IMPROVEMENTS IN GAS Motor ENGINES
Year: 1883

page_text: LETTERS PATENT to Francis James Odling of Chaddesden Works Derby in
the County of Derby for an Invention of "IMPROVEMENTS IN GAS Motor
ENGINES"
PROVISIONAL SPECIFICATION left by the said Francis James Odling at
the Office of the Commissioners of Patents on the 9th January 1883.
FRANCIS JAMES ODLING, of Chaddesden Works, Derby in the County of Derby
"IMPROVEMENTS IN GAS MOTOR ENGINES"
My invention relates to a construction and modo of working of a gas motor
engine in such a manner as to avoid the explosive shock resulting from too rapid
combustion of the charge by retarding the combustion within the cylinder and to
utilise the heat of the combustion by increasing the pressure and volume of
incombustible fluid such as air within the cylinder.
For the purpose of retarding the combustion I provide in the cylinder a loosely
fitting piston, which is porous or perforated, consisting of layers of wire gauze or
of a number of small tubes or concentric rings, or otherwise constructed with
passages such that flame cannot pass through them. At the time when the cylinder
is charged, ready for ignition, this piston is in such a position that only a small
portion of the combustible charge is on one side of it, next the point of ignition,
whilst the greater portion of the charge is on the other side of the piston.
When the charge is ignited on one side of the piston, the fluid on the other side
of it is caused by the movement of the piston to pass through its pores or
perforations to the side where the ignition exists, and thus the combustion of the
whole charge is rendered gradual.
.
In order to utilise the beat of the combustion I provide at the end of the cylinder
behind the part where the combustion takes place a chamber fitted with a loose
piston, this chamber being before ignition charged with air or incombustible fluid.
On the gaseous charge in front of this piston being ignited, the increase of
pressure forces the piston back displacing the air or incombustible fluid and
causing it to flow through suitable passages to the front of the piston and to
become heated by the combustion and thereby to have its pressure and volume
increased.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Francis James Odling in the Great Seal Patent Office on the
7th July 1883.
FRANCIS JAMES ODLING of Chaddesden Works Derby in the County of Derby
"IMPROVEMENTS IN GAS MOTOR ENGINES"
My invention relates to a construction and mode of working of a gas motor
engine in such a manner as to avoid the explosivo shock resulting from too rapid
combustion of the charge by retarding the combustion within the cylinder, and to
utilise the heat of the combustion by increasing the pressure and volume of
incombustible fluid such as air within the cylinder.
For the purpose of retarding the combustion I provide in the cylinder a loosely
fitting piston, which is porous or perforated, consisting of layers of wire gauze or
of a number of small tubes or concentric rings, or otherwise constructed with
passages such that flame cannot pass through them. At the time when the cylinder
is charged, ready for ignition, this piston is in such a position that only a small
portion of the combustible charge is on one side of it, next the point of ignition,
whilst the greater portion of the charge is on the other side of the piston.
When the charge is ignited on one side of the piston, the fluid on the other side
of it is caused by the movement of the piston to pass through its pores or
perforations to the side where the ignition exists, and thus the combustion of the
whole charge is rendered gradual.
In order to utilise the heat of the combustion, I provide at the end of the cylinder
behind the part where the combustion takes place, a chamber fitted with a looso.
piston, this chamber being before ignition charged with air or incombustible fluid.
On the gaseous charge in front of this piston being ignited, the increase of
pressure forces the piston back, displacing the air or incombustible fluid and
causing it to flow through suitable passages to the front of the piston, and to
become heated by the combustion and thereby to have its pressure and volumo
increased.
