IMPROVEMENTS IN ROTARY ENGINES TO BE WORKED BY STEAM OR OTHER AERIFORM FLUIDS
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DUCHEMIN
VICTOR, of the City of London, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Nineteenth day of March, in the first year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Duchemin
Victor, Her especial licence, sole privilege and authority, that I, the said
Duchemin Victor, my exors, admors, and assigns, or such others as I, the said
Duchemin Victor, my exors, admors, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention "IMPROVEMENTS IN ROTARY ENGINES TO BE WORKED BY STEAM OR OTHER
AERIFORM FLUIDS;" in which said Letters Patent there is contained a proviso
obliging me, the said Duchemin Victor, by an instrument in writing under
my hand and seal, particularly to describe and ascertain the nature of the
aforesaid Invention, and in what manner the same is to be performed, and
to cause the same to be inrolled in Her said Majesty's High Court of
Chancery within six calendar months next and immediately after the date
of the said in part recited Letters Patent, as in and by the same, reference
being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Duchemin Victor, do hereby declare that the nature of the aforesaid Invention,
and the manner in which the same is to be performed, is described and ascer-
tained as follows, that is to say:
The aforesaid improvements chiefly consist in the united use, first, of a
constant equilibrium of the pressure upon the interior cylinder, which is
concentric; secondly, of an exterior cylinder, constructed so as to present as
much resistance to the pressure as may be required, whatever the size of its
diameter may be, and whatever may be its height from one base to the other;
thirdly, of an apparatus, the effect of which is to prevent in any way the
pieces or pistons receiving the impulsion of the steam, and making the same
act as pistons without rubbing upon any other surface but the inside of the
cylinder, and consequently they are not more injured than the ordinary pistons,
which three advantages above mentioned are combined in the engine, the
Invention of which I am in possession, the peculiar construction of which is
quite free from any inconvenience, of which the force can be as great as one
can wish, which cannot fail of procuring the great advantages which can be
expected only from a good rotary system, which is the only one which can
allow to avoid the very great loss of power resulting from the use of a crank
for the transferring of the straight movement in a circular motion, and which
can be thus specified in a few words. Rotary engine to be worked by steam
or other aeriform fluids, with two or four moveable pieces or pistons entering
by the means of an exterior arrangement of machinery in an interior and
concentric cylinder, upon which the pressure is always equal, it always presses
simultaneously upon equal and opposite surfaces, and of which the great
cylinder, that is inwardly cylindric in all its parts, and is not cut for the
passage of any piece or piston, which gives the advantage of all the strength
of the metal' can have, a great diameter and a great height from one base to
the other.
This engine, which I have introduced in England, where my pecuniary
means do not enable me to put it into operation on a large scale, according
to my wish that it should be at first constructed, because I am persuaded that
it will be favorably received by all the distinguished engineers of this country,
who will easily appreciate the immense advantages resulting from the use of
it, both to manufactories and for navigation, for which it is particularly appli-
cable, on account of the great economy of fuel which takes place. By this
plan you avoid the loss of force resulting from the use of a crank, you obtain
great lightness, and it occupies very little space. What makes me hope that it
will be very soon put into execution on a very great scale by one of them,

page_text: so much the more that by gratitude I will grant him willingly all my especial
rights on very advantageous conditions. It is exactly represented in four
different ways, and on a scale of one eighth of scale for more than a hundred
horse power under a useful pressure equal to three atmospherical pressures,
upon the Drawing, which I join to the present Specification. I have preferred
representing this engine with four pieces or pistons receiving the impulsion of
the steam, because I believe it is the arrangement which is best adapted for
navigation, the force being greater under the same volume, and equal in
every part of the course, since the steam acts always usefully upon two of
these pieces or pistons; and because I believe it to be capable of rendering a
revolution in steam navigation, principally if it works by steam coming from
boilers composed of a great quantity of tubes of a small diameter, presenting
a great surface to the action of fire, and a great generation of steam con-
paratively to the mass of water which they might contain. These boilers,
so formed, could not burst, and could be supplied by soft water even for
very great voyages, in continually pumping into the boiler the water coming
from the steam, which would have served, and which would be condensed in
pipes placed outside under the water line, and it would be only necessary to
replace the small quantity of water which might issue. For an engine
employed at a manufactory, I prefer that it should have but two pieces or
pistons receiving the impulsion of the steam, and to profit by the expansion
during a part of the course; but then it ought to have a fly-wheel and a slide,
which would permit during the time wished for the admission of the steam,
which always ought to be interrupted at the moment the moveable pieces
or pistons pass before the separations or abatements fixed in the great cylinder.
