Year: 1888

page_text: I, HUGH CAMPBELL, of 27 Gerrard Street, Halifax, in the County of York, Engineer,
do hereby declare the nature of this invention to be as follows:-
:―
My improvements have reference to that description of gas motor Engines where
two cylinders are employed, arranged side by side, one of which is called the pump
cylinder, and the other the motor cylinder, the function of the former being to supply
at a given time combustible mixture to the latter cylinder, where it is afterwards com-
pressed, ignited, expanded, and exhausted. My improvements in such engines relate
firstly to the cylinders, which have hitherto been cast together, but it is now my inten-
tion to cast such cylinders separately, and to couple them together by an arm or bracket
projecting from (preferably) the pump cylinder, which is fastened by bolts or other
suitable means to the jacket of the motor cylinder, whereby I dispense with the necessity
of having the compression chamber and pump cast together, as is now the case; con-
sequently greater simplicity and efficiency are obtained.
Secondly, my invention has reference to the pipe which supplies the mixture of air
and gas from the pump cylinder to the motor cylinder. Hitherto this admission pipe
has been made to branch from the bottom of the pump to the motor cylinder, con-
sequently when grease or other matter was lodging in the bottom of the cylinder, it
would be forced through the admission pipe into the compression chamber. To obviate
this I place the said admission pipe about the centre of the pump, or any other place
above the level of the bottom, so that nothing but the admixture of air can be forced
through the said pipe.
Thirdly, my improvements refer to the means for supplying the combustible mixture
to gas Engines, and this I accomplish by opening the gas and air inlet valves, which
valves I preferably make of the slide typo, and they may be made rectangular or
circular in section. Passages are made in and through this slide valve for the air and
gas to be drawn by the action of the piston in the pump cylinder; to permit this to
be done I make a recess in the back of the slide, and communicating with this recess
I arrange the air and gas parts in such a manner that the air is drawn across the gas
parts, and on the gas issuing therefrom, such air and gas would be thoroughly mixed.

page_text: The slide is pushed open at the proper time by means of an eccentric or cam pusher,
therefore when the Engine runs at its normal speed the slide is pushed open by the
eccentric or cam pusher, thereby allowing a proper charge of gas and air to be drawn
into the said cylinder; but should the said Engine exceed the normal speed the
governors would immediately disengage a vertical rod from the said pusher, allowing
the slide to remain shut, and consequently neither gas nor air taken into the cylinder.
This arrangement ensures economy of gas, for there are no waste spaces; and there is
also greater certainty of ignition, as by the use of the slide I am better able to propor-
tion the gas and air than hitherto. At the same time the arrangement herein specified
permits me to dispense with one valve.
Fourthly, my invention relates to the method of igniting the gas, and has reference
to a prior Patent granted to me, No. 69908; but instead of using the igniting
instruments for the purpose of igniting in two chambers by means of one bent red-
hot tube, I now propose to use only one red-hot tube for one cylinder. From practical
experience I find that it is best to arrange the tube in a vertical position, and the tube
itself to be straight, without any bends, and also the communicating passage between
the tube and the comprersion or ignition chamber should be as short in length and as
small in diameter as it is possible to be. To effect this purpose I fix the ignition tube
on the top of the compression chamber end, and communicating therewith by a small
hole. I also make that part of the chamber end where the tube is fixed of a reduced
diameter, whereby I am enabled to use a much shorter ignition tube.
By the employment of the apparatus as above set forth, the number of working parts
and consequent wear and tear thereof are reduced, and in engines of the type referred
to herein at least four valves with their attendant connections have hitherto been
employed for the proper working of the engine, but in gas engines constructed
according to my invention only two valves are required, which are of the most simple
construction.

