Improvements in Apparatus for Igniting the Compressed Charges in Gas or Oil Motors.
Year: 1897

page_text: Date of Application, 18th Mar., 1897
Complete Specification Left, 16th Dec., 1897-Accepted, 12th Mar., 1898
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Igniting the Compressed Charges in
Gas or Oil Motors.
I, WILLIAM T. ROWDEN, of Lenzie, in the County of Dumbartonshire, Pro-
fessor of Applied Mechanics in the Glasgow and West of Scotland Technical
College, Glasgow, do hereby declare the nature of this invention to be as follows:-
-
The object of my invention is the securing of prompt and certain ignitions of the
compressed inflammable mixtures in gas or oil motors, and it is specially applicable
to motors that revolve at high speeds, and also to those using slowly burning
mixtures such as air and producer gas or air and blast-furnace gas.
In carrying out my invention I employ a small cylinder fitted with a piston
which I shall hereafter call the ignition cylinder and ignition piston. The
cylinder may be merely a hole carefully drilled either in a separate piece or in the
base of a burner for heating the ignition tube.
One end of this hole is plugged to form a cylinder end. Connexion between the
interior of the ignition tube and the charge to be fired is made through this
ignition cylinder by holes of smaller diameter than its bore, the axes of the holes
and of the cylinder being preferably at right angles. I prefer also to have the
holes on opposite sides of the ignition cylinder with their axes in the same
straight line, and to have the hole leading from the ignition cylinder to the motor
cylinder a little larger than the hole leading to the ignition tube, so that the stream
of ignited gas ejected from the ignition tube shall impinge as little as possible
on the surface of the ignition cylinder.
The ignition piston, preferably of the same material as the ignition cylinder,
may be a simple rod, made a good working fit in the cylinder so that when pushed
fully in it shall cut off communication between the interiors of the hot tube and
the motor cylinder, and open communication when pulled a little forward.
The cylinder & piston described form a valve which may be worked by any
suitable mechanism. Such a valve will leak more or less during compression of
the charge, and the leakage, unless removed, would interfere with the precision
of its action as a timing valve.
To effect this removal I make an axial hole in the ignition piston from its
outside end nearly to the inside end, and I connect this hole with the inside of the
ignition tube by a small hole through the ignition piston. In this way any leakage
during the compression of the charge in the motor cylinder passes at once to the
outside and does not affect the pressure inside the ignition tube, which remains at
atmospheric pressure.
At the proper moment the ignition piston is caused to travel rapidly outward,
thus closing communication between the ignition tube and the outside and opening
communication between it and the compressed charge, part of which rushes in,
is heated, inflamed, expanded, and discharged by its increased pressure into the
main body of the compressed charge.
Dated this 17th day of March 1907

page_text: Improvements in Apparatus for Igniting the Compressed Charges in
Gas or Oil Motors.
I, WILLIAM THOMAS ROWDEN, of Lenzie, in the County of Dumbartonshire, Pro-
fessor of Applied Mechanics in the Glasgow and West of Scotland Technical
College, Glasgow, 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:―
The object of my invention is the securing of prompt and certain ignitions of
the compressed inflammable mixtures in gas and oil motors, especially in such
motors as revolve at high speeds or use slowly burning mixtures such as air and
producer gas, or air and blast furnace gas.
In carrying out my invention I employ a small cylinder fitted with a piston.
These I shall hereafter call the ignition cylinder and the ignition piston, or
plunger.
The cylinder may be formed by merely drilling a hole either in a separate piece
of metal or in the base of a burner used for heating the ignition tube.
In the accompanying sheet of drawings the sectional drawing Fig. 1 shows the
hole which is to form the bore of the ignition cylinder drilled in a separate
piece A inserted between the Bunsen burner B and the engine cylinder C, this
piece being held in position by the bolts 1 that secure the burner, as shown in the
other drawing Fig. 2 which is an elevation of the valve separate from the burner.
One end of this hole E is plugged to form a cylinder end. Connexion between
the interior of the ignition tube F and the charge to be fired is made through this
ignition cylinder by holes H, H, of smaller diameter than its bore, the axes of the
holes and of the cylinder being preferably at right angles.
I prefer also to have the holes H, H, on opposite sides of the ignition cylinder
with their axes in the same straight line, so that the streams of ignited gas ejected
from the ignition tube into the main. cylinder C, and vice versa, may impinge as
little as possible upon the surface of the ignition cylinder E.
The ignition piston K L, preferably of the same material as the cylinder in
which it works, may be a simple rod, made a good working fit in the cylinder A,
so that when its end L is pushed beyond the holes H H leading to the ignition
tube and engine cylinder respectively it shall cut off communication between them.
The cylinder & piston above described form a valve which may be driven by
any suitable mechanism. As shown in the drawings the piston or plunger K L
is acted on by a spring S which constantly urges it outwards. The end of a lever
or rod fitting loosely into the notch at the outer end of the plunger K L, and
driven by a cam, gives the piston K L the necessary motion at the proper time
and in the usual manner.
Such a valve, like most other valves, will be liable to leakage, more or less,
during the compression of the charges of gas and air in the main cylinder C, the
valve piston being then in the position shown in the sectional drawing. This
leakage into the ignition tube interferes with the regularity of the ignitions of the
charges. It might either accelerate or delay ignitions according to circumstances.
To remove any leakage and to keep the gases in the ignition tube at atmospheric
pressure up to the instant that the plunger K L is allowed to drop for firing the
charge, I make a hole M N in the plunger from its outside end nearly to the
inside end and I connect this hole with the inside of the ignition tube by a small
hole P in the plunger on that side that faces the ignition tube, as shown in the
section, Fig. 1.
At the proper instant the plunger is allowed to travel rapidly outward till its
2

page_text: end is clear of the ports leading respectively to the ignition tube & to the com-
pressed charge, part of which rushes into the ignition tube, is ignited, & by the
heat generated is expanded & the flame shot out into the main body of the
compressed charge.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
An ignition valve for gas or oil vapour engines in which a connexion between
the interior of the ignition tube and the external air is provided for by means of a
hole through the plunger for the purposes set forth and in a manner substantially
as described.
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