The accompanying drawing is a longitudinal section of the cylinder and
contiguous parts of a Gas Motor engine according to my invention. This cylinder
is made with its front part A to operate as a charging pump drawing in air and
gas through the slide B and valve C as the piston makes its outstroke, and sending
the charge past the cheque valve D into the cylinder under the working piston E,
as this piston (which is rigidly connected as a trunk to the charging piston) makes
its instroke. is a discharge outlet by which a portion of the exhaust escapes as
the pistons are approaching to and returning from the extreme of their outstroke,
and G is the exhaust valve worked by an eccentric or cam from the engine shaft,
and kept open during a portion of the instroke of the pistons. At the end of the
cylinder there is a cavity H loosely fitted with a hollow piston I in the cavity of
which is loosely fitted a porforated piston J covered with several layers of wire
gauze or perforated metal. The stems of the pistons I and J are pressed upwards
by springs i and j, and in order to relieve the spring i of the greater part of the
strain imposed on it when high pressure is developed in the cylinder, I prefer to
partly balance this pressure by making the stem of I of reduced area work as a
plunger in a cavity communicating freely with H. K is the ignition slide.
The piston being connected in the usual way to a crank on a flywheel shaft
which by suitable eccentrics or cams works the gas supply valve C, the supply and
ignition slides B and K, and the exhaust valve G, the operation of the engine is as
follows. The piston being caused to make its outstroke by the pressure below E

page_text: draws into the front part A of the cylinder first a mixture of air and gas, and
then, the valve C being closed, air alone. As the piston E approaches the end of
its outstroko a portion of the contents of the cylinder below it escape by the
outlet F, and the pressure in the cylinder being thus reduced the pistons I and J
are pushed by their respective springs to the positions indicated in the figure. The
pistons are caused by the momentum of the flywheel to make their instroke.
During part of this stroke the exhaust valve G is kopt open, and the contents of
the smaller part of the cylinder and also a portion of the discharge from the larger
part A escape. Sometime before the piston E reaches the extreme of its instroke,
the valve G is closed, and thereupon the fluid contained in the smaller part of the
cylinder as well as that discharged from the larger part A, and the contents of the
cavity H and of the hollow piston I, become compressed. At the end of the instroko
the cavity H contains mostly air, but the hollow of J and the passage L having
received from A the last part of its charge, contain a combustible mixture of gas
and air. This being ignited by the movement of the slide K, the pressure within
the cylinder and passages is raised, propelling the piston E and also forcing back
the pistons J and I. The combustible mixture passing through the perforations
of J serves to prolong the combustion, while the air from H becomes heated in
passing into the main cylinder. The pistons being propelled by the fluid expanding
in the cylinder give the working power to the crank. The power may be regulated
by a governor, of any suitable known kind, acting on the gas valve C, so as to close
it sooner or later during the outstroke according as the engine acquires a speed
exceeding or falling short of its normal rate.
Although I have shewn in the drawing the two pistons I and J arranged so as
to act in conjunction in one engine, it is obvious that each might be made to
perform its function without the other. Thus the piston I might be made without
any cavity, the piston J being dispensed with, in which case there would be no
retardation or prolongation of the combustion such as I have described. Or the
cavity H and piston I might be dispensed with, the piston J acting then alone for
prolonging the combustion.
Having thus described the nature of my invention and in what manner the samo
is to be performed, I claim in respect of gas motor engines:
First. The herein described method of retarding or prolonging the combustion of
the charge by dividing it into two portions separated by a perforated or porous
spring piston, which being moved by the increase of pressure resulting from tho
combustion of the first portion causes the second portion of combustible fluid to
pass through it so as to be burned in its turn.
Second. The herein described method of utilising the heat of the combustion by
providing a cavity charged with air or incombustible fluid separated from the space
containing the combustible mixture by a loosely fitting spring piston, which being
moved by the increase of pressure resulting from the combustion of the charge,
displaces the fluid from the cavity into the heated part of the cylinder.
Third. The combination of the cavity H and the spring pistons I and J, arranged
and operating as and for the purposes herein set forth.
In Witness whereof I the said Francis James Odling have hereunto set my
hand and seal this Third day of July in the year of our Lord One thousand
eight hundred and eighty three.