Improvement in Gas and Vapour Motor Engines and the like.
Year: 1893

page_text: Date of Application, 12th July, 1893
Complete Specification Left, 12th Apr., 1894-Accepted, 7th July, 1894
PROVISIONAL SPECIFICATION.
Improvement in Gas and Vapour Motor Engines and the like.
We AUGUSTIN FIDDES and FRANCIS AUGUSTIN FIDDES Engineers both of
Water Lane Temple in the City and County of Bristol do hereby declare the
nature of this invention to be as follows:-
Our invention relates to improvements in gas motor engines and has for its object
to increase the power of the engine or lessen the consumption of gas by causing a
cleansing charge of air to pass through the working end of the cylinder at the same
time the engine is exhausting and causing another charge of air to pass in the
working end of the cylinder the same time the engine is compressing the combustible
charge and in what manner the same can be performed and worked. In our invention
the cylinder is made of two diameters and the piston is made of two diameters
to correspond with the cylinder the smaller diameter is the working end and the
larger diameter formes a circular space round the piston and formes an air pump
which air is used one stroke for cleansing the engine and charging the space beyond
the stroke of the working end of the piston. The other stroke is used to increase
the charge of the engine.
In this invention the working power of the engine is once in two revolutions of
the crank shaft the larger diameter or air pump acts every revolution of the crank
shaft. The cycle of opperation of our invention is as follows. When the charge
ignites it expands and forces the piston on its outward working stroke the same
time the valve is open leading to the circular space or air pump and fills the
space with fresh air from the atmosphere. On its exhausting or in stroke the
said valve closes from the atmosphere and the communication valve opens leading
to the working end of the cylinder and the charge of air from the circular space
or air pump is forced by the inward stroke through the cylinder the same time
the engine is exhausting and leaving a portion of the air in the space beyond
the stroke of the working end of the piston which is called the cleansing stroke
from the circular space or air pump.
When the piston is on its outward or charging stroke and charging the
smaller diameter with combustible mixture the circular space or air pump
is again being charge with air or deluted gas and air. When on its inward or
compressing stroke the communication valve open leading to the working end of
the cylinder and the charge is compress from the circular space or air pump
with the charge being compress in the working end of the cylinder the larger
end of the piston travells to the end of its space and empty the space of its
contents into the space beyond the stroke of the working end of the piston.
By this cycle of opperation we have the space beyond the stroke of the
working end of the piston charge with air or combustible mixture instead of
burnt gases.
We have the stroke of the working piston in the cylinder charge
with combustible mixture and we have the charge from the circular space or air
pump all compress in the space beyond the end of the working piston ready for
ignition and the opperation is again repeated.
Dated this Eleventh day of July 1892
AUGUSTIN FIDDES.
FRANCIS AUGUSTIN FIDDES.

page_text: Improvement in Gas and Vapour Motor Engines and the like.
We, AUGUSTIN FIDDES and FRANCIS AUGUSTIN FIDDES, of Water Lane,
Temple, Bristol, Engineers, 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 improvements in gas and vapor motor engines, and
has for its object to increase the power of the engine, and to lessen the con-
sumption of gas; which is accomplished by causing a charge of pure atmospheric
air to pass through the working or back end of the cylinder while the piston
is driving out the burned gases, and thus render the air left at the back of the
piston comparatively pure; and also to send a similar charge of pure air (slightly
diluted with gas, if necessary) into the cylinder while the piston is compressing
the charge of air and gas admitted through the inlet valves.
The difficulty with gas, engines, up to the present time, has been how most
effectually to exhaust the burned gases left in the cylinder after each explosion,
and the exhaust appliances at present in operation are only able to remove
about two thirds, leaving one third of the deleterious mixture in the cylinder to
depreciate the next charge; by our invention a considerable volume of pure air
is pumped into the back of the cylinder at the same time that the rear of the
piston is driving the burned gases through the exhaust port, which will necessarily
result in the expulsion of the foul air, and its place supplied by pure air, while
a charge of air can be sent into the cylinder during the time that the gas and
air therein is being compressed.
Our invention may be carried into effect by attaching an ordinary air pump
near the cylinder of the engine, operating it by an eccentric or crank from the
central shaft, but this involves a division and consequent loss of power, we
therefore prefer to surround the piston with an annular air chamber, which is
caused by an elongation and enlargement of the cylinder and also of the piston,
the space between these two enlargements being opened and closed at each
revolution of the crank shaft, sending a charge of pure air to clear out the
burned gases, and also to surcharge the explosive mixture.
Most gas engines are made to operate with one impulse or explosion to two
revolutions, one forward stroke filling the cylinder, and the other exploding the
charge after compression: while our invention may be used for all kinds of
engines from which it is desirable to clear the burned gases, it is especially
adapted for use on the class named, and the following description with accom-
panying drawings, illustrate a gas engine of this kind with an annular chamber
formed by the enlargement of the piston and cylinder: the alterations necessary
to adapt it to any other class of engine are so slight, that any gas engineer will
be able to arrange the parts to suit any particular engine without description
of any modifications.
In the accompanying sheet of drawings, Fig. 1 is a vertical section of a cylinder
and piston fitted to form an air chamber and punip: Fig. 2 is a cross section,
showing the piston and enlarged cylinder, the space between being the air chamber;
Fig. 3 is a vertical section, and Fig. 4 a sectional plan of part of a gas engine, with
the water jacket round that part of the cylinder where the explosions are made, the
usual appliances for the inlet of gas and air, and for the discharge of burned gases,
with cams and gearing from the secondary shaft for regulating the same; only such
parts, however, are lettered and described as are necessary to show the nature of
our improvement, which is essentially, the cleansing of that portion of the cylinder
in which the burned gases are driven by the back stroke of the piston, and forcing
an additional quantity of air into the cylinder and compressing it at the same time
that the charge of gas and air is compressed.

