either directly or by means of a lever or levers to the terminal pressure
or exhaust valve. This piston or diaphragm is subjected alternately to pressure
and vacuum by the working of the engine and the motion thus imparted is used
for the purpose of opening and shutting the exhaust valve. When the power
piston has fully uncovered the exhaust or terminal pressure ports and the pressure
in the power cylinder is reduced to that of the atmosphere the power piston puts
a small port communicating with the vacuum into communication with the piston
or diaphragm connected to the exhaust or terminal pressure valve thereby creating
a vacuum under the piston or diaphragın and closing the exhaust valve before the
engine completes its stroke or communication is made between the power and
vacuum cylinders. The same port on the return stroke of the power piston is
uncovered and the back pressure in the vacuum cylinder breaks the vacuum under
the piston or diaphragm thus opening the exhaust valve ready for the next
exhaustion
Or we may cause the vacuum to act upon the piston or diaphragm so as to open
the exhaust valve ready for exhaustion and when the power piston fully uncovers
the exhaust port communication is made (by means of a small hole) between the
power cylinder and the valve piston or diaphragm thereby breaking the vacuum
and releasing the piston or diaphragm the former of which aided by a spring or the
diaphragm by its own elasticity or a spring thus closing the exhaust valve before
a vacuum is established in the power cylinder
In carrying out the third part of our invention we employ a differential cylinder
fitted with two pistons connected together. The smaller cylinder we use as a gas
pump and the larger cylinder as the means of actuating the gas pump piston the
operation being as follows; upon the outstroke of the engine a vacuum is formed
in the vacuum cylinder communication is made (by means of a slide or other valve
or other known device) with the top side of the larger piston thus raising both
pistons in the cylinder and drawing in a charge of gas or mixture below the
smaller piston. Upon the return stroke of the engine compression takes place in
the power cylinder and communication is made (by means of the valve previously
mentioned) between the larger piston of the gas pump and the power cylinder
The increasing compression in the power cylinder caused by the return of the
power piston causes the larger piston of the gas pump to descend by reason of its
greater area thus forcing the gas or mixture from below the smaller piston into
the power cylinder where it mixes with the air contained therein.

page_text: We prefer to force the gas or mixture into the power cylinder through a number
of small holes arranged circumferentially so as to ensure a thorough diffusion of
the gas.
We employ back pressure valves between the gas pump and power cylinder and
between the gas pump and gas supply
In carrying out the fourth part of our invention we fit a number of pipes or
tubes either filled with or surrounded by water and we draw the products of
combustion at or about atmospheric pressure around or through the tubes (as the
case may be) before entering the vacuum cylinder We thus reduce the temperature
and increase the efficiency of the engine We may also use other well known
means for the purpose of cooling the hot gases in their passage from the power
cylinder to the vacuum cylinder
In carrying out the fifth part of our invention which is applicable to all forms
of Gas Motor Engines in which compression is used we fit a metallic tube which is
heated externally by a Bunsen or other powerful burner This tube communicates
with the interior of the power cylinder and during compression a small quantity
of the combustible mixture is forced outwards and burns in the hot tube The
products of combustion escape into the atmosphere through a small valve and when
the power piston arrives at the end of its stroke this valve is shut and the outward
current being thus arrested the flame strikes back into the interior of the cylinder
and ignites the combustible charge
In carrying out the sixth part of our invention which relates to engines having
the power and vacuum cylinders arranged tandem or in the same line. We use
two sets of ports which are arranged circumferentially The first set of ports
which are uncovered by the power piston lead (by a belt cast round the cylinder)
to the terminal pressure or exhaust valve; and the second set of ports which are
uncovered by the further travel of the power piston communicate with the vacuum
cylinder. The products of combustion are at the proper moment reduced to
atmospheric pressure by the opening of the terminal pressure ports by the piston
which travels a short distance more before opening the ports communicating with
the vacuum cylinder. We have previously described means of shutting the
terminal pressure valve quickly before the vacuum cylinder is put into
communication with the power cylinder
The seventh part of our invention is carried out as follows; we employ two
cylinders placed side by side and so arrange their respective ports pistons and
cranks so that the pistons act to a certain extent as slide valves opening and
closing the ports at the proper times Thus when the working piston has nearly
completed its outward stroke it commences to open ports which allow the
terminal pressure in the power cylinder to fall to atmospheric pressure after which
the piston in the vacuum cylinder passing over similar ports puts the power
cylinder into communication with the vacuuin cylinder and thus extracts a portion
of the products of combustion still remaining in the power cylinder and thus
reducing the pressure in the power cylinder considerably below that of tho
atmosphere The deficiency is made up by the new charge of mixed gas and air
