IMPROVEMENTS IN GAS ENGINES
Year: 1884

page_text: .
I, JAMES ATKINSON, Engineer, 3 Nassington Road, Hampstead, London, N.W.
do hereby declare the nature of my invention for IMPROVEMENTS IN GAS ENGINES
to be as follows:--
These engines are constructed with a single acting working cylinder, and a
single acting compression pump for compressing a uniform combustible mixture
into the working cylinder, wherein it is ignited and performs work. There is
nothing novel in using a working cylinder and pump, but I connect them and the
necessary valves so that they operate in a special manner.
The working cylinder is fitted with a piston, connected to a connecting rod and
crank pin, fixed between two equal fly-wheels, having the main bearings outside
the fly wheels, as claimed by me in Letters Patent 40861; the piston has only
sufficient clearance when at the completion of its inner stroke, to allow for the
unavoidable deposit of burnt oil, carbon, &c. that takes place, and there, is no large
cavity or chamber here; the piston of the pump, (which has about the same capacity
as the working cylinder), is also connected to a connecting rod and crank pin,
(which may be outside one of the main bearings), this crank pin is fixed at a swall
angle following the main crank; the clearance space in the pump and passages
when the piston is at the completion of its inner stroke, is as small as possible
consistant with safety.
The pump is fitted with a special suction valve which, also operates as a governor
to the engine. The gas. is drawn through a number of small holes froin a chamber
to which the gas supply is attached; the air, also is drawn through a greater
number of holes from another chamber; these holes are covered with a self-acting
flap of indiarubber or other suitable material, which may have a metalic plate
lightly pressing the indiarubber against the holes, either by its own weight, or by a
spring, the suction of the pump is thus made uniform on the gas and air; also
when the engine is standing with the gas supply open, no gas can escape into the
engine, or the place in which the engine stands. The combined gas and air are then
drawn through the suction valve proper, which is a self-acting valve lightly held
against its seat by a suitable spring, or by its own weight. Its provision for,
working as a governor is as follows:-the valve is allowed to lift a suitable
distauce against the light spring, to work as an ordinary suction valve, when it
[Price 6d1

page_text: is stopped by coming in contact with a stronger spring, already under adjustable
compression or tension; the rush of the gas and air past the suction valve
determines whether it will overcome the stronger spring or not; if it does not
the suction goes on to the end of the outward stroke of the pump, if it does the
suction valve opens further but closes onto a seating on its inward side preventing
the admission of any more gas and air to the pump, which can thus only deliver a
smaller amount of combustible mixture, and the engine will give a less powerful
stroke in consequence, thus controling the engine.
The delivery valve from the pump is held closed by a strong spring until allowed
to open by suitable gear operated by an excentric or other convenient method;
there is also another valve which works somewhat as a delivery valve but is of
novel description as will be hereinafter explained; the combustible mixture passes
through both of these valves on its way to the pump; (in some instances these two
valves may be combined in one); the object of the latter valve is to prevent any
flame passing back into the pump; it is a valve of large area and very restricted lift,
and it can only lift at all by compressing or expanding a spring; the seating also
is of novel form, it is made rather wide and instead of being flat or bevelled is
made curved in such a manner that the area for the passage of the gas and air
when the valve is open is uniform, so that they can pass through it at an uniform
speed, the object of this is to allow the valve to lift steadily against the spring,
and without any pulsations, as is usual with ordinary valves.
The igniting arrangement I prefer to use is the one described by me in Letters
Patent No 3213 79.
The exhaust valve is similar to that shown in Figs. 1. 2. 3. Sheet 1. of Letters
Patent N° 4086 81 granted to me; operated by an excentric or by any ordinary means.
The operation of the engine is as follows.-The working piston, on its return
inward stroke expels the contents of the working cylinder through the exhaust
valve which remains open till near the termination of its inward stroke, when it is
closed; at this time or shortly afterwards the pump piston having compressed a
pump full of gas and air to a high pressure (say about 60 or 75 lbs.) in the end of
the pump, the delivery valve is allowed to open, and the compressed charge passes
into the working cylinder, the igniting arrangement ignites it as it enters or shortly
afterwards; the working crank is now turning its dead centre, or it may be a little
past it, the pressure rapidly rises in both the cylinder and pump owing to the com-
bustion of part of the gas and air in the working cylinder, the pump crank passes
its dead centre shortly after the main crank, expelling the remainder of the gas
and air into the power cylinder, which continuing to burn, rapidly increases the
pressure therein; the pump on its outward stroke draws in a fresh charge ready
for the next working stroke.
It will be seen from this description that the engine is, more or less, what is
known as a 'continuous combustion engine; but, owing to the gas and air being
compressed to a high pressure previously to their admission into the working
cylinder, the time of this continuous combustion is exceedingly limited, the time
also which elapses before the igniter communicates flame to the entering charge,
and the effects of disociation due to high temperature, delay the maximum pressure
till the main crank is well on its working stroke, and the pump piston has almost
or quite completed its compressing stroke; thus all the benefits of an explosive
arrangement are attained with the increased advantages and simplicity of an engine
constructed on this method.
ip
It will be seen that no slide is required; that there are only two valves that
require controlling, viz: the delivery valve from the pump, and the exhaust valve;
these two valves are controled by excentrics or cams on the main shaft, which only
require a short stroke, also there is no gearing used, and consequently these engines
can be driven at a very high rate of speed, with great economy and durability.
These engines may be arranged to work horizontally or vertically, also the
working piston and pump piston may be connected to one crank pin, the cylinders
being inclined to each other so as to give the necessary lead to the working piston,
"

