IMPROVEMENTS IN GAS-MOTOR ENGINES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, WILLIAM JOHN MUNDEN, of 17 Sutton Street, York Road, Lambeth, in the
County of Surrey, Engineer, do hereby declare the nature of my invention. for
IMPROVEMENTS IN GAS-MOTOR ENGINES to be as follows:-
This Invention relates to that description of Gas-motor Engines wherein the
mixture of air, and any inflammable gas, or vapour is drawn into the cylinder, and
ignited when at, or about the same pressure as the atmosphere. In this description
of Gas-motor Engines as at present constructed one or more slide valves are used
for the purpose of opening and closing the igniting port; regulating the ingress of
the mixture of air, and gas, and the egress of the products of combustion, or
exhaust; and this valve, or these valves are actuated by one or more excentrics,
cams, or wheels upon the crank shaft, or upon an intermediate shaft used for that
purpose. This Invention has more particularly for its object the construction of
a Gas-motor Engine in which the valves regulating the admission of the mixture
of air and gas, and the egress of the exhaust products of combustion are what are
commonly called automatic; that is requiring neither excentrics, cams, wheels, or
rods of any kind to move them, but are actuated either by the effects of Gravity;
by the suction of the piston; or by the pressure produced in cylinder by explosion
of the charge.
This is effected in a single-acting vertical Engine, in which the upper end of the
cylinder is open to the atmosphere as follows:-A vertical passage is made by the
side of the cylinder, one end of which passage opens into the lower end of
the cylinder, underneath the air-valve; the other end is so arranged that it is open
to the upper, or open end of the bore of the cylinder at such a height that it
remains open during the first half of the stroke of the piston while the mixture of
air and gas is being inspired, but is closed by the piston covering such opening
at the instant of ignition. This passage may be made to open through the side of
the cylinder at its closed end, but is preferably continued into the cylinder cover,
and thence the mixture of air and gas passes into the cylinder through a valve
hinged upon one side of the inside face of the cylinder cover. When this valve is
open for the passage of the air into the cylinder, the gas is also being admitted, as
the same valve regulates the admission of both air and gas, and secures a thorough
admixture of the two; and the same motion of the air-valve when it rises to
admit the mixture, closes the exhaust valve; which is hinged upon the other part

page_text: of the inside face of the cylinder cover in such a manner that it opens, (in the
absence of pressure in the cylinder,) by the Gravity of its own counterweight;
except when it is held close by the upward pressure of the air-valve, which is of
greatly superior area.
The cycle of operation is as follows:-The piston being at the lower end of its
stroke, and the Exhaust valve still open, (as it has been during the down, or
exhaust stroke previous) the crank shaft being kept in motion by the momentum
of the fly-wheel, the crank draws the connecting-rod, and thereby the piston,
upwards. During the first part, (about half) of this upward stroke, the upper end of
air-passage will be open, by reason of the piston not yet having reached, and thereby
closed it. The air passes down through this passage, and through the cylinder
cover; the air-valve is drawn open by the suction of the piston, and the air
Intimately mixing with the gas as it passes through the valve, follows the piston
into the cylinder, until the upper end of the air-passage is reached, and covered by
the upper edge of the piston. At the same instant the ignition is effected, either
by the motion of the piston uncovering a port placed in the side of the cylinder
for that purpose, or by any of the ordinary means of ignition available. The
increased pressure on the inside of the cylinder, consequent upon combustion causes
the air valve to close, and also holds the exhaust valve closed until the piston has
been forced nearly to the end of its stroke, when its motion uncovers a port open
to the atmosphere, and this reduces the pressure in the cylinder to that of the
atmosphere; and Gravity then opens the exhaust valve, thus enabling the remaining
products of combustion to escape freely during the downstroke of the piston,
thereby completing the cycle, and being in the same position as before.
Dated this eighth day of March 1884

