IMPROVEMENTS IN GAS ENGINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Andrew Nicol Porteous
at the Office of the Commissioners of Patents on the 1st May 1882.
ANDREW NICOL PORTEOUS of Edinburgh Scotland Engineer "IMPROVEMENTS IN
GAS ENGINES"
My Invention relates to Gas Engines wherein the air to be used in forming
part of the explosive mixture is first compressed and afterwards mixed with gas,
and the mixture is then exploded in a chamber at one end of the cylinder.
For this purpose one end of the cylinder is used to compress the air admitted
thereinto, and at the other end the mixture of air and gas is exploded in order to
obtain the motive power as required.
The piston is constructed with an internal chamber into which the air under
compression is caused to enter through a valve and wherein it is stored and carried
until the piston arrives at the position where the pressure is required to be relieved
by the air being allowed to pass through a port formed in the piston and through
another port in the cylinder into the end of the cylinder where the explosion is
to take place. The piston has also formed in it an exhaust port which is adapted to
work the exhaust as required in combination with an exhaust port near the
middle of the cylinder, which is uncovered when the piston arrives at the end of
its stroke, thereby allowing all the pressure to escape or be removed.
said communicating exhaust port in the piston is closed by a valve before the
explosion and is kept closed by the pressure of the gases, but when this pressure
is removed by the escape of the gases through the port in the cylinder becoming
uncovered, the said valve of the port in the piston is opened by means of a spring
or a weight, and allows the remainder of the gases or vapours to escape.
And the
The air and gas are made to circulate round the exterior of the Cylinder,
whereby the air is greatly heated before it is compressed thereby enconomising
fuel: And the gas is forced into the cylinder by means of a pump suitably
Price Gil

page_text: proportioned to the capacity of the cylinder, but in some cases it is or may be
drawn into the cylinder by the induction caused by the current of compressed air
rushing from the piston through the port in the cylinder.
In order to explode the mixture of air and gas as required two jets are employed,
one of which is moveable and is thrust by suitable mechanism into the interior of
the cylinder as soon as the piston reaches the position at which the passage in
the cylinder is uncovered to allow of the entrance of this light, while the other
jet is stationary and is used for the purpose of relighting the said moveable jet
On the exterior of the cylinder is used an evaporating vessel for the purpose of
moistening the air as it is heated.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Andrew Nicol Porteous in the Great Seal Patent Office on the
26th October 1882.
ANDREW NICOL PORTEOUS of Edinburgh Scotland Engineer
IN GAS ENGINES"
"IMPROVEMENTS
My Invention relates to gas engines wherein the air to be used in forming part
of the explosive mixture is first compressed and afterwards mixed with gas and
the mixture is then exploded in a chamber at one end of the cylinder.
For this purpose one end of the cylinder is used to compress the air admitted
thereinto, and at the other end the mixture of air and gas is exploded in order to
obtain the motive power as required.
The piston is constructed with an internal chamber into which the air under
compression is caused to enter through a valve, and wherein it is stored and carried
until the piston arrives at the position where the pressure is required to be relieved
by the air being allowed to pass through a port formed in the piston, and through
another port in the cylinder into the end of the cylinder where the explosion is to
take place.
The gas pump piston has also formed in it an exhaust port which is adapted to
work the exhaust as required in combination with an exhaust port near the
middle of the cylinder, which is uncovered when the cylinder arrives at the end of
its stroke, thereby allowing all the pressure to escape or be removed. And the
said communicating exhaust port in the pump piston is closed by a valve before
the explosion, and is kept closed by the pressure of the gases, but when this
pressure is removed by the escape of the gases through the port in the cylinder
becoming uncovered, the said valve of the port in the pump piston is opened by
means of a spring or a weight and allows the remainder of the gases or vapours
to escape.
The air and gas are made to circulate round the exterior of the cylinder, whereby
the air is greatly heated before it is compressed thereby economising fuel. And
the gas is forced into the cylinder by means of a pump suitably proportioned to

