IMPROVEMENTS IN ROTARY ENGINES
Year: 1853

page_text: LETTERS PATENT to Auguste Edouard Loradoux Bellford, of 16,
Castle Street, Holborn, City, London, Patent Agent, for the Inven-
PROVISIONAL SPECIFICATION left by the said Auguste Edouard
Loradoux Bellford at the Office of the Commissioners of Patents,
with his Petition, on the 25th November 1853.
I, AUGUSTE EDOUARD LORADOUX BELLFORD, of 16, Castle Street,
Holborn, (City,) London, Patent Agent, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN ROTARY ENGINES" to be as
follows, viz.
These improvements consist, first, in new arrangements of engines by
which a rotary movement can be obtained directly by the steam;
secondly, in a new mode of obtaining the expansion of the steam;
thirdly, in a new arrangement for employing steam, at a high pressure,
and of producing by means of this steam after it has been used,
a jet for increasing the draught of the chimney, & for condensing
afterwards the steam which remains in the. engine, so that the
A

page_text: counter pressure of it may not be greater than that of condensing
engines.
Fig. 1, of Sheet 1, is a vertical section of a rotary engine. The
driving shaft is supposed as having in the interior an equal radius at o, a.
The projecting part upon which the steam should act projects a distance
determined by the difference between the interior radius of the empty
cylinder constituting the engine and the radius o, a. This wing is
formed by a, convex surface, which commences from a right line parallel
to the axis, is described by the curved line represented upon Fig. 1,
by a, m, b. This profile or curved line is formed from a to b, by an
undulated curve composed of ars of a circle; the other part of the
curved line is formed by a spiral, which begins from the point a, and is
terminated at the point b, laterally.. The wing. is formed by two plates,
the planes of which are combined with those of the bottom of the
cylinder of the engine. Upon this wing a diaphragm e acts, having
the form of a double slide; this diaphragm may be moved in the direc-
tion of the cylinder, and it may be projecting in the interior of the
engine, or be out of it entirely; for this purpose it passes into a square
hole made in the cylinder, and it moves between two grooves in the
interior of the two bottoms of the cylinder in the same manner as the
gates of a lock. In order to render the movement of the stop more
easy and regular I place upon each of its faces a smooth plate upon
which the slide glides; these two plates are divided so as to leave the
interior of the cylinder free, and to permit the passage of the wing;
the two plates are solidly fixed in the cylinder; the lower part of the
stop is furnished with a small moveable cylinder by which it rests con-
tinually upon the convex surface of the wing.
which is forced
The steam enters by the opening c', in the guide formed by the
stop, and by the undulated forin of the
'to move circularly, whilst the stop resting by its lower part on
the convex surface of the wing is raised gradually until the point b,
'reaching the opening c', allows the steam to rush into the chimney;
'the stop at this moment is raised completely, and offers no obstacle to
the passage of the wing; the stop then resumes its first position by the
effect of its own weight, or under the action of a spring, by gliding

page_text: upon the undulated plane of the wing, which is arranged so as to pre-
vent or lessen the shock which would take place without it in this
descent. The opening d, made in the vertical part of. the cylinder, com-
municates with a condenser and
some moments. after
the opening of the aperture c', when the wing has passed the stop.
An ordinary valve placed in the pipe which communicates with the
escape c', and closes it from the outside to the inside; communication
with the air is interrupted, and the steam which remains in the interior
of the cylinder rushes into the condenser, thus diminishing the effect of
the counter pressure, which consequently becomes as weak as if the
steam were in complete condensation. It is easily imagined that all
desired prominency may be given to the opening c', removing it from
the stop itself, more than is shown in the Figure, so as at the unstop-
ping of the opening d, there only remains a very small quantity. of
steam to be condensed. This rotary engine may be usefully applied
when a great speed is not desired, nor a reverse of action, which cannot
be effected with it.
Another arrangement of rotary engine, based upon the same prin-
ciple, is represented in section, Figs. 2, and 3, Sheet 1. It is pro-
vided with all necessary mechanical properties, so that it may be
applied to all purposes for which rotary engines are designed. The
wing, instead of being surrounded with a convex surface, having the
form of a wing, is constituted by an excentric, which I call a driving
excentric; and which fixed immoveably and solidly to the shaft may
turn in the interior of the cylinder. The length of the wing should be
measured upon the diameter which passes through the centre of the
figure of the driving excentric, and through the centre of motion. At
the extremity of this diameter the convex surface of the excentric is
in geometrical contact with the concave surface, of the cylinder, whilst
at the other extremity it is in contact with the convex surface of the
shaft in such a manner that the difference between the interior radius
of the cylinder and that of the shaft from the length of the wing, tho
form and manner in which the stop acts, are the same as in the pre-
ceding arrangement, except that the lower part of this stop is furnished
with a jointed piece, which being under the curve of the convex surface

