IMPROVEMENTS IN GAS ENGINES
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Eloy Nicolas Schmitz at the
Office of the Commissioners of Patents, with his Petition, on the
3rd July 1871.
I, ELOY NICOLAS SCHMITZ, of Paris, Boulevart de Strasbourg, 23,
Engineer, do hereby declare the nature of the said Invention for
IMPROVEMENTS IN GAS ENGINES," to be as follows :-
65
This improved gas engine is characterized chiefly by an oscillating
curvilinear slide presently explained, is actuated by making alternate
use of the pressure resulting from the deflagration of explosive mixtures
of air and gas introduced into a cylinder and of the exterior atmospheric
pressure acting upon the vacuum or relative vacuum produced in the
cylinder by the combustion of the mixture of air and gas.
The alternate action is produced under the following conditions :-
First, the piston alternating receiving the two distinct pressures caused
by the combustion and by the vacuum moves throughout its course
with varying quickness in consequence of the resistance it meets with.
This variable movement is transformed into a regular one upon the axis
of the shaft to which the piston is connected. Secondly, the mixtures of

page_text: an and gas are themselves introduced under pressuy ama
of the atmosphere. Thirdly, the temperature developed by the com-
bustion of these mixtures is maintained at the degree most suitable
for the good action of the engine by a refrigerant of varying surface and
constant volume.
These conditions are fulfilled by the following arrangement of
mechanism :—A piston working in a cylinder is connected by a rod
to a curvilinear slide which oscillates upon an axis supported upon the
frame of the machine. The slide in its oscillating movement puts a
block over which it slides into motion, and this block in its turn actuates
the centre shaft of the machine. Two eccentrics are keyed parallelly
upon one side of the centre shaft and actuate by means of rods and levers
an air pump and a gas pump. The air pump communicates through a
pipe with a reservoir, and the gas pump communicates through a pipe
with another reservoir. These two reservoirs are both in communication
with a chamber by separate pipes, and orifices made through the
chamber admit the volumes of air and gas under distributing valves
actuated by two eccentrics keyed upon the centre shaft. Each of the
two reservoirs has a cock opening upon a seat, to the edges of which
they are held by the action of a spring. The volumes of air and gas
generated by the pumps are variable in consequence of the varying
courses which may be communicated to their pistons. Their pressures
are also variable and always exactly regulated by the action of the regu-
lating cocks. The interior or main cylinder is enveloped by an exterior
cylinder and the space between them is occupied by a series of rings.
The chamber forms the back of this double cylinder and contains, a
vertical collection of tubes which terminate in a chimney, through
which the burnt gases escape after having acted upon the piston.
Each tube in this collection is composed of two concentric tubes very
close together, the outer tube resting upon the bottom of the chamber
but somewhat less in height than the inner tube. The latter or inner
tube traverses the plate at the bottom of the chamber upon which it is
set, and the cubical interior capacity of the chamber is put into com-
munication with the space between the inner and outer cylinders by
means of the two openings pierced at the top and bottom of the outer
cylinder. The chamber is filled with water to about half way between
the two levels of the upper orifices of the tubes contained one within
the other which constitute the tubular refrigerator. The mass of water

page_text: is heated by contact with the outside of the inner cylinder in which
heat is developed. The warmer portion of the water rises to the upper
level and so comes into the space between each of the two concentric
tubes of the refrigerator. The escape of the burnt gases through the
chimney produces a brisk current of air which traverses the inner tubes
of the refrigerator. The water which envelopes the latter rapidly cools,
falls to the lower part of the tubes, and escapes by holes pierced in the
enveloping tubes and enters again the envelope of the inner cylinder,
against which it is again heated and goes through the same process as
before.