page_text: the capacity of the cylinder, but in some cases it is or may be drawn into the
cylinder by the induction caused by the current of compressed air rushing from
the piston through the port in the cylinder. In order to explode the mixture of
air and gas as required, two jets are employed one of which is moveable and is
thrust by suitable mechanism into the interior of the cylinder as soon as the piston
reaches the position at which the passage in the cylinder is uncovered to allow of
the entrance of this light, while the other jet is stationary and is used for the
purpose of relighting the said moveable jet.
On the exterior of the cylinder is used an evaporating vessel for the purpose of
moistening the air as it is heated.
Having thus stated the nature of the said Invention I will proceed to describe
more particularly in what manner the same is to be performed by the aid of the
accompanying Drawings in which are represented the parts of a gas engine above
referred to.
Fig: 1 is a longitudinal vertical section of the engine fitted with the chambered
piston and showing the gas pump air valves, ports and exhaust ports.
Fig 2 is a horizontal section of the engine and fitted with the chambered piston
and shows the gas pump, ports, double jet with its piston valves and ports, also
the cams and springs which work them in conjunction with the gas pump.
A represents the valve through which the air enters the cylinder where it is
compressed by the forward motion of the piston and is forced through the valve B
into the chamber C. C. which is formed of a suitable capacity in the interior of
the piston in which chamber the air is stored and used at the proper part of the
stroke.
The air escapes from the chamber by means of the port D through which it
passes into the combustion chamber E, which is formed in the cylinder between
the chambered piston and the gas pump piston, where it is mixed with a proportion
of gas and burned or exploded at the required interval by the jet O. After
performing the work required the products of the combustion of the gas and air
escape through the exhaust port M which is opened when the piston has passed
over it, and a communicating or auxiliary exhaust port N placed or formed in the
pump piston G is closed (by itself acting as a valve) before the explosion takes
place by the cams K. K. and is kept closed by the pressure of the gases, but when
this pressure is removed by the port M becoming uncovered, the said valve N is
opened by the springs T. T. and allows the remainder of the gases or vapours to
escape. The gas is forced into the cylinder by means of the pump G drawing the
gas through the pipe F, when the piston has been moved forward by the re-action
of the springs T. T. but when the cams K. K. begin to shut the pump, the gas
contained therein is forced through the port H into the combustion chamber of
the cylinder E where the mixture of gas and air is burned or exploded by the jet O.
The pipe F is fitted with a return valve and the stroke of the pump G is suitably
proportioned to act as a measure for the quantity of gas to be used at each stroke.
The moveable jet O is placed between the valve pistons P. P. and the flame
enters or is thrust into the cylinder through a small port which can be opened and
covered by the valve pistons P. P. which are worked as required by the springs
T. T. and the cams K. K. The stationary jet R is placed in a convenient position
near the space S, over which the piston valve passes until the jet O is in the
middle of the space S, where it is relighted by the jet R, and the space between
the pistons P. P. freed from all products of combustion. A suitable lever is
provided for working the jet O and the piston G by hand when required for the
purpose of starting the Engine.
The air chamber C. C. may if preferred be formed of two or more pistons kept a
certain distance apart from one another, and also the end of the cylinder where

page_text: the air is compressed is or may be of larger diameter than the end where the
explosion takes place. Also the form of valve used may be varied.
Having thus described the nature of the said Invention and in what manner the
same is to be performed I hereby declare that what I claim as of my Invention is.
First The construction of gas engines in which the air admitted at one end of
the cylinder is compressed in a chamber formed in the interior of a piston or
formed by two or more pistons, and afterwards mixed with gas and the mixture
exploded at the other end of the cylinder in the manner and by the means
substantially as hereinbefore described.
Secondly: The combination of admission valves and exhaust ports in the
manner and for the purpose substantially as herein before described.
Thirdly-The use of a gas pump fitted in the engine cylinder for the purpose
of forcing the gas in the manner substantially as hereinbefore described.
Fourthly A moveable jet for effecting explosions worked in combination with
a stationary jet with its piston valves in the manner and by the means substantially
as herein before described.
And lastly. The general arrangement and combination of parts forming a gas
engine adapted to work in the manner substantially as herein before described.
In witness whereof I the said Andrew Nicol Porteous have hereunto set my
hand and seal the Thirteenth day of October in the year of our Lord
One thousand eight hundred and eighty two.