Improvements in or connected with Engines Operated by the Explosion of Mixtures of Combustible Vapour or Gas and Air.
Year: 1890

page_text: Date of Application, 8th Oct., 1890
Complete Specification Left, 8th July, 1891-Accepted, 3rd Oct., 1891
PROVISIONAL SPECIFICATION,
Improvements in or connected with Engines Operated by the
Explosion of Mixtures of Combustible Vapour or Gas and Air.
We, HERBERT AKROYD STUART, of Bletchley Iron and Tin Plate Works.
Bletchley, in the County of Buckingham, Mechanical Engineer, and CHARLES
RICHARD BINNEY, of 5. Hackney Road, in the County of Middlesex,
Consulting Engineer, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to engines operated by the explosion of mixtures of gas
or hydrocarbon vapour and air.
In the Specification filed with our application for Letters Patent dated
February 8 1890, No. 7146, we have described means for preventing the pre-
ignition of an explosive charge of combustible vapour or gas and air when a
permanent igniter (such as a continuous electric spark or a highly heated
igniting chamber) is in communication with the interior of the cylinder, by first
of all compressing the necessary quantity of air for the charge, and then introducing
into this quantity of compressed air the necessary supply of combustible vapour
or gas to produce the explosive mixture.
The chief object of our present invention is to provide means, whereby the
necessary quantities of combustible vapour or gas and of air may be drawn in
during the suction or outstroke of the piston, notwithstanding that a permanent
igniter is employed, without liability of pre-ignition.
In carrying out our invention we attach to one end of the cylinder an explosion
chamber (which chamber in a liquid hydrocarbon engine also serves as the
vaporizer) of sufficient capacity to contain the charge of combustible vapour or
gas and the necessary quantity of air to render the same explosive, the opening of
passage which establishes communication between the cylinder and the explosion
chamber being of less diameter or area than the cylinder or the explosion chamber
in transverse section. The inlet for the hydrocarbon liquid or the combustible
vapour or gas is within the explosion chamber whilst that for the air is formed in
the cylinder, so that during the suction or outstroke of the piston the gas is drawn
or forced into the explosion chamber and the air into the cylinder, no perceptible
mixing taking place owing to the relatively small area of the communicating
opening or passage. During the return or compression stroke of the piston the
necessary quantity of the air in the cylinder to render the vapour or gas explosive
is forced into the explosion chamber, the explosion then taking place owing to the
heat of the chamber itself or the use of any suitable igniting device.
In order to regulate the quantity of air entering the explosion chamber to form
he combustible mixture, we in some cases provide means for regulating. the
capacity of the said chamber.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in, or connected with Engines Operated by the
Explosion of Mixtures of Combustible Vapour or Gas and Air.
We, HERBERT AKROYD STUART, of Bletchley Iron and Tin Plate Works,
Bletchley, in the County of Buckingham, Mechanical Engineer, and CHARLES
RICHARD BINNEY, of 5, Hackney Road, in the County of Middlesex, Consulting
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 :-
.Our invention relates to engines operated by the explosion of mixtures of gas or
hydrocarbon vapour and air.
In the Specification filed with our application for Letters Patent dated
May 8th 1890 No. 7146, we have described means for preventing the premature or
pre-ignition of an explosive charge of combustible vapour or gas and air when a
permanent igniter (such as a continuous electric spark or a highly heated igniting
chamber) is in communication with the interior of the cylinder, by first of all
compressing the necessary quantity of air for the charge, and then introducing into
this quantity of compressed air the necessary supply of combustible liquid, vapour
or gas to produce the explosive mixture.
the
The chief object of our present invention is to provide means, whereby the
necessary quantities of combustible vapour or gas and of air may be drawn in
during the suction or outstroke of the piston, when a permanent igniter is employed.
without liability of pre-ignition, and for this purpose we attach to one end of the
cylinder an explosion chamber (which chamber in a liquid hydrocarbon engine
also serves as the vaporizer) of sufficient capacity to contain the combustible
charge; the opening or passage which establishes communication between
cylinder and the explosion chamber being contracted in area, that is to say, of
much less diameter or area than the cylinder or the explosion chamber in transverse
section; and we form the inlet for the air in the walls of the cylinder and that for
the hydrocarbon liquid or other combustible vapour or gas in the walls of the
explosion chamber, so that air can only enter the explosion chamber from the
cy inder, through the contracted passage
To enable our invention to he fully understood we will describe the same with
reference to the accompanying drawing, in which :—
Figure 1 is a longitudinal section of a portion of a liquid hydrocarbon engine
having our
improvements applied thereto; and,
Figure 2 is a section on the line xx, Figure 1.
a indicates the engine cylinder, and b the piston or trunk. c is the explosion
chamber, which, as shewn, is formed integral with the cylinder-cover d, and e is
the contracted passage which establishes communication between the explosion.
chainber and the cylinder.
f is a nozzle through which liquid hydrocarbon is injected into the explosion
chamber, and g is the passage through which air is drawn into the cylinder. This
passage communicates with a chamber h containing two valves i, j, the former of
which may either open automatically under the action of the suction or be actuated
to admit air during the outstroke of the piston, whilst the latter is operated by a
cam through the medium of a lever or by other suitable means at the proper
times to allow the products of combustion to be exhausted from the cylinder.
The engine shewn in the drawing is designed to have liquid hydrocarbon
injected into the explosion chamber and formed into spray before impinging upon
the heated walls of the said chamber; it will be obvious, however, that where the
explosive mixture is to be composed of gas and air, the gas-inlet to the explosion
chamber can be provided with a valve adapted to admit gas by suction or in any
other suitable manner.

page_text: When liquid hydrocarbon is employed the injections may be so timed as to
occur at the beginning or at any portion of the suction stroke or during the
compression stroke. We prefer, however, to give sufficient time for complete
vaporization in order to obtain the maximum economy of combustible liquid, aud
this can be accomplished by injecting the hydrocarbon during the suction stroke
when the combustible liquid, after coming into contact with the hot walls of the
explosion chamber, vaporizes very completely and occupies the combustion space
displacing a sinall portion of its contents (air or the burned gases of the previous
explosion) through the contracted passage e. The piston is in the meantime
performing its out-stroke and a charge of air is being drawn into the cylinder
through the valve i and the passage g, and although a small portion of inflammable
vapour may pass from the explosion chamber into the air in the cylinder, yet no
mixing sufficient to cause an explosion will take place owing to the contracted
area of the communicating passage until on the return or compression stroke of
the piston sufficient air is forced from the cylinder into the explosion chamber to
produce a mixture capable of explosion. The cubical contents of the engine
cylinder and the explosion chamber are so proportioned that the mixture in the
explosion chamber during compression is rendered explosive in time to secure the
ignition at or near the end of the compression stroke.
In practice we prefer to make a relatively large clearance space 1, as shewn,
whereby a layer of air remains between the piston and the charge in the explosion
chamber. We have found that when no clearance space or only the usual very
small clearance space is left, the back of the piston and walls of the cylinder
become rapidly fouled with deposit and that, when a clearance space of, say, a
quarter of a diameter is left, this deposit is obviated. We believe the layer of
air in the clearance space has the effect of preventing the contact of the products
of combustion with the piston and the walls of the cylinder and thereby obviating
the deposit thereon. The volume of relatively pure compressed air also supplies
an excess of oxygen to complete the combustion originated in the explosion
chamber and thereby burn up the carbon, which might otherwise form deposit.
When the explosion chamber is used as a vaporizer the internal surfaces
thereof may be ribbed (as described in the Specification of our Patent before
referred to) or, corrugated; and instead of injecting the liquid hydrocarbon by
means of a pump it may be drawn into the cylinder by the partial vacuum produced
in the cylinder during the suction stroke, suitable arrangements being made to
ineasure the liquid charges and prevent admission of air in any prejudicial
quantity.
When the engine is used as a gas engine or as an oil engine, using a liquid fuel
vaporizer outside the combustion chamber, the inflammable gas or vapour may
also be drawn or forced into the explosion chamber. In such cases the explosion
chamber may or may not be highly heated, and it may or may not be used to fire
the explosive charge when formed by the compression of air from the cylinder
into the chamber. When the chamber is not highly heated, ignition of the explosive
charge may be effected by an incandescent tube, by continuous electric sparks or
by other known means of igniting. We preferably, however, use the highly heated
explosion chamber for igniting the charges, and we heat it by a lamp or other
means when starting the engine, the successive explosions serving to maintain the
explosion chamber at the requisite temperature for igniting the charges, as described
in the Specification of the Patent before referred to.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :
1. In an engine operated by the explosion of mixtures, of gas, or hydrocarbon
vapour and air, a chamber adapted to be highly heated for igniting the explosive
mixture and, when hydrocarbon vapour and air are employed, for vaporizing the
liquid hydrocarbon, the said chamber communicating directly with the working

page_text: cylinder by a contracted passage always open to the said cylinder, in combination
with an air-inlet valve so arranged that the air on entering does not pass through
the vaporizing chamber, substantially as, and for the purpose, described.
2. In an engine operated by the explosion of mixtures, of combustible vapour or
gas and air, the arrangement whereby the combustible vapour or gas is introduced
into an explosion chamber at all times freely open to the cylinder and the air into
the cylinder, the explosive mixture being produced by compressing a sufficient
portion of the contents of the cylinder into the chamber containing the inflammable
vapour or gas, on the back or compressing stroke of the piston, so
that no
explosion can take place until the charges are compressed together, substantially as
described.
3. In an engine of the kind hereinbefore described having an explosion chamber
communicating with the working cylinder through a contracted passage at all
times freely open as set forth, introducing inflammable liquid, vapour, or gas into
the explosion chamber and the air into the cylinder during the suction or outstroke
of the piston, substantially as, and for the purposes, specified.
4. In an engine operated by the explosion of mistures of combustible vapour..
or gas and air the combination of a combustion chamber having a contracted
passage always open to the cylinder, such chamber and contracted passage being
in the same or substantially the same axial direction as the cylinder, a fuel inlet
into the combustion chamber and an air-inlet into the cylinder, substantially as
described.
5. In an engine of the kind hereinbefore described having an explosion chamber
communicating with the working eylinder through a contracted passage at all
times freely open and in which the combustible liquid, vapour or gas and the air
are introduced separately, viz.:-the one into the combustion chamber and the
other into the cylinder as set forth, the use of the hot surfaces of the explosion
chamber for the purpose of igniting the charge when explosive, substantially as
described.
6. In a vapour or gas engine of the kind herein before described an explosion
chamber communicating with the working cylinder through a contracted passage
freely open to the cylinder and a clearance space between the piston and the back
end of the cylinder, the said space serving to contain a layer of air to prevent
fouling, substantially as described.
7. The improved arrangement of vapour or gas engine, substantially such as
herein before described and illustrated in the accompanying drawings.
Dated the 8th day of July 1891
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.