Improvements in Gas Engines.
Year: 1892

page_text: Date of Application, 24th Aug., 1892
Complete Specification Left, 26th June, 1893-Accepted, 19th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Gas Engines.
I, EUSTACE FITZMAURICE PIERS of 103 Cheapside in the City of London
Engineer do hereby declare the nature of my invention to be as follows:-
My invention has for its object the utilization of the force which is left in the
products after the explosion in a gas engine cylinder (which I will call the high
pressure cylinder) when the said products have done their work on the piston of
that cylinder in driving it forward.
To attain this object employ a second cylinder (which I will call the low
pressure cylinder) of a greater capacity than the high pressure cylinder. The
piston of this low pressure cylinder I connect to a crank on the gas engine shaft
which is at 180° or thereabouts from the crank of the high pressure cylinder so
that when the piston of the high pressure cylinder is making its forward movement,
the piston of the low pressure cylinder is making a return movement and is
compressing the air which it had drawn in during its last forward movement.
Between these high and low pressure cylinders I arrange a passage or passages and
a valve or valves so that when the air in the low pressure cylinder owing to the
return movement of its piston and consequent compression of the air exceeds in
force that of the products of the explosion in the high pressure cylinder (which
force in the high pressure cylinder is decreasing as the high pressure piston moves
forward) the said valve or valves opens or open and the air is driven into the high
pressure cylinder and there mixing with the heated products of the explosion
expand, and is then by the return movement of the piston of the high pressure
cylinder driven into the low pressure cylinder where it does work owing to the
heat gained from the mixture.
Dated this 24th day of August 1892.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Gas Engines.
1, EUSTACE FITZMAURICE PIERS of 103 Cheapside, in the City of London,
Engineer, do hereby declare the nature of this 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 has for its object the utilization of the force (in the form of heat)
which is left in the products after the explosion in a gas engine cylinder (which I
will call the high pressure cylinder) when the said products have done their 'work
on the piston of that cylinder in driving the said piston forward.
To attain this object I employ a second cylinder (which I will call the low.
pressure cylinder) of a greater capacity than the high pressure cylinder. The
piston of this low pressure cylinder I connect to a crank on the gas engine shaft
which is at 180° or thereabouts from the crank of the high pressure cylinder so
that when the piston of the high pressure cylinder is making its forward movement,
the piston of the low pressure cylinder is making a return movement and is
compressing the air which it had drawn in during its last forward movement.
Between these high and low pressure cylinders I arrange a passage or passages, and
a valve or valves so that when the air in the low pressure cylinder owing to the
return movement of its piston and consequent compression of the air exceeds in

page_text: force that of the products of the explosion in the high pressure cylinder (which
force in the high pressure cylinder is decreasing as the high pressure piston moves
forward) the said valve or valves opens or open and the air is driven into the high
pressure cylinder and there mixing with the heated products of the explosion
expands, and is then, by the return movement of the piston of the high pressure
cylinder, driven into the low pressure cylinder where it does work owing to the
heat gained from the mixture.
The accompanying diagram will serve to further explain the nature of my
invention and the manner in which it can be carried into practical effect.
A is the cylinder in which the explosion takes place, which cylinder I call the
high pressure cylinder. B is the cylinder which I call the low pressure cylinder.
C is the crank shaft having two cranks at or about 180° to each other. To these
cranks the piston rods of the cylinders A. and B are respectively connected. D is
the passage giving communication between the cylinders A and B, and E is a valve
controlling the said passage. F is the exhaust passage with valve from the
cylinder B and 2 is the inlet for air thereto. The inlet passages for gas and air
to the cylinder A may be arranged as in ordinary gas engines.
During the outward movement of the piston of the cylinder A consequently
upon ignition of the explosive charge therein the inward movement of the piston
of the cylinder B compresses a charge of air therein. As soon as the pressure in
the cylinder B exceeds that in the cylinder A. the compressed air opens the
valve E and passes into the cylinder A and becomes heated thereby and on the
return movement of the piston of the cylinder A. (the valve E being kept open at
this time by the cam G) the air passes into the cylinder B and exerts force upon
the piston of that cylinder. The piston of the cylinder A by its next outward
stroke draws in an explosive charge of air and gas by the inlets therefor and the
piston of the cylinder B expels the contents by the exhaust F which is then opened
by the cam H. During the next inward movement of the piston of the cylinder A
the explosive charge is compressed and the piston of the cylinder B draws in air
at the inlet and this is compressed and passes into the cylinder A after the next
explosion and so on whilst the engine is operating.
The valves E and F are operated by the cams so as to be opened at the requisite
times. This may be effected from the crank shaft by the gearing i and shaft I
operating the cam shaft J.
In place of passing the compressed air into the high pressure cylinder the hot
exhaust products from the high pressure cylinder may be caused to pass therefrom
into the compressed air in the low pressure cylinder. In this case the piston of the
low pressure cylinder will not travel to the end of the cylinder but will leave a
space into which the air is compressed to a degree less than the pressure of the
exhaust in the high pressure cylinder so that the return of the piston of the high
pressure cylinder forces the hot contents thereof into the air so compressed in the
said space.
It will be readily understood that by duplicating the arrangements at each end
of the cylinders the engine may be made double acting.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In gas engines the combination with the cylinder in which the explosion takes
place of a larger cylinder in which air is compressed which air is afterwards
mixed with the heated contents of the explosion cylinder substantially as and for
the purpose hereinbefore explained.
2. In gas engines the combination with the cylinder in which the explosion takes
place of a larger cylinder which compresses a charge of air which passes into the
explosion cylinder and thence back to the larger cylinder to exert therein the force
due to the heat which it derives from the explosion cylinder substantially as
herein before described.

page_text: 3. In gas engines the combination of what I have termed high and low pressure
cylinders air and gas inlets to the high pressure cylinder and a valve controlled
passage therefrom to the low pressure cylinder, air inlet and exhaust from the low
pressure cylinder and a crank shaft with cranks for the respective cylinders set at
or about 180° to each other all substantially as hereinbefore described and
illustrated by the accompanying drawing.
Dated this 26th day of June 1893.
EUSTACE F. PIERS.
J. H. Johnson & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.