CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1820

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CARTER, of St. Agnes Circus, Old Street Road, in the County of Middlesex,
Printer, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth did, by His
Letters Patent under the Great Seal of that part of the United Kingdom of Great
Britain and Ireland called England, bearing date at Westminster, the Eleventh
day of November, in the first year of His reign, give and grant unto me, the said
William Carter, my exors, adññors, and assigns, His especial licence, full power,
sole privilege and authority, that I, the said William Carter, my exors,
adiñors, and assigns, during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVEMENTS IN
STEAM ENGINES;" in which said Letters Patent there is contained a proviso that
if I, the said William Carter, shall not particularly describe and ascertain the
nature of my said Invention, and in what manner the same is to be performed,
by an instrument in writing under my hand and seal, and cause the same to be
inrolled in His Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said Letters Patent, that then
the said Letters Patent, and all liberties and advantages whatsoever thereby
granted, shall utterly cease, determine, and become void, as in and by the
same, relation being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Carter, do hereby declare that the nature of my said Invention, and

page_text: the manner in which the same is to be performed, are particularly described
and ascertained in and by the Drawings hereunto annexed, and the following
description thereof (that is to say):-
I produce a continuous circular motion by employing the force or pressure
of steam to act upon four rectangular leaves, which are so disposed within a
hollow cylinder that the said pressure will turn the cylinder round about its
axis with a continuous-circular motion in one direction. These four internal
leaves move with the cylinder two together, in pairs, and operate alternately
to produce the motion of the cylinder; whilst one pair are in action the other
pair stand still, to sustain the reaction of the steam; but their motion is
always in the same direction, so that reciprocation or change of direction is
avoided, the change being only from rest to motion, and from motion
to rest.
For the full explanation of my Invention, I have hereunto annexed two
Sheets of Drawings of a rotary steam engine constructed according to my
improvement (the same letters of reference and the same colours denote the
same parts in all the different Figures).
A, A, Figures 1 and 9, represents the hollow revolving.cylinders, supported
in bearings or collars B, B, one at each end, so that it can be turned round
about its axis or center line by the force of the steam acting against the four
leaves within it. The cylinder may be placed either vertically or horizontally,
and its motion communicated to the machinery it is intended. to work by a
ring of cogs, which are formed round it at a, a. The internal surface of the
cylinder is bored smooth and true, and the edges of the four internal leaves
C, D, and E, F, Fig. 9, fit closely to it; the opposite leaves C and D, are
united and form one pair; and the other opposite leaves E and F, are also
united, and form the other pair. The two leaves C and D (which for
distinction I call the narrow leaves) are affixed to a solid axis G, which occu-
pies the center of the cylinder; and the other two leaves E and F (which I
call the broad leaves), are united at each end to two circular plates H and I,
which are closely fitted into recesses at each end of the cylinder, so as to form
ends thereto; but the cylinder can turn round (in the direction shewn the
arrows) independently of these two ends, or of the leaves, which are affixed
to them. The axis G of the other two leaves pass through a hole in the
center of the end plate H, with a stuffing box z.
A hollow axis K proceeds
from the opposite end plate I; and there are passages within it to convey the
steam from the boiler into the engine; the same hollow axis also receives the
eduction pipe M, which carries the steam away from the engine to the con-
.densing apparatus, as will be herein-after explained. By these four leaves

