IMPROVEMENTS IN GAS ENGINES
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and
W. Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents for an Invention of IMPROVEMENTS IN GAS ENGINES
communicated to him from abroad by the Economic Motor Company of the
city, county and state of New York, United States of America
'
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 4th September 1883.
"
ALEXANDER MELVILLE CLARK, of the firm of A. M. and W. Clark of 53 Chancery
Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents
"IMPROVEMENTS IN GAS ENGINES [Communicated to him from abroad by the
Economic Motor Company of the city, county and state of New York, United
States of America]
This Invention relates to the class of gas engines in which an explosive mixture
of combustible gas and common air is drawn into the cylinder during the early part
of the stroke of the piston and subsequently exploded, the expansion of the gases
propelling the piston through the remainder of the stroke. And the invention
consists in an igniter formed of a disc of platinum supported at its edges by a
non-conductor of heat and maintained in a state of incandescence by a blow pipé
flame; in an air pump driven by the engine and serving the double purpose of a
governor to the gas supply of the engine and of supplying the igniter blow pipe
with air; in a slide valve formed of two independently adjustable pistons admitting
of regulating the admission of gas and the exhaust of the products of combustion
independently of each other; in a valve motion which insures a quick opening and
closing of the gas and air supply valves while allowing them to remain wide open'
during the period of supply and the period of exhaust; in a regulator for the air
check valve by means of which the lift of the valve may be regulated from the.
outside of the valve without the necessity of opening it for the purpose; in. the
combination of a check valve with the gas and air supply for preventing the-heat

page_text: .
resulting from the explosion in the cylinder from reaching the gas and air check
valves, and in an automatic cut off which shuts off the gas supply as soon as the
engine stops.
The cylinder is single acting and the piston is directly connected by a connecting
rod with the end of a weigh lever which is connected by another rod with the
driving crank.
In front of the path of the crank is mounted a short shaft eccentric to the main
driving shaft being below and at one side thereof. To the inner end of this short
shaft is secured a crank arm of less radius than the main crank, and is connected
with the outer end of the main crank pin by means of a link.
The outer end of the short shaft carries a still shorter crank arm which is
connected by a rod with the shoe-valve rod.. The slide valve consists of two
pistons working in an open ended cylinder screwed upon the same rod so that they
may be readily adjusted in relation to the gas supply, air supply and exhaust ports
in the sides of the valve cylinder. The valve cylinder communicates with the
concave chamber at bottom of the main cylinder, and communicating with the
valve cylinder through the air port there is an air check valve formed by a flexible
disc covering a circle of holes in the cover of the valve casing and held in its place
on the inner surface of the cover by a central clamping screw.
This screw is tapped to receive an adjusting screw which carries on its inner end
a concave disc at the back of the valve and whose periphery is about opposite the
ring of holes in the valve seat. By turning the screw the distance of the disc
from the valve can be adjusted to limit the lift of the valve and regulate the air
supply.
The concave bottom of the main cylinder is filled with snarls of wire, or with
broken pumice stone or other incombustible granular or fibrous material which
serves to intimately mix the gas and air on their passage to the body of the
cylinder and this material is held in place by a perforated disc.
The gas supply port communicates with a gas check valve which is connected
with a regulating valve which in turn is connected with a gas bag by means of a
soft rubber tube.
The gas check valve, is of the ordinary description and the regulating valve is
an ordinary globe valve having a more conical valve and valve seat than usual.
The rubber tube which connects the regulating valve and the gas bag passes
between a plate carried by an adjusting screw and a plate carried by a sliding rod
attached to a flexible diaphragm forming the bottom of the air reservoir of an air
pump so that by the action of the latter the flexible tube can be compressed
between the plates to check the gas supply. The air pump piston is connected
with a short arm of the weigh lever and has a flexible valve opening inwards and
covering a series of air holes through the piston. The cylinder of the air pump is
divided by a perforated partition, into a working barrel, and an air reservoir for
receiving the air forced by the piston through the holes in the partition, which is
provided with a valve, covering these holes to prevent the return of the air to the
pump barrel.
