IMPROVEMENTS IN MOTIVE POWER ENGINES
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Johann Maximilian Plessner at
the Office of the Commissioners of Patents, with his Petition, on
the 1st December 1873.
I, JOHANN MAXIMILIAN PLESSNER, of Golden Square, in the County
of Middlesex, late Captain in the Prussian Army, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN MOTIVE POWER ENGINES,"
to be as follows:-
This Invention relates to improvements upon the Patent which I have
recently obtained, bearing date May 3rd 1873, No. 1604, for improve-
ments in motive power engines. That Invention relates to the obtaining
of motive power from atmospheric pressure by means of a partial
vacuum produced by the action of the flashes or flames on air contained
in a cylinder, which can be hermetically.closed.
For the obtaining of rotary motion I applied one, two, or more
vertical cylinders open to the atmosphere from above and for the
admittance of a flame from underneath, acting thus with the flame.only
on one side of the piston, thereby obtaining only the down stroke under.

page_text: pressure, whilst the up stroke had to be accomplished by the inertia of
a fly wheel (in case only one cylinder was used) or by the power of
the down stroke of a second piston, attached to one and the same axis,
with cranks standing in opposition to each other. This arrangement
necessitates for the obtaining of a uniform rotary motion, the application
of at least two cylinders and two pistons, whilst my present improve-
ment secures the same result with only one cylinder and one piston, in
consequence of the production of a partial vacuum alternately on
opposite sides of the piston.
For this purpose I place a horizontal cylinder between two flame or
vacuum chambers, which latter are covered at top and bottom by
gratings or slotted plates. To these plates are fitted valves which are
slotted to correspond to the slots in the plates and arranged in such a
way as to close the vacuum chambers air-tight when the slides are
moved in one direction, and opening them to the atmosphere when
returning in the opposite direction.
In order to prevent a considerable diminution of power by the volume
of air contained in the cylinder, and which would rush into the vacuum
after its production in one of the chambers, I do away with this air
space by attaching to each side of the piston a cylindrical box of a
diameter that will allow of its moving in the cylinder without touching
the walls thereof. These boxes I fill with some light substance like
wood or with wood and water combined.
The piston rod which enters through one of the vacuum chambers I
propose to protect against over heating by means of a tubular covering
attached and sliding with the piston rod, and the space between both I
fill with water.
When the piston rod is connected directly with the crank, as is the
case in trunk engines, I use a double-walled trunk to protect it against
over heating, the space in it being filled by water.
Underneath the two vacuum chambers are placed the flame producing
apparatus, the construction of which varies according to the nature of
the substance employed for producing the flashes or flames:
The valves for opening and closing the vacuum chambers are moved
by a rod which is worked by a cam attached to the shaft of the engine,
and a somewhat similar arrangement is provided for working the slides.

page_text: which 'serve to regulate the production and the 'total or partial extin-
guishing of the vacuum 'flames.
The two top and the two bottom slides of the vacuum chambers are
connected with each other, and this in such a way that when 'the top
and bottom slots of one chamber are opened those of the 'other chamber
will be-closed, and vice versa. Thus one.rod will suffice for the moving
of all four slides. The two flame producing apparatuses must however
have each its own rod, since the producing and extinguishing of a flame
from one apparatus takes place whilst the other remains closed. This
arrangement allows of the production of a partial vacuum on alternate
sides of the piston, lasting while the atmosphere has admittance to the
other vacuum chamber, to press the piston to the end of its stroke in the
direction of the chamber in which the vacuum exists.
•
The vacuum to be produced by the flame will rarely amount to
24 inch mercury (equal to a pressure of about 12lbs. on the square
inch). This pressure will diminish to zero in case the gaseous residue
in the vacuum chamber after the completion of the stroke of the piston
is of atmospheric tension. I however secure the possibility of a greater
average power on the piston by giving to the vacuum chambers such
dimensions that when entirely filled with a flame an exhaustion will be
produced sufficient to leave an attenuated atmosphere in the chamber after
the finishing of the stroke. This arrangement allows at the same time the
application of a regulator, which by a self-acting increase or diminution
of the volume of flame will increase or diminish in proportion the power
acting on the piston. This object may be obtained by either regulating
the stroke of the valves of the vacuum chamber (thereby limiting or
increasing the space for the admittance of flame) or by regulating the
stroke of the flame producing apparatus, or by both combined.
In cases where with the lighting of the flames smoke is produced I
attach a chimney to the engine, putting a smoke box over each of the
vacuum chambers, and connecting these boxes with a chimney.
For securing a constant and cheap lubrication of the slide valves
I cause water to flow into grooves provided on the sliding surface, and
thereby at the same time prevent an over heating of the valves.
In engines of large dimensions I counterbalance the top valves of the
vacuum chambers, and in order to do away with the remaining vacuum,

page_text: after the completion of the stroke, a way is opened to the atmosphere
before the slide valves are set in motion to relieve the valves of atmos-
pheric pressure.
Where no fly wheel can be applied I use two, three, or more working
cylinders and pistons connected with a cranked axle.