Improvements in Gas Motor Engines.
Year: 1893

page_text: Date of Application, 22nd Dec., 1893
Complete Specification Left, 19th Oct. 1894-Accepted, 24th Nov., 1894
:
PROVISIONAL SPECIFICATION.
Improvements in Gas Motor Engines.
1, HUGH CAMPBELL, of the Firm of The Campbell Gas Engine Company,
Limited, of Halifax, in the County of York, Engineers, do hereby declare the
nature of this invention to be as follows:-
This invention has reference to that construction of engine known as the
"Otto" or four cycle engines, my improvements therein consisting firstly, to a new
arrangement of inlet and exhaust valve; secondly, to the system of governing the
engine; thirdly, to the use of a valve and an arrangement of lever for timing or
regulating the ignition or explosion of combustible mixture in the cylinder of the
engine, and fourthly, to the use of a hand pump for forcing to the engine cylinder
a supply of combustible mixture with which to start the engine from rest, either
with or without any load upon it.
In constructing such an engine according to my invention I arrange the inlet and
exhaust valves close together, and at one end of the cylinder. The gas passes
through a suitable opening to an annular chamber around the jacket of the inlet
valve, certain openings or perforations being made to form one or more com-
munications between the annular chamber and the seating of the valve which is
preferably of the mushroom type, such said valve being opened by the pressure of
the atmosphere each time the movement of the piston creates a partial vacuum in
the cylinder a spiral spring being used to close the said valve.
The gaseous mixture on being admitted passes through the said perforations to
the cylinder and at the same time atmospheric air passes to the cylinder through the
main opening of the valve, but when the latter is closed the admission of both air
and gas is shut off. The piston of the engine compresses the air and gases within
the compression chamber when the said combustible mixture is ignited on the
return stroke of the piston, and during the time the crank is turning over the dead
centre. The ignition of the combustible mixture takes place by contact with the
ignition tube. After the mixture has performed its function in the cylinder of the
engines, which takes place during the outstroke of the piston, the spent mixture is
exhausted to the atmosphere through the exhaust valve opened by a constantly
reciprocating rod receiving its motion from a cam or eccentric driven at half the
speed of the crank shaft, such said reduced speed being obtained by the use of spur
or other wheels.
--
When the engine overruns the normal speed a centrifugal governor causes a
lever to drop into position so as to hold the exhaust valve open a little while,
thereby preventing a vacuum being formed in the cylinder and thus preventing the
inlet valve being opened for the admission of a fresh supply of air and gas; the
exhaust valve being thus kept open by the lever actuated from the governors
the products of combustion and air to be drawn alternately into the cylinder and
expelled therefrom by the action of the piston, and this goes on until the speed of
the engine falls to the normal, when the action of the governor will remove the
holding lever and permit the inlet valve to act. The reciprocating rod which opens
the exhaust valve during each forward stroke always advances far enough to act
upon the lever of the exhaust valve and this releases the pressure on the holding
lever from the governor in order that it may be free to move upward when the
governors demand it.
Thirdly. Means to be employed for timing or regulating the ignition or explosion

page_text: of the combustible mixture. To do this, I place a valve in the end of the cylinder
near the ignition tube, which valve is opened at a given time by means of a lever
operated by eccentric or cam so as to obtain the best results from the explosion.
A spiral spring operates the valve in the opposite direction.
Fourthly. The invention relates to the use of a pump for forcing a supply of
combustible mixture to the engine for the purpose of starting it instead of as
hitherto moving the fly wheel by manual labour. Accordingly I connect a small
pump to the engine, the piston of which is operated by a suitable arrangement of
levers. This pump forces the supply of atmospheric air and gas into the com-
pression chamber which on being ignited explodes so as to give the first impetus to
the fly wheel. Afterwards the supply of combustible mixture follows on in the
ordinary manner.
Dated this 21st day of December 1893.
TASKER & CROSSLEY,
Halifax, Agents.
COMPLETE SPECIFICATION.
Improvements in Gas Motor Engines.
I, HUGH CAMPBELL, of the Firm of The Campbell Gas Engine Company
Limited, of Halifax, in the County of York, 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 :-
This invention has reference to that construction of gas engine known as the
"Otto" or four cycle engine, my improvements therein relating, firstly, to a new
arrangement of inlet and exhaust valves.
In order that my improvements in cycle engines may be more clearly understood
I will make reference to the accompanying sheets of drawings wherein Fig. 1 is
end elevation of a gas engine, Fig. 2 is sectional plan of same, Fig. 3 vertical
longitudinal section on line A, B, of Fig. 1, and Fig. 4 vertical longitudinal section
on line A, C, of Fig. 1, where E is the inlet valve for supplying the gaseous
mixture and atmospheric air to the cylinder F, whilst G is the exhaust valve which
permits the escape of the spent gases. These two valves are arranged in close
proximity to each other and are both situated at one end of the cylinder.
The explosive gas is admitted to an annular chamber H arranged around the
jucket of the inlet valve, certain small openings or perforations a being made
through the valve casing to form a communication between the annular chamber
and the seating of the valve, which is preferably of the mushroom type, such said
valve being opened by the pressure of the atmosphere each time the movement of
the piston creates a partial vacuum in the cylinder, a spiral spring I being used to
close the said valve. The gaseous mixture on being admitted to the annular
chamber H passes through the said perforations a to the cylinder, and at the same
time atmospheric air passes through opening J and through the main opening of
the valve when the latter is opened, but when the said valve is closed the admission
of both air and gas is shut off. The piston of the engine compresses the air and
gases within the compression chamber, after which the combustible mixture is
ignited on the return stroke of the piston and during the time the crank is turning
over the dead centre. When the combustible mixture has exploded and performed
its function in the cylinder of the engine, which takes place during the outstroke of
the piston, the spent gases are exhausted to the atmosphere through the exhaust
valve G which is opened by a constantly reciprocating rod K shewn in elevation of
Fig. 5 and plan view Fig. 6. The rod K receives its reciprocating movement from
a cam or eccentric driven at half the speed of the crank shaft, such reduced speed
being obtained by the use of spur or other bevil wheels as is common with this
class of engine. It will be seen on reference to Figs. 5 and 6 that the outer end of