The bottom of the air reservoir consists of a flexible diaphragm to the centre of
which is attached the rod above mentioned. In the side of the air reservoir there
is an air outlet tube furnished with a screw valve by which the outlet may be
closed more or less. A tube communicating with this outlet tube at a point
between the valve and the air reservoir leads to a compound blow pipe placed
axially in line with the centre of the igniter on the side of the main cylinder and
supplied with gas through a tube.
The igniter consists of a plate of platinum having its edges turned outward and
clamped between a conical ring and a conical seat in a plate bolted adjustably over
à slot in the side of the main cylinder in which the conical support of the platinum
plate is received. A heat insulating medium such as asbestos is interposed between
the platinum and its support to prevent the heat from boing conducted away by
the metal parts of the support. The igniter can be adjusted within, prescribed

page_text: limits so as to vary the time of the ignition of the gas relative to the stroke of
the main piston.
Gas is supplied to the gas bag through a flexible tube which is embraced by a
fork on the end of a sliding rod actuated by the rise and fall of the weighted arms
of a centrifugal ball governor, so that whenever the engine stops from any cause
the balls drop and cause the fork to compress and choke the flexible tube thereby
shutting off the gas.
·
The operation of the improved gas engine is as follows:-On turning the fly
wheel the governor balls rise and allow gas to enter the gas bag. The gas at the
blow pipe having been previously lighted, the air blast from the air pump forces a
strong flame against the platinum plate, rendering it incandescent. The slide-valve
being in position to close the exhaust port and to uncover the gas and air ports,
gas and air are drawn in by the motion of the piston through their respective check
valves in the proper proportions and are thoroughly mixed in passing through the
contents of the concave cylinder bottom. When the piston passes the incandescent
platinum plate, the mixture of gas and air becomes ignited and explodes, driving
the piston to the other end of the cylinder. The movements of the slide valve
and the piston are so timed relatively to each other that as the piston passes the
igniter, the gas port of the slide valve will be closed. The air port is allowed to
remain open until after the explosion to admit air in case of the formation of a
vacuum after the explosion and before the exhaust port is opened. The air port
closes before the piston reaches the limit of its stroke, and the exhaust port is
opened at beginning of the return stroke, and remains open until the end of the
stroke, when it closes. After the engine is started by a few turns of the flywheel,
the gas and air is drawn in, the explosion takes place, and the products of combus-
tion are expelled at every revolution of the engine, the operation of the engine
being entirely automatic. Should an increase in speed occur, the extra amount of
pressure of air upon the diaphragm of the air reservoir of the air pump will shut
off more or less of the supply of gas and thus regulate the speed of the engine.
In gas engines of small size, the gas and air check valves are connected directly
with the cylinder bottom by a tube having on its inner end a flap valve, and the
exhaust valve is connected with the concave cylinder bottom by means of a tubular
connection. The ignition valve in this case consists of a conical mouth fixed in the
side of the cylinder and terminating in an opening over which hangs a flap valve
opening inwards. The valve seat is bevelled so that the normal position of the
valve is open. Outside the ignition valve and parallel with its face is supported a
flame protector formed of several thicknesses of wire cloth or perforated sheet
metal, and between the protector and the ignition valve is placed the end of a
Bunsen gas burner having at its upper end a deflector which spreads the flame and
prevents any blast from the ignition valve from blowing it out. By this arrange-
ment of valve protector and burner, a very hot atmosphere is maintained around
the ignition valve. In this case the gas and air enter through their respective
valves and the explosive mixture passes through the internal check valve to the
body of the cylinder, and when the piston rises above the ignition valve the flame
of the igniting burner is drawn into the cylinder, the explosive charge is ignited
and forces the piston the remainder of its stroke while at the same time the
ignition valve and the internal check valve are both closed during the continuance
of pressure resulting from the explosion and also while the piston makes its return
stroke expelling the products of combustion through the exhaust valve which is
then open.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Patent Office on the 4th March
1884.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53. Chancery
Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents
"IMPROVEMENTS IN GAS ENGINES' A communication to me from abroad by
the Economic Motor Company, of the City County and State of New York,
United States of America
This Invention relates to the class of gas engines in which an explosive mixture
of. combustible gas and common air is drawn into the cylinder during the early
part of the stroke of the piston and subsequently exploded, the expansion of the
gases propelling the piston through the remainder of the stroke. And the invention
consists in an igniter formed of a disc of platinum supported at its edges by a non-
conductor of heat and maintained in a state of incandescence by a blow pipe flame;
in an air pump driven by the engine and serving the double purpose of a governor
to the gas supply of the engine and of supplying the ignited blow pipe with air
in a slide valve formed of two independently adjustable pistons admitting of
regulating the admission of gas and the exhaust of the products of combustion
independently of each other; in a valve motion which insures a quick opening and
closing of the gas and air supply valves while allowing them to remain wide open
during the period of supply and the period of exhaust; in a regulator for the air
check valve by means of which the lift of the valve may be regulated from the
outside of the valve without the necessity of opening it for the purpose; in the
.combination of a check valve with the gas and air supply for preventing the heat
resulting from the explosion in the cylinder from reaching the gas and air chock
valves, and in an automatic cut off which shuts off the gas supply as soon as the
engine stops.
