An Improved Igniting Device for Starting Gas Motor Engines.
Year: 1890

page_text: Date of Application, 4th Dec., 1890
Complete Specification Left, 3rd Oct., 1891-Accepted, 4th Jan.. 1892
PROVISIONAL SPECIFICATION.
An Improved Igniting Device for Starting Gas Motor Engines.
I, FREDERICK WILLIAM LANCHESTER, of 13 Bedford Row, London, W.c.
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to a modification of the method of igniting the charge
when starting gas engines and it is applicable to the starting arrangements
described in the Specification of Patent No. 5479 of 1890. It is intended to
permit of the use of an ordinary flame igniter such as is adopted for igniting
charges of gas and air at or near atmospheric pressure in the well-known Bischoff
non-compression gas engine. The ordinary flame ignition apparatus of this kind
consists of an external flame which is drawn through an aperture covered by a flap,
pin, or other valve, which valve opens and allows the external flame to be drawn
in to ignite the charge. This arrangement is inapplicable to starting a compression
gas engine of the Otto type and my invention provides modifications and arranges
the starting cycle in order to apply it.
In carrying the invention into effect the engine on its charging stroke takes in a
charge of gas & air, and on the return stroke the exhaust valve is held open
during the complete or nearly complete stroke. During the charging stroke the
flame is prevented from entering the cylinder either by closing the valve
mechanically or by reducing the gas flame mechanically so that although the lift
valve opens air only enters the cylinder by the igniting port and the flame is too
far removed to be admitted. I prefer however, when I reduce or cut off the gas
flame to accomplish this by connecting the gas pipe supplying the flame with the
gas or gas and air inlet in such manner that when the charge is drawn into the
cylinder the "suck" causes the flame to be reduced, or extinguished in which case
a pilot flame re-lights it again. An adjusting cock, valve, or screw, is connected
to regulate the "suck" on the flame. The charge is thus taken into the cylinder
without igniting. When the piston begins its next forward stroke that is its
working stroke the external flame is admitted either mechanically or by the fact
that it is sufficiently large to enter by the suction through the valve. The engine
thus receives an impulse due to a low pressure explosion and so starts, the low
pressure explosion being repeated at every second stroke to get up the speed.
Sometimes I close the exhaust valve earlier than the end of the stroke, in which
case the pressure does not fall to atmosphere till the piston has moved on its
working stroke to some extent and the ignition does not occur till the flame can be
drawn in. By this means I can time the ignition in starting to obtain any required
volume of mixture at atmospheric pressure. The earlier the exhaust valve closes
the later the starting ignition occurs and the greater is the volume of mixture
ignited at atmospheric pressure.
Dated this 2-1 1..
Dambau 100n
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for Applicant.
COMPLETE SPECIFICATION.
An Improved Igniting Device for Starting Gas Motor Engines.
I, FREDERICK WILLIAM LANCHESTER, of 13 Bedford Row, London W.C.
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 invention relates to a modification of the method of igniting the charge

