IMPROVEMENTS IN MOTIVE-POWER ENGINES WORKING WITH HYDROCARBON GAS OR VAPOR
Year: 1877

page_text: LETTERS PATENT to Dugald Clerk, of Glasgow, in the County of Lanark,
North Britain, Analytical Chemist, for the Invention of "IMPROVEMENTS IN
MOTIVE-POWER ENGINES WORKING WITH HYDROCARBON GAS OR VAPOR."
ealed the 13th July 1877, and dated the 19th January 1877,
PROVISIONAL SPECIFICATION left by the said Dugald Clerk at the Office
of the Commissioners of Patents on the 19th January 1877.
"
DUGALD CLERK, of Glasgow, in the County of Lanark, North Britain,
Analytical Chemist. IMPROVEMENTS IN MOTIVE-POWER ENGINES WORKING
WITH HYDROCARBON GAS OR VAPOR."
This Invention relates to motive-power engines in which the power is obtained
by igniting hydrocarbon gas or vapor mixed with a suitable proportion of air, and
the object of the improvements is to render such engines more economical and other-
wise better than existing gas motor engines.
In carrying out the Invention any convenient kind of motive-power engine such
as is commonly worked by steam is worked by a gaseous mixture which is under
pressure and is supplied from a reservoir, whilst the exhaust passage communicates
with an intermediate vessel placed between the reservoir and an explosion or com-
bustion chamber. The explosion chamber is fitted with one or more lift valves
opening into the intermediate chamber, and this intermediate chamber is similarly
fitted with one or more lift valves opening into the reservoir. The explosion
chamber is fitted with suitable valve details, and by preference of the kind herein-
after described for admitting the necessary quantities of combustible gas or vapor
and air, and for igniting or exploding the mixtures at suitable intervals.
an explosion takes place the expanded gases open the valves into the intermediate
chamber and into the reservoir. An increase of pressure is thus produced in the
reservoir and is retained by the immediate closing of the valve or valves between
the reservoir and the intermediate chamber.
When

page_text: The valve or valves between the intermediate chamber and the explosion chamber
also close immediately after the explosion, and then those chambers become in a
more or less vacuous condition, and in consequence a check valve in the exhaust
passage from the engine to the intermediate chamber opens and allows the exhaust
gas from the engine to pass into the intermediate chamber. The pressure in the
engine thus works against a pressure which is at intervals below that of the
atmosphere. The partial vacuum in the explosion chamber causes atmospheric air
and gas, or vapor, to enter for the next explosion on simply opening the inlet valve,
or the supply of air and gas or vapor may be obtained otherwise, as herein-after
explained.
The admission of air and combustible gas or vapor is controlled by one sliding
valve plate worked from the engine, and there are by preference two air inlet ports
with a single gas inlet port between them.
The ignition is effected by means of two gas jets, one of which turns continually
at a little distance in front of the air ports, whilst the other is placed so as to direct
a rat tail or other suitable jet of gas across the continually burning jet into the air
port. The tap of the rat-tail jet is opened by the valve slide just as the air ports
are being closed, and the jet getting ignited by the permanent jet carries the flame
sufficiently inwards to ignite the mixture in the explosion chamber. The gearing
for working the admission slide of the explosion chamber is arranged so as on the
pressure in the reservoir exceeding a certain amount to become disengaged, and so
that the explosions are interrupted until from the working of the engine the
pressure becomes lower again.
Instead of the supplies of air and gas, or vapor, entering the explosion chamber
in consequence of a partial vacuum in that chamber, they may be made to enter by
moving a piston or diaphragm therein towards the intermediate chamber. This
piston or diaphragm, which need not fit very tightly, is in place of the fixed
partition between the explosion chamber and the intermediate chamber, and it is
fitted with the lift valve or valves herein-before referred to as between those
chambers.
The piston or diaphragm is moved slowly by the engine, and after an explosion
it is moved back to the bottom or end of the explosion chamber.
By this arrange-
ment the force due to the vacuum, and which is more than is necessary for taking
in the supplies of air and gas, or vapor, is rendered to a greater extent available in
the intermediate chamber and in connection with the exhaust of the engine.
