IMPROVEMENTS IN THE CONSTRUCTION OF AND METHODS OF WORKING GAS ENGINES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Edward Primerose Howard
Vaughan at the Office of the Commissioners of Patents, with his
Petition, on the 11th May 1870.-A communication from abroad
by Lars Albert Leonard Söderström and George Alexander Dick,
both residing at Paris, in the Empire of France.
I, EDWARD PRIMEROSE HOWARD VAUGHAN, of 54, Chancery Lane, in
the County of Middlesex, Patent Agent, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF AND
METHODS OF WORKING GAS ENGINES," being a communication to me from
abroad by Lars Albert Leonard Söderström and George Alexander Dick,
both residing at Paris, in the Empire of France, to be as follows:-
This Invention consists in certain improvements in the construction
of and the methods of working gas engines in which the mixture of air
and combustible gas is introduced into the cylinder between two pistons,.
one of which is loose and the other connected to the main crank shaft
by means of a rod. In such engines, upon the explosion taking place,
the loose piston is projected towards the end of the cylinder where it is
retained or kept suspended whilst the vacuum in the cylinder, which

page_text: follows upon the explosion, acts upon the second or driving piston con-
nected to the main shaft. Before arriving at the end of its stroke this
second piston drives the gas resulting from the explosion out of the
cylinder; the two pistons meet and return together to their former
position, but the second or driving piston before it arrives at the end of
its return stroke leaves the loose piston (which is again retained or kept
suspended) and sucks in the combustible gas and air. The driving piston
having reached the end of its return stroke the explosion of the gas and
air thus sucked in again takes place, by which the loose piston is again
projected towards the end of the cylinder, the like operation being
repeated. In this arrangement it has been found difficult to retain or
keep suspended the loose piston at the exact instant required, and it
has been proposed to effect that object by enclosing air between the
loose piston and the end of the cylinder at the proper moment, and to
regulate the same by means of a slide valve, but it has been found
impossible to determine the exact moment of the explosion of the gas
in the cylinder, or the exact duration of the projection of the loose
piston, and that the use of a slide valve alone is insufficient to attain
the desired result. This difficulty is obviated by the present Invention,
in accordance with which an outlet valve is applied in addition to the
slide valve, and by the combined use of which the suspension of the
loose piston is automatically regulated, and in order to avoid the noise
which would otherwise take place from the air rushing out of the outlet
valve a closed or partly closed air chamber is applied, into which the
said valve opens. A rod is fixed to the loose piston and passes through
the valve and air chamber, so as to indicate from the outside the move-
ments of the loose piston, and to facilitate the rapid opening and
shutting of the outlet valve.
J
In vertical engines water or other suitable liquid is used above the
loose piston for the purpose of reducing as much as possible or to
entirely prevent the air space left between the top of the loose piston
and the outlet valve. Instead of using the flat slide valves hitherto in
use in gas engines, slide valves having a circular section, and working
freely to and fro as does a piston in a steam cylinder, are employed.
The speed of the engine is regulated by the introduction of a greater or
smaller quantity of combustible gas into the cylinder, and in order
to make the regulation automatic a pneumatic regulator worked by an
air pump, and the piston. of which consists of one of the cylindrical

page_text: slide valves above mentioned is employed, thus utilizing the slide valve
for two distinct operations at the same time.
By means of this Invention the construction of that part of the
machine used for igniting the mixture of combustible gas and air
contained in the cylinder is simplified; and the necessity for compressing
the combustible gas or of a short backward stroke of the piston is
avoided. This object is effected by the use of a hole bored in such a
way as to place the inside part of the cylinder containing the mixture
of gas and air ready for explosion in communication with the space in
which the flame for igniting the mixture is situated, the hole being
of so small a diameter that the flame cannot traverse it, although it
allows of a continued supply of combustible gas to the flame for the
purpose of producing combustion.
In order to simplify as much as possible the construction of vertical
engines made in accordance with this Invention the cylinder is mounted
on a hollow support or column which is made in two parts and dividing
at the main shaft, such support or column serving at the same time as
bearings for the main shaft,