In the accompanying drawings Figure 1 is a side elevation of the improved gas
engine. Figure 2, is a plan view of the same. Figure 3 is a vertical section of
the cylinder and piston taken through the centre of the igniter. Figure 4 is a
vertical section of the slide valve and air check valve. Figure 5 is a vertical
longitudinal section of the gas regulating valve and gas check valve. Figure 6 is
au enlarged vertical section of the igniter. Figure 7 is a vertical section of the
air pump and governor. Figure 8 is an enlarged vertical section and Figure 9 an
enlarged horizontal section of the arrangement of valves and igniting burner
employed in engines of the smaller sizes.
Referring to the drawings the frame A is cast integral with the base plate B
and cylinder C, and has an arm D in which is journalled the bearing E of the
lever F the latter extending from its bearing to a point over the centre of the
cylinder where it is jointed to a connecting rod a the lower end of which is
attached by a pivotal joint b to the piston G, in the cylinder C.
At a point about one third of the length of the lever F from the free end of the
same a connecting rod c is jointed to the said lever, and extends downward
receiving in its lower end the pin h of the crank H on the main shaft I of the
engine. The shaft I is journalled in a boss d cast with the frame. A and carries
the fly wheel J. In front of the path of the crank H, there is an arm c-secured to
the frame A, and having in its upper end the bearing of a short shaft whose
axis is eccentric to that of the main shaft I being below and at one side thereof.
To the inner end of the shaft f is secured an arm g which is shorter than the
crank H and is connected with the outer end of the più of the said crank by
means of a link i.
The outer end of the shaft carries a crank; which is connected by a rod k
with the valve rod l. The two parts m n of the valve K are threaded internally and
the valve rod is threaded externally so that the position of the parts m n of the
valve may be changed on the valve rod by turning them in one direction or the

page_text: other, so as to vary their adjustment in relation to the gas supply port o air supply
port p and exhaust port q in the valve cylinder L. The valve cylinder L
communicates by a tubular connection with the concave bottom M of the
cylinder A and attached to one side of the valve cylinder and communicating
therewith through the air port p there is an air check valve N having a casing 8
to which is secured a plate t provided with a circular row of holes u covered by
a flexible valve v, held in its place on the inner surface of the plate t by a
tubular internally threaded screw w which passes centrally through the valve and
the plate. A screw a passing through the tubular screw w carries on its inner end
a concave metallic disc whose periphery is about opposite the row of holes u. The
said concave disc can be moved by means of the screw toward or away from
the valve vso as to limit the lift of the valve and in this way regulate the air
supply.
The concave bottom M of the cylinder C is filled with snarls of wire or with
broken pumice stone or other incombustible granular or fibrous material which
serves to intimately mix the gas and air on their passage to the body of the
cylinder C and this material is held in place by a perforated disc Z secured to the
upper surface of the concave bottom.
The gas supply port o communicates with the gas check valve O through the
pipe a and the check valve O is connected with a regulating valve P which in
turn is connected with the gas bag Q by means of the soft rubber tube R.
The gas check valve O is of the ordinary well known description and the
regulating valve P differs from the ordinary well known globe valve only in having
a more conical valve and valve seat.
The rubber tube R which connects the valve P and the gas bag Q passes through
a rectangular frame b' secure to the base of the engine and having in the lower
side an adjusting screw c² carrying on its inner end a plate dupon which the
rubber tube R rests. Directly above the frame b¹ there is
an air pump
T attached
to the frame A and provided with a piston e¹ connected with the short arm f¹ of
the lever F, by means of the rod g². The piston e¹ has a valve h¹ opening downward
and covering a series of air holes passing vertically through the piston. The
cylinder of the air pump is divided by a horizontal partition into the compart-
ment containing the piston e¹ and the compartment forming an air reservoir
for receiving the air forced by the downward stroke of the piston through holes
in the horizontal partition.. A valve covering these holes prevents the air
from returning to the pump barrel. The piston e' is reciprocated by the lever F
and each time the piston rises the air passing through its valve enters the
compartment whence it is forced by the downward stroke of the piston into the air
reservoir ¹. The bottom of the air reservoir ¹ consists of a flexible diaphragm m¹
clamped by its edges between collars n¹ secured to the lower end of the pump
barrel. A rod o¹ secured to the centre of the diaphragm m¹ extends downward
through the top of the frame b' and is provided with a plate p' touching the top of
the rubber tube R.
In the side of the reservoir k¹ there is an air outlet tube q' having in its outer
end a screw valve ¹ by which it may be closed more or less. In the side of the
air outlet tube q' outside of the seat of this valve there is an opening 8¹
communicating directly with the external air, and a tube t¹ communicating with
the air tube q' between the seat of the valve r¹ and the air reservoir k¹ leads to a
compound blow pipe U placed axially in line with the centre of the igniter V.
The blow pipe is of the ordinary well known form and receives its gas through
the tube u¹.
The igniter V consists of a plate v₁ of platinum having its edges turned outward
and clamped between the conical ring w¹ and the conical seat in the plate x¹ a leat
insulating medium y¹ such as abestos being interposed between the platinum and
its support to prevent the heat from being conducted away by the metal parts of
the support.
•
The plate al is slotted to receive two screws which clamp it to the side of the

page_text: "
cylinder and the conical support of the platinum plate v¹ projects into an oblong
slot in the side of the cylinder. The igniter can be adjusted vertically within
prescribed limits so as to vary the time of the ignition of the gas relative to the
stroke of the piston G.
Gas is supplied to the gas bag Q through the flexible tube a' extending along
the upper side of the bracket W attached to the edge of the frame A and supporting
the upper end of the gas bag. Upon the bracket. W is mounted a small centrifugal
ball governor A consisting of a sleeve be enclosing the rod e² and journalled in
the arm d of the bracket W the weighted arms of jointed to the top of the sleeve ba
and the sleeve f* connected with the weighted arms e by links g and with the
rod of by a transverse pin passing through a slot in the sleeve o into the said
rod of..
The lower end of the rod c² carries a fork which embraces the tube a² and the
bracket W loosely and is capable of being moved up and down by the governor.
The governor A is driven by a belt from a small pulley on the main shaft of
the engine and when in notion it supports the fork out of contact with the
flexible tube a but whenever the engine stops from any cause the balls drop
forcing downward the parts connected therewith including the fork and the
latter compresses the flexible tube a shutting off the gas.
In gas engines of small size the gas valve O and air valve. N aro connected
directly with the cylinder bottom M by means of the tube having on its inner
end a flap valve and the exhaust valve L is connected with the concave cylinder
bottom M by means of the tubular connection as shown in figures 8 and 9.
The ignition valve V³ in this case consists of a conical mouth a terminating in
an opening be over which hangs a flap valve c³. The valve sent is bevelled so that
the normal position of the valve is open. Over the ignition valve and parallel with
its face is supported a flame protector d formed of several thicknesses of wire
cloth or perforated sheet metal. Between the protector d³ and the ignition valve is
placed the end of a Bunsen gas burner having at its upper and a deflector f
which spreads the flame and prevents any blast from the ignition valve from
blowing out the flame. By this arrangement of valve protector and burner a very
hot atmosphere is maintained around the ignition valve.
The operation of the improved gas engine is as follows: On turning the wheel J
the balls of the governor A' are raised by centrifugal force carrying with them the
fork. permitting the flexible tube a³ to open and allowing gas to enter the bag Q.
The gas at the blow pipo U having been previously lighted the air blast. caused by
the operation of the air pump I forces a strong flame against the platinum plate v¹
rendering it incandescent. The slide valve K being in position to close the exhaust
port g and to uncover the ports o and p gas and air are drawn in through their
respective valves O and N in the proper proportions and follow the piston G, in
its upward movement having been thoroughly mixed in passing through the
contents of the concave cylinder bottom M. When the piston passes above the
incandescent platinum plate v the mixture of gas and air coming into contact with
the platinum becomes ignited and explodes driving the piston G to the upper end
of the cylinder. The movements of the valve K and the piston G are so timed
relative to each other that as the piston passes the igniter V tho gas port o will be
closed. The air port is allowed to remain open until after the explosion to admit
air in case of the formation of a vacuum after the explosion and before the exhaust
port g is opened. The air port p closes before the piston G reaches the limit of the
upward stroke and the exhaust port q is opened at the beginning of the downward
stroke of the piston and remains open until the end of the stroke, when it closos.
After the engine is started by a few turns of the fly wheel the gas and air is
drawn in the explosion takes place and the products of combustion are expelled at
every revolution of the engine the operation of the engine being entirely
automatic. Should an increase in speed occur the extra amount of pressure of air
upon the diaphragm m³ will force the plate p downward and shut off more or less
of the supply of gas and thus regulate the speed of the engine..

page_text: Should the engine stop from any cause the gas will be shut off by the governor.
A¹ preventing any escape of gas from the engine or its connections. In the
smaller sizes of this engine the gas and air enter through their respective valves
(as shown in Figures 8 and 9) and the explosive mixture passes through the
internal check valve to the body of the cylinder and when the piston rises above
the ignition valve V³ the flame of the igniting burner is drawn into the cylinder
the explosive charge is ignited and the piston is forced upwards while at the same
time the ignition valve and the internal check valve are both closed during the
continuance of pressure resulting from the explosion and also while the piston
makes its down stroke expelling the products of combustion through the exhaust
valve which is then open.
Having described the nature of the said Invention and the manner of performing
the same I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is:
1st In a gas engine, an igniter formed of a disc of platinum supported at its
edges by a non-conductor of heat, in combination with a blow pipe, capable of
maintaining the platinum in a state of incandescence as specified.
2nd In a gas engine made as herein specified the combination of the air pump T,
blow pipe U and igniter V as shown and described.
3rd In a gas engine, the air pump T having the reservoir and flexible
diaphragm m in combination with the flexible gas supply tube R as herein shown
and described.
4th In a gas engine, the combination of the flexible air pressed diaphragm m¹
flexible gas supply tube R and adjusting screw c¹ as specified.
5th In a gas engine, constructed as herein described the air pump T, having the
diaphragm m and regulating valve 1, the gas supply pipe R and blow pipe U in
couibination as and for the purposes specified.
6th In a gas engine, the piston slide valve K made in two parts m, n, mounted
adjustably on the valve rod as herein specified.
7th In a gas engine the shaft f carrying the crank arms j, g, and journalled
eccentrically in relation to the main shaft I, the link i and crank H in combination
for operating the valve K as herein specified.
8th The combination of the discy and adjusting screw a with the air check
valve vas herein specified..
9th In a gas engine, the combination of the gas valve O, air valve N disconnected
and acting independently and the normally open valve 2 as herein specified.
10th The combination in a gas engine of the valves N O, 7, L, and cylinder C
substantially as specified.
11th In a gas engine, the concave cylinder bottom M filled with granular or
fibrous noncombustible material and provided with the perforated plate as shown
and described.
12th In a gas engine, the combination of the centrifugal governor A' and
fork with the flexible gas supply pipe a² as herein specified.
13th In a gas engine, the combination of the ignition valve V³ and the Bunsen
burner es provided with the deflector f³ as specified.
14th In a gas engine, the combination of the protector d³ the valve V³ and
burner e as specified.
In witness whereof, I the said Alexander Melville Clark, have hereunto set my
hand and seal this Fourth day of March A.D. 1884.
A. M. CLARK (LS)