page_text: of the driving excentric rests upon it, so that upon a certain distance
there is between them a perfect contact. In Sheet I, Figs. 8, 9, and
10, are represented upon a larger scale the details of the stop.. It is
easily understood that the steam, in penetrating on one side or the other
of the stop by means of the hole a, or a², (Figs. 2, and 3, Plate 1,) will
force by its pressure the stop and its jointed part, thus increasing the
contact between the sliding parts and rendering the passage of the
steam on this side impossible. With regard to the other extremity of
the excentric, so that there may be no loss of steam at that point, I
place upon the excentric, and upon the line of contact with the cylinder,
an elastic plate, so that it may thus turn on it, whilst on one side it rests
upon the convex surface of the other rising; forced by the steam it ad-
heres to the concave surface of the cylinder, and prevents loss of steam.
By noting the Figures 2, and 3, Sheet 1, it may be perceived that
the rising of the stop is effected gradually by the driving excentric
a half turn by passing from the vertical position shown in Fig. 1, to
the other vertical position in the opposite direction, but during the other
half turn the stop becomes free; an exterior pressure is necessary to
maintain always the contact with the excentric in gradually descending
in a proportion corresponding to the position which it takes succes-
sively. It is evident that this could be effected by means of a spring
for pressure, but instead of that I have invented three different arrange-
ments, by means of which all the parts are always held together, and
thus made continuous. The first of these arrangements is shown in
Sheet 1, Fig. 11, and 12; it consists of two collars fitted to the two
extremities of the excentric, and which uniting to the jointed part of
the stop, force it to follow constantly the excentric, as is seen in Fig. 12.
However, in this mode there is the defect of increasing the difficulty
of preventing the escape of the steam by the joints of the collars;
besides the two zones correspond in size, and consume uselessly a certain
portion of the steam, because the pressure which takes place upon
them has no useful effect.
The second arrangement, represented in Sheet 1, Figs. 14, and 15,
consists of two other excentrics placed exteriorly, and having the same
position and the same dimensions as that of the interior. From the

page_text: upper part of the stop two rods project to the exterior by means of
two stuffing boxes, as is seen in Fig. 15, and bent at a right angle
joint to the cranks of the outer excentrics. In this case the inotion
of the stop is entirely dependent on the excentrics, and the stop
and the interior excentric are constantly in contact. The motion
of these outer excentrics is employed to set in motion the feed pumps
and the steam valves.
The third arrangement is shown in Sheet 2, Fig. 1, 2, and 3, and
for many reasons it may be preferred to the others. Three of these
rotary machines are placed on the same shaft; those at the extremities
have their distributing apparatus at the upper part, and their driving
excentrics are placed symetrically and in the same direction. On the
contrary the intermediate machine is turned in the opposite direction,
but all three have perfectly equal dimensions; these three engines are
arranged so that when the two excentrics of the side engines raise
their stops those of the centre one perform the portion of their
rotation in which their stop remains free, and could only be raised by
the aid of an extrinsic force; and, on the other hand, when that works
upon the stop by lowering it, the others leave theirs free, so that if the
rods which are disengaged from the stop are fixed and held together by
means of a horizontal bar it will follow that while the intermediate
excentric lowers its stop the others must also be lowered, and, vice
versa, when the extreme excentrics raise theirs that of the middle
excentric ought also to be raised, and thus preserve between the stops
and the interior excentrics the necessary contact. In this manner
neither of the excentrics is intended to effect the accessory move-
ments; and the working of the pumps, as well as that of the steam
valves, may be effected by the alternate and rectilinear motion of
the exterior rods. The distributing apparatus is arranged in the fol-
lowing manner-Upon the cylinder and on each side of the stop
two square holes a, b, a', ', are made, Fig. 2, 3, and 5, Sheet 1.
The holes a, a, are for the entrance of the steam, which takes place by
one or the other, following the direction which is desired by the motion
of the engine; the other two servė for the exit, & either is used
according to the direction of the motion; if, for example, the hole a, is