It is a special feature of this Invention that the expanded gases due to the ex-
plosion act directly through the lift valves on air or gases, a portion of which they
force into the reservoir instead of acting on a piston as in other explosion motor
engines.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Dugald Clerk in the Great Seal Patent Office on the 18th July
1877.
DUGALD CLERK, of Glasgow, in the County of Lanark, North Britain,
Analytical Chemist. "IMPROVEMENTS IN MOTIVE-POWER ENGINES WORKING WITH
DYDROCARBON GAS OR VAPOR."
My said Invention relates to motive-power engines in which the power is obtained
by igniting hydrocarbon gas or vapor mixed with a suitable proportion of air, and
the object of my improvements is to render such engines more economical and other-
wise better than existing gas motor engines.
It is a special feature of my Invention that the expanded gases due to the ex-

page_text: plosion act directly through valves on air or gases, a portion of which they force
into a reservoir instead of acting on a piston, as in other explosion motor engines.
The explosion takes place in a chamber between which and the reservoir there is
an intermediate chamber, and any convenient kind of motive-power engine such as
is commonly worked by steam is worked by the gaseous mixture under pressure
which is in the reservoir. The valves between the explosion chamber and the in-
termediate chamber, and between the intermediate chamber and the reservoir, may
be moved by the gases or by mechanism from the engine. A piston is by preference
worked in the explosion chamber for drawing in the supplies of gas, or vapor and
air, for each explosion. The exhaust passage of the engine is in some modifications
arranged to communicate through an automatic lift valve with the intermediate
chamber, so that on the pressure in that chamber becoming lower than that of
the atmosphere the partial vacuum may be taken advantage of in working the
engine.
And in order that my said Invention and the manner of performing the same may
be properly understood, I hereunto append two Sheets of explanatory Drawings to
be herein-after referred to, and representing one modification of apparatus for
storing or accumulating pressure due to the explosion of hydrocarbon gas, or vapor
and air, for the purpose of obtaining motive power according to my Invention. In
these Drawings the same reference numerals are used to mark the same or like parts
wherever they are repeated.
Figure 1, on Sheet 1 of the accompanying Drawings, is an elevation of the
apparatus; and Figure 2, on Sheet 2, is a vertical section as at right angles to
Figure 1.
Figure 3 is an enlarged view of the valve by which the admission of gas or vapor
and air is controlled, Figure 4 being a corresponding view of the port face on which
the valve works, whilst Figure 5 is a horizontal section of the valve and port face
together.
The principal parts of the apparatus are an explosion chamber 1, an intermediate
chamber 2, and a reservoir 3, all three being by preference cylindrical, whilst the
reservoir 3 is shown as made of boiler plate, the intermediate chamber 2 and explo-
sion chamber 1 being of cast iron, and the last being made with a jacket space 4
for a current of water to be passed through to prevent it from becoming overheated.
In the explosion chamber 1 there is a piston 5 made an accurate but easy fit to the
chamber, and formed with small grooves round it. The piston 5 is attached to a
rod 6, which passing out through a stuffing box in the bottom of the chamber has
attached to it a cross head 7 fitted to slide in guides on the inner sides of castings 8,
which support the apparatus, and this cross head is made with a horizontal slot in
which there works a crank pin 9 fixed in a disc 10 upon a horizontal shaft 11,
which has a fly wheel 12 on it, and is to be driven by the engine. The piston 5
when ascending expels any non-combustible gases from the chamber 1, and when
descending draws in a supply of gas or vapor and air by an inlet passage 13 near
the top of the chamber, that is, when the action of the valve 14, herein-after
explained, allows fresh gas or vapor to enter. Between the explosion chamber 1
and the intermediate chamber 2 there is a valve 15, which is in the form of a light
disc, the outer part of which, when the valve is closed, rests on a ring of asbestos
packed into a groove formed for it in the metal seat. This valve 15, which is nearly
as large as the intermediate chamber 2, moves freely on a central guide rod 16,
which is attached to an upper disc-shaped valve 17, and has its lower end guided
by entering down into the rod 6 of the piston 5 made tubular for the purpose.
