An Improved Method of Starting Gas Engines.
Year: 1891

page_text: Date of Application, 11th Nov., 1891
Complete Specification Left. 30th July. 1892-Accepted, 3rd Sept., 1892...
PROVISIONAL SPECIFICATION!
An Improved Method of Starting Gas Engines.
I JOHN FIELDING of. Somerset Lawn in the City and County of Gloucester
Engineer do hereby declare the nature of this invention to be as follows:
=
In starting gas engines according to my invention the crank is put slightly
forward of the dead centre nearest to the cylinder, gas is then admitted to the
combustion chamber, an outlet cock being open to allow of the escape of air
therefrom, the cylinder, thus being practically filled with gas, the inlet and outlet
cocks are closed and sufficient air under pressure is admitted to constitute with the
gas, an explosive mixture which is then ignited by any suitable means, such as a
hot tube igniter, or electric spark, the resultant explosion driving the piston
forward, setting the engine into motion with such force as to maintain it in motion
until the ordinary working cycle comes into operation.
The compressed air may be taken from any convenient source but it is found
advantageous to charge a reservoir during the compression strokes of the engine
piston, gas being suddenly turned off whilst the engine is running, a suitable non-
return valve and cock being provided for this purpose between the engine cylinder
and reservoir.
1001
JOHN FIELDING.
COMPLETE SPECIFICATION.
An Improved Method. of Starting Gas Engines.
I JOHN FIELDING of Somerset. Lawn. in the City and County of Gloucester
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:→
In starting gas engines according to my invention the crank is put slightly
forward of the dead centre nearest to the cylinder, gas is then admitted' to the
combustion chamber, an outlet cock being open to allow of the escape of air
therefrom the cylinder thus being practically filled with gas, the inlet and outlet
cocks are closed and sufficient air under pressure is admitted to constitute with the
gas an explosive mixture which is then ignited by any suitable means, such as a
hot tube igniter, or electric spark, the resultant explosion driving the piston
forward, setting the engine into motion with such force as to maintain it in motion
until the ordinary working cycle comes into operation.
The compressed air may be taken from any convenient source but it is found
advantageous to charge a reservoir during the compression strokes of the engine
piston, gas being suddenly turned off whilst the engine is running, a suitable non-
return valve and cock being provided for this purpose between the engine cylinder
and reservoir.

page_text: T is the compressed air reservoir, which communicates by pipe F¹ with valve
box G.
G contains two valves, G¹ and G³, the former is a back pressure valve which
retains pressure in reservoir when latter is being charged by the strokes of the
piston...
.. '
It can however be locked down upon its seat by the screw G³.
Gis a screw stop valve, for admitting compressed air from reservoir to the
cylinder.
H is the gas supply cock, I the passage leading by port J to space A.
The angle of port J causes the incoming gas to more thoroughly expel the air
from space A, and also afterwards causes the compressed air to more thoroughly
mingle with the gas.
K is the igniting port leading to igniting tube L, which is heated in the usual
manner by a Bunsen burner such as M.
N is a valve or cock which when open, allows the air to escape from space A
(when the latter is being filled with gas) through a pipe N' terminating above the
chimney of Bunsen burner.
1
When the air has been expelled and gas escapes from N' it is ignited by the
Bunsen flame, and as soon as the jet issuing from N¹ burns with a steady flame it is
known that the space A is sufficiently filled with gas.
2
Figure 3. shows to a larger scale the valve box G, valves G¹ and G², screw
stop G³ and gas supply cock H, also passage I and port J.
It will of course be understood that the cylinder is provided with the usual
gas and air supply valves and exhaust valve, which may be of any suitable
description.
The igniting tube may also be fitted in conjunction with a timing valve, which
will of course be open when the engine crank is in the proper position for
starting.
The operation of starting an engine in accordance with my invention will be as
follows viz.
The crank being being in about the position shown in Figure 1. and the engine
at that part of its cycle corresponding to the piston making its acting stroke, the
igniting tube having been properly heated and the valves G and G' being closed,
the main gas supply valve is opened slightly.
The gas supply cock H and outlet valve N are then opened, gas enters and
expels the air from space A through the igniting port K, valve N and pipe N¹.
When the air has been driven out and gas begins to escape at N' it is ignited
by the Bunsen flame, and as soon as it burns steadily, N and H are closed.
The valve G2 is then opened, admitting compressed air from reservoir, the air
quickly mingles with the gas, forming an explosive mixture which is forced by the
pressure up into the igniting tube and an explosion takes place driving the piston
forward with great force.
The reservoir may be charged in the following manner whilst the engine is
running, the main gas supply is shut off and the screw G³ slackened out, air being
delivered past the valve G¹ during the pistons compressing strokes.
The reservoir being once charged up, it is generally found that the amount of air
withdrawn in starting may be restored when stopping the engine after the gas has
been turned off.
I do not restrict myself exclusively to the exact details shown in the drawing,
these may be modified in many ways without departing from the essence of my
invention.
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. The herein described method of starting a gas motor engine by somewhat

page_text: advancing the piston in its working stroke, filling the space in the cylinder behind
the piston with gas, introducing into this a charge of compressed air so as to form
a combustible mixture under pressure and igniting this mixture.
Dated this 29th day of July 1892.
JOHN FIELDING.