page_text: opened, the hole 6 also is opened at the same time; and, on the con-
trary, if a, b, are open, a, b, will be closed. The cylinder in its upper
part is terminated by a plate upon which are made four spaces or
chambers; each of these chambers is opened only at its upper part, and
at its lower part corresponds to one of the four orifices. In both
chambers nearest the stop the boxes c, c', are placed which communi-
cate with the common chamber n, (Fig. 2, and 3, Sheet 1.) In both
the others the boxes d, d', are placed, communicating also with the
chamber m A common plate at the upper end of the chamber shuts
the boxes, and gives a passage only to the pipes for communication
with the chambers m, and n, as is seen in the horizontal section,
(Fig 7.) This combination of the different distributing boxes and
pipes for communication with the chambers m, and n, is easily under-
stood by the Figs. 11, 12, 14, 15, Sheet 1; and Figs. 1, 2, 3, Sheet 2,
which have the appearance of cylinders seen from the side are com-
pared with Figs. 2, and 3, Sheet 1, which are vertical sections of the
cylinder, by two plans separated the same distance from the centre one.
In one of the bottoms of the cylinder two other holes g, g', are made,
which communicate with the chamber o, placed outside, as is seen in
Fig. 4, Sheet 1, and this by the intervention of a pipe which is
separated from the upper part, and is in communication with the
condenser. The opening g, is open at the same time as b, whilst the
other remains shut, as well as band vice versa, according to the
direction of the motion. Let us suppose that the motion be deter-
mined by the opening of the holes a, b, and g', whilst all the others
remain closed; the engine would then work as follows:-The steam by
means of a pipe continually enters into the chamber, and: consc-
quently passes through a, in the interior of the cylinder, between
the stop and, a portion of the convex surface of the excentric for
driving. The pressure effects a force upon the part of the convex
surface which remains exposed to the action of the steam, which,
by following a certain law of variation, determines the rotation of
the engine; the end of the driving excentric reaching the hole b',
lets the steam rush into into the chamber m, passing by the box d
and thence to the chimney by means of a pipe. which goes from

page_text: its extremity to the opening of the pipe. For communication with
the chamber m, there is a valve opening from within outwards, and
presenting to the steam going out all necessary space. When the
saine end of the excéntric has passed the stop by travelling a certain
angular space, the hole g', closed before by the even surface of the
driving excentric, is exposed, and by reason of its coinmunication with;
the condenser a suction occurs which instantly causes the escape valve
to close hermetically, interrupting at the same time all communication
with the atmosphere, so that all the steam remaining goes into the
condenser and is precipitated. This same distributing apparatus is
applied also to the engine represented, Fig. 1, Sheet 1, the details of
which have been omitted, because they are the same as those of the
engine which I have just described, and which may be considered as an
improvement on the preceding.
The apparatus for the reversing motion should be in itself very
simple, if it were not necessary to apply the expansion gear for economy
in the use of the engines. All will be accomplished by combining the
opening and the closing of certain orifices, a combination: which may
be effected by very simple means. However, to attain the purpose
required, I have made the following arrangements :-Above the plate.
of the cylinder in the boxes d', d, are placed two valves with a double
slide worked by rods which pass outside; these valves mově upon slides!
The same thing is effected by the holes g, and g¹, whicli-open and shut
by means of two valves having the same form, but placed vertically.
All the details may be seen in Figs.. 2, 3, 4, and 6, Sheet 1: All these
rods are kept together in a common framework, so that each expulsion
which is given to it effects the working of all the valves by opening
those which exist on the same side, and by closing the others, and vice
versa, according to the direction of the inovénient of the engine..
As regards the ingress valves a, and a', they ought not only to
remain open and shut alternately, but when once the motion is deter-
mined by the opening of one of them, the ingress should take place at
the beginning of the course of the driving excentric, and should stop
after a longer or shorter moment, according to the expansion desired."
The following is the mode in which this result is obtained-In the

page_text: boxes c, and c', I place two cylinders hollowed into a division greater
or less than the normal division of the axis, and that upon the length
corresponding to the square holes a, and a¹; at its extremity are placed
two pivots, one of which goes out and is attached to a handle; the
pivots may turn in two journals placed suitably at each side, and the
rotary movement is communicated to the handle by means of a crank
by the exterior rods of the rotary engine.
The rotation of the cylinder having a hollow sector determines the
ingress of the steam for a single portion of the period of the rotation,
a period which will be moreover more or less long according to the size
of the hollow sector. This may be easily understood by examining
Figs. 2, and 3, Sheet 1, in which the hollow part is equal to half the
cylinders. By rendering a part of the full sector moveable around the
axis of the cylinder the distance between the full and empty parts of
the cylinder may be varied by means of a register or regulator, and
consequently the expansion may be varied according to the need or
wish of the engineer. The engine not only serves as a more complete
and efficacious application of the expansion by carrying it to an indefi-
nite limit, but besides renders it variable at will by an apparatus simple
and easy, which hitherto has only been very imperfectly obtained, and
by means of very complicated mechanism. In the engine shown in
Figs. 11, and 12, Sheet 1, where the stop is obliged to adhere to the
driving excentric by means of two collars, the motion of the crank and
the handles is obtained by an excentric fixed upon the axis, as is done
now for moving the sliders." This crank, by an easy method of
mechanism, may be engaged with either of the handles according to the
working of the engine. This arrangement is not indicated in the
Drawings, because it is easily understood.
For the system described in Figs. 14, and 15, Sheet 1, I have effected
a mechanical arrangement which I will describe, and which is applied
also to that shown in Figs. 1, 2, and 3, Sheets 2. From one of the
horizontal elbows of the rod attached to the stop a vertical rod branches,
which is divided into two forks descending on each side of the axle.
These forks are in the shaft which passes by the centre of motion of
the two handles. The alternate rectilinear movement of the stop is