But, nevertheless, this engine can be made use of at any pressure, and with
condenser and air-pump, and it could be worked equally well by gases, in case
one could be found more economical than the steam.
EXPLANATION OF THE DIFFERENT PARTS OF THE FOUR DRAWINGS CONTAINED ON
THE SHEET HEREUNTO ANNEXED.
Figure 1, the elevation of the engine. Figure 2, the side view. Figure 3,
a section by C, D. Figure 4, another section by A, B, A, C. a, in
(Figures 1, 2, 3, and 4) is the foundation plate, upon which are fixed all
the pieces which compose the engine. 6 is the exterior or great cylinder
of the engine; it is fixed upon the foundation plate, and is shut at each
extremity (Figure 3) by a ring, which forms at the same time the fixed
and uneven part of a stuffing box. The capacity between this cylinder
and the interior cylinder (Figure 4) is divided into two equal parts by

page_text: separations or abutments which resist the pressure of the steam; these
separations or abutments are furnished with blades whose length is equal to
the height of the interior cylinder, and which are squarely finished, in order
that the part which will approach by degrees to replace the part worn out
may be always of the same length. These blades, which serve to render
the closing exact, are constantly pushed by small springs. c is the interior
and concentric cylinder; it is fixed upon the axletree. This cylinder, whose
four arms (Figure 4) are prolonged on the outside (Figures 1 and 3),
and are split open in their full length, and sufficiently deep (Figure 3) to
permit the pieces receiving the impulsion of the steam to communicate the
motion to the axletree to lodge themselves in, when they pass before the
separations or abutments (Figure 4) they are so placed at each extremity
(Figure 4) as to enable the ring to be fixed (Figures 2 and 3), forming the
part of the stuffing box (whose surface is polished, and which moves itself
with the interior cylinder). Small plates also are fixed at the extremities
of the arms (Figures 1, 3, and 4) finish to shut the issue to the steam. The
moveable pieces or pistons, making the same use as pistons (Figures 3 and 4),
are furnished as the separations or abutments with blades constantly pushed
by small springs; these blades, by means of the peculiar arrangement of the
extremities of the cylinder (Figure 3), complete an entire closing at the same
time on every side. The going out of these blades is limited by small pins
(Figure 3). Small cavities reserved on each side in the arms (Figures 3
and 4) serve to diminish the rubbing of the moveable pieces. d shews a
cross fixed upon the axletree at each extremity of the cylinder, and upon the
middle of each arm of the cross is placed, precisely opposite, the moveable
pieces serving to guide a sliding piece (Figures 2 and 3) which receives the
motion on one side by a roller, and communicates it by the other to the
moveable pieces by means of a rod passing in a small stuffing box. 6 shews
the pieces in which the rollers run, and whose centre is the axle of the engine.