page_text: The same letters of reference are used in each of the figures. A is an ordinary
cylinder, extended and enlarged at B; C is the piston also extended, which operates in
the cylinder A; at the extreme end of the piston is an enlargement D, which
operates in the enlarged cylinder B, and as the piston moves forward, an annular
space E is formed and enclosed between the piston and cylinder; F is an air pipe,
attached over an aperture in the stand or other convenient portion of the engine,
fitted with an automatic valve f, which opens to supply the air chamber, and is
closed by the pressure of air when the piston returns; G is a tube leading to and
from the air chamber, and H is a continuation of the same to the inlet pipe I, opened
and closed automatically by the valve; J is that part of the cylinder which is
beyond the stroke of the piston,. and which serves as a chamber in which the gas
and air are mixed and compressed before explosion, being fitted with the ordinary
inlet port for the admission of gas and air, and an exhaust port for the discharge of
the burned gases.
Other parts, which are immaterial to this invention, will be
understood from the drawings.
As before mentioned, the description and illustrations refer particularly to the
use of our invention on engines made on the principle of one impulse to two
revolutions, and the action of such engines with our annular air pump is as follows:-
On the first outstroke of the piston, the cylinder is charged with gas and air, and
the chamber E is at the same time filled with atmospheric air through the inlet F, G;
the instroke compress the gas and air in the cylinder into the space J, and at the
same time the piston D forces the air back through the tube G, H, the valve ƒ
closing with the pressure, and the air is passed on through the valve i and tube I to
the space J, where it is mixed and compressed with the combustible mixture already
in the cylinder, forming a more highly compressed and explosive compound, which
will exert an increased force on the outward passage of the piston; the charge
being ignited (by any known contrivance), the valve i is closed, and the second
outstroke, which impels the piston, again fills the air chamber E, and the back
stroke drives the air through the tubes G, H, I into the cylinder, partially mixing
it with the burned gases as they are driven through the exhaust ports, which are
opened and closed by cams from the secondary shaft, and by the greater volume
and force of the air, nearly all the noxious smoke or vapor is expelled, and its place
occupied by air which is comparatively pure, ready to be mixed with the next
supply of gas and air drawn into the cylinder; this cycle of operation is repeated
at each alternate revolution of the principal shaft, and by this means the
back part of the cylinder is cleansed of the burned gas, and a nearly pure air
substituted therefor, while an additional volume of air is mixed with the charge of
air and gas as it is compressed before ignition, producing considerable increase of
power.
The automatic valves in the tubes may be replaced by ordinary valves, actuated
by cams and gearing from the secondary shaft, if required; and in case the quantity
of air supplied by the air chamber to the end of the cylinder is too great for the
purpose of an effective explosion, a pipe y may be connected from the gas valve to
the inlet tube F, which, under the control of the governor, will at each alternate
passage of air to the chamber, open the valve and allow a prescribed quantity of
gas to mix therewith; or instead of the back plate being made straight, as shown
in Figs. 3 and 4, it may be made concave, as shown in Fig. 1.
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 gas and vapor motor engines, the construction of the cylinders with
diameters of two sizes and pistons of corresponding sizes to fit the cylinders, forming.
air pumps to supply air to the exhaust part of the cylinders, to clean out the burned
gases and surcharge the compressed gas and air in the cylinder with additional air,
substantially as and for the purposes herein set forth and described, and illustrated
in the accompanying drawings.

page_text: 2. In gas and vapor motor engines, the more rapid expulsion of burned gases
from the cylinder by the injection of pure air from a pump formed by the
combined action of a piston and cylinder constructed substantially as described and
⚫shewn.
3. In gas and vapor motor engines, the compression of an additional quantity of
air in the mixing space at the rear of the piston by the operation of an air pump
formed by the combined action of a piston and cylinder constructed substantially as
.described and shown.
4. In gas and vapor motor engines, the method of pumping air into the exhaust
chamber to assist in the expulsion of burned gases, and surcharging the compressed
gas and air with additional atmospheric air, substantially for the purposes herein set
forth and described.
J. G. WESTLAKE,
2, John Street, Bristol, Applicants' Agent.
J. G. WESTLAKE,
2, John Street, Bristol, Applicants' Agent.