Year: 1886

page_text: Date of Application, 17th May, 1886.
Complete Left, 17th Feb., 1887.
Complete Accepted, 22nd Mar., 1887.
1, JOHN GILLESPIE, of Stevenage, in the County of Hertford, Engineer, do hereby
declare the nature of my said Invention to be as follows:-
In Gas Motor Engines, of the type commonly known as non compression, that is,
in engines where the combustible mixture is not compressed before ignited, con-
siderable loss of power, and irregularity, is caused by the use of valves which are
closed mechanically before ignition takes place, which is usually before the piston has
completed the first half of its stroke, because, whilst the area behind the piston at that
time is rapidly increasing, the valve opening is being diminished, and completely
closed when ignition takes place; causing a partial vacuum in the cylinder, and
detracting from the explosive power of the charge. This is obviated by employing a
valve (as described in the Specification to Letters Patent granted to Edward Cobham
and to me John Gillespie, and dated 18th February 1884, No. 3495) admitting the
combustible mixture, and acting automatically, being drawn from its seat by the
suction of the piston until ignition takes place, when it is closed by the force of
the explosion; but, as when this is done the piston has not completed its full stroke,
and has still a considerable distance to travel after the explosive force of the com-
bustible charge has been expended, the valve is again drawn from its seat by the
suction of the piston, thus admitting a second supply of explosive mixture to the
cylinder, which cannot be utilized as force in the engine. To obviate this I employ a
valve worked by a crank, eccentric, lever or other similar device, which valve has a
port, or passage, which uncovers an opening to the cylinder through which the
explosive mixture is admitted, and which is closed when ignition takes place, the valve
has also a port or passage opening to the cylinder, and having communication with a
valve or valves working automatically, through which valve or valves atmospheric air
or non-explosive mixture has free access to the cylinder after ignition, and the
effective force of the exploded mixture has taken place, thus preventing a second
charge of explosive mixture from entering the cylinder, and preventing the pressure
in the cylinder falling below that of the atmosphere, by which means I obtain a much
more economic working of the engine, a more regular supply of the explosive mixture,
and greater effect of the explosive force.

page_text: 1, JOHN GILLESPIE, of Stevenage, in the County of Hertford, Engineer, do hereby
declare the nature of my said invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
My invention relates to that class of Gas motor engines, in which the combustible
mixture is not compressed before its ignition, commonly called non-compression gas
motor-engines.
It is well known that considerable loss of power, and irregularity of pressure, is
caused by the closing of the inlet valves, which occurs before the piston has completed
the first half of its stroke. After explosion has taken place, the initial pressure
speedily falls, and, when only a small quantity of gas has been admitted, there
frequently occurs a partial vacuum behind the piston, during the latter part of the
stroke, entailing much loss of power and efficiency. It is also well known that when
the lighting of the explosive mixture happens to fail, the retardation of the motion
causes great inconvenience and delay, and, some cases, damage is caused by the
stoppage of the machinery driven by the Engine.
Now the object of my invention is to remedy such defects by means of an additional
valve, so arranged as to admit atmospheric air or any non-explosive mixture,
automatically, when the pressure in the cylinder falls below that of the external
atmosphere.
And in order that my said invention may be clearly described and ascertained,
reference is hereby made to the accompanying drawings, in which similar letters of
reference indicate corresponding parts.
Fig. 1. is a plan of a gas-engine, shewing my improved valve-arrangement, (in
section) and Fig. 2 is an enlarged section of the valve, on the line ab of Fig. 1.
e is the cylinder, d the lighting jet, e is the eccentric which governs the eduction
valve, in the usual manner; y is the eduction passage; his the main valve eccentric;
the rod, and the valve. is the ordinary inlet valve for air, and m is the inlet pipe
for the regulated quantity of gas, which air and gas mix and enter the cylinder, in the
usual manner, when the valve is in the position shewn.
The valve is formed with an additional port or passage n as shewn, which com-
municates with and opens to the cylinder, when the supply of air and gas is cut off
by the motion of the valve.
The valve cylinder o is fitted with an inlet valve p, for admitting air or any non-
explosive mixture to the passage n, and, through the passage n and cylinder port, to
the cylinder.
The operation is as follows: When the explosive mixture has been admitted to the
cylinder, and fired, (the supply having been cut off by the outward motion of the
valve) the piston is driven outward by the pressure, as usual; and, if the pressure
continues above that of the atmosphere throughout the stroke, the valve p remains
closed. But in case the internal pressure, from any cause, becomes reduced below

page_text: that of the atmosphere, the valve p immediately opens and admits atmospheric air or
any non-explosive mixture to the cylinder, and thus prevents an unbalanced external
pressure taking place upon the piston. In like manner, in case the firing happens to
fail, the valve p supplies air or any non explosive mixture to the cylinder during the
out stroke, and thus prevents the stoppage of the piston from the outward pressure of
the atmosphere.
Although a cylindrical valve is shewn in the drawings, I wish it to be understood
that I do not limit myself to the particular details shewn therein, as it is obvious that,
by suitable modifications, rectangular and other valves may be adapted to effect the
same purpose, the ports being arranged in a manner well understood.
Also that my invention applicable to vertical, horizontal, and other forms of gas
engines.
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. The method of admitting an additional supply of air or any non-explosive
mixture to the cylinders of gas-motor engines, of the description aforesaid, by means
of the valve p and passage n, substantially as and for the purposes described and
illustrated by the drawings.
2. In gas-motor engines of the description aforesaid, the application and use of the
additional valve p and passage n, in combination with the ordinary valve, or equivalent
formations, substantially as hereinbefore described and illustrated by the drawings.
3. The general construction combination and arrangement of the valves and ports,
together constituting my improvements in gas motor engines, substantially as herein-
before described and illustrated by the drawings.