page_text: I, HUGH CAMPBELL, of 27 Gerrard Street, Halifax, in the County of York,
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 :-
My improvements have reference to that description of gas motor engines where
two cylinders are employed, arranged side by side, one of which is called the pump
cylinder, and the other the motor cylinder, the function of the former being to supply
at a given time combustible mixture to the latter cylinder, where it is afterwards
compressed, ignited, expanded, and exhausted.
My improvements in such engines relate, firstly, to the cylinders, which have hitherto
been cast together, but it is now my intention to cast such cylinders separately, and to
couple them together by an arm or bracket projecting from (preferably) the pump
cylinder, which is fastened by bolts or other suitable means to the jacket of the inotor
cylinder, whereby I dispense with the necessity of having the compression chamber
and pump cast together, as is now the case; consequently greater simplicity and
efficiency are obtained.
In order that the first part of my invention may be better understood, I herein
give reference to the accompanying sheet of drawings, wherein Fig. 1 is an end
elevation of such parts of a gas motor engine as is necessary to shew my
improvements.
Fig. 2 is a view of the opposite end of the said engine.
Fig. 3 is sectional elevation.
Fig. 4 is sectional plan, and
Fig. 5 cross section through the line a-b of Fig. 4, shewing exhaust port a'.
In the drawings A represents the pump cylinder, the function of which is to supply
at a given time combustible mixture to the motor cylinder B where the combustible
mixture is compressed and ignited, and instead of these two cylinders forming one
casting, as hitherto, I form on the pump cylinder a bracket C, which by means of bolts c,
such bracket is attached and made secure to the jacket of the motor cylinder A. Of
course it is obvious that the bracket C may project from the jacket of the motor
cylinder, and be attached by bolts to the pump cylinder, but I prefer the bracket to
project from the pump cylinder. By making these two cylinders in separate castings,
they are easier to be moved, and if one of the cylinders should happen to be faulty,
a fresh one can be formed without destroying both of them, which was formerly
unavoidable.
Secondly, my invention has reference to the pipe which supplies the mixture of air
and gus from the pump cylinder to the motor cylinder. Hitherto this admission pipe
has been made to branch from the bottom of the pump to the motor cylinder, con-
sequently when grease or other matter was lodging in the bottom of the pump, cylinder
it would be forced through the admission pipe into the compression chamber.
To

