CERTAIN IMPROVEMENTS IN ROTARY AND OTHER ENGINES
Year: 1851

page_text: "TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, VICTOR
LEMOIGN, of Cette, in the Republic of. France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Thirty-first day of July, One
thousand eight hundred and fifty-one, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Victor Lemoign, Her especial
licence, sole privilege and authority, that I, the said Victor Lemoign, my
exors, adñors, and assigns, and such, others as I, the said Victor. Lemoign,
my exors, admors, and 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 (within the Islands of Jersey,
Guernsey, Alderney, Sark, and Man, and also within all Her Majesty's
Colonies and Plantations abroad), my Invention of "CERTAIN IMPROVEMENTS
IN ROTARY AND OTHER ENGINES;" in which said Letters Patent there is con-
tained a proviso obliging" me, the said Victor Lemoign, by an instrument in
writing under my hand and seal, particularly to describe and ascertain the
nature of my said Invention, and in what manner the same is to be performed;
and to cause the same to be enrolled in Her 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 there-
unto had; will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Victor Lemoign, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are described and
ascertained by the Drawing hereunto annexed, and forming part thereof,
and words following, that is to say:-
My said Invention rélates (in the first place, to a peculiar form or arrange-
ment of a rotary steam engine, having an external steam chamber or cylinder
of irregular internal contour, and fitted with an internal revolving piston or
cylindrical barrel placed éccentrically, in reference to the axis of the steam
chamber, and carrying four adjustable blades or diaphragms to receive the
action of the steam. This engine is fully delineated in the seven Figures on
my sheet of Drawings. Figure 1 is a complete external side elevation of the
engine. Figure 2 is a corresponding edge view at right angles to Figure 1;
and Figures 3 and 4 are vertical sections at right angles to each other,
corresponding with the positions of the elevations Figures 1 and 2. Figure 5
is an edge view of two of the connected blades detached, one blade being in
section; and Figure 6 is a corresponding plan of the same; one blade having
its packing pieces removed. Figure 7 is a side view of one of the guide
eccentrics or cams placed outside the cylinder.
is the fixed
external steam chamber, leaving within it the revolving piston D fast on the
main shaft Xpassed through the two sides or ends of the. fixed chamber by
two stuffing boxes, and supported in two external pedestals or journal bearings.
This piston is fitted with four blades A, A, A, A, each pair being connected
together by an intermediate. loop piece pasted over the shaft, so that each pair
of blades may work or slide diametrically.across or through the piston, their
sliding surface being made tight by packing at the parts T, T', for the end
wear, and at H, H', for their passage through the rim of the piston. From
the peculiar contour of the interior working surface of the stationary cylinder,
it will be obvious that the revolution of the piston will cause a continuous
series of sliding movements of the blades at intervals to and from the circum-
ferential surface of the cylinder, as at present arranged. The arrow indicates
the direction of the revolution of the piston; and two of the blades A and A
are protruded from their piston to their fullest extent, so as to bear against the
long portion of the cylinder's internal surface, which is concentric with the
piston's axis. At each revolution of the piston one. blade remains at its full
extent of projection for the steam action for nearly one, fourth of a revolution,
as from S to S';, through which traverse they work steam tight by their
packing. The steam is admitted, by a common slide valve M, contained in the