rushing in as soon as the inlet valve opens The return of the working piston
shuts the ports. In engines arranged as above described the exhaust valve may be
arranged in various ways but we prefer to let it be carried by the piston of the
vacuum cylinder and so arranged that it shuts against a seating formed on that
piston The valve may also have a tube formed on it which passes over the piston
rod and through the gland. The gland produces friction on this tube and thus
ensures the opening and shutting of the valve
In carrying out the eighth part of our invention which is applicable to gas
engines generally, having a vacuum cylinder we provide a catch in conjunction
with the exhaust valve and actuated by the governor in such a manner that
when the engine runs too fast this catch will hold the exhaust valve open but will
be released on the engine slowing down again and so allow the exhaust valve to

page_text: shut This method of governing releives the engine from the pull of the vacuum
and is consequently more economical than merely cutting off the gas
In carrying out the ninth part of our invention which is applicable to engines
having a vacuum cylinder we use a detaining motion for preventing the admission
valve opening too soon so as to prevent unnecessary waste arising from a portion
of the new charge entering the vacuum cylinder. The detaining motion may be
conveniently made as follows; The admission valve is held down to its seat by a
ring which prevents it rising until the ring has been moved into such a position
as to bring certain recesses on the ring opposite certain corresponding projections
carried by the valve. The valve then lifts under the influence of the vacuum.
The movement of the ring is effected by means of an eccentric on the shaft and a
lever and the eccentric can be set so as to delay the opening of the valve to any
required extent
The tenth part of our invention has for its object the clearing of the pocket of
the firing slide from the products of combustion When applied to engines using a
vacuum cylinder we put the firing pocket at a certain portion of its stroke under
the influence of the vacuum in order to withdraw or clear out the products of
combustion remaining therein. In some cases where the air which forms a portion
of the new charge is driven into the working cylinder by enforcement a portion of
the air in a compressed state and with which the gas is not mixed may be used for
flushing the firing pocket the slide valve being so arranged as to open a
communication between the compressed air and the firing pocket at the proper
moment We may also use an independent pump for clearing out the products of
combustion from the firing pocket in the slide valve
In one modification of our invention this pump is used as a vacuum producing
pump or suction pump being so arranged as to suck out the products of combustion
In another arrangement it is used as an air forcing pump so that at the proper point
in the stroke the pocket is subjected to a current of compressed air which sweeps
out the products of combustion remaining in the pocket. This enables the clearing
out or flushing action to be applied to the firing pockets in slide valves of engines
which are not provided with a vacuum or compression cylinder The port leading
into the cylinder by which the flame in the firing pocket is communicated to the
charge in the cylinder will also after every ignition become charged with products of
combustion In some engines the new charge is drawn or forced in through this
port and naturally carries these products before it thus clearing the port of the
products of combustion When a seperate admission valve is used we provide a
small port in the slide valve so arranged that it will admit air into the port
leading into the cylinder. When this system is applied to an engine working on
the vacuum principle we arrange this port to open just as the vacuum is acting on
the power cylinder so that air will be sucked through the firing port which will
thus be cleared of the products of combustion This system may also be applied
in conjunction with a compressing pump so arranged that the products of
combustion in the port will be cleared by a small stream of compressed air or the
flushing of the port may be accomplished by a portion of the new charge being
forced in under pressure or drawn in by means of the vacuum
Another part of our improvements consists in an improved form of admission
valve by which the new charge of mixed gas and air is admitted to the working
cylinder For this purpose we use two mushroom valves of different sizes The
longer of these valves opens direct into the cylinder concentric with this larger
valve is a smaller valve which admits the gas Around the gas valve there is a
sufficient space for the passage of the air and the gas and air mixing together pass
on in their mixed state through the larger valve into the working cylinder
In another form of inlet valve we use a mushroom valve as above described
opening direct into the cylinder and in conjunction with this we use an annular
valve fitting on to an annular seat and so arranged that when lifted air is admitted
from the outer circumference while the gas issues up through an opening in the

page_text: annular seat The air is thus caused to sweep over the orifice from which the gas
issues and thus becomes thoroughly mixed with it In another part of our
invention we use a gas & air valve for mixing so arranged that when the vacuum
is communicated to the power cylinder we draw in first pure air & afterwards a
mixture of air & gas, so that the pure air will flush the power cylinder driving
before it the products of combustion The mixture closely follows the pure air &
is compressed & ignited as before
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Miller Williamson, James Malam, and William Allerston
Ireland in the Patent Office on the 10th April 1884.