page_text: Engines may be compounded in exactly the same manner as described by me in
Letters Patent No 3039 84. When compounded, the capacity of the pump may be
increased with advantage.
The self-starting gear is arranged in the following novel manner.- -The starting
valve is similar to that described by me and illustrated in Figs. 8. & 9. Sheet 2. in
Letters Patent N° 4388 82; it forms a communication between a pressure reservoir
and the working cylinder. The valve is opened by hand only against a spring that
tends to close it, and it cannot be opened by any connection with the engine; there
is however a suitable connection with some moving part of the engine that prevents
its being opened excepting at a proper time; the exhaust excentric which is timed
suitably may be employed for this purpose. The pressure reservoir may be charged
through the same valve with consumed gasses by easing the valve up by hand so as
to pass some of the contents of the working cylinder into the pressure reservoir
when the maximum pressure is in the cylinder; the valve always having a
permissive action and not a positive one.
In larger engines the gas and air may be compressed in two stages, the last stage
being in the pump working the same as hereinbefore described, the first stage
may be in the inner end of the working cylinder provided with a cover for this
purpose.
+

page_text: I, JAMES ATKINSON of 3 Nassington Road, Hampstead, in the county of
Middlesex, Engineer do hereby declare the nature of my invention for IMPROVE-
MENTS IN GAS ENGINES and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
These engines are constructed with a single-acting working cylinder, and a
single-acting compression pump, for compressing an uniform combustible mixture
into the working cylinder wherein it is ignited and performs work. There is
nothing novel in using a working cylinder and separate pump, but I connect them
and the necessary valves so that they operate in a special manner as hereinafter
described and illustrated in the accompanying sheets of drawings; wherein Fig. 1,
Sheet I, is a plan of a complete engine; Fig. 2, Sheet I, an elevation; Fig. 3,
Sheet II, a section through the admission valves; and Fig. 4, Sheet II, a section
through the governor and suction valves, in which like figures refer to like parts.
The working cylinder 1. is fitted with a piston connected to a connecting rod
and crank-pin fixed between two equal fly-wheels, having the main bearings outside
the flywheels as claimed by me in Letters Patent 4086/81; this piston has only
sufficient clearance when at the completion of its inner stroke to allow for the
unavoidable deposit of burnt oil, carbon, &c. that takes place, and there is no large
cavity or chamber here. The piston of the pump 2 (which has about the same
capacity as the working cylinder 1.) is also connected to a connecting rod and crank
pin 3. (which may be outside one of the main bearings as shown). This crank
pin 3 is fixed at a small angle following the main crank; the clearance space in
the pump and passages when the piston is at the completion of its inner stroke is
as small as possible consistent with safety.
The pump 2 is fitted with a special suction valve 4, which is shown to a larger
- scale in section, Fig. 4; this valve also operates as a governor, and its action is as
follows: The gas is drawn through a number of small holes 4, from a chamber 5,
to which the gas supply is attached; the air also is drawn through a greater
number of holes 6, from another chamber 7%; these holes 4 and 6 are covered with
a self-acting flap of india-rubber or other suitable material 8, which may have a
metallic plate 9 lightly pressing the india-rubber 8 against the holes 4 and 6 either
by its own weight, or by means of a spring as shown; the suction of the pump 2
is thus made uniform on the gas and air, also when the engine is standing with the
gas supply open no gas can escape into the engine, or the place in which the engine
stands. The combined gas and air are then drawn through the suction valve
proper 29, which is a self-acting valve lightly held against its seat by a suitable
spring 10 as shown, or by its own weight. Its provision for working as a governor
is as follows:-The valve 29 is allowed to lift a suitable distance against the light
spring 10, to work as an ordinary suction valve, when it is stopped by coming in
contact with the ferrule 11, which transmits the pressure to a stronger spring 12,
already under adjustable compression (or tension), which spring 12 is adjusted to