page_text: I, WILLIAM JOHN MUNDEN, of 17 Sutton Street, York Road, Lambeth, in the
county of Surrey, Engineer, do hereby declare the nature of my invention for
IMPROVEMENTS IN GAS-MOTOR ENGINES, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This Invention relates to that description of gas-motor engines wherein the
mixture of air, and any inflammable gas, or vapour is drawn into the cylinder,
and ignited when at, or about the same pressure as the atmosphere. In this
description of gas-motor engines as at present constructed, one or more slide-valves
are used for the purpose of opening and closing the igniting port, regulating the
ingress of the mixture of air and gas, and the egress of the products of combustion
or exhaust; and this valve, or these valves are actuated by one or more exentries,
cams, or wheels upon the crank shaft, or upon an intermediate shaft used for that
purpose. This Invention has more particularly for its object the construction of
a gas-motor engine in which the valves regulating the a mission of the mixture
of air and gas, and the egress of the exhaust products of combustion are what is
commonly called automatic, that is requiring neither excentrics, cams, wheels, or
rods of any kind to move them, but are actuated either by the effects of gravity,
by the suction of the piston, or by the pressure produced in the cylinder, by
explosion of the charge.
This is effected in a single-acting vertical engine in which the upper end of the
cylinder is open to the atmosphere as follows:-A vertical passage is made by the
side of the cylinder, one end of which passage opens into the lower end of
the cylinder underneath the air valve; the other end is so arranged that it is open
to the upper or opend end of the bore of the cylinder at such a height that it
remains open during the first half of the upstroke of the piston while the mixture
of air and gas is being inspired, but is closed by the piston covering such opening
at the instant of ignition. This passage may be made to open through the side of
the cylinder at its closed end, but is preferably continued into the cylinder cover,
and thence the mixture of air and gas passes into the cylinder through a valve
hinged upon one side of the inside face of the cylinder cover. When this valve is
open for the passage of the air into the cylinder, the gas is also being admitted, as
the same valve regulates the admission of both air and gas, and secures a thorough
admixture of the two; and the same motion of the air valve when it rises to admit
the mixture, closes the exhaust valve, which is hinged upon the the other part of
the inside face of the cylinder cover, in such a manner that it opens, (in the
absence of pressure in the cylinder), by the gravity of its counterweight, except
when it is held close by the upward pressure of the air valve which is of greatly
superior area.
These valves can be applied either to a vertical, or horizontal engine, the only
difference being that where the valves are placed upon a vertical face, or seating,
or under a horizontal face or seating the weight of the exhaust valve itself will
cause it to open, whereas when the valves are placed upon a horizontal face or
seating, a counterweight is necessary to effect this, but by the introduction of a light
spring connecting the two valves, so as to hold the exhaust valve open, the air and
gas valve G may be utilized as a counterweight for the exhaust valve J.
In the accompanying Drawing:-
Fig. 1 is a longitudinal vertical section of a horizontal engine, through the centre
of the cylinder.
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2 is a plan of the same with the cylinder and cover in section.
3 is a plan, to an enlarged scale, of the valves for such an engine, with the

page_text: Fig. 4 is a vertical section of the same, showing also the cylinder cover and
passages.
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5 is a vertical section of the valves, and cylinder cover, as applied to a
vertical engine in which the cylinder is under the crank shaft.
6 is a vertical section of the valves, and cylinder cover, as applied to a
vertical engine in which the cylinder is inverted over the crank shaft.
The same letters apply to the same parts in either figure; and the Drawing
shews the piston and valves in position at half stroke, just as an explosion takes
place closing the valves G and J.
The action of the engine is as follows :—
The air enters the open front end of the cylinder, (that is the end nearer the
crank shaft Fig 1.) is drawn through the opening A, and along the passage B until
it reaches a continuation C of this passage into the cover D, whence mixing with
the gas coming from the orifices F, and the pipe E, this mixture is admitted by the
lifting of the valve G into the bore of the cylinder H. This valve G is hinged
upon the pin O and is lifted by the suction of the piston I during the first half of
its outstroke. This continues until the piston I has during its outstroke reached
and covered the opening A of the passage B, thereby preventing the further
admission of air to the passage B. At this instant the mixture of air and gas
already amitted to the cylinder H is ignited by any means available, and the
pressure resulting from explosion causes the piston to complete its outward stroke,
the thrust from which is communicated in the ordinary manner by means of
a connecting rod to the crank, and crank shaft upon which is fixed a fly-wheel
which by its momentum causes the crank shaft to continue its rotation. The
pressure in the cylinder consequent upon explosion also closes the air and gas
valve G, (thereby stopping the passage of both air and gas,) and holds close the
exhaust valve J, (which is preferably hinged upon the same pin O, as the air and
gas valve G) until the piston reaches nearly to the end of its outstroke, and
uncovers the end K (Fig. 1) of the exhaust passage L, (which communicates
through the exhaust pipe M with the atmosphere,) thereby allowing the escape of
part of the exhaust products of combustion, and reducing the pressure in the
cylinder to that of the atmosphere. This pressure being so reduced, allows the
opening of the exhaust valve J, (by its own weight as shown in Figs. 3, 4, and 6;
and as shewn in Fig. 5 by the weight of its counterweight N), until the stop N
meets the air and gas valve G which prevents it from opening further, and it
remains in this open position during the instroke of the piston, thus allowing the
escape into the exhaust pipe M of the remaining products of combustion. This
being completed the piston commences another outstroke, its suction closes the
light return valve P, and (the end A. Fig. 1 of the air passage B being uncovered),
the air and gas valve G is drawn open, pressing upon the stop N, and closing the
exhaust valve J, (thus preventing the re-adinission of products of combustion,)
during the first half of the outstroke while a charge of air and gas is being inspired,
when the charge being ignited as before, an explosion results, thus completing the
cycle of operation.
The water chamber R is used for the purpose of keeping the cylinder cool.
I wish it to be understood that I make no claim to the use of air passage B by
the side of the cylinder, as it is not necessary to the working of the engine; as the
passage in the cover D can open direct into the atmosphere, and its charge of air
be drawn direct from thence; but the use of the passage B is preferable.
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
(1) A gas-motor engine in which the valves regulating the admission of the
mixture of air and gas, and the escape of the exhaust products of combus-
tion are constructed so as to be actuated automatically substantially in the
manner and for the purnese hereinbefore described.

page_text: (2) The use of an exhaust valve which closes, and is held close by the pressure
resulting in the cylinder from explosion of the charge of air and gas, but
opens automatically as soon as the pressure is so reduced that it is nearly
equal to that of the atmosphere, substantially as herein described.
(3) The use of the light return valve to assist the exhaust valve in closing, and
preventing the re-admission of the exhaust products of combustion.
Dated this 25th day of November 1884.
WILLIAM JOHN MUNDEN.