THOMAS MILLER WILLIAMSON JAMES MALAM and WILLIAM ALLERSTON IRELAND,
all of Southport in the county of Lancaster "IMPROVEMENTS IN GAS MOTOR
ENGINES
">
In carrying out the first part our invention we employ metallic valves of the
mushroom type having either flat or conical seats. Secured to the body of the
valve we use asbestos millboard or other suitable material which we cover with a
cap of thin sheet metal secured in such a manner as to protect the asbestos or other
material from the outrush of the hot gases and the beating of the valve on its seat.
The thin metallic covering forms a seating and the shock of metallic contact is
lessened by the yielding material between the body of the valve and the seating-
Two forms of valves of this description are shewn in Figs 1 & 2 of the
accompanying drawings-A A are the valve spindles, B B the asbestos packings
and CC the thin sheet metal caps. These drawings show how the various parts
are fixed together.
Referring to the second part of our invention it has been found that in engines
of the type wherein a vacuum is used it is necessary to reduce the pressure of the
burnt gases (by exhaustion) to that of the atmosphere before the vacuum cylinder
is put into communication with the power cylinder. Difficulties have been
experienced in closing the terminal pressure or exhaust valve quickly enough, it
has been done previously by cams and eccentrics in our invention we propose to
carry it out as follows: We employ a small cylinder and piston or diaphragm
which is connected either directly or by means of a lever or levers to the terminal
pressure or exhaust valve. This piston or diaphragm is subjected alternately to
pressure and vacuum by the working of the engine and the motion thus imparted
is used for the purpose of opening and shutting the exhaust valve. When the
power piston has fully uncovered the exhaust or terminal pressure ports and the
pressure in the power cylinder is reduced to that of the atmosphere, the power
piston puts a small port communicating with the vacuum into communication with
the piston or diaphragm connected to the exhaust or terminal pressure valve
thereby creating a vacuum under the piston or diaphragm and closing the exhaust
valve before the engine completes its stroke and communication is made between
the power and vacuum cylinder. The same port on the return of the power piston
is uncovered and the back pressure in the vacuum cylinder breaks the vacuum

page_text: under the piston or diaphragm thus opening the exhaust valve ready for the next
exhaustion. Or we may cause the vacuum to act upon the piston or diaphragm so
as to open the exhaust valve ready for exhaustion and when the power piston fully
uncovers the exhaust port communication is made between the working cylinder
and the valve piston or diaphragm thereby breaking the vacuum and releasing the
piston or diaphragm the former of which aided by a spring or the diaphragm by
its own elasticity or a spring thus closing the exhaust valve before a vacuum is
established in the power cylinder. A valve of this description is shown in Fig 3
A is the exhaust or terminal pressure valve. B is the small piston upon which
the vacuum cylinder acts at the proper time by the opening of ports in the main
piston, communicating with the lower side of the small piston B by the pipe C-
D is the outlet for the products of combustion from the working cylinder
In carrying out the third part of our invention we employ a differential cylinder
fitted with pistons connected together. The smaller cylinder we use as a gas
pump and the larger cylinder as a means of actuating the gas pump piston the
operation being as follows: upon the outstroke of the engine a vacuum is formed
in the vacuum cylinder communication is made (by means of a slide or other valve
or other known device) with the top side of the larger piston thus raising both.
