CONSTRUCTION OF GAS MOTOR ENGINES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Pierre Fernand Forest at the
Office of the Commissioners of Patents on the 1st January 1883.
PIERRE FERNAND FOREST of Paris in the French Republic
CONSTRUCTION OF GAS MOTOR ENGINES"
"AN IMPROVED
This invention relates to improvements in Gas Motor Engines having for their
objects simplicity and economy of construction and certainty and efficiency of
operation. The cylinder passages for admission, emission and ignition are governed
by a slide valve which may either be rotary or have a rectilineal reciprocating
movement. I will first describe the engine having a rotary valve. The cylinder
is placed horizontally its front end open and its rear end closed by a cover in
which is fitted the conical slide valve having its axis horizontal and transverso to
that of the cylinder. Both the cylinder and the slide case have helical ribs
projecting from their exterior, which give strength and expose extended conducting
surface for cooling. The piston is linked to a vertical beam on a rocking shaft,
and from an arm on this shaft a connecting rod extends backwards at the side of
the cylinder to a crank on the engine shaft which is the axis of the rotary valve.
The valve case has a passage on one side direct into the cylinder and it has other
passages for admission of gas and air, for emission of products of combustion and
for ignition of the charge, the valve itself being made with chambers and passages
arranged so that as it revolves it brings the several passages of the case into
communication with the cylinder in due order. The ignition passage outside of
which the igniting flame is kept burning has inside of it a light check valve which
is closed by the slightest excess of internal pressure, thus preventing extinction of
the external flame. To facilitate the opening of this valve it is made of iron or
steel and a magnet is placed behind it tending to keep it open by attraction.

page_text: When a rectilineally reciprocating slide is employed, it is fitted to slide vertically
at the closed end of the cylinder and is worked by a cam on the engine shaft
which, as when the rotary slide is employed, revolves in bearings at the rear end
of the cylinder. Springs are applied to the slide to deaden shock, and it is of
advantage to provide in the slide a passage fitted with a light check valve so as to 5
admit air while the piston advances in case the charge should have failed to ignite;
this check valve may be provided with a magnet like the ignition valve. Instead
of placing the reciprocating slide vertically at the end of the cylinder, it may be
fitted to slide horizontally at the side of the cylinder governing a passage into the
cylinder close to its rear end, the slide being in this case moved in the one 1
direction by a cam on the shaft and in the opposite direction by a spring.
reciprocating slide may be either of flat or of cylindrical form provided with the
necessary passages and chambers relatively to the ports in the casing for admission,
emission and ignition.
The

page_text: Fig. 1 of the accompanying drawings shews a side view of a motor engine
constructed according to my before described invention; Fig. 2 shews a sectional
plan of the same on line a b Fig. 1; Fig. 3 shews a cross section on line c d e f
Fig. 2, and figs 4 and 5 shew sectional plans of the slide and slide casing, shewing
the positions of the slide for the admission and ignition of the combustible charge.
The motor engine consists of a cylinder A, formed with a helical rib either solid
as at a or hollow, as at a¹, water being in the latter case admitted into the hollow
at a' and discharged at a³. The cylinder is carried by standards B on a base C; it
is open at one end, and at the other end it is closed by a cover D having brackets D¹
which carry the engine shaft E. The piston F has a hinged piston rod G pivotted
at g to a lever H pivotted at h to the base O, and serving to transmit rotary
motion to the shaft E through the connecting rod I and crank K at one end of the
shaft, the other end of which carries a flywheel V. The shaft furthermore carries
a cam L against which the roller connected to the slide-M is continually made to
bear by means of the spring m abutting against the surface m' on the framing and
against the surface m³ on the slide. The profile of the cam corresponds to the
threo periods of the function of the slide, namely: the admission of the combustible
charge, the ignition thereof and the escape of the products, the position of the slide
for the first two functions being shown respectively at figs 4 and 5, while that for
the last is shewn at figs 1 and 2.
The slide consists of a hollow piece M divided into two chambers M' M³
separated by a partition; it works in a casing O and has at one end the roller l, and
at the other end the stem Ms, serving as guide to the spring m.
In the vertical front wall of the mixing chamber M' are formed openings n
serving for the entrance of air into this chamber, and vertical channels N',
permitting the entrance of gas through small holes n². The vertical back wall of
this chamber has holes n' serving for the introduction of the combustible mixture
into the cylinder by means of the openings n" formed in the plate P. The lower

page_text: side of the chamber M¹ has two openings M³, through which the products of
combustion escape into the passage M' of the slide casing. The chamber M*
contains the igniting flame p, and it has an opening p' for the passage of the flame,
which ignites the charge when it comes opposite the opening p of the plate P.
The ignition of the mixture is insured by means of the partition Q which forms a
baffle and forces the mixture to pass in of the jet p.
A second gas flame q is provided for rë-igniting the jet p in case the in case this
0, into
should be extinguished by an explosion. The slide casing O has a channel
which the gas passes from the pipe o' in order to be distributed by the conduits o'
in the vertical channels n' of the slide, when these latter are made to face them by
the action of the cam. The vertical side of the slide has openings of through which
the air required for the mixture enters, and in order to regulate the speed of the
engine, there is provided on the slide face a plato R having openings corresponding
to o, which can be moved either by hand or by a centrifugal or other governor so
as to diminish or increase the openings o₂- On the drawings, the plate is regulated
. by a governor S driven directly by the shaft E, the sleeve of the governor being
made to actuate an inclined plane u by means of a lever T pivotted at t to the
cover of the cylinder, the plate R being provided with rollers r that are made to
bear against the inclined plane by means of springs r'. The plate R is guided
between rails" fixed to the slide casing
Having thus described the nature of my invention and in what manner the samio
is to be performed, I claim :-
First: The herein described improved construction of gas motor engines wherein
the engine shaft situated at the back end of the engine directly actuates the
ignition and admission slide by means of a cam, and is itself driven by the piston
rod through a rocking beam in front and a connecting rod passing from a lever on
the shaft of the rocking beam to a crank on the engine shaft at the back.
Second: Constructing the engine cylinder with external helical ribs which may
be either solid or hollow, in order to accelerate the cooling of the cylinder,
substantially as herein described
Third: The herein described, improved construction of hollow slide valve with
chambers for the mixture of the gas and air forming the combustible charges and
openings and channels for the admission of gas and air to the said chamber and
thenco to the working cylinder.
In Witness whereof, I the said Pierre Fernand Forest have hereunto set my
hand and seal this nineteenth day of June in the year of our Lord, one
Thousand eight hundred and eighty-three.
NAR HAMS