page_text: suit the speed at which the engine is intended to run; the rush of the gas and air,
past the suction valve 29 determines whether it will overcome the resistance of the
governor spring 12 or not; if it does not, the suction goes on to the end of the
outward stroke of the pump 2; if it does, the suction valve 29.travels further and
closes on to a seating 13 on its inward side preventing the admission of anymore gas
and air to the pump 2, which can thus only deliver a smaller amount of combustible
mixture, and the engine will give a less poweful stroke in consequence, thus con-
trolling the engine. In the arrangement shown in Fig. 4 the compression of the
governor spring 12 is adjusted by means of the locknuts 14; this arrangement,
has worked well in practice, but it will be readily understood that it may be arranged
in other suitable forms, as for instance the suction valve 29 may be inverted so,
that when acting only as a suction valve its own weight will be sufficient to close
it, and also the spring. 12 might be substituted by a weight.
The delivery. valve 15, Fig. 3,.is held closed by a strong spring 16 (Figs. 1 and 2)*
until allowed to open by suitable gear, 17, operated by an eccentric 18, or other,
convenient method; there is also another valve 19 (Fig. 3) which also works some-
what as a delivery valve, but is of a novel description as will be hereinafter
explained; the combustible mixture passes through both of these valves 15 and 19,
on its way from the pump 2 (in some instances these two valves 15 and 19 may be
combined in one); the object of the latter valve, 19, is 'to prevent any flame passing
back into the pump 2; it is a valve of large area and very restricted lift, and it.
can only lift at all by compressing, or expanding, a spring 20; the seating 21 is,
also of novel form, it is made rather wide and instead of being flat or bevelled..
is made curved as shown, in such a manner that the area for the passage of the gas
and air, when the valve is open, is uniform, so. that they can pass through it at an.
uniform speed, that is to say, the width of opening due. to a suitable lift of the..
valve at the smaller diameter of the seating 21, is greater than the width of opening
due to the same lift at the greater diameter of the seating 21, in such a proportion
as the smaller circumferance multiplied by the greater lift gives an area equal to
the larger circumferance multiplied by the smaller lift, and similarly at any
intermediate part of the seating; the object of this is to allow the valve 19 to lift
steadily against the spring 20 and without any pulsations as is usual with ordinary
valves. It will be observed that the seating of the suction valve 29 is similarly.
formed for the same reason, and also to cause less resistance.
The exhaust valve 22, Fig. 2, is similar to that shown in Figs. 1, 2, and 3,
Sheet I, of Letters Patent 4086/81 granted to me, it is operated by an eccentric 23,
ór by any ordinary means.
The operation of the engine is as follows:-The working piston on its return
inward stroke expels the contents of the working cylinder 1 through the exhaust
valve 22 which remains open till near the termination of this inward stroke, when
it is closed; at this time, or shortly afterwards, the pump piston having compressed
a pump-full of gas and air to a high pressure (say about 60 lbs to 75 lbs) at the
end of the pump.2, the delivery valve 15, Fig. 3, is allowed to open, and the
compressed charge passes into the working cylinder, the igniting arrangement
ignites it as it enters, or shortly afterwards; the working crank is now turning its.
dead centre, or it may be a little past it, the pressure rapidly rises in both the
cylinder and pump owing to the combustion of part of the gas and air in the
working cylinder, the pump crank passes its dead centre shortly after the main
crank, expelling the remaining gas and air into the power cylinder, which gas and
air continuing to burn rapidly increases the pressure therein, the pump piston on
its outward stroke draws in a fresh charge ready for the next working stroke.
The igniting arrangement I prefer to use is the one described by me in Letters
Patent No 3213/79 consisting of a small tube of suitable material kept permanently
red hot by an external flame; it is always open to the end of the working
cylinder.
It will be seen from this description that the engine is more or less what is
known as a continuous combustion engine; but, owing to the gas and air being