One of these pieces is placed on each side of the cylinder, on the outside of the
crosses, and is fixed upon the foundation plate. The rollers which communi-
cate the motion to the sliding piece, and then to the moveable pieces, run in
parallel guides to the axle (Figure 2) in the parts placed opposite the
separations or abutments, sufficiently that the moveable pieces may pass before
these separations or abutments without touching them. f are the boxes with
bearings, in which turns the axletree of the engine, whose weight they
support. They have regulating screws acting upon these bearings, which
serve to keep always and in every way (notwithstanding the wearing out)
the axletree in the position which is convenient. First of all the four screws,

page_text: time to strongly fix the
The semicircular overture
box, gives the facility of
placed on a parallel to the axle (Figures 1, 2, and 3), in pushing a side of
the bearings upon a ring fixed upon the axletree (Figure 3), keeps the
axletree, and then the basis of the interior cylinder, continually in the same
position relatively to those of the exterior cylinder; nevertheless the moveable
pieces are so disposed, that no inconvenience can result from a slight variation.
The regulating screw placed on the right below (Figure 2), pushes a wedge
(Figure 8) to raise up by degrees the under bearing when wearing out.
The screws placed at the right and left, a little higher (Figure 2), push the
bearing to the left or to the right, as it is necessary. The upper bearing
is kept by two bolts, which serve at the same
under part of the box upon the foundation plate.
which exists at the under and fixed part of the
assuring ones self, as often as one wishes, that the concentricity is always
complete. g is the axletree of the engine, by which the motion is transmitted ;.
hare the pipes and cock for the admission of the steam into the cylinder;
i shews two cocks (Figures 1 and 3), permitting alternately the entrance of
the steam into the cylinder, whilst its going out takes place by the other,
according to the direction in which the engine works; j are pipes, serving
alternately for the entrance or going out of the steam; these pipes are
forked (Figures 2 and 4), in order that the steam may be introduced simul-
taneously upon equal and diametrically opposite surfaces, and may act
constantly and in a contrary direction upon two of the four moveable pieces,
and may also, when it has served, get out at the same time by the two
opposite sides. It is to be remarked, that at each time the steam goes out
it is only the quantity which was contained in the capacity between two
moveable pieces; are the pipes for the going out of the steam, which has
served.
In conclusion I will remark that this engine is extremely simple, and all
the parts can be easily examined in arranging the foundation plate, so as one
of its extremities might be taken down, which would permit the exterior
cylinder to glide. It can likewise be put in motion in one direction or in
the other, or can be stopped with the greatest facility, since it is only
necessary to change the handle (l) (Figures 1, 2, and 3) which operates at
the same time upon the three cocks (Figures 1 and 3), by means of three
tooth wheels, one which has thirty teeth and the others forty; thus, in the
position where the handle is (Figure 3) the cock (h) for the admission and the
cock (i) on the left are open, so as to permit the introduction of the steam
into the cylinder by the pipes (j) on the left, whilst its going out takes place
by the pipes (j) and by the cock (i) on the right, which establishes the

page_text: communication with the pipe (k). In this position of the handle the pipes (j),
(Figure 4), serve for the going out of the steam from the engine, which
turns from the left to the right in passing by the uppermost. In order to
stay the engine it is sufficient that the handle (Figure 3) makes a sixth part
of a circle (that is to say), it must be placed perpendicular, because then
the overtures on the right and on the left of the cock (h) are shut. If one
wishes that the engine may turn in a contrary direction, the handle (Figure 3)
must be turned again in another sixth of a circle in going to the right, and
then the steam will enter by the pipes on the right, and will go out by those
on the left. In this new position of the handle the pipes (j) Figure (4)
will serve for the introduction of the steam, and the engine will turn from
right to left in passing by the uppermost.
In witness whereof, I, the said Duchemin Victor, have hereunto set
my hand and seal, the Thirteenth day of June, in the year of our
Lord One thousand eight hundred and thirt ht
DUCHEMIN (L.S.) VICTOR.
AND BE IT REMEMBERED, that on. the Thirteenth day of June, in the
year of our Lord 1888, the aforesaid Duchemin Victor came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Fifteenth day of June, in the year of our Lord One
thousand eight hundred and thirty-eight.