The upper
valve 17 is between the intermediate chamber 2 and the reservoir 3, and,
like the lower valve 15, it rests when closed on asbestos packed into a groove in
the seat. It is important to have the valves 15 and 17 as large as possible, and
arranged so as not to check the expansive action due to the explosion more than
what cannot be avoided, the object being to get the expansive action to take effect
as directly as possible on the gaseous contents of the intermediate chamber 2 and

page_text: reservoir 3, and with the least possible hindrance from friction either of the
mechanism or of the gases themselves. When an explosion takes place in the
chamber the expanding gases carry up the valve 15 and the gases in the interme-
diate chamber 2, and opening the upper valve 17 force a portion of the gases into the
reservoir 3. The expanding condition due to the explosion is of short duration,
and is succeeded by a collapse and partial vacuum. The upper valve 17 closes
immediately on the presure diminishing, being assisted by the action of a spring 18,
which however it does not begin to compress until after being opened a certain
extent. This spring 18 acts principally as an elastic stop to the rising motion of
the valve, and is placed on the rod 16, which is extended above the valve 17, and
has its upper end entered into a guide formed in a box 19 fitted with an oil cup 20
for admitting a little lubricant, which is found desirable. A pipe 21 leads the gas
or gaseous mixture from the reservoir 3 to the motive-power engine, which is not
shown in the Drawings, but which may be of any suitable known kind, such as is at
present worked by steam. The exhaust pipe of the engine is to be connected to a
casting formed with a passage 22 leading through a clack valve 23 into the inter-
mediate chamber 2, so that whenever the pressure in the intermediate chamber is
below that of the atmosphere the exhaust from the engine takes place into it through
the valve 23. Whenever the pressure in the passage 22 is above that of the atmo-
sphere an escape valve 24 opens, and prevents the exhaust pressure from becoming
greater. The passage 22 also communicates by a pipe 25 with the bottom of the
explosion chamber 1, so that if when the piston 5 rises the pressure beneath it should
be less than in the passage 22 some of the gas in that passage may be drawn from
it by the action of the piston, and so assist the engine.
An arrangement of valve for controlling the admission of the explosive mixture,
and which is described in my Provisional Specification relative hereto, having been
found objectionable in practice, I have substituted the modification shown in the
Drawings; but I make no claim respecting it, merely remarking that I at present
believe it to be the most suitable for my purpose.
The valve 14 for controlling the admission of the explosive mixture is of a
circular form, and has a reciprocating angular motion on a stud 26 fixed in a piece
27 formed with a port face and passages, and fixed on the admission pipe 13, a
spring on the stud 26 keeping the valve against the port face. The valve 14 is
made with cavities, which are indicated in dotted lines in Figure 3, so that their
relation to the port face may be more easily understood than from an inverted face
view of the valve. The hydrocarbon gas or vapor proceeds from a holder 28 by a
pipe 29 fitted with a regulating valve 30 to a port 31, and air has access from two
external orifices to a port 32 between the gas port 31 and a port 33 communi-
cating with the admission passage 13. A cavity 34 in the valve 14 covers these
ports 31, 32, 33 when the explosive mixture is to be admitted to the chamber 1,
the valve being then turned from the position in which it is shown in Figure 3, so
as to raise the cavity 34. As the valve 14 moves it puts two cavities 35 over air
inlets 36, and a port 37 leading by a pipe 38 into the intermediate chamber 2, and
insures that the pressure in that chamber shall be up to atmospheric pressure when
the explosion is about to take place.
