GAS MOTOR ENGINES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by the said Robert Ord at the Office
of the Commissioners of Patents on the 26th July 1881.
ROBERT ORD, of Devizes, in the County of Wilts, Engineer.
GAS MOTOR ENGINES."
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IMPROVEMENTS IN
My Invention relating to improvements in gas engines having a piston working
in a cylinder in which an explosion of a mixture of gas or combustible vapor and
air is effected, causing the piston to move and communicate motion through a
connecting rod or other attachment to a crank shaft, has for its object increasing
the certainty of firing the mixture of air and gas in the cylinder, and thus enable
the engine to be run at a greater speed than heretofore; and it consists in combining
with the cylinder or cylinders of a gas engine a pump or pumps for the purpose
of forcing gas into the lighting chamber or chambers and air into or contiguous
to the chamber or chambers, whereby a certainty of ignition of the charge is
obtained.
According to one mode of carrying out my Invention I provide on the side or
on the end of the cylinder a face having one or more ports leading to the interior
of the cylinder, and through which port or ports the charge of air and gas is
admitted to the cylinder by means of a slide valve, in the lower part of which
valve is formed a chamber which I call the lighting chamber. When this valve is
depressed by a cam on the crank shaft or otherwise, the ports are open to the
cylinder, and air and gas then flow into it and forin the explosive charge; at the
same time the lighting chamber in the slide valve is exposed to the open air, and a
quantity of gas is forced through convenient passages into this lighting chamber
by a pump, whilst a flame from a fixed burner in the open air is forced by another
pump into or close to the lighting chamber, thus igniting the gas flowing into it
from the gas pump.
At a point about one third of the stroke of piston the slide
valve is suddenly raised, thereby cutting off the supply of air and gas, and at the

page_text: same time bringing the lighting chamber in communication with a cylinder port
and firing the charge therein, thus giving motion to the piston.
Upon the piston arriving at the end of the stroke, a slide valve on another face
of the cylinder is opened, permitting the spent charge to leave the cylinder through
a pipe to the open air. This valve, which I call the exhaust valve, together with
the air pump and the gas pump, I prefer to give motion to from an eccentric keyed
on to the crank shaft, but separate eccentrics or other means may be used.
Instead of employing two pumps, as herein before described, one compound pump
may be employed to force the gas to the lighting chamber, and the air (which
carries the flame from the fixed burner) to its immediate vicinity.
According to another mode of carrying out my Invention, I make openings in
the side of the piston, and also an enlargement of the internal diameter of the
cylinder for about one third of the stroke up, or from one end thereof, and admit
the air of the charge to flow through and be cut off by the openings in the piston,
the gas to complete the charge being admitted by a slide valve similar to and
worked in the same manner as that before described with reference to the first
modification; the slide valve however may be smaller, as it has only to admit to
the cylinder gas, or gas with a small admixture of air, and to ignite the charge, and
is used in the larger engines in preference to increasing the size of the slide valve.
In combination with this arrangement of piston I employ two pumps, or a compound
pump, as in the previously described arrangement.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Ord in the Great Seal Patent Office on the 4th January
1882.
ROBERT ORD, of Devizes, in the County of Wilts, Engineer. "IMPROVEMENTS IN
GAS MOTOR ENGINES."
My said Invention relates to improvements in gas engines having a piston
working in a cylinder in which an explosion of a mixture of gas or combustible
vapour and air is effected, causing the piston to move and communicate motion
through a connecting rod or other attachment to a crank shaft, and it has for its
object increasing the certainty of firing the mixture of air and gas in the cylinder,
thus enabling the engine to be run at a greater speed than heretofore. In order to
effect this object I employ a pump for forcing gas into the lighting chamber, and
another pump for forcing air into or contiguous to the lighting chamber in such a
manner as to blow the flame of a fixed light into the said chamber in order that
the ignition of the gas therein may be effected preparatorily to the firing of the
charge in the cylinder. Or in lieu of using two separate pumps, one for air and
the other for gas, I may employ a compound pump for the same purpose. I also
sometimes form ports in the piston for the admission of the air, or a portion
thereof, necessary to form the explosive charge.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheets of Drawings, the same letters of reference
indicating corresponding parts in. all the Figures.
Figures 1 and 2 (on Sheet 1) of the accompanying Drawings represent respec-
tively elevation of opposite ends of a gas motor engine constructed according to
my said Invention, Figure 1 being shown partly in section and with the flywheel
removed; Figure 3 is a sectional elevation taken at right angles to Figures 1 and 2;
and Figure 4 is an elevation; and Figure 5 (Sheet 2) is a sectional elevation of
portions of the engine; Figure 6 is a face view of the back plate for the induction
slide valve, hereinafter referred to; Figures 7 and 7 represent the induction slide
valve in detail; Figures 8 and 9 are respectively a vertical and a horizontal section
of a portion of an engine constructed according to a modification of the arrange-
ment illustrated in Figure 1 to 7; Figure 10 represents in detail the induction
slide valve adapted for the modification shewn in Figures 8 and 9; and Figure 11
is a view of the face of the back plate against which the valve works.
Referring to Figure 1 to 7º, A is the cylinder of the engine in which the
explosive charge of gas and air is fired, so as to impart motion to a piston B fitted
in the said cylinder, and which is connected by a rod C with the crank of a crank
shaft D mounted in bearings in the frame E of the engine, and carrying a
flywheel Z
The admission of gas and air to the cylinder and to the lighting chamber, and
the ignition of the lighting charge, and the firing of the main charge are con-
trolled by a slide valve F (shewn in detail in Figure 7, which is forced downwards
by means of a snail cam G on the shaft D acting on the end of the connecting
rod a, and as soon as the projection b releases the rod it is raised again under the
action of a spring c taking its bearing upon a projection d of the main frame, n
spring bolt e being employed for limiting the rise and preventing concussion in the
working of the valve, for which purpose it is provided with a bevelled end f acting
upon a corresponding inclined surface on the valve rod. The cam G is mounted
loose on the shaft D and formed with a groove 11, so shaped that during the
rotation of the shaft in the right direction the cam will partake of its motion by
reason of a spring bolt 12 in a collar 13 fast on the shaft engaging with the saiḍ
groove, whilst if the shaft be turned in the opposite direction the spring bolt 12
will be inoperative upon the cam.
The spent gases are discharged from the cylinder by means of a slide valve H

page_text: operated by an eccentric I on the shaft D, through the intervention of a connecting
rod g and crosshead h, the gases escaping through a passage 16 at port 15 in the
valve, and a port 14 in a back plate M into the atmosphere. The eccentric I also
operates an air pump K and a gas pump L, the plungers k, l, respectively of the
pumps being connected at their lower ends to the crosshead h.
These pumps, the use of which for the purposes hereinafter explained forms an
important feature of my Invention, perform the following functions. The gas
pump L supplies gas to a lighting chamber i in the slide valve F for firing the
charge. The air pump K supplies a current of air to act upon the protruding flame
from a fixed light at m in a cone n, in such a manner that when the lighting
chamber is brought within range of it, the light and air are blown into the lighting
chamber, and the gas which has been admitted therein is ignited in readiness for
firing the main charge.
The gas for supplying the engine generally is admitted from the main at o to a
chamber p. It then passes in one direction into a gas bag q, from which it is
conducted through a regulating valve into a smaller gas bag s, whence it passes
through pipes and passages t to ports u in the back plate v (see Figures 3 and 6)
of the slide valve, and thence (when such parts are uncovered) into the interior of
the slide valve, and through a port w into the cylinder. Air (to form with the gas
the explosive mixture) is admitted from the open atmosphere through ports, and
(when such ports are uncovered by the slide valve) through port w to the cylinder.
From the chamber p the gas is also supplied to the burner m in the cone n
through a pipe y, a regulating cock z being provided in the said pipe.
The supply of gas for the gas pump L is also derived from the chamber p through
the intervention of a pipe 1. The gas so drawn in is then forced by the pump
through a valve 2 into a pipe 3, whence it is conducted by pipes 4 to a port 5,
opening (when uncovered by the slide valve) into the lighting chamber Z¹, the
pipe 4 being provided with a suitable regulating valve 6, and a surplus pressure
valve 7 (Figure 5) being also arranged in connection with the pipe for conducting
any excess back again into the chamber p.
The air for forcing the flame from the cone into the lighting chamber is drawn
from the external atmosphere through a suction valve 8 and then forced by the air
pump K through a delivery valve 9 and pipe 10, which latter terminates opposite the
. protruding flame from the cone, so that when the slidė valve F is in its lowest
position with the open side of the lighting chamber opposite the cone, the flame
and air will be forced into the lighting chamber, thus effecting the ignition of the
gas contained therein.
Spaces N for containing water are provided in the framing of the engine and in
the back plates.
The engine operates in the following manner :-
Upon the main cock (not shewn in the Drawings) and the small cocks and G
being opened, gas is admitted through the chamber p to fill the gas bag q, also the
pipes 1 and y; the gas at the burner m in the cone n is then lighted, the regulating
valve opened, and the fly wheel Z2 pulled round in the direction indicated by the
arrow, Figure 2.
As the plungers k, l, of the pumps K, L, descend, air enters the pump K through
the valve 8, and gas enters the pump L through the pipe 1.
When the piston B
has arrived at the bottom of its stroke the plungers k, l, will have accomplished
one half of their upward stroke, the plunger in the pump L will have passed a
groove formed in the pump barrel at the part where the pipe 1 is connected to it,
so that all the gas above it must pass through the valve 2 and pipes and passages 3
and 4. The piston B being at the bottom of its stroke and the fly wheel being
still pulled round, the cam & depresses the valve F through the intervention of the
rod a, thus opening the lighting chamber i to the outer air, and also opening the
small port 5 through which, and the pipes 3, 4, gas is being forced by the pump L;
this gas is at the same time lit by the frame protruding from the cone n, being
-blown into it by the air from the pump K coming through the pipe 10.

page_text: The air ports x and gas ports u are at this time also open, admitting the explosive
charge beneath the piston B through the valve F and port w.
When about one third of the up stroke of the piston B has been accomplished,
the cam C permits the spring c to raise suddenly the valve F, thereby closing all
the ports in the back plate v and opening the lighting chamber i to the port W,
thus igniting the charge in the cylinder. (In my Drawings the ports are
represented as having just arrived at this position.) The explosion caused by the
ignition of the charge forces the piston up to the top of its stroke, when the port 15
in the valve H is by the action of the eccentric I brought opposite the passage 16
in the cylinder and the port 14 in the back plate M, thus permitting the exit of
the spent charge.
Should more gas than is required be forced through the lighting chamber i the
cock 6 is turned partially off, when the pressure in the pipe 4 causes a valve 7
(Figure 5) in the bottom of the chamber p to open, and the excess is conducted
back into that chamber,
In the modification illustrated in Figures 8, 9, 10, and 11, a small valve F
(Figure 10) is used for the admission of the gas, and only small ports (Figure 11)
are provided in the back plate v for a small portion of the air of the explosive
charge, the bulk of the air according to this modification is admitted to the cylinder
through apertures 17 in the piston B, and through two segmento-annular recesses 18
formed at the lower part of the cylinder.
As the piston travels upward from the bottom of the stroke air is admitted
through the apertures 17, and gas and a small portion of air is admitted through
the valve F until the piston arrives at the position shown in Figure 8, when the
apertures 17 are closed by the small port 19 of the cylinder. At the same moment
the cam G (not shewn in Figure 8) permits the spring c (also omitted in the
Figure) to raise the valve F, thus cutting off the supply of gas and firing the charge
in the manner hereinbefore described with reference to the arrangement illustrated
in Figures 1 to 7ª,
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
First. In a gas motor engine, in which the charge of air and gas is not
compressed, the use of a pump for forcing gas into the lighting chamber, substantially
as hereinbefore described.
Second. In a gas motor engine, the use of a pump for forcing gas into the lighting
chamber in combination with another pump for forcing air into or contiguous to
the lighting chamber, substantially as and for the purpose herein before described.
Third. In a gas motor engine, the use of a compound pump for forcing gas into
the lighting chamber, and for forcing air into or contiguous to the lighting chamber,
substantially as and for the purposes berein before described.
Fourth. In a gas motor engine, constructing the piston with ports for the
adınission of the air or a portion of the air of the explosive charge, substantially as
hereinbefore described.
In witness whereof, I, the said Robert Ord, have to this my Specification
set my hand and seal, this Thirtieth day of December, One thousand eight
hundred and nighty one
ROBERT ORD. (L.S.)