AN IMPROVED ROTARY STEAM ENGINE
Year: 1878

page_text: LETTERS PATENT to Ernest de Pass, of the Office for British and Foreign
Patents, 68, Fleet Street, in the City of London, Patent Agent, for the
Invention of "AN IMPROVED ROTARY STEAM ENGINE." A communication
from abroad by Alexis Corrot and François Foulieron, both of No. 1, Boulevard
Saint Denis, Paris, France.
Sealed the 6th May 1879, and dated the 29th November 1878.
PROVISIONAL SPECIFICATION left by the said Ernest de Pass at the
Office of the Commissioners of Patents on the 29th November 1878.
ERNEST DE PASS, of the Office for British and Foreign Patents, 68, Fleet
Street, in the City of London, Patent Agent. "AN IMPROVED ROTARY STEAM
ENGINE." A communication from abroad by Alexis Corrot and François
Foulieron, both of No. 1, Boulevard Saint Denis, Paris, France.
According to this Invention the improved rotary steam engine is composed of
two distinct parts, the first comprising the mechanism which annuls the pressure of
the steam on the piston, the driving shaft, and its bearings; the second part is com-
posed of mechanism forming a cylinder, and which permits of the fitting of springs
on the piston, the object of such springs being to give slight friction and perfect
tightness in the steam chest.
The cylinder forms the steam chest, and is destined to replace the upright cylinders
of ordinary engines. One part of this cylinder receives the piston, which acts from
left to right, and which therefore passes into the other part of the said steam chest,
which is however slightly eccentric, so as not to fatigue the piston, which it must
simply direct in its rotary movement.
The cylinder is divided into two parts by a block or piece, the outer part of which
is circular and the inner partially eccentric; it is therefore necessary to give to the
Price Gdi

page_text: Sittve is keyed on the small so as to give
length to the passage in the shaft through which this bar passes.
SECOND PART.
On the driving shaft is keyed, an eccentric, which causes an eccentric rod to move
from right to left only; this eccentric rod has at its upper extremity a stud or pin
.which enters a slotted elbow piece mounted on an axis, all these pieces being placed
behind the bottom of the cylinder. When the eccentric rod moves to the left it
forces the stud or pin to follow its circular line on which it is guided by another
pin or stud forming the point of centre, and being fixed to the other extremity of
the eccentric rod therefore causes the end of the slotted elbow piece to rise.
A connecting piece or rod mounted on the same axis as the slotted elbow piece
operates a valve up to the moment that the piston enters the first part of the
cylinder.
To the end of the slotted elbow piece a curved portion having its centre on the
pin or stud fixed to the extremity of the eccentric rod is provided for the purpose
of stopping the slotted elbow piece, the valve, and the rod connected therewith,
notwithstanding the continuity of movement of the eccentric rod to the left. When
this eccentric rod returns to the right it has no effect on the pieces above mentioned
until its arrival at the end of the curve of the elbow piece, but when it reaches this
point it forces these pieces to effect an inverse movement to that above described;
then the valve being lowered the closing of the cylinder is effected.
As the mechanism must not be fatigued when the steam is at full pressure a
curve is contrived at the heel of the slotted elbow piece, and acts identically like
that above mentioned at the other end of the same piece, that is to say, the
mechanism remains at rest during the full pressure of the steam.
For the introduction of the steam into the cylinder the slide valves are replaced
by a circular distributing apparatus. A plug forming a slide valve is set in move-
ment by a lever connected to the eccentric rod, which having a regular displacement
from right to left gives the same movement to the plug which opens and closes the
inlet of the steam with the same regularity.
The exhaust of the steam is produced when the end of the piston which is near
the inlet port reaches the exhaust port.
A back movement of the machine may be obtained by placing at the right hand
side of the cylinder a valve and the apparatus necessary for its movement, similar
to those already described. By means of a lever one of the two movements can be
started or stopped at will. To give constant pressure to the machine two or three
similar cylinders may be placed on the driving shaft.

page_text: The slide guide L, as well as the piece O (Fig. 2), is keyed on the axis N. This
piece O carries with it in its movement the sluice valve H (vanne) up to the moment
that the piston enters the portion B of the cylinder.
As it is not necessary to raise the sluice valve H higher, a curved portion, the
centre of which is at M, is fixed at the extremity of the slide guide L, and has for
object to stop the pieces L, O, H, notwithstanding the continuity of movement of
the connecting rod to the left. When this connecting rod returns to the right it has
no effect on the pieces L, O, H, until its arrival at the end of the curve, but on this
point being reached it forces these pieces to make the reverse movement to that
defined above; then the sluice-valve being lowered the closing of the cylinder takes
place.
As the mechanism must not be fatigued at the moment that the steam is at full
pressure a curve is fixed to the heel of the piece L, and acts identically like that
above described at the extremity of this same piece, that is to say, the mechanism
remains at rest during the whole duration of the pressure of the steam.
For the admission of the steam into the cylinder a circular distributing apparatus
has been substituted for the slide valves. The piece P forming slide valve is set in
motion by a lever Q corresponding to the eccentric rod. This eccentric rod having
a regular displacement from right to left naturally gives the same movement to the
piece P, which with the same regularity opens and closes the steam port. The
Drawings, Figures 1, 2, and 3, show the exact moment of rest of the mechanism and
of the admission of the steam into the cylinder.
The exhaust of the steam is effected when the bottom of the piston reaches the
height of the opening R. It is easy to obtain from the engine a backward move-
ment by placing on the right side of the cylinder a sluice valve (vanne), and the
apparatus necessary for its movement, similar to those just described. By the aid
of a lever one of the two movements can either be started or stopped. To give
constant pressure to the engine two or three cylinders may be placed on the shaft of
the fly-wheel.
Having now described the nature of the said Invention and in what manner the
same may be performed, I declare that I claim,―
The improved rotary steam engine, having its parts arranged, combined, and
operating substantially as herein described, and shewn in the Drawings.
In witness whereof, I, the said Ernest de Pass, have hereunto set my hand
and seal, this Fifth day of May, in the year One thousand eight hundred
and seventy nine.