page_text: obviate this I place the said admission pipe about the centre of the pump, or any other
place above the level of the bottom, so that nothing but the admixture of air can be
forced through the said pipe.
This part of my invention is shewn in Fig. 1, where A and B are respectively
the pump and motor cylinders, and D is the branch pipe, which conveys the com-
bustible mixture from the pump cylinder to the motor cylinder, which pipe, it will be
observed, is made to branch from the middle of the pump cylinder, consequently the
greasy or other objectionable matter which is lying below the orifice of the said branch
pipe cannot make its way through the branch pipe into the motor cylinder, by which
means nothing but gas, free from impurities, can enter into the valves and motor
cylinders.
Thirdly, my improvements refer to the means for supplying the combustible mixture
to gas engines, and this I accomplish by opening the gas and air inlet valves, which
valves I preferably make of the slide type, rectangular or circular in section. Passages
are made in and through this slide valve, for the air and gas to be drawn, by the
action of the piston, into the pump cylinder; to permit this to be done I make a recess
in the back of the slide, and communicating with this recess I arrange the air and gas
ports in such a manner that the air is drawn across the gas ports, and on the gas
issuing therefrom, such air and gas would be thoroughly mixed. This part of my
invention is illustrated in Fig. 1, which is end elevation of valve arrangement, and
Fig. 6 cross section of same. The valve casing Fis fixed upon the air box F¹, and G
is the inlet pipe for the reception of atmospheric air, which passes through the port d.
The inlet for gas is shewn at H, such gas passing through a number of small apertures e.
The sliding valve is indicated by letter I, the back of which is cut away or recessed
at f, such recessed part communicating with two ports g and h, formed in the said
valve, so that when the ports in the sliding valve become opposite to the parts and d,
the atmospheric air and gas are admitted together and meet in the recessed part f
formed at the back of the slide valve, whereby the air and gas mix and blend together
before passing through porti and into the pipe D on their way to the pump cylinder A.
The slide 1 is pushed at the proper time by means of the rod J which has a
reciprocatory motion given to it by cam, eccentric, or other means. The reciprocatory
rod strikes the lower end of the cranked rod K connected to the forked lever L, the
forked end of which lever passes around a sleeve M of the governors, therefore when
the engine runs at its normal speed the lower end of the cranked rod K is immediately
opposite the point of the reciprocatory rod J, by which means the slide is pushed
forward with exact regularity, thereby allowing a proper charge of gas and air to be
drawn into the motor cylinder, but should the engine exceed the normal speed, the
governors would immediately open out, causing the sleeve M to rise, in doing which,
the forked lever L would cause the lower end of the cranked lever K to descend
beyond the reach of the point of the reciprocatory rod J, consequently the valve
would not be operated, therefore neither gas nor air would enter the cylinder, in
which case the engine would immediately stop.
The arrangement above described ensures economy of gas, and there is also greater
certainty of ignition, as by the use of the slide I am better able to proportion the gas
and air than has hitherto been possible. At the same time the arrangement herein
specified permits me to dispense with one valve hitherto used for this purpose.
Fourthly. My invention relates to the method of igniting the gas, and has reference
to a prior Patent granted to me, No. 6990; but instead of using the igniting
instruments for the purpose of igniting in two chambers by means of one bent red
hot tube, I now propose to use only one red hot tube for one cylinder. From practical
experience I find that it is best to arrange the tube in a vertical position, and the tube
itself to be straight, without any bends, and also the communicating passage between
the tube and the compression or ignition chamber should be as short in length and as
small in diameter as it is possible to be. To effect this purpose 1 fix the ignition tube
on the top of the compression chamber end, and communicating therewith by a small
hole. Prior to my invention the orifice of the ignition tube was placed directly over
the centre of the admission valve, where it was thought the combustible mixture

page_text: would be strongest and ignition most sure, but in practice it is found, that to place
the tube in that position, caused premature ignitions of the combustible mixture,
therefore I form a chamber or recess in the end of the compression chamber, into which
I place the orifice of the tube. I also make that part of the chamber end where the
tube is fixed of a reduced diameter, whereby I am enabled to use a much shorter
ignition tube.
This part of my invention is shewn in Figs. 3 and 4, where E represents the gas
compression chamber, one end of which I make taper or less in diameter, and in this
tapered part of the compression chamber I form a chamber or recess n into which is
inserted the igniting tube N. By this means I am enabled to dispense with the use of
the bent tube hitherto employed, using instead thereof a straight tube without any
bends, consequently there is less length of tubing to be heated, thereby diminishing
the amount of fuel required to bring the tabe into an incandescent condition.
By the employment of the apparatus as above set forth, the number of working parts
and consequent wear and tear thereof are reduced, and in engines of the type referred
to herein at least four valves with their attendant connections have hitherto been
employed for the proper working of the engine, but in gas engines constructed
according to my invention, only two valves are required, which are of the most simple
construction.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is :-
Firstly. In gas motor engines, the formation of the pump cylinder and motor cylinder
separately, and connecting them together by brackets in manner substantially as
herein described and illustrated.
Secondly. In gas motor engines, the employment of a slide valve having a recessed
part at the back thereof where the gas and air meet and mingle previous to entering the
ignition chamber, all arranged and operated in the manner shewn and described.
Thirdly. In gas motor engines, the formation of the chamber n in the end of the
compression chamber for the reception of an ignition pipe such as N, as described and
shewn in the drawings.
Fourthly. The general combination and arrangement of parts forming my improved
gas motor engine, substantially as herein shewn and described.
.. 1000
TASKER & CROSSLEY,
Halifax, Agents.