page_text: the internal capacity of the cylinder is divided into four compartments (see
Fig. 9), for each leaf extends from the axis G in the center of the cylinder,
and applies to its internal surface, and also to its two ends H and I. Hemp
packing is fitted into grooves in the edges of the leaves, to prevent the steam
passing from one compartment to another, although either pair of leaves is
capable of moving (in the direction shewn by the arrows) independently of
the cylinder, or of moving with the cylinder (in the opposite direction), inde-
pendently of the other pair of leaves. When either of the pairs of leaves is
moved with the cylinder, whilst the other pair remains motionless, two of the
compartments will be enlarged, whilst the other two will be contracted; and
when the two pairs of leaves are brought nearly into contact, as C and F, and
D and E, Fig. 9, two of the compartments will be quite collapsed, and the
other two will be fully extended, and will then be about equal to one fourth of
the internal capacity of the cylinder. Each pair of leaves is provided with an
apparatus (herein-after described) which prevents any. retrogade motion,
although the leaves may move freely forwards in that direction in which they
are intended to turn the cylinder (as shewn by the arrows), and each pair of
leaves has a similar apparatus, which operates upon the cylinder to connect it
with that pair of leaves which moves forwards, and thereby carry the cylinder
round, but to allow the cylinder to move freely forwards independently of that
pair of leaves which remains motionless. The leaves and the cylinder are put
in motion by introducing steam from the boiler into those two compartments
which are collapsed, so as to dilate them by its pressure; and at the same
time the steam is drawn off from the other two compartments, which are
distended to exhaust and make them collapse. By this means, whilst one side
of each leaf bears no pressure, the opposite side is pressed by the steam, and
this pressure, acting on the adjacent surfaces of two leaves, tends to force
them asunder, one backwards, and the other forwards; but, as the retrograde
motion is prevented, that leaf which is urged backwards becomes stationary,
and sustains the reaction of the steam whilst it is forcing the other leaf
forwards, and that carries the cylinder with it. This force of distention is
which are collapsed, so as to
exerted alternately in the different compartments
keep up a continual action; but whilst one pair of leaves is acting to carry the
cylinder forwards, the other pair remain motionless, and bear the reaction of
the steam. The eduction pipe M, Figures 1 and 7, is fixed within the hollow
axis K, and the end is closely joined with cement to the end plate I, which is
made in one piece with the hollow axis, so that the pipe turns round with the
axis, and the other extremity of the pipe is joined by a stuffing box or turning
joint L, Fig. 1, to the pipe N, which goes to the condenser. As the hollow in

page_text: the axis K is larger than the eduction pipe M, a space K, M, is left between
them, which serves as a passage to convey the steam from the boiler into the
engine. The steam is brought from the boiler by the pipe O, Fig. 1, in a
hollow box P, through which the hollow axis K and the eduction pipe M pass,
and the junctions are made tight by stuffing boxes, but which allow the axis
and pipe to turn. That end of the axis K which is within the box P is
perforated with a number of holes to admit the steam into the space between
the pipe M and the axis K; and similar perforations are made in the axis
near the end plate I, to allow the steam to pass out into the steam box Q, which
is a circular channel at the outside of the end plate I, with a cover R screwed on
so as to form a circular box, which is always kept full of steam brought by
passage M, K, and the pipe O from the boiler. S is the distributing valve,
which gives the steam admission from the steam box Q into the two collapsed
compartments of the cylinder, and allows it to escape from the two distended
compartments by the eduction pipe M to the condenser. The distributing
valve S is a circular ring, see Figs. 3 and 5, which surrounds the axis K, and
occupies the bottom part of the steam box; its flat surface is accurately fitted
to the surface of the end plate I by grinding, and four square passages d, e, f, g,
Figs. 8 and 9, are cut through the end plate. close to the surfaces of the two
broad leaves E and F, to admit the steam into or out of the cylinder; but the
annular valve S covers these passages so as to stop them, except when the
valve is so placed that certain holes which are cut through it correspond with
those passages. There are four holes cut through the annular valve S, S, at
h, i, k, l, Figs. 3 and 5; but, as these holes are farther apart than the passages
-d-and-e, f-and-g, in the end-plate-I,-they-can-never-be all open-at-once, but
when any opposite two passages (d and f, for instance, Fig. 5) are open the
other two opposite passages e and g will be shut, and visa versa (see Fig. 3).
There are also two other passages m and n hollowed out in the end plate in
the middle, between the other passages d, e, and f, g; they do not pass through
the plate, but pass within the thickness of the same, and communicate by
crooked passages, as shewn at Fig. 1, with the eduction pipe M, to carry away
the steam. The valve S has two cavities o, p, hollowed out in it, but they do
not come through. These cavities are in all cases opposite to the eduction
passages m and n; but, as they are much wider than those passages, the valve
may be placed so as to reach over either of the adjacent passages d or e, f or g,
in order to make a communication from those passages to the eduction pipe.
The requisite changes in the distribution of the steam are all produced by
turning the annular valve S round a small distance and back again, in order to
-place it alternately in the two positions shewn in Figures 3 and 5. To com-

page_text: municate motion to the valve, four steel pins are fixed into it at the back, and
project some distance. The ends of these pins are received into holes made
in a thin circular ring q, Fig. 1, which is accurately fitted to the inside of the
lid R of the steam box, and is pressed towards it by springs, so as to apply
closely. A pin r is fixed into the ring q, and comes through an oblong slit in
the lid R to the outside; so that, by moving this pin, the valve S is moved
within the steam box, but the internal ring 9 prevents the escape of steam
through the slit by the side of the pin r. t, Figs. 1 and 2, is a short forked
lever, which takes hold of the projecting end of the pin r to give it motion.
This lever is fixed to one end of an axis T, Fig. 1, which passes through the
end plate I, and is received in a recess in the edge of the broad leaf E, so that
it goes within the cylinder; it passes through the other end plate H, and a
short lever v is fixed on the extreme end. This lever is moved by two pins or
studs w, fixed in a cog wheel W, which is attached to the solid axis G, and
therefore moves with the two leaves C, D, which belong to that axis.
2°
When
either pair of leaves have moved so far that two of the compartments become
nearly distended with steam, one of the pins w strikes the lever v, and by the
axis T, lever t, and pin changes the position of the valve S within the steam
box, in order to draw off the steam from the distended compartments, and
admit fresh steam into the collapsed compartments. To make the valve S
move quickly into the requisite positions, and to keep it steady after it is so
moved, a roller (see Fig. 2) is fitted in the tail of the lever t, and this is acted
upon by a curve cut out in the end of a slider X, which is fitted into a socket
or tube Y, belonging to a cog wheel V, which is fixed on the hollow axis K.
A spiral spring is contained within the socket Y, and presses the slider X with
force against the roller a of the lever t, and by the curve the roller is thrown
either to one side or the other, as shewn by the dotted lines, Fig. 2, and the
valve S is then properly placed, with the passages fully open or fully shut ;
the pressure of the spring keeps it steady in either position. It now remains
to explain how the retrograde motion of the leaves is prevented. For this
purpose there is an immmoveable ring 1, Figs. 1 and 11, opposite to the end
of the cylinder A. It is firmly fastened to the same framing as the bear-
ings B, B, which sustain the cylinder. This fixed ring encompasses the
axis G, and a circular boss 2 is fixed on that axis within the ring 1 to support
certain wedges 3, 3, which are formed in the same piece with the boss 2, and
loose pieces 4, 4, which I call clamps, are fitted on these wedges 3, to fill up
the space between them and the internal surface of the fixed ring 1, to which
they are exactly fitted. Small springs 5 are fastened to the wedges 3, and the
ends press behind the clamps 4 to push them forwards. The instant that the

page_text: axis G and the wedge pieces begin to move backwards, the inclination of the
wedges 3 force the clamps 4 outwards, so as to jamb them fast against the
internal surface of the fixed ring 1, and prevent any farther retrograde motion
of the wedge pieces or axis; and the greater the force to push the axis back-
wards, so will the clamp pieces be jambed with greater force into the fixed
ring, but the instant that the axis and wedge pieces begin to move forwards in
the direction of the arrows, the wedges, by their inclination, retreat from the
clamps, and allow them to contract a little towards the center, whereby they
are loosened from the fixed ring 1, and have liberty to slide round freely
therein. In this motion the springs 5 push the loose clamps 4 before them,
but the strength of these springs is not sufficient to force the clamps forwards
so as to jamb them in the ring. By the wedges 3, 3, and clamps 4, 4, Fig. 11,
the pair of narrow leaves C, D, are prevented from moving backwards, and there
is another pair of wedges 6 and clamping piece 7, Fig. 1 and 7, belonging to
the other pair of leaves E, F, and operating within the same fixed ring 1.
The wedges 6 are formed at the extremities of two pieces 8 (see Fig. 7),
which project from the end plate H in a direction parallel to the axis; there-
fore, the wedges 7 and their clamps prevent the pair of broad E, F, from ever
moving backwards. There are also two other pair of similar wedges and
clamps, which act within an enlarged part 18, 18, Fig. 1 and 8, formed at the
end of the cylinder A, A. One of these pairs of wedges 10, 10, Fig. 10, are
formed out of the same prices as the wedges 3, but are inclined in opposite
direction. They act to jamb two clamps 13 into the end 18 of cylinder
whenever the leaves C, D, and the axis begin to move forwards. It is by
these that the cylinder is put in motion, but at the same time those leaves,
may stand still whilst the cylinder moves forwards with the other pair of leaves,
because the wedges 10 will release the clamps 13, and then they form no
impediment to the motion of the cylinder. The remaining pair of wedges 11, 11,
are formed on the, same projecting pieces 8 as the former wedges 6 (see Fig. 7),
but are inclined in an opposite direction thereto. The clamp pieces 12, which
belong to these wedges, act within the enlargement 18 at the end of the
cylinder, as shewn in Fig. 1 and Fig. 8, so as to jamb therein and attach the
two leaves E, F, to the cylinder whenever those leaves move forwards, but
whilst the cylinder is moving forwards with the other pair of leaves the
wedges 11 disengage the clamps 12, and allow the cylinder to move without
resistance from these clamps. The condensing apparatus for this engine may
be constructed in the usual manner as for any other engine, but instead of an
air pump an apparatus may be constructed in the same form as the engine,
viz, with two pair of leaves like C, D, and E, F, inclosed within a cylinder,

page_text: but which must be fixed instead of revolving; and the axis must be placed
parallel to that of the engine, and at such a distance that the two toothed
wheels which answer to the wheels V and W may work in those wheels. By
this means the two leaves of the air pump will be moved in a similar manner
to the leaves of the engine, and the compartments of the air pump, being
thereby continually expanded and contracted, will draw off the air and injection
water from the condenser to keep a continual vacuum therein.
OPERATION OF THIS ENGINE.
Suppose the steam box Q to be continually supplied with steam from the
boiler, and that a vacuum is made within the condenser. Suppose the parts
of the engine in the position of the section Fig. 9, where the leaves C and F,
and D and E, are close together, so that those two compartments are col-
lapsed, and the leaves C and E, and D and F, being separated, these two com-
partments are fully distended. The distributing valve S being turned into
the position of Figs. 3 and 4, the holes i and I will be opposite to the passages g
and e, and will admit the steam to enter into the two collapsed compart-
ments; also the cavities o and p, in the valve, form communications by the
passages f and d from the two distended compartments to the eduction pipe M,
by the passages m and n; the steam is thus drawn off from the distended com-
partments and a vacuum formed thereon, as expressed in Fig. 3, whilst the
fresh steam is introduced into the collapsed compartiments, where it tends to
separate the leaves F from C and E from D; but the leaves E and F cannot
turn backwards, because their wedges 6 jamb their clamps 7 into the fixed
ring 1, therefore the other pair of leaves C and D, must advance forwards in
the direction of the arrows, and, as soon as they begin to move, their wedges 10
jamb their clamps 13 into the end 18 of the cylinder, and they carry the
cylinder round with those leaves, and by the ring of teeth a gives motion
to the machinery which the engine is intended to turn. This motion continues
until the leaft C has approached near to the leaf E, and D near to F, nearly in
the position of Figure 5; one of the two pins w, Fig. 1, in the wheel W, then
presses the lever v, which, by the axis T and lever t and pin r, turns the annular
valve S; in this motion the roller (see Figure 2) acts in the oblique part of
the curve of the slider X, so as to push it outwards from the axis of the
cylinder, and condense the spiral spring within the socket Y; but the instant
that the roller X has passed the most prominent part of the curve in the slider,
the obliquity of the curve being in a contrary direction, the slider returns and
throws the rollera and lever t suddenly over, as shewn in Figure 2, whereby
the annular valve is placed in the position shewn in Figure 5; the holes h and
now admit the steam to enter through the passages d and f into the two