page_text: chest N, on the top of the cylinder which is supplied with steam by the pipe V.
As the valve is now set, the steam passes hence through the part
.i
and side branch. V¹ into the upper side of the steam chamber where it presses
against the bottom blade A, forcing it round as shewn by the arrow, whilst the
steam which. has already forced round the preceding blade A escapes by the
exhaust passage V, through the cup of the slide valve, and out by the efflux
pipe R. In tracing the course of the blades, it is obvious that in, the position
of the blade A111 its onward course, will cause it to be forced inwards towards
the centre of motion of the piston, by reason of the flat curve of the interior of
the cylinder, at the part immediately before the blade. This forcing in goes
on until the blade arrives at the packed surface F, where the eccentric"
position. of the piston brings the latter into working contact with the two
packings F, F, as steam abutments. At this point the blade has been
tled completely into its piston, in which position it remains until again
protruded by the corresponding sliding inwards of its opposite blade A¹. This
sliding in of the blade A of course pushes out the opposite one A¹ cor-
respondingly, the course of the latter, during its revolution at this part,
being marked out by the red line on the left side of the cylinder.. In like
manner when. the slide valve is reversed, to make the pipe, V the steam
omission channel, the piston and blades revolve in the reverse direction, and
the course of the blade A is along the red line on the right side of the
cylinder.
The details Figures 5 and 6 represent the arrangement of the blades, cach
pair of which is connected by a slotted piece a, a. The plan, Figure 6, shews
the two sides of the piece a, a, are not in the same line with the edges of the
two blades, and also that in each blade are two projections, b, b', the surfaces
of which are rounded at b, b, in. the section of the same Figure., Two identical
eccentrics or cams are fixed to the framework of the engine, one on each side
inside the framing. These cams are of the shape shewn in the enlarged view
Figure 7. They occupy the space included between the two projecting faces b, b,
or 6', 6', of the blades, so that when one of the, blades comes in contact with the
edge of the eccentric it must follow the contour of the latter. The two opposite
extremities of the eccentrics are shaped to arcs of circles described from the
same centre, but of two very different edii, the sum of which is equal to the
distance between the projections b, b, or b', 6', of the blades; the radius of
the larger arce, being as much greater than that of the smaller one as the
length of the transverse of the blades. The two other sides of the eccentrics
are parabolic curves, which I find much preferable to straight lines.
In my Drawing Figure 3, the blade A is delineated as sustaining the full

page_text: pressure of the steam, whilst its opposite or fellow blade is pushed quite. home,
the projections b, b, and 6', 6', resting on the two opposite arcs of the
eccentrics. The blade A¹; which has just passed the small varc of the circle,
has its projection 6, 6, in contact with the left side of the eccentric, which
forming an inclined plane has already begun to force out the blade A, and
press in correspondingly the opposite blade A; the blade Acontinuing. its
outward traverse by the action of the left side of the eccentric, arrives at the
great are of the eccentric 'c, and the blade A at the small are. It is obvious
that by this arrangement the functions of the eccentrics have the twofold
purpose of forcing out the blades from the piston, and of keeping themi for tlie
requisite period under the action of the steam, and that the inward traverse
of these blades is only the result of the outward motion of each opposite blade;
It is to be remarked, that the red and blue curved lines in Figure 4 represent
the course of the blades as they alternately traverse during the piston's
revolution. In this engine the central portion of the apparatus is quite open
to the view of the attendant, allowing him free command over the most
important of the working details. Plates P, P, are placed paralleltion each
side as covers, which are easily removeable, affording great facility for getting
at the blades, in as far as they protrude from the piston. The engine works
with very slight friction, as it is only necessary that the packings of the blades
"should bear against the cylinder in their traverse from Sto Sah
Although the above arrangement of parts is only described in reference
to a rotary steam engine, it is obvious to the practical, man that the same
'principles are equally applicable to rotary pumps and air pumps of steam
engines generally...
30
Having how described and particularly 'ascertained the nature of, my Inven-
tion, and the manner in which the same is or may be used or carried into
effect, I may observe in conclusion, that I do not confine or restrict myself, to
the precise details or arrangements which I have had occasion to describe or
refer to, as many variations may be made therefrom' without deviating from
the principles 'or main' features of my Invention: But what I'consider to be
novel and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent, is,-
Firstly, claim the general arrangement and construction of the rotary
engine, as herein-before described."
Secondly, I claim the peculiar form of eccentrics or cams for working the
blades, as delineated in Figure 7 of the Drawings.
Thirdly, I claim the system or mode of actuating the blades, as herein-before
described. i

page_text: Fourthly, I claim the application and use of external eccentrics or cams, for
e purpose herein-before described.
In witness whereof, I, the said Victor Lemoign, have hereunto set my
hand and seal, this Sixteenth day of January, in the year of our Lord
One thousand eight hundred and fifty-two.