Improvements in Gas Motor Engines.
Year: 1888

page_text: Date of Application, 2nd July, 1888
Complete Specification Left, 1st Apr., 1889-Accepted, 22nd June, 1889
PROVISIONAL SPECIFICATION.
Improvements in Gas Motor Engines.
JOHN DOUGILL 83 Choir Street Broughton Lane Manchester Gas Engineer do
hereby declare the nature of this invention to be as follows :-
This improvement belongs to that class of engines which are propelled by expansion
caused by the combustion of a mixture of gas and air. The engine is constructed so
that a mixture of gas and air is taken into the cylinder by the first ontstroke of the
piston, and compressed into a space at the end of the cylinder where the piston never
reaches. By the next instroke of the piston, the mixture is ignited as the piston
commences the second outstroke propelling it to the end of this stroke. The exhaust
valve is then opened and remains so untill the piston as completed the next instroke,
so that the cycle of the engine is performed in two revulutions of the crankshaft,
which is four successive movements of the piston namely. First the outstroke drawing
in the mixture. Second the instroke compressing the mixture. Third the next outstroke
expanding the ignited gases. Fourth the next introke expelling the burnt gases by
way of the exhaust valve which is moved by a lever the lever being operated by a
cam fixed upon the side shaft, which is driven at half speed of the crankshaft.
Similar cams and levers are used operated in the same manner for the movement of
the air and gas valves respectively, the valves being timed to admit to the cylinder
such proportions of gas and air that may be found advisable. For the ignition of the
mixture, I use a Tube which communicates with the inside of the cylinder. The
outer end of the tube being closed this tube is kept hot by an external gas flame.
Dated this 30th day of June 1888.
JOHN DOUGILL.
COMPLETE SPECIFICATION.
Improvements in Gas Motor Engines.
JOHN DOUGILL 83 Choir Street Broughton Lane Manchester, Gas engineer do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
This engine is constructed so that the gas and air are taken into the cylinder
during the first outward movement of the piston, and are compressed into the space
at the end of the cylinder (which is of greater length than the portion traversed by
the piston) during its first inward movement. The combustible mixture (gas and air)
is ignited at the commencment of the second outward movement of the piston, and
the expansion of the gases propel it to the end of this movement, and the momuntum
of the fly wheel enables the piston to perform the second inward movement.
The cycle of the engine is performed in two revolutions of the crankshaft, and four
successive movements of the piston. The valves may be of any known kind and
operated by any known means, but by preference I use mushroom valves operated by
cams and levers, the cams are so formed that they give movement to the valves
according to the following description. Assuming the piston to be commencing the
first outward movement the air valve is opened, admitting air into the cylinder
during the first portion of this movement, say, one fourth or thereabout much will
depend upon the quality of the gas used as to how much air is admitted before
and after the mixture within the cylinder, the gas valve is then opened and the
gas and air mix together and flow into the cylinder until the piston has performed
about three fourths of this movement, the gas valve is then closed and air alone
allowed to enter the cylinder until the first outward movement is completed, the air

page_text: valve is then closed, the piston now performs the first inward movement, compressing
the contents of the cylinder into the space provided for this purpose. The combustible
mixture is then ignited and the expansion of the gases prop the piston to the end of
the second outward movement, the exhan-t valve is oneil and romains so until the
piston performs the second inward movement, which expels from the cylinder the
largost portion of the burnt products atter combustion, a portion however remains in
the compression chamber which together with a portion of the air afterwards
admitted form an envelope, which surrounds the combustible mixture.
The object of the inventor is to locate the most combustible portion of the mixture
admitted to the cylinder, as near as possible in the middle of the cube contents
thereof, in such a manner that the combustible mixture will be enveloped by the air
and noncombustible gases within the cylinder. The utility of consuming the com-
bustible mixture within an envelope of air or air and noncombustible gases is to
prevent to a large extent the flame bring suddenly cooled by contret with the piston
and walls of the cylinder, the heat being absorbed from the flame by the non-
combustible gases which cause them to expand, and assist in propelling the piston,
the air valve is also kept cooler in consequence of containing air alone at the time of
ignition. A modification of the above invention may be performed by introducing a
tube for the purpose of convoy ing gas alone into the middle of the cube contents to
be mixed with the air after entering the cylinder as shown upon the drawings on
sheet two, the valve controlling the admission of gas being simmiliarly timed to the
one previously described.
I will now proceed to describe the drawings. Fig. 1 represents a sortional elevation
of the cylinder and the compression chamber 6, with the piston commencing the first
outward movement. Fig. 2 represents the cylinder with the piston having travelled
about three fourths of the first outward movement and the combustible mixture
entering the cylinder. Fig. 8 represents the piston having completed the first
outward movement with the combustible mixture loented in the center of the cube
contents of the cylinder. Fig. 4 represents the piston having completed the first
inward movement with the compressed mixture ready for ignition. Fig. 5 represents
a modification of the above, with cylinder compression chamber and passage C. for
air, and gas tubo A. through which gas alone flows to the cylinder, to be afterwards
mixed with the air, also the piston about to commence the first outward movement.
Fig. 6 represents the piston having travelled about three fourths of its first outward
movement and the flow of gas from tube A, and the combustible mixture more
centrally located than shown in Fig. 2. Fig. 7 represents the piston having completed
the first outward movement and the combustible mixturo mora centrally located than
shown in Fig. 8. Fig. 8 represents the piston having completed the first inward
movement with tho compressed contents ready for the ignition.
For the ignition of the combustible mixture I use the apparatus which I will now
describe and is represented by the drawings on sheet number 8 hereof, A represents
the interior of the cylinder through the wall of which, a tube letter B, is screwed or
otherwise fixed, the inner end protruding into the cylinder as shown. Tho passage C.
communicates with the chamber D the size of which can be enlarged or diminished
by means of the movable plug E, the climber D, being a device for enabling the
constructor to use the tube I of much shorter length than would otherwise be
nocossary. The cock F, controles the communication between the passage U, and
chambor G, which is adjusted by enp H. The letter I ropresents the tubo which is
attached to tho tubo B. and communicates with the passage (. J, represents the gus
tube, with a burner attached for the purpose of keeping the tube I in an incandescent
state, about the part marked K. The combustible mixture is ignited when the ongina
is running at its normal speed in the following manner, by passing from the cylinder
along the passage C. and the interior of tube I, until it comes into contact with the
incandescent portion thereof and is thereby ignited.
For convenience, when the engine is being started (by hand) thero being a less
pressure within the cylinder, the cock F. is brought into action and opens the passage
between C. and the chambor G. thureby the gas is allowed to flow to the required

page_text: place at a lower pressure within the tube I, as soon as the engine has attained its
normal speed and the full amount of gas admitted to the cylinder the cock F. must
then be closed.
Having now particularly described the nature of my invention and in what manner
the same is be performed I now claim, in respect of motor engines operated by gas or
Hydrocarbon vapour working with cycle herein described by this Specification.
First. The method of timing the movement of the valves whereby the combustible
mixture is admitted to the cylinder between two holies of air, as and for the purpose
described and shown.
Second. The method of timing the movement of the valves whereby gas is admitted
into a body of air situated within the cylinder of a motor engine, to be mixed there-
with and forming an explosive mixture after entering the cylinder, as and for the
purpose described and shown.
Third. The arrangement of the parts forming a gas motor engine wherein the gas is
admitted compressed and ignited as described and shown.
Fourth. The arrangement of the parts constituting the igniting apparatus sub-
stantially as described and shown.
00:1 1
1000
JOHN DOUGILL.