pistons in the cylinder and drawing in the charge of gas or mixture below the
smaller piston. Upon the return stroke of the engine compression takes place in
the power cylinder and communication is made (by means of the valve previously
mentioned) between the top of the larger piston of the gas pump and the power
cylinder. The increasing compression in the power cylinder by the return of the
power piston causes the larger piston of the gas pump to descend by reason of its
greater area thus forcing the gas or mixture from below the smaller piston into
the power cylinder where it mixes with the air contained therein. We prefer to
force the gas or mixture through a number of small holes arranged circumferentially
so as to ensure a thorough diffusion of the gas. We employ back pressure valves
between the gas pump and power cylinder and between the gas pump and gas
supply This arrangement is shown by Fig 4. A. A is the larger cylinder which
by means of a slide valve in connection with the pipe B communicates alternately
with the power and the vacuum cylinder CC is the piston or rather two pistons
connected together. D D is the smaller cylinder to which the gas is drawn
through the back pressure valve E. The gas is forced out of the small cylinder D
through the valve F by the pressure acting on the superior area of the piston in
the larger cylinder A A The arrows show the course of the gas. From the
valve F it is led by a pipe to the power cylinder
In carrying out the fourth part of our invention we fit a number of pipes or
tubes either filled with or surrounded by water and draw the products of combus-
tion at or nearly at atmospheric pressure round or through the tubes (as the case
may be) before entering the vacuum cylinder We thus reduce the temperature and
increase the efficiency of the engine. We may also use other well known methods
for the purpose of cooling the hot gases in their passage between the power cylinder
and the vacuum cylinder
In carrying out the fifth part of our invention which is applicable to all forms of
gas motor engines in which compression is used we fit à metallic tube which is
heated externally by a Bunsen or other powerful burner. This tube communicates
with the interior of the power cylinder and during compression a small quantity
of the combustible mixture is forced outwards and burns in the hot tube. The
products of combustion escape into the atmosphere through a small valve and
when the power piston arrives at the end of its stroke the valve is shut and the
outward current being thus arrested the flame strikes back into the interior of the
cylinder and thus ignites the combustible charge
In Figs 5 & 6 AA is the end of the working cylinder, B is the metallic tube
which we prefer to be of platinum and which is heated by means of the Bunsen
burner C. D is a tap which at the right moment is shut by any suitable mechanism
actuated by the engine and so turns back the rush of ignited mixture into the

page_text: cylinder and so ignites the charge. E is a casing or chimney lined with fire clay
or other refractory material as sbewn at F F in order to concentrate the heat on
the tube B
In carrying out the sixth part of our invention which relates to engines having
the power and vacuum cylinders arranged tandem. We use two sets of ports
which are arranged circumferentially the first set of ports which are uncovered by
the power piston lead (by a belt cast round the cylinder) to the terminal pressure
or exhaust valve and the second set of ports which are uncovered by the further
travel of the power piston communicate with the vacuum cylinder. The products
of combustion are at the proper moment reduced to atmospheric pressure by the
opening of the terminal pressure ports by the piston which travels a short
distance further before opening the ports communicating with the vacuum
cylinder
We have previously described means of shutting the terminal pressure valve
quickly before the vacuum cylinder is put into communication with the power
cylinder. This arrangement is shewn in Figs 7 & 7a. Fig 7 being a longitudinal
section and Fig 7a a cross section taken on the line xx in Fig 7. A is the
working cylinder and B the vacuum cylinder-C. C. are the terminal pressure ports
opening into the belt D which leads to the terminal pressure valve. E E are the
vacuum ports leading direct into the vacuum cylinder B F. F is the piston which
is furnished with the ports G. G. which on the outward stroke of the piston
successively opens the working cylinder to the ports C. C and E. E.
The seventh part of our invention is carried out as follows: We use two cylinders
side by side and so arrange their respective ports pistons and cranks that the pistons
act to a certain extent as slide valves opening the ports at the proper times. Thus
when the working piston has nearly completed its outward stroke it commences to
open ports which allow the terminal pressure in the cylinder to fall to atmospheric
pressure, after which the piston in the vacuum cylinder passing over similar ports
puts the power cylinder into communication with the vacuum cylinder and thus
extracts a portion of the products of combustion still remaining in the working
cylinder reducing the pressure in the power cylinder considerably below atmospheric
pressure. This deficiency is made up by the new charge of mixed gas and air
rushing in as soon as the inlet valve opens. The return of the working piston.
shuts the ports. Fig 8 is a general side view and Fig 9 is a sectional plan of a gas
engine made in accordance with this part of our invention Fig is shewn with
one pulley removed and only one of the cranks is shewn to avoid confusion. In
Fig 9 the connecting rods are shewn removed. A is the working cylinder and B
the vacuum cylinder both these cylinders being water jacketted as shewn at
C. C. C. The working piston is shewn at E with its connecting rod F coupled to
the crank G on the crank shaft The crank shaft also carries the crank H which
by means of its connecting rod (not shewn in the drawing) actuates the piston I of
the vacuum cylinder. L L is the exhaust pipe. The cranks G and H are so placed
that the crank H will in its rotation be a certain definate degree behind the
crank G so that when in its outward stroke the piston E will have begun to open
the ports K the piston I will not yet have reached these ports. The consequence is
that the products of combustion in the working cylinder and which will still be at
a considerable pressure can rush out through the ports K to the exhaust pipe L.