Another cavity 39 in the valve 14 is for putting a port 40 connected with the
admission passage 13 in communication with a port 41 connected by a pipe 42 with
the bottom of the explosion chamber for a purpose herein-after explained. The
valve 14 is worked by a lever 43 to which there is jointed a rod 44 guided in a
swivelling bush and fitted with an antifriction roller at its lower end which rests on
a cam 45 on the continuously revolving shaft 11. The valve lever 43 is also con-
nected by a link 46 to a lever 47 on a spindle, having on it a short lever 48 con-
nected to a rod 49 which is acted on by a spring 50, and is also connected to a
flexible diaphragm 51 covering an opening into the reservoir 3. When the pressure
in the reservoir 3 exceeds that for which the parts are adjusted, its action on the
diaphragm 51 prevents the valve 14 from acting by keeping the bottom end of the

page_text: •
rod 44 raised clear of the cam 45; but at other times the spring 50 and the weight
of the parts cause the rod 44 to descend on the lower part of the cam 45 coming
round under it, the continued motion of the cam subsequently raising it up again.
This causes the valve 14 to make one double reciprocation which has the effect of
admitting to the chamber 1 the supply of gas or vapor and air necessary for an
explosion. The valve lever 43 also causes the ignition of the explosive mixture,
being arranged to act by a lever 52 on a hollow valve plug 53, shown in section in
Figure 5, and which has an opening 54 in its side. In one position of the valve
plug 53 its opening 54 coincides with an opening in the under side of the valve
shell and then an external continuously burning gas jet 55 ignites an internal gas
jet 56 from a burner inside the valve shell. The valve plug 53 is moved suddenly
into its other position, in which, whilst it closes the external orifice in the shell, it
puts its port 54 in communication with a passage 57 leading by the admission
passage 13 to the explosion chamber 1. In this way the ignition of the explosive
mixture is effected by a flame which is at the moment of that ignition quite shut off
from the exterior.
I prefer to keep the shaft 11 revolving continuously, so that the piston 5 recipro-
cates even when explosions are not taking place, and at such times the valve 14 is
in such a position that air or gas can pass freely from one side of the piston 5 to the
other by the pipe 42. As it is not desirable that the valve 14 should be in the
position with the rod +4 down for less than the period provided for in the form of
the cam 45, a lever 58 is provided to keep up the rod 44, excepting when a par-
ticular part of the cam comes under it. This lever 58 is acted on by a spring 59
which tends to move its upper end under the rod 44 whenever that rod is raised,
whilst a projection 60 on the face of the cam 45 moves the lever 58 from under 'the
rod 44 at the periods when it may drop.
Instead of arranging the valve 15 between the explosion chamber 1 and the
intermediate chamber 2 to be lifted by the gases, and in order to allow of a freer
expansive action of the explosive mixture, there may be substituted a pair of slides
arranged to move across the top of the explosion chamber 1 so as to meet each other
at a diametrical line, such slides being withdrawn in opposite directions, just before
the explosive mixture is ignited by rods worked by levers from a cam on the con-
tinuously revolving shaft 11, or by other suitable mechanism. Or the explosive
mixture may be drawn into the explosion chamber 1 below the piston 5 by the
upward movement of that piston, and be transferred through light valves in the
piston to its upper side by the next descent of the piston, and prior to being ignited,
in which case a valve will not be required between the explosion chamber 1 and the
intermediate chamber 2, whilst the admission passage 13 must communicate with
the lower part of the explosion chamber 1 and be fitted with a check valve pre-
venting a return of the gases outwards through it, and the ignition passage 57 must
communicate directly with a suitable part of the explosion chamber instead of with
the passage 13.
Having thus particularly described my said Invention and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
1. The system or mode of working motive-power engines with hydrocarbon gas
or vapor wherein there operates a gaseous mixture stored or accumulated under
pressure through the action of exploded mixtures of the gas or vapor and air with-
out the intervention of an air-tight piston in improved apparatus, substantially such
as herein described and delineated.
2. The system or mode of working motive-power engines with hydrocarbon gas
or vapor, wherein the partial vacuum succeeding each explosion is made to directly
assist the exhaust of engines driven by stored pressure caused by successive
explosions in improved apparatus, substantially such as herein-before described,

page_text: 3. The combination of the explosion chamber (1), intermediate chamber (2), and
pressure reservoir (3), substantially as and for the purpose herein-before described.
In witness whereof, I, the said Dugald Clerk, have hereunto set my hand
and seal, this Sixteenth day of July, in the year of our Lord One thousand
eight hundred and seventy-seven.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
DUGALD CLERK. (L.S.)