page_text: when starting gas engines, and it is applicable to the starting arrangements
described in the Specification of Patent No. 5479 of 1890. It is intended to
permit of the use of an ordinary flame igniter such as is adopted for igniting
charges of gas and air at or near atmospheric pressure in the well known Bischoff
non-compression engine. In the Bischoff engines, however, the ignition is timed
by the movement of the piston. The ordinary flame ignition apparatus of this
kind consists of an external flame which is drawn through an aperture covered by
a flap, or other valve, which valve opens and allows the external flame to be drawn
in to ignite the charge. This arrangement is applicable to starting a compression
gas engine of the Otto type, and my invention provides modifications and arranges
the starting cycle in order to apply it.
Referring to the accompanying sheet of drawings which illustrate my invention,
at Figures 1 to 5.
"
In carrying the invention into effect the engine on its charging stroke takes in a
charge of gas and air and on the return stroke the exhaust valve is held open
during the complete or nearly complete stroke. During the charging stroke the
flame is prevented from entering the cylinder either by closing the valve
mechanically or by reducing the gas flame mechanically, so that although the
lift valve opens, air only enters the cylinder by the igniting port and the flame is
too far removed to be admitted. In Figure 1 an aperture is closed by a flap
valve a, hung inside the passage e leading to the cylinder and a flame c plays
against the aperture. On the charging stroke the cock or valve d is closed
mechanically so as to shut off or reduce the flame c which burns from the nozzle c¹;
or the valve (Figure 3) may be employed to close the aperture mechanically
and thus shut off the flame c from the flap valve a and prevent access to the
passage e. When the suction stroke is completed, however, the flame c
may be turned up as at Figure 1 or admitted as at Figure 3 by mechanical
action from the engine gear. I prefer, however, when I reduce or cut off
the gas
flame to accomplish this by connecting the gas pipe as f
(see Figure 2), supplying the flame c, with the gas or gas and air inlet, in such
manner that when the charge is drawn into the cylinder the "suck
causes the
flame to be reduced or extinguished in which case a pilot flame relights it again.
This may be accomplished by connecting the pipe to the gas pipe g which
supplies the gas to the engine. When the charge is being sucked into the engine
the pressure in the gas pipe g falls and so reduces the pressure in f so that the
flame e becomes too small to reach a. When the charge suction ceases the
pressure in increases and the flame expands as shown in dotted lines (Figure 2)
so as to reach the aperture band is drawn through the flap valve to ignite the
charge when required. An adjusting cock, valve, or screw, is sometimes connected
between the pipe f and the main gas supply pipe g to regulate the "suck" on the
flame. The pipe f may also receive part of its gas supply from another source.
The charge is thus taken into the cylinder without igniting. When the piston
begins its next forward stroke that is, its working stroke, the external flame is
admitted either mechanically as at Figures 1 and 3 by a cock d or a valve as h
which may be actuated from the engine by a lever as i or other known arrange-
ment, or by the fact that it is sufficiently large to enter by the suction through the
valve, a, Figures 1, 2, 3, and 5. The engine thus receive an impulse due to a low
pressure explosion and so starts, the low pressure explosion being repeated at every
second stroke to get up speed.
Sometimes I close the exhaust valve earlier than the end of the stroke in which
case pressure does not fall to atmosphere till the piston has moved on its working
stroke to some extent and the ignition does not occur till the flame can be drawn
in. By this means I can time the ignition in starting to obtain any required
volume of mixture at atmospheric pressure. The earlier the exhaust valve closes
the later the starting ignition occurs, and the greater is the volume of mixture
ignited at atmospheric pressure.
At Figure I show a convenient arrangement for producing a Bunsen flame

page_text: where c¹ is the nozzle and c² is a hood in which the gas and air mixes forming the
flame. At Figure 5 I show a modified arrangement where the passage e is long
and formed within a tube as m. The passage is arranged of such length that
although the flame e³ enters by the flap valve a, it is extinguished before reaching
the cylinder A and no ignition can occur unless the passage e is filled with
combustible mixture. On the charging stroke e is necessarily filled with the
burned gases of the previous explosion, and so no ignition occurs, although the
flame centers e, but during the return stroke mixture is blown past the ball
valve kande is filled with mixture so that immediately the piston begins to move
forward on its working stroke, the flame e passes the valve a and ignites the
mixture in e and so explodes the mixture in the cylinder a. I is a cock to shut off e
when the engine has been started.
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
1
(1) The herein described method of starting a gas motor engine working with
compressed charges by keeping an exhaust port open during the ordinary
compression strokes thus allowing a portion of the contents of the cylinder to
escape, and igniting the remaining portion by a flame drawn into the charge and
continuing this mode of working until the engine acquires sufficient momentum to
effect the compression of the charges.
(2) In starting gas motor engines as described in the preceding claim, the
herein before described method of confining the action of the igniting flame to the
stroke in which it is required to ignite the charge, by removing it from incoming
gases during the charging stroke either by extinguishing or reducing it sufficiently
or by placing a sufficiently long port between it and the cylinder.
(3) An igniting device for starting gas motor engines in which a flame is
sucked through an aperture to explode the inflammable mixture in the cylinder,
and the explosion is produced after increase of the said flame, this increase being
accomplished by mechanically opening the supply cock or by increase of gas
pressure in the gas supply pipe after fall of pressure due to the influence of the gas
suction stroke substantially as hereinbefore described.
(4) The construction and arrangement of igniting devices for starting gas
motor engines as herein before described and illustrated at Figures 1, 2, 3, 4, and 5
of the accompanying drawings.
Dated this 2nd day of Ontahan 1901
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicant.