AN IMPROVEMENT IN OTTO OAS MOTOR ENGINES, A PART OF WHICH IS ALSO APPLICABLE TO OTHER GAS ENGINES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, FRANCIS WILLIAM CROSSLEY of Openshaw, Manchester, in the county of
Lancaster, Engineer, do hereby declare the nature of my invention for "AN
IMPROVEMENT IN OTTO OAS MOTOR ENGINES, A PART OF WHICH IS ALSO APPLICABLE
TO OTHER GAS ENGINES" to be as follows:-
In Gas Motor Engines of the "Otto" kind, operating with a cycle of 4 strokes,
for charging compressing, propelling, and discharging respectively, a countershaft,
revolving at half the speed of the main engine shaft, is employed to work the slide
for charging and igniting the exhaust valve, and the gas supply valve under
regulation of the governor. My invention relates to means of effecting these
operations without the aid of a countershaft and its gearing, employing wholly or
partly for this purpose variations of pressure that occur in the engine cylinder in
different parts of the cycle.
Parts of the apparatus which I employ for this purpose are applicable in Glas
Engines other than tho-o above referred to.
For charging, I employ two clack valves, one of them for air, opening towards
the cylinder so as to admit air when the piston creates a partial vacuum by its
forward charging stroke, but closing at all other parts of the cycle when the
pressure in the cylinder exceeds that of the atmosphere. The gas valve is opened
against the pressure of the gas supply by a lever or arm worked by the air valve,
so as to admit gas to the passage leading to the air valve above-mentioned, so that
the air and gas enter the cylinder together. But between the stem of the gas
valve and the lever or arm which works it I interpose a transversely sliding filling
piece connected to the governor in such a way that, when the speed exceeds the
normal rate, this sliding piece is withdrawn, and the air valve opens without
opening the gas valve; when, however, the speed is at or under the normal rate,
the governor allows the filling piece to be interposed by a spring between the stem
of the valve and the lever or arm of the air valve, so that when the latter moves
to admit air to the cylinder, the gas valve is opened to admit gas along with the
air. The governor may be of the ordinary centrifugal kind, having its lever
connected to the interposed sliding piece to operate as described. I prefer, however,
to employ a simpler form of governor admitting of direct connection to the sliding
piece. It consists of a boss having two or more wings inclined like the blades of
Den

page_text: a propeller; and, the 'bo-s being fitted to slide along its spindle in opposition to an
adjustable spring, whenever the speed exceeds the normal rate, the reaction of the
air on the inclined revolving wings causes the boss to move along its. spindle
withdrawing the sliding picce, and so leaving the air valve to open without opening
the gas valve.
For the purpose of igniting the charge in the cylinder, I employ a tube bent
into the form of an inverted U kept hot by an external flame as described in the
specification of my Patent N° 4489 of the year 1882, and, in order to prevent
circulation through the tube or passage of flame from its heated part except when
à current of mixed gas and air is forced through it, I place in the limbs of the tube
wires presenting between them narrow interstices through which the mixed gases
are forced at the moment of ignition by a small plunger attached to or worked by
the main piston when it completes its compressing stroke.
The above described arrangements for governing and igniting, being independent
of the particular cycle of strokes employed in the "Otto" engine, are obviously
applicable to gas engines of other kinds.
For the purpose of opening the exhaust valve during the discharging stroke,
I attach the stern of the exhaust valve, which opens towards the cylinder, to a
piston working in a small cylinder, which may be charged with oil, this piston
being pressed by adjustable springs.
The oil in the cylinder is in communication with a passage leading to the front
part of the main cylinder, and in the main piston there is a corresponding pas-nge,
so arranged that when the piston is about the end of its compressing stroke, these
two passages are in communication with one another. Thus, at or about the
moment of maximum compression or of ignition in the cylinder, the passage to the
oil cylinder becomes charged with a portion of the charge or of the products of its
combustion under considerable pressure, which, acting on the piston in the oil
cylinder, tends to open the exhaust valve; but this valve, being subject at the
same time to equal pressure in the cylinder remains closed. When, however, the
main piston has advanced towards the end of its outstroke, so that the pressure
within the cylinder is much reduced, the piston of the oil cylinder being still subject
to the pressure stored up in the passage lending to it, overcomes the springs and
opens the exhaust. In order to ensure sufficient reduction of the pressure in the
main cylinder, it may be provided with a side port which becomes uncovered by
the piston ns it completes its outstroke and permits escape of a portion of the
contents of the cylinder, thus reducing the pressure sufficiently to allow of the
exhaust valve being opened by the superior pressure acting on the piston of the
oil cylinder.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.

page_text: COMPLETE SPECIFICATION.
I, FRANCIS WILLIAM CROSSLEY, of Openshaw Manchester, in the county of
Lancaster, Engineer do hereby declare the nature of my said invention for "AN
IMPROVEMENT IN OTTO GAS MOTOR ENGINES A PART OF WHICH IS APPLICARLE
TO OTHER GAS ENGINES" and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement :—
In Gas Motor Engines of the "Otto" kind, operating with a cycle of 4 strokes,
for charging, compressing propelling, and discharging respectively, a countershaft,
revolving at half the speed of the main engine shaft, is employed to work the slide
for charging and igniting the exhaust valve, and the gas supply valve under
regulation of the governor. My invention relates to means of effecting these
operations without the aid of a countershaft and its gearing, employing wholly
or partly for this purpose variations of pressure that occur in the engine cylinder
in different parts of the cycle. Parts of the apparatus which I employ for this
purpose are applicable in Gas Engines other than those above referred to.
For charging, I employ two clack valves, one of them for air, opening towards
the cylinder so as to admit air when the piston creates a partial vacuum by its
forward charging stroke but closing at all other parts of the cycle when the
pressure in the cylinder exceeds that of the atmosphere. The gas valve is opened
against pressure of the gas supply by a lever or arm worked by the air valve, so
as to admit gas to the passage leading to the air valve above mentioned, so that
the air and gas enter the cylinder together. But between the stem of the gas
valve and the lever or arm which works it, I interp sen transversely sliding filling
piece connected to the governor in such a way that, when the speed exceeds tho
normal rate, this sliding piece is withdrawn, and the air valve opens without
opening the gas valve; when, however, the speed is at or under the normal rate,
the governor allows the filling piece to be interposed by a spring between the stem
of the valve and the lever or arm of the air-valve, so that, when the latter moves
to adunit air to the cylinder, the gas valve is opened to admit gns along with the
air. The governor may be of the ordinary centrifugal kind, having its lever
connected to the interposed sliding piece to operate as described. I prefer however
to employ a simpler form of governor, admitting of direct connection to the sliding
piece. It consists of a boss having two or more wings inclined liko the blades of
a propeller, and the boss being fitted to slide along its spindle in opposition to an
ndjustable spring; whenever the speed exceeds the normal rate, the reaction of the
air on the inclined revolving wings causes the boss to move along its spindle
withdrawing the sliding piece and so leaving the air valve to open, without
opening the gas valve.
For the purpose of igniting the charge in the cylinder, I employ a tube bent
into the form of an inverted U, kept hot by an external flame, as described in the
specification to my patent No 4489 of the yoar 1882, and in order to present

page_text: circulation through the tube or passage of flame from its heated part except when
a current of mixed gas and air is forced through it, I place in the limbs of the
tube wires presenting between them narrow interstices, through which the mixed
gases are forced at the moment of ignition by a small plunger attached to or
worked by the main piston when it completes its compressing stroke.
The above described arrangements for governing and igniting, being independent
of the particular cycle of strokes employed in the "Otto" gas engine, are obviously
applicable to gas engines of other kinds.
For the purpose of opening the exhaust valve during the discharging stroke,
I attach the stem of the exhaust valve, which opens towards the cylinder, to
a piston working in a small cylinder, which may be charged with oil, this piston
being pressed by adjustable springs.
The oil in the cylinder is in communication with a passage lending to the front
part of the main cylinder, and in the main piston there is a corresponding passage
so arranged that when the piston is about the end of its compressing stroke, these
two passages are in communication with one another.
Thus at or about the moment of maximum compression or of ignition in the
cylinder the passage to the oil cylinder becomes charged with a portion of the
charge or of the products of its combustion under considerable pressure, which,
acting on the piston in the oil cylinder tends to open the exhaust valve; but this
valve, being subject at the Faino time to equal pressure in the cylinder, remains
closed. When, however, the main piston has advanced towards the end of its
outstroke, so that the pressure within the cylinder is much reduced, the piston of
the cylinder being still subject to the pressure stored up in the passage leading
to it overcomes the springs and opens the exhaust. In order to ensure sufficient
reduction of the pressure in the main cylinder, it may be provided with a side port
which becomes uncovered by the piston as its completes its outstroke and permits
escape of a portion of the contents of the cylinder, thus reducing the pressure
sufficiently to allow of the exhaust valve being opened by the superior pressure
acting on the piston of the oil cylinder. Fig. 1 of the accompanying drawings is
a side view, fig. 2 is an end view, and fig. 3 is a plan, of the cylinder of a gas
motor engine with my invention applied thereto Parts of these figures are drawn
as if in section in order to shew the internal construction. E is the air supply
valve which opens upwards towards the cylinder but is kept closed by its weight
and a light spring e except when the piston makes its outward charging stroke
creating a partial vacuum in the cylinder; the valve is then opened by the excess
of atmospheric pressure, and air enters the cylinder following the piston in its
outstroke. G is the gas supply valve which is usually kept closed by the pressure
of the gas, but which is opened when the air valve E opens by means of the
lever F, that is raised by the stem of the air valve and raises the bent arm B
which is interposed between it and the stem of the gas valve G. The arm B is
jointed to a ring held between collars on the boss of the governor which is made
with inclined blades A, this boss being capable of sliding longitudinally in opposi-
tion to a spring adjustable by a screw nut a. When the engine exceeds its normal
rate the wings A in revolving rapidly through the air are pressed towards the
left and withdraw the arm B from under the stem of the gas valve G. In that
case the ascent of the air valve E and the lever F fails to raise the gas valve, and
thus the engine receives no supply of gas until the speed becomes so far moderated
that the spring presses back the governor boss and wings; and again brings the
arm B in position to act on the stem of the gas valve.
For igniting the charge of combustible mixture in the cylinder, the bent tube m
extending from the cavity above the air valve E to an orifice at the end of the
cylinder, is heated by the flame of an annular burner L which is supplied with a
mixture of gas and air from a mixing ball X. In the lower part of the tube m
there is a bundle of wires i which, by throttling the passage through the tube, and
by their cooling influence on any gas passing down the tube, prevent ignition of

page_text: gaseous mixture in the cylinder except when it is forced upwards through the
interstices of the wires and through the beated part of the tube, by the plunger H
which is attached to the main piston D. When the piston D makes its back stroke,
compressing the charge in the cylinder, a portion of the gaseous mixture is forced
by the plunger H past the wires i, becoming gradually heated by them on its way
until it is ignited by the hot upper part of the tube and communicates ignition to
the compressed charge in the cylinder.
The exhaust valve U which is usually held down by a light spring & as well as
by the pressure of the fluid contents of the cylinder, is opened for discharge in the
following manner. A vessel P, partly filled with oil, communicates at its upper
part by a pipe o with a lateral orifice of the cylinder. Above this vessel is fitted a
piston valve g, between which and a collar on the stem of the exhaust valve there
is a spring r. When the main piston D is beginning its outstroke subject to the
pressure of the ignited charge, a passage n through the piston, in passing over the
mouth of onllows a portion of the high pressure fluid to flow from the cylinder into
the top of the vessel P. This presses oil up the pipe P¹ into the cavity V where it
acts on the piston valve 9 pressing it upwards to its seat. This compresses tho
spring r, but this spring cannot lift the valve U because it is held down by the
pressure of the fluid in the cylinder. When, however the piston D has so far
advanced in its outstroke that the pressure in the cylinder is less than the force of
the spring, the exhaust valve U opens allowing escape from the cylinder. In
order to ensure sufficient reduction of pressure in the cylinder, I provide a lateral
escape port T which is uncovered by the piston D, as it approaches the end of its
outstroke. With arrangements such as I have described for the admission and
ignition of the charge and for discharge of the exhaust, an engine working after
the manner of the "Otto" engine acts in the following cycle of four strokes
occupying two complete revolutions of the crank shaft. Assuining the speed to be
moderate, so that the arm B is immediately under the stem of the gas valve G, the
piston D makes-
1st Its charging outstroke, during which the atmospheric pressure, lifts the air
valve E and the lever F opens the gas valve G, while the spring & keeps the
exhaust valve U closed. The cylinder having thus received its charge of air and
gas, the piston D makes--
2nd, its return in-stroke compressing the charge. By the pressure in the cylinder
the air valve E and the exhaust valve U are kept closed during this stroke. As
the piston approaches the end of its instroke the plunger H. forces a portion of the
combustible mixture through the tube m, and thus the compressed charge is
ignited.
3rd, The piston D is now propelled by the expansion of the ignited charge, the
pressure of which keeps the air valve E and the exhaust valve U closed. A portion
of the high pressure contents of the cylinder passes by n and o to the vessel P
where it effects the closing of the piston valve 9 and the compression of the
spring r. As the piston D approaches the end of its outstroke, uncovering the
port T and so relieving the pressure in the cylinder, the exhaust valve U is opened
by the spring r and kept open by the pressure which is still maintained in P.
4th The piston D now makes its back-stroke expelling products of combustion by
the exhaust valve U until, as it approaches the end of its stroke making
communication from o to n, the pressure in P is relieved and the exhaust valve Ū
closes.
The cycle is then repeated.
Although I have described the charging, gas governing and igniting apparatus
as employed in the action of an engine of the "Otto kind with a cycle of
4 strokes as above set forth, it is obvious that independently of this particular
cycle, the apparatus might be applied in any gas engine in which the main piston
by its outstroke draws in the cylinder charge and, by the succeeding instroke,
compresses it.

page_text: 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 in respect of gas motor engines, is
1, Effecting admission of the cylinder charge and emission of the exhaust by
valves worked by the variations of pressure in the cylinder, without the
interposition of cains or their equivalents on a revolving shaft, substantially as
herein described.
2, Regulating the engine speed by means of an arm which is raised by the
opening of the air supply valve, and which, as determined by a governor, is
brought into position to act or not to act in opening the gas supply valve,
substantially as herein described.
3, Effecting ignition of the cylinder charge by a plunger attached to the piston
forcing a portion of the combustible mixture through a heated tubo containing
wires, substantially as herein described.
4. Opening the exhaust valve by a spring which is strained by a piston acted on
by fluid, subject, for a time, to the pressure of the ignited charge in the cylinder,
substantially as herein described.