page_text: the spindle of the exhaust valve G is connected to a lever L working upon a
fulcrum M. Therefore when the end of rod K comes into contact with the
adjustable nut b on lever L the exhaust valve will be opened and this is timed to
take place after each explosion of combustible mixture.
The spiral spring N attached to lever L closes the exhaust valve.
Secondly. My invention relates to the system of governing the engine, and the
method I adopt is illustrated in Figs. 1, 5 and 6 of the accompanying drawings..
O represents the centrifugal governors attached to a sleeve P, and Q is a clutch.
fork on the end of horizontal lever R, therefore when the engine overruns its normal
speed the governors will rise, taking with them the sleeve P and clutch fork Q
causing the opposite end of lever R to descend and place the piece c (see Fig. 5) in
front of one end of the lever L and thus hold the exhaust valve open a little while,.
thereby preventing a vacuum being formed in the cylinder, consequently the inlet
valve will not be opened for the admission of a fresh supply of air and gas; by this
means the exhaust valve is kept open by the lever R actuated direct from the
governors consequently the products of combustion and air to be drawn alternately
into the cylinder and expelled therefrom by the action of the piston are for the
time being temporarily arrested, and this goes on until the speed of the engine falls
to the normal when the action of the governors will remove the holding piece o
from contact with the end of the lever L and permit the inlet valve to act.
reciprocating rod K which strikes nut on lever L and opens the exhaust valve.
during each forward stroke, always advances far enough to act upon the lever of the
exhaust valve, and this forward movement releases the pressure of the holding
piece c from the lever L in order that the said piece c may be free to move upward
when the governors demand it.
The
Thirdly. My invention relates to means to be employed for timing or regulating
the ignition or explosion of the combustible mixture so as to obtain the best results
from the explosion.
This part of my invention is illustrated in Figs. 1, 6 and 7, where S is a valve
placed near to and in connection with the ignition tube d. This valve is regulated
to be opened at what is considered to be the best time for the explosion of the
gases by means of lever T working upon a fulcrum e actuated by a constantly
reciprocating rod U operated like rod K from a crank or eccentric from any
convenient part of the engine. The valve S is closed by spiral spring f.
Fourthly. The invention relates to the use of a pump for forcing a small supply
of combustible mixture into the cylinder of the engine for the purpose of starting
it, instead of as hitherto, moving the fly wheel by manual labour. This part of my
invention is shewn in Figs. 1, 6 and 8, where V is an auxiliary cylinder fastened to
the side of the engine. This cylinder is provided with a piston W which can be
operated by lever X and thus a small quantity of combustible mixture is forced
into the compression chamber through passage Y which on being ignited by the
ignition tube explodes so as to give the first impetus to the fly wheel, afterwards
the larger supply of combustible mixture follows on in the ordinary manner for
working the engine.
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 :-
Firstly. In a gas motor engine, the arrangement of the inlet and exhaust valves,
the former having an annular space H and air passage a arranged and operated as
herein described.
Secondly. In gas motor engines, the arrangement of parts for governing the
engine and regulating the action of the inlet and exhaust valve as shewn and
described.
Thirdly. In gas motor engines, the combination with the ignition tube of a valve
such as S for timing the explosion of the combustible mixture, operated as
described and shewn in Figs. 6 and 7.

page_text: Fourthly. In gas motor engines, the use of a hand pump for forcing a supply of
⚫ combustible mixture into the combustion chamber, operating in the manner
described and shewn in Figs. 6 and 8.
Dated this 18th dev. of October 1894.
TASKER & CROSSLEY,
Halifax, Patent Agents.