The pressure in the working cylinder immediately falls to atmospheric pressure.
The piston I then follows up shutting off communication between the ports K and
the exhaust pipe L and opening the vacuum cylinder to the working cylinder and
thus drawing out a certain portion of the remaining contents. The deficiency is
made up by the new charge entering through the admission valve M which should.
be arranged to open simultaneously with the opening of the vacuum to exhaust
cylinder. This admission valve may be of the construction described in the
specification of a Patent No 3685 granted to Hugh Williams and to the within
named James Malam and dated 10th day of September 1880 or it may be of other
convenient construction. With regard to the cranks we find that a good result is

page_text: obtained when they are set at an angle of 35° to each other and the ports set out
accordingly. In engines arranged as above described the exhaust valve may be
arranged in various ways but we prefer to let it be carried by the piston of the
vacuum cylinder and so arranged that it shuts against a seating formed in
the piston The valve may also have a tube formed on it which passes over the
piston rod and through the gland. The gland produces friction in this tube and
thus ensures the opening and shutting of the valve. N is the exhaust valve and
O. O. the tube formed on it.
In carrying out the eighth part of our invention which is applicable to Gas
Engines having a vacuum cylinder we provide a catch in conjunction with the
exhaust valve and actuated by the governor in such a manner that when the
engine runs too fast this catch will hold the exhaust valve open but will be released
on the engine slowing down again and so allow the exhaust valve to shut This
method of governing releives the engine from the pull of the vacuum and is
consequently more economical than merely cutting off the gas
Figs 10 & 11 are two views of this arrangement Fig 10 being the position
when the engine is running at its normal speed and Fig 11 when the engine is
running too fast. A A is the crosshead on the end of the piston rod of the exhaust
piston; this crosshead carries the fulcrum of the catch lever B B. C. C. is the end
of the tube O in Fig 9 which is carried by the exhaust valve and this end of the
tube is provided with the collar D. D upon which the catch lever operates. When
the engine is running at its normal speed the governor balls assume the position
shewn in Fig 10 thus dropping on their upright spindle and lowering one end of
the small lever E. The other end of this lever is raised to a corresponding extent
and this also raises the stop F which is connected to it so that when the exhaust
piston reaches the extremity of its inward stroke the tail of the catch lever B B
comes into contact with this stop and thus the catch is raised up and prevented
engaging in the collar D on the tubular stem of the exhaust valve. This valve is
thus allowed to shut by outward movement of the exhaust piston and thus creates
the necessary amount of vacuum to bring in the next charge. But when the
engine is running too fast the balls fly out into the position shewn in Fig 11 The
stop F is thereby depressed so that the tail piece on the catch lever does not come
in contact with it and the catch is free to engage in the collar D and thus prevent
the valve from shutting. The consequence is that no vacuum is created in the
succeeding stroke and no new charge is drawn into the working cylinder
With regard to the ninth part of our invention we do not find the detaining
motion to act economically
The tenth part of our invention has for its object the cleaning of the pocket of
the firing slide from the products of combustion. When applied to engines using a
vacuum cylinder we put the firing pocket at a certain portion of its stroke under
the influence of the vacuum in order to withdraw or clear out the products of
combustion remaining therein
In Figs 12, 13, 14 and 15 are shewn various views of a firing valve and its
accessories constructed upon a principle well known to makers of gas engines.
Fig 12 shows the false plate that the slide valve works against. Fig 13 is the
valve itself
Fig 14 is a plan shewing the valve and valve cover in position and Fig 15 is
a vertical section taken through the various lines indicated in Figs 12, 13 & 14
A A is the firing pocket in the slide valve, after igniting a charge this pocket
becomes filled with the products of combustion and the object of this part of our
invention is to clear these products out. We accomplish this as follows: the
pipe B B (shewn at P in Fig 8) leads to the vacuum or exhaust cylinder and
communication is made by the passage CC with the small port D in front of the
loose plate.
The slide valve has the port E cut through it into the firing pocket.