page_text: communicated to this rod, and kept up by guides which regulate its
action. In Fig. 4, Sheet 2, is seen the form of this rod, and the
details of the apparatus. Two plates, which are seen isolated in.
Fig. 6, Sheet 2, receive in their slides the pivots fixed in the lower
part of the cranks for the movement of the handles. As is seen in
Fig. 4, Sheet 2, these plates are joined together by means of a cross
bar, and slide themselves also in two slides fixed upon the outer part
of the bottom of the cylinder, and the motion is imparted to them
by the combination of levers indicated in Fig. 4, Sheet 2. The
two vertical branches terminate at their extremity by two forked
bars. The extremity of the fork has an opening like that of the stop.
The pivot of the crank is prolonged outwardly, and is surmounted by
a button which may be caught by the fork.
In the apparatus of Figs. 1, 2, and 3, Sheet 2, the forked bars aro
placed upon the same vertical rods which unite the stops, and the
Fig. 2, Sheet 2, shows one of these bars for putting the handles in
motion of the two consecutive engines. By making the two plates
slide on one side or the other, one or the other of the two cranks
remains engaged, and consequently the rotary motion of one or the
other crank is produced. When the arrangement of the plates
has traversed the full length of their movement the button of the
crank, which remains disengaged, should become in its interme-
diate position indicated by Fig. 4, Sheet 2, and in this position
the ingress hole remains closed hermetically. The motion of the
levers shown in Fig. 4, is effected by the framework itself, to which are
attached the valve rods of the other holes, so that one single impulsion
given by the engineer suffices to completely determine the direction of
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Auguste Edouard Loradoux Bellford in the Great
Seal Patent Office, on the 16th March 1854.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria; by Her
Letters Patent, bearing date the Twenty-fifth day of November, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Auguste Edouard Loradoux Bellford,
Her special licence that I, the said Auguste Edouard Loradoux Bellford,
my executors, 'administrators, and assigns, or such others as I, the said
Auguste Edouard Loradoux Bellford, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN ROTARY ENGINES,"
being a communication from a foreigner residing abroad, upon the con-
dition (amongst others) that I, the said Auguste Edouard Loradoux
Bellford, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calen-
dar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Auguste Edouard Loradoux
Bellford, do hereby declare the nature of the said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:
My improvements in rotary engines consist, firstly, of a new arrange-
ment of machinery for obtaining a rotary motion by the direct action of
steam; secondly, of a new contrivance or contrivances for obtaining from 1
the expansion of steam a more useful effect than hitherto, by carrying
it out to an indefinite extent; thirdly, in a new arrangement for using
steam at a high pressure, and for producing by means of this steam,
after it has acted, a jet for increasing the draught of the chimney;
also for condensing afterwards the steam which remains in the engine
in such manner that the back pressure does not exceed the back'
pressure in condensing engines.

page_text: : Fig. 1, Pl. I., is a vertical section of a rotary engine of my Inven-
tion. The driving shaft may be supposed to have in the interior of the
engine a radius equal to o, a. The vane or projecting part on which the
steam acts projects by a quantity, which is equal to the difference
between the interior radius of the cylinder and the radius o, a.. This
vane is formed by a convex curved surface generated by a straight
line moving parallel to the axis along the line represented in Fig. 1,
by the letters a, m, b. This line consists, from a to b, in an undulating
curve made up of ares of circles; the remaining portion is a spiral,
starting from a to the left, and terminating at b. On the ends the vane
is terminated. by two plates, which fit on the cylinder bottoms. A
diaphragm e, resembling a double slide, acts upon the vane; this
diaphragm is capable of being moved in the direction of the cylinder,
and may either.project in the inside of the cylinder, or be withdrawn
entirely from it. For this purpose it passes through a rectangular
aperture in the periphery of the cylinder, and slides in groves left in
the cylinder bottoms. In order to render the motion of the slide
easier and more regular I encase it between two smooth plates,
between which it slides; this case is cut so as to leave the interior of
the cylinder free to the passage of the vane. It is firmly fixed in the
body of the cylinder.
The lower end of the slide carries a little moveable roller, which
rests constantly on the curved surface of the vane. The steam enters
by the port c, into the sector formed by the slide, and the undulated
surface of the vane, which is thus forced to turn round, whilst the
slide resting with its lower edge on the convex surface of the propelling
vanie is gradually lifted up till the point b, reaches the port c, and
allows the steam to rush into the chimney. The slide is lifted at this
precise moment beyond the reach of the vane, which it allows to pass,
and then takes again its former position by its weight or the action of
a spring. Whilst it thus descends it slides on the undulated face
of the vane, whose object it is to prevent or diminish the shock or
impact which would otherwise take place at this part of the turn. The
port d, in the end of the cylinder communicates with a condenser, and
gets uncovered some instants after the opening of the port c', when the

page_text: vane has turned past the slide. An ordinary lifting valve placed in
the pipe leading from the exit port, and closing towards the outside,
shuts off the external atmosphere, and the steam which remains in the
machine rushes into the condenser, thus diminishing the back pressure,
and reducing it as low as in engines with complete condensation. It
is easily seen that any desired lead may be given to the port c', by
removing it from the slide e, still more than is shewn in the Figure;
the result will be that there will only be a small quantity of steam to
be condensed when the opening d, is unmasked.
This rotary engine is used with advantage when neither a great
speed nor a change of direction is required, as it is not capable of
being reversed. To obviate this defect I have devised another rotary
engine, which is arranged on the same principle as represented on
Fl. I., Figs. 2, & 3. This engine possesses all the necessary qualities
for being applicable in all the cases where common engines are used.
The vane, instead of being formed by a curved surface, as described,
consists of an excentric, which I call driving excentric, fixed firmly on
the driving shaft, and capable of turning in the inside of the cylinder.
The working length of the vane in this case has to be measured on the
diameter which passes through the centre of the excentric and the
centre of motion. At the end of this diameter the convex surface of
the driving excentric is in tight contact with or fits tight to the concave
surface of the cylinder; at the other end it merges into the surface of
the shaft, so that the difference between the interior radius of the
cylinder and that of the shaft form the length of the vane. The slide
acts in the same manner as in the rotary engine first described, with
the exception that the lower edge of this slide carries a hinged piece
which on its under side has the same curvature as the driving excen-
tric with which it is in tight contact. Figs. 11, 12, & 13, Pl. I., shew
the details of the slide on a greater scale.
Fig. 8, Pl. I., shews on a large scale the different positions of the driv-
ing excentric in relation to those of the slide, and the angular positions
which the contact piece of the slide takes in order to keep in contact
with the excentric. It will be readily understood that the steam entering
on one or the other side of the slide; by the ports a, or a', Fig. 2, & 3,

page_text: Pl. I., will press on the slide and the hinged contact piece, and thus
make a steam-tight joint. In order to prevent the loss of steam at
the other extremity of the excentric I apply to it an elastic strip, which
forms contact between the excentric and the cylinder; thus whilst this
strip rests on the convex surface of the excentric it is also lifted by the
pressure of the steam so as to press against the concave surface of the
cylinder, and prevent loss of steam. For obtaining the same object the
following arrangement may also be adopted :-Instead of keying the
driving excentric fast on its shaft, it may be slotted so as to be capable
of moving in the line passing through the centre of motion, and the
point of contact of the excentric with the cylinder. The excentric is
kept in contact with the latter by means of strong springs placed.
inside the cylinder, combined with the centrifugal force created by the
rotary motion. Upon examining Fig. 2, & 3, of Pl. I. it will be seen
that the rising of the slide is effected gradually by the driving excentric
passing during half a revolution from the vertical position shewn to
that opposite. During the other half turn, however, the slide is free,
and the intervention of an external force is necessary for keeping it
always in contact with the driving excentric by causing it to descend
into the positions it occupies successively. This may be effected by a
pressing spring, but instead I have devised three different arrange-
ments, by means of which all the parts always constantly remain
in contact. The first arrangement is represented in Figs. 14, 15, & 16,
Pl. I. It consists of two collars or rings on the ends of the excentric,
which are fastened to the hinged part of the slide, & force it to follow
always the excentric, as seen in Fig. 2. This arrangement, how-
ever, has the inconvenience of adding to the difficulties attending leak-
age, since it is necessary to prevent the steam from escaping through.
the joints of the collars; besides which the two zones corresponding to
the width of the collars cause a useless consumption of steam, as the
pressure on them is not available. The second arrangement, shewn in
Plate I., Figs. 17, & 18, consists of two other excentrics placed. ex-
ternally, and having the same position and dimensions as the one
inside. The upper part of the slide carries two rods, passing through
stuffing boxes similar to those shewn in Fig. 2, & joining the rods of

page_text: the external excentrics by means of elbows. Thus the motion of the
slide is governed entirely by the excentrics, which keep it in constant
contact with the driving excentric. The motion of the external excen-
trics is also made use of for the feed pumps & the slide valves. The
third arrangement is shewn on Plate II., Figs. 1, 2, & 3, and is pré-
ferable to the other two in many points. Three of these rotary
engines are placed on the same shaft, those at the ends having their
slide valve gear placed on the upper side, & their driving excentrics
placed symmetrically, & moving in the same direction. The middle
engine is placed in the opposite direction, but it is of the same size as
the other two. The result of this relative position of the three engines
will be that when the driving excentric of each of the outside engines
lifts its slide, the driving excentric of the middle engine performs that
portion of its revolution in which the slide belonging to it is free, & has
to be lifted by an external force; and, vice versa, whilst the middle
driving excentric lifts its slide, the outside ones do not act on theirs.
If, therefore, the rods on the slides are connected with each other by
horizontal bar the result will be that whilst the middle driving excen-
tric depresses its slide, the slides of the others are forced to slide down
at the same rate; and vice versa, whilst the outside driving excentrics
lift their slides, the middle slide is necessarily lifted will them, so that
the contact between the slides & the driving excentrics is strictly
maintained. In this arrangement the pumps & slide valves may be
driven by the rectilinear reciprocating motion of the external bars.
8
The slide valve gear is arranged in the following manner: On the
cylinder side, and on each side of the slide, are rectangular apertures
a, b, a', b', Fig. 2, 3, & 5, Pl. I. The apertures a, a', are for the ad-
mission of steam, which takes place by one or by the other, according
to the direction in which the engine has to move. The two others are
for the exhaust, and are used either one or the other, according to the
direction of motion; thus if the port a is opened, the port b', must be
shut; and, vice versa, if a', b, are open, a, b, have to be shut: The
cylinder terminates on its upper side by a raised platform, in which are
left four empty spaces or chambers a, b, d, c, formed and separated
from each other by plates-m, which are distinctly seen in Fig. 8,

page_text: | Pl. I., and in. Figs. 9, & 10, shewing on a smaller scale a detached
side & front view of the cylinder, These chambers are only open at
the top, & correspond at their lower end with the four ports.. In. those
nearest to the slide fit the steam boxes c, c', which communicate witli
the common chamber n, Figs. 2 & 3, Pl. I. The two others contain
the boxes d, d', which communicate with the chamber m. A. plate.at
the top of the chambers closes the boxes, and leaves open only the
passages to the chambers m, & n, as seen in the horizontal section,
Fig. 7. This combination of the different steam boxes, and of. the
passages leading to the chambers m, n, is easily understood by com-
paring the Figs. 14, 15, 16, 17, and 18, of Pl. I., and Fig. 1, Pl. II.,
which give side views of the cylinders, with Figs. 2, & 3, of Pl. I.;
which give two vertical sections at an equal distance from the middle
of the cylinder. In one of the cylinder bottoms are two other ports g, 9';
which communicate with the chamber a, situated outside the cylinder,
as seen in Fig. 4, Pl. I. This chamber a, communicates with the
condenser by means of a pipe,, which is fixed on its upper side. The
port g, is open at the same time as b, whilst the other is shut. with b';
and vice versa, according to the direction of motion.
Let us suppose that motion takes place by the opening. of the ports
a, b, and g, whilst all the others remain shut; the engine will then work
in the following manner:--The steam constantly enters the chamber n,
by a pipe, and therefore passes through a, into the cylinder, between
the slide and a portion of the convex surface of the driving excentric.
The pressure thus exerted by the steam on the exposed portion of
the convex surface of the driving excentric, produces the rotary motion
of the engine with certain variations governed by the nature of steam.
The extremity of the driving excentric reaching the port b', allows the
steam to rush into the chamber m, through the steam box d, and from
thence it exits into the chimney by means of a pipe fixed on its ex-
tremity. At the mouth of the duct to the chamber m, there is a valve
opening outwards, and giving ample passage to the issuing steam. After
the same extremity of the excentric has passed the slide, and moved
through a certain angular space, the port g, which was previously shut
by-the-flat surface of the driving excentric, is uncovered, and being: in

page_text: communication with the condenser causes a kind of suction which
forces the exit valve to close steam-tight, thus shutting out the atmo-
sphere, and causing all the remaining steam to rush into the condenser.
This method of distribution is also applicable to the engine shewn,
Fig. 1, Pl. I., of which the details are not represented, as those just
described are an improvement upon them.
The reversing apparatus would be very simple in itself if it were not
necessary to apply it to expansion, as is done in all useful steam engines.
Without expansion the reversing motion would consist in a combination
of the opening and shutting of certain ports attainable by very simple
means. For expansive gear I have contrived the following arrange-
ments Two double slide valves are placed in the steam boxes d, d',
on the face of the cylinder. These slide valves are moved on the
cylinder face by rods. The same apparatus is applied to the ports g, & g',
which open and shut by means of two similar valves placed vertically.
All the valve
These details are shewn in Fig. 2, 3, 4, 5, 6, of Pl. I.
rods are connected with each other by a frame, so that the motion
communicated to the frame causes all the valves to act together, and
those on one side to open, and those on the other to shut, & vice versa,
if the motion has to be reversed.
As to the inlet valves a, & a', besides being one or the other alter-
nately opened and shut, they have to fulfil the following conditions.
After the direction in which the engine moves has been determined by
the opening of one of the valves, it has always to open at the beginning
of the course of the driving excentric, and to remain so as long as
expansion requires. The apparatus by which these motions are obtained
is constructed as follows:-I lodge in the steam boxes c, c', two cylin-
ders which have sectors greater or less hollowed out all the length of
the rectangular ports a, a¹. These cylinders have gudgeons at their
ends, one of which projects outside the steam chest and carries a crank.
By means of this crank and rods from the rotary engine these cylinders
are set to turn and admit the steam during one period of their revolu-
tion. This period corresponds with the size of the sector hollowed out,
as is easily seen in Figs. 2, and 3, Pl. I., in which the hollowed out
part is equal to one half the cylinder. By making a portion of the full

page_text: sector moveable, the proportion of the full sector to the hollow sector
can be varied by means of a regulator, and thus the expansion altered
as may be desired.
My engine is therefore not only capable of an
efficient and unlimited application of expansion, but this expansion may
also be varied by means of a simple and manageable apparatus, instead
of a complicated expansion gear, as hitherto used. In the engine re-
presented in Figs. 14, 15, & 16, Pl. I., and in which the slide is kept
in contact with the driving excentric by means of two collars, the
motion of the rod and the cranks of the cylindrical valves is obtained
by an excentric on the shaft, as usual. The engineer can easily throw
the rod into gear with one or the other of the cranks, according to the
direction of the engine; this arrangement is not shewn in the annexed
Drawings, because it presents no practical difficulty.
I have contrived the following motion for the system of engines de-
scribed in Figs. 17, 18, Pl. I. This motion is also applicable to engines
as shewn in Figs. 1, 2, & 3, Pl. II. To one of the horizontal elbows of the
slide rods is fixed a vertical rod which divides into two branches round
the driving shaft. These branches coincide with the vertical line which
passes through the centre of motion of the two cranks. The motion
of the slide is communicated to the vertical rod, which is steadied by
guides. Fig. 4, Pl. II., shews the form of the vertical rod with all the
details. Two slotted plates, shewn in detail Fig. 6, Pl. II., receive in
their slots the pins which are fixed on the lower ends of the connect-
ing rods for turning the cylindrical valves. These slotted plates are
cast in one piece, and can be shifted by means of slots on the outside of
the cylinder bottoms; this is done by a combination of levers shewn on
the left in Fig. 4. The two vertical branches terminate at their lower
extremities by two forks, whose extreme aperture is equal to the course
of the slide; the pins on the ends of each connecting rod project so as
to have their button end scized by the bottom of the fork. In the gear
shewn, Figs. 1, 2, & 3, Pl. II., the forks are placed on the vertical rods
that unite the slides; and Fig. 2, represents one of these forks for
setting in motion two consecutive engines. From this brief description
it will appear that by sliding the slotted plates either to the right or to
the left, one or the other of the two connecting rods is thrown in gear,
B

page_text: and one of the cranks turned, whilst the other remains stationary.
When the slotted plates are shifted the pin of the disengaged connect-
ing rod must be in the position shewn in Fig. 4, in which position the
corresponding port is shut. This sliding is effected by the frame to
which are attached the rods of the valves, so that by one impulsive
motion given by the engineer the engine is reversed.
Amongst the divers applications of this Invention the most impor-
tant is that to locomotives engines, so as to substitute rotary to recipro-
cating engines. The locomotive represented on Pl. III. is built to run
on steep inclines. I prefer to shew this adaptation of my engine pre-
cišely because it is one of the most difficult applications; and in order
to simplify the question I have only put my rotary engines in lieu of
the cylinders. This arrangement will prove that although it may be
difficult to adapt them directly to the driving axle, yet my rotary
engines are capable of being applied to these kind of locomotive
engines. The driving excentrics, of which there is one on each side
of the locomotive, are placed in opposite directions, so that, like in the
case of the present cranks, when one of them is at the dead point the
other excentric is at the point of its maximum effect. The driving
shaft runs in bushes fixed on the frame sides of the locomotive. The
rotary motion is transmitted to the driving axles by connecting rods,
which also serve to couple the wheels of the locomotive, as is seen in
Fig. 1, Pl. I. For the reasons stated I have chosen to adapt to this
locomotive the apparatus shewn, Figs. 17, & 18, Pl. I. The engine
represented in Figs. 1, 2, & 3, Pl. II., might however be applied with
less difficulty and more advantage, as in that engine a permanent effect
is exerted on the shaft. The smoke box has a double partition to
enclose the two rotary engines, as seen in Fig. 3, PI. III.
The steam pipe leading out of the boiler divides into two branches,
conveying the steam directly to the steam chests. Similarly the exhaust
pipes join into one blast pipe which is in the centre of the chimney.
These different arrangements are distinctly shewn in Fig 1; 2, & 3,
Pl. III. The condensers are formed by two cylindrical vessels mounted
with a dome, and placed in the sides of the locomotive, as shewn,
Fig. 1. Pl. III. The steam chests o, of the two engines, communicate

page_text: outside with the said vessels by means of a pipe. Another pipe runs
on each side of the cylinder, in order to convey the water from the
tender to the two condensers; and in order to give the condensing jet
a certain force the pipes have to be placed lower than the bottom of
the tank. The flow of the condensing water is regulated by a cock,
which is within reach of the engine driver. Two other pipes of the
same diameter start from the bottom of the condensers, and run along
the engine to the platform of the engine driver, where they are mounted
with two cocks at his command. Near this platform these two pipes
communicate with a large pipe, which bends so as to run along the
lower part of the boiler as far as the feed pumps, where it divides into
two branches, which run into the plunger barrels of the feed pumps.
These large pipes are not shewn in the Drawings; but they have a
considerable capacity so as to be used as a reservoir of hot feed water:
Their extent and bent shape serves to render the working of the pumps
more regular by cooling the water which is too hot at the moment, of
condensation. As seen in the Drawings, the clack valves are placed
lower than the large pipe, so that too hot water runs into the plunger
barrel by gravity alone, and is then forced into the boiler by the
plunger.
The object of the domes on the condensers is to receive the air which
is evolved by the heating of the water or otherwise. At their top, as
well as at the mouth of the exhaust pipe, are placed two valves, one of
which opens outwards, and the other inwards. When the air collected
in the dome, as well as the steam which is produced at the condensing.
temperature, exceeds the pressure of the atmosphere, the valve of the
exhaust pipe sluts, and that on the domes opens, and the condensation
is thus interrupted. The engine driver, warned by the noise of a
whistle on the outer valve, shuts the exit cock of the condensation, and
leaves open the induction cock. Thus the condenser is filled with hot
water till it reaches the top of the dome, and entirely expels the air-
collected in it. The engine driver then opens again the cock last men-.
tioned, and the engine is again in its normal state. During this short
interruption the slide valve gear continues to work, because, although
the condenser is shut, yet the blast pipe in the chimney is constantly
B 2

page_text: opened. Thus the condenser, as described, acts both by condensing
and by heating, and thus does away with the necessity of heating the
water and expelling the air from it at the stations.
In order that the accompanying Drawings may be more clearly
understood I annex the following table of reference.
Plate I., Fig. 1, vertical cross section of a rotary vane engine. Figs:
2, & 3, vertical cross sections through the lines 3, 4, & 5, 6, Fig. 14..
Fig. 4, vertical cross section through the line 7, 8, Fig. 14. Figs. 5, 6,
& 7, horizontal sections through the lines 1, 2, 3, 4, 5, 6, Fig. 2, respec-
tively. Fig. 8, cross section of the same cylinder mounted with two plates
and the vane, showing the different positions of the excentric and the
hinged part of the slide. Figs. 9, and 10, detached side & front views
of the cylinder. Fig. 11, side view of slide with its case and external
flanches; one half is in section. Figs. 12, & 13, transversal sections of
the slide and case through lines 1, 2, 3, 4, Fig. 11, respectively.
Fig. 14, side view of cylinder of second arrangement, with slide valve
gear. Fig. 15, vertical section through the axis, showing inside view.
of the driving excentric and collars or rings for lifting and lowering
the slide. Fig. 16, horizontal section through the line 1, 2, of Fig. 14.
Fig. 17, above-mentioned cylinders, with the excentries for raising and
lowering the slide, steam chest, and reversing apparatus. Fig. 18,
vertical section, similar to that represented in Fig. 15.
Plate II., Fig. 1, side view of shaft with three engines on it.
Fig. 2, connecting rod between the first and second engine. Fig. 3,
single rod outside the side engines. Fig. 4, details on a larger scale of
the rod moved by the horizontal branch of the slide rod, shewn in
Figs. 17, & 18, Pl. I. Fig. 5, side view of the same. Fig. 6, slotted
disengaging plates. Fig. 7, relative position of the cranks and steain
valves.
PLATE III., Fig. 1, 2, & 3, application of the apparatus shewn in
Figs. 17, & 18, Pl. I., to an incline locomotive. The levers of the valve
gear are not shewn for simplicity's sake.
I claim, firstly, the rotary engine described in Fig. 1, Pl. I., as well
as the arrangements of rotary engines and apparatus connected there-
with described on Plates I. and II., the object of these engines being

page_text: to obtain, 1°, a rotary motion from the direct action of the steam;
2°, a more useful and extended application of constant and variable
expansion; 3°, by a partial condensation, the same effect as produced
by a complete one, using at the same time heated feed water, high
pressure steam, and chimney blast.
Secondly, applying the said rotary engines and apparatus connected
therewith to all useful purposes to which steam engines are applied.
In witness whereof, I, the said Auguste Edouard Loradoux Bell-
ford, have hereunto set my hand and scal, this Sixth day of
March, in the year of our Lord One thousand eight hundred
and fifty-four.
A. E. LORADOUX BELLFORD. (L.S.)
A. E. LORADOUX BELLFORD. (L.S.)