page_text: collapsed compartments, and also the cavities o and p in the valve form com-
munication by the passages e and g from the two distended compartments to
the eduction pipe M, by the passages m and n; the steam is now drawn
off from the distended compartments and a vacuum formed therein, as
expressed in Figure 5, whilst the fresh steam is introduced into the collapsed
compartments, where it tends to seperate the leaves F from D and E from C;
but the leaves D and C cannot turn backwards because their wedges 6 jamb
their clamps 7 into the fixed ring 1, therefore the other pair of leaves E and F
must advance forwards in the direction of the arrows, and, as soon as they
begin to move, their wedges 11 jamb their clamps 12 into the end 18 of the
cylinder, and they carry the cylinder round with those leaves so as to continue
its motion. When the leaves have approached near to the position of Figure 3,
the lever v, Fig. 1, overtakes the pin w in the wheel W, and by the axis T,
lever t, and pin r, the distributing valve S is turned, and, as before mentioned,
the curved part of the slider X acting on the roller a throws the levert over,
and moves the valve suddenly to return it into the position of Figure 3 by
the time that the leaves have arrived at the position there shewn; all the parts
are now in the position first described, and ready to repeat their operations.
In this way the two pairs of leaves are continually pursuing and overtaking
each other, but those which move always carry the cylinder with them, so as to
keep it in continual motion.
The Drawings sufficiently explain the form and proportions of the different
parts, and where the hemp packing is to be applied to keep the moveable
joints steam-tight. The narrow leaves C and D have grooves 15 to receive
packings at their outer edges, which apply to. the interior surface of the
cylinder A, A, and these leaves have also grooves also for packing at both
their ends, which apply to the end plates H and I. One of these grooves
extends quite across the end of the axis G, as shewn at 17, Figure 11, so that
the packing therein will cross the centre of the end plate I. A small aperture
is cut in the axis G, at 14, Figs. 1 and 10, to receive a packing, which keeps
a tight joint between the axis and the hole in the end plate H which receives
it; the hemp in the stuffing box Z makes a close fitting round the axis G; the
two broad leaves E and F have each two grooves 16, 16, at their outer edges,
for double packings, to apply to the interior of the cylinder, and they have each
one groove at the inside, to receive a packing 19, Figs. 8 and 9, which applies
to the central axis G. A small cavity, as shown at 21, Fig. 8, is cut out across
the center of the end plate I, to receive a packing, which will apply across the
end of the axis G to prevent the steam passing between the end of the axis
and the plate. The circular edges of the end plates H and I are accurately

page_text: fitted into the recesses at the ends of the cylinder by grinding, and the end I has
a screw cut upon it, and a ring 20, Fig. 1 and 7, is screwed on to fit into the
recess, and this can be lightened up as it wears. By removing this ring
the engine may be taken to pieces for the convenience of examining or renewing
the packings. A narrow opening is framed in one side of the cylinder, which
is exactly filled up by a door screwed on to make the inside of the cylinder
perfect, but this door can be removed. The two leaves E and F, Fig. 7, are
cast solid with the end plate I, but the end plate II is screwed to the ring after
the narrow leaves C and D are put in.
-
Note. A Patent was granted to Jonathan Hornblower, dated the Eighth of
June, One thousand seven hundred and ninety-eight, for an engine to operate by
two leaves within a fixed cylinder, to give continuous rotary motion to an axis.
My improvements on that engine consist in the particular construction of
the engine as herein-before described, and in which it differs from Mr. Horn-
blower's, engine, viz*,-
First, my method of introducing and distributing the steam, and conveying
it away.
Second, my method, of applying clamps to prevent the retrograde motion.
Third, in making the cylinder revolve, in order to give motion to the
machinery.
And, fourthly, in applying two pairs of leaves, instead of two single leaves,
whereby the force is made equal on the opposite sides of the centre or axis
of motion.
In witness whereof, I, the said William Carter, have hereunto set my
hand and seal, this Eleventh day of May, in the year of our Lord One
thousand eight hundred and twenty-one.
Inrolled the Eleventh day of May, in the year of our Lord One
thousand eight hundred and twenty-one.