The relative positions of the ports D and E are such that the motion of the slide
valve on its return stroke after the ignition of a charge will open the port E to the
port D and thus the products of combustion will be drawn out by the vacuum,

page_text: The pipe B should be furnished with a fap by which the pull of the vacuum can
be regulated. In some cases where the air which forms a portion of the new charge
is introduced into the working cylinder by enforcement a portion of this air in a
compressed state and with which the gas is not mixed may be used for flushing the
firing pocket the slide valve being so arranged as to open a communication between
the compressed air and the firing pocket at the proper moment
In this arrange-
ment the ports would be constructed in a similar manner to those described first,
the only difference being that the pipe B in this case would convey a charge of
compressed air to the firing pocket which would blow the products of combustion
up the chimney on the return stroke of the valve. We may also use an independent
pump for clearing out the products of combustion from the firing pocket in the
slide valve. In one modification of our invention this pump is used as a vacuum
producing pump or suction pump being arranged as to suck out the products of
combustion. In another arrangement it is used as an air forcing pump so that at
the proper point in the stroke the pocket is subjected to a current of compressed
air which sweeps out the products of combustion remaining in the pocket This
enables the clearing out or flushing action to be applied to the firing pockets of
slide valves of engines which are not provided with a vacuum or compression
cylinder. A convenient form of pump for this purpose is shewn in Figs 16 and 17.
Fig 16 being a longitudinal section and Fig 17 a cross section through the valves
A A is the barrel of the pump, E the ram, C is the suction valve and D the
delivery valve. This pump may be driven by any convenient arrangement of
mechanism from the engine. When the pump is used for clearing out the pocket
by suction the pipe B Figs 12 and 15 is connected to the suction valve C of the
pump and the delivery valve may be connected to the exhaust pipe. On the other
hand when the pump is used for clearing out the products of combustion by forcing
a charge of compressed air into the firing pocket and thus flushing it, the pipe B
Figs 12 and 15 is connected to the delivery valve D and the suction valve C simply
opens to the atmosphere. The port leading into the cylinder by which the flame
in the firing pocket is communicated to the charge in the cylinder will also after
every ignition become charged with products of combustion.
In some engines the new charge is drawn or forced in through this port and
naturally carries these products before it thus clearing the port of the products of
combustion Where a seperate admission valve is used we provide a small port in
the slide valve so arranged that it will admit air into the port leading to the
cylinder. A port of this description is shewn in dotted lines at F F Figs 13 & 14.
It is simply a shallow groove or recess at the back of the valve and when this
system is applied to an engine working on the vacuum principle we arrange this
port to open just as the vacuum is acting on the power cylinder and the other end
of this port being open to the atmosphere air will be sucked through the firing
port which will be thus cleared of the products of combustion. This system may
be also applied in conjunction with a compressing pump so arranged that the
products of combustion in the port will be cleared by a small stream of compressed
air or the flushing of the port may be accomplished by a portion of the new charge
being forced in under pressure or drawn in by means of the vacuum
In this case
the compressed air would be conveyed from the pump or the portion of the new
charge would be led from the cylinder to the port G Fig 12 in the loose plate and
the port or recess F F instead of opening to the atmosphere would only be
sufficiently long to put the port G into communication with the firing port leading
to the cylinder at the proper moment
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be carried out we declare that
what we claim is:
Firstly. The application to Gas Motor Engines of valves of the description referred
to in the first part of our invention

page_text: .
Secondly. In Gas Motor Engines constructed on the vacuum principle the use of
the auxilliary piston or diaphragm for the purpose of opening and shutting the
exhaust valve substantially as described in the second part of our invention
Thirdly The application of a cooling medium between the working and vacuum
cylinders substantially as described in the fourth part of our invention
Fourthly. The method of ignition as applied to Gas Motor Engines generally
substantially as described in the fifth part of our invention
Fiftbly The arrangement of ports as applied to Gas Motor Engines constructed
on the vacuum principle substantially as described in the sixth part of our
invention
Sixthly. The arrangement of cylinders with their relative positions of ports and
cranks substantially as and for the purposes set forth and described in the seventh
part of our invention
Seventhly. Governing engines constructed on the vacuum principle by holding
open the delivery valve of the vacuum cylinder substantially as described in the
eighth part of our invention
Eighthly Clearing the pocket of firing slide by making communication between it
and the vacuum cylinder at the proper moment substantially as described in the
tenth part of our invention
In witness whereof the said Thomas Miller Williamson, James Malam and
William Allerston Ireland have hereunto set their bands and seals this ninth day
of April in the year of Our Lord One thousand eight hundred and eighty four.
THOMAS MILLER WILLIAMSUN (L.S.)
JAMES MALAM
(LS.)
(LS)
Signed sealed and delivered by
all the within named parties
in the presence of
C. WILDEN. KING
Southport
W A. IRELAND