page_text: 1*11
11. +
A
compressed to a high pressure previously to their admission into the, working
cylinder the time of this continuous combustion is exceedinly limited, the time also
which elapses, before the igniter communicates flame to the entering, charge,, and
the effects of dissociation due to the liigh temperature, delay the maximum pressure
till the main crank is well on its working stroke, and the pump piston has almost
or quite completed its compressing stroke; thus all the benefits of an explosive
arrangement are attained with the increased advantages and simplicity of, an
engine constructed on this method. It will be seen that no slide is required; that
there are only two valves that require controlling, viz: the delivery valve, 15,
Fig. 3, from the pump 2 and the exhaust valve 22, Fig. 2; these two valves are
controlled by eccentrics or cams on the main shaft, which only require a short
stroke; also there is no gearing used and consequently these engines can be driven
at a very high rate of speed with great economy and durability.
.
1
These engines may be arranged to work horizontally or vertically, also the
working piston and pump piston may be connected to one crank pin, the cylinders
being inclined to each other so as to give the necessary lead to the working piston.
These engines may be compounded in exactly the same manner as described by
me in Letters Patent 3039/84. When compounded the capacity of the pump may
be increased with advantage.
1!
1
The arrangement of governor as shown in Fig. 4, Sheet 2, may be used for other
types of gas engines, as for instance in engines working with what is known as the
"Otto" cycle; the suction valve closing on to the governor seat as decided by the
speed of the engine and the resistance of the valve to being thus closed; also a
separate valve may be used in the same manner, with or without another separate
valve of any description for the suction valve. It will be seen that in all instances
when the governor valve closes previously to the completion of the drawing in of
the combustible mixture, the pressure in the pump or cylinder will gradually fall
below that of the atmosphere; on the return compression stroke of the piston the
charge will be compressed until it recovers atmospheric pressure at about the same
point as that at which the governor valve closed during the drawing in stroke:
there is thus no loss of power in governing gas engines in this manner.
The self-starting gear is arranged in the following novel manner :-The starting
valve is similar to that described by me and illustrated in Figs. 8 and 9, Sheet 2,
of Letters Patent 4388/82; it forms a communication between a pressure reservoir
and the working cylinder. The valve is opened by hand only, against a spring
that tends to close it, and it cannot be opened by any connection with the engine;
there is however a suitable connection with some moving part of the engine that
prevents it from being opened excepting at a proper time. The exhaust eccentric,
which is turned suitably, may be employed for this purpose. The pressure reservoir
may be charged through the same valve with consumed gas, by easing the valve up
by hand, so as to pass some of the contents of the working cylinder into the
pressure reservoir, when the maximum pressure is in the cylinder; the valve
having a permissive action as regards its opening, and not a positive one.
In larger engines the gas and air may be compressed in two stages, the last stage
being in a pump working the same as herein, before described, and the first stage
may be in the inner end of the working cylinder provided with a cover and valves
for that purpose.
I wish it to be understood that I do not confine myself to the precise arrange-
ments of details as shown in the drawings, as they may be varied to suit special
circumstances, without departing from the peculiar character of the invention.
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
First. The general arrangement and construction of the improved gas engine
operating substantially as herein before described and represented in the accom-
Dánving drawings

page_text: Second. In gas engines the employment of delivery or suction valves having
curved seatings as and for the purposes herein described.
Third. Governing gas engines by means of a governor valve operated by the
suction of the working fluid, when being drawn in, in the manner described and
illustrated in Fig. 4, Sheet 2, or any modification thereof in which the drawing in
piston causes a partial vacuum after the closing of this valve.
Fourth. In self-starting gear for gas engines the employment of a starting valve
which must be opened by hand, but can only be open at the proper time, and which
is kept closed at any other time by means of a stop